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Mobile stroke teams treat patients faster and reduce disability
Having a mobile interventional stroke team (MIST) travel to treat stroke patients soon after stroke onset may improve patient outcomes, according to a new study. A retrospective analysis of a pilot program in New York found that
“The use of a Mobile Interventional Stroke Team (MIST) traveling to Thrombectomy Capable Stroke Centers to perform endovascular thrombectomy has been shown to be significantly faster with improved discharge outcomes,” wrote lead author Jacob Morey, a doctoral Candidate at Icahn School of Medicine at Mount Sinai in New York and coauthors in the paper. Prior to this study, “the effect of the MIST model stratified by time of presentation” had yet to be studied.
The findings were published online on Aug. 5 in Stroke.
MIST model versus drip-and-ship
The researchers analyzed 226 patients who underwent endovascular thrombectomy between January 2017 and February 2020 at four hospitals in the Mount Sinai health system using the NYC MIST Trial and a stroke database. At baseline, all patients were functionally independent as assessed by the modified Rankin Scale (mRS, score of 0-2). 106 patients were treated by a MIST team – staffed by a neurointerventionalist, a fellow or physician assistant, and radiologic technologist – that traveled to the patient’s location. A total of 120 patients were transferred to a comprehensive stroke center (CSC) or a hospital with endovascular thrombectomy expertise. The analysis was stratified based on whether the patient presented in the early time window (≤ 6 hours) or late time window (> 6 hours).
Patients treated in the early time window were significantly more likely to be mobile and able to perform daily tasks (mRS ≤ 2) 90 days after the procedure in the MIST group (54%), compared with the transferred group (28%, P < 0.01). Outcomes did not differ significantly between groups in the late time window (35% vs. 41%, P = 0.77).
Similarly, early-time-window patients in the MIST group were more likely to have higher functionality at discharge, compared with transferred patients, based on the on the National Institutes of Health Stroke Scale (median score of 5.0 vs. 12.0, P < 0.01). There was no significant difference between groups treated in the late time window (median score of 5.0 vs. 11.0, P = 0.11).
“Ischemic strokes often progress rapidly and can cause severe damage because brain tissue dies quickly without oxygen, resulting in serious long-term disabilities or death,“ said Johanna Fifi, MD, of Icahn School of Medicine, said in a statement to the American Heart Association. “Assessing and treating stroke patients in the early window means that a greater number of fast-progressing strokes are identified and treated.”
Time is brain
Endovascular thrombectomy is a time-sensitive surgical procedure to remove large blood clots in acute ischemic stroke that has “historically been limited to comprehensive stroke centers,” the authors wrote in their paper. It is considered the standard of care in ischemic strokes, which make up 90% of all strokes. “Less than 50% of Americans have direct access to endovascular thrombectomy, the others must be transferred to a thrombectomy-capable hospital for treatment, often losing over 2 hours of time to treatment,” said Dr. Fifi. “Every minute is precious in treating stroke, and getting to a center that offers thrombectomy is very important. The MIST model would address this by providing faster access to this potentially life-saving, disability-reducing procedure.”
Access to timely endovascular thrombectomy is gradually improving as “more institutions and cities have implemented the [MIST] model.” Dr. Fifi said.
“This study stresses the importance of ‘time is brain,’ especially for patients in the early time window. Although the study is limited by the observational, retrospective design and was performed at a single integrated center, the findings are provocative,” said Louise McCullough, MD, of the University of Texas Health Science Center at Houston said in a statement to the American Heart Association. “The use of a MIST model highlights the potential benefit of early and urgent treatment for patients with large-vessel stroke. Stroke systems of care need to take advantage of any opportunity to treat patients early, wherever they are.”
The study was partly funded by a Stryker Foundation grant.
Having a mobile interventional stroke team (MIST) travel to treat stroke patients soon after stroke onset may improve patient outcomes, according to a new study. A retrospective analysis of a pilot program in New York found that
“The use of a Mobile Interventional Stroke Team (MIST) traveling to Thrombectomy Capable Stroke Centers to perform endovascular thrombectomy has been shown to be significantly faster with improved discharge outcomes,” wrote lead author Jacob Morey, a doctoral Candidate at Icahn School of Medicine at Mount Sinai in New York and coauthors in the paper. Prior to this study, “the effect of the MIST model stratified by time of presentation” had yet to be studied.
The findings were published online on Aug. 5 in Stroke.
MIST model versus drip-and-ship
The researchers analyzed 226 patients who underwent endovascular thrombectomy between January 2017 and February 2020 at four hospitals in the Mount Sinai health system using the NYC MIST Trial and a stroke database. At baseline, all patients were functionally independent as assessed by the modified Rankin Scale (mRS, score of 0-2). 106 patients were treated by a MIST team – staffed by a neurointerventionalist, a fellow or physician assistant, and radiologic technologist – that traveled to the patient’s location. A total of 120 patients were transferred to a comprehensive stroke center (CSC) or a hospital with endovascular thrombectomy expertise. The analysis was stratified based on whether the patient presented in the early time window (≤ 6 hours) or late time window (> 6 hours).
Patients treated in the early time window were significantly more likely to be mobile and able to perform daily tasks (mRS ≤ 2) 90 days after the procedure in the MIST group (54%), compared with the transferred group (28%, P < 0.01). Outcomes did not differ significantly between groups in the late time window (35% vs. 41%, P = 0.77).
Similarly, early-time-window patients in the MIST group were more likely to have higher functionality at discharge, compared with transferred patients, based on the on the National Institutes of Health Stroke Scale (median score of 5.0 vs. 12.0, P < 0.01). There was no significant difference between groups treated in the late time window (median score of 5.0 vs. 11.0, P = 0.11).
“Ischemic strokes often progress rapidly and can cause severe damage because brain tissue dies quickly without oxygen, resulting in serious long-term disabilities or death,“ said Johanna Fifi, MD, of Icahn School of Medicine, said in a statement to the American Heart Association. “Assessing and treating stroke patients in the early window means that a greater number of fast-progressing strokes are identified and treated.”
Time is brain
Endovascular thrombectomy is a time-sensitive surgical procedure to remove large blood clots in acute ischemic stroke that has “historically been limited to comprehensive stroke centers,” the authors wrote in their paper. It is considered the standard of care in ischemic strokes, which make up 90% of all strokes. “Less than 50% of Americans have direct access to endovascular thrombectomy, the others must be transferred to a thrombectomy-capable hospital for treatment, often losing over 2 hours of time to treatment,” said Dr. Fifi. “Every minute is precious in treating stroke, and getting to a center that offers thrombectomy is very important. The MIST model would address this by providing faster access to this potentially life-saving, disability-reducing procedure.”
Access to timely endovascular thrombectomy is gradually improving as “more institutions and cities have implemented the [MIST] model.” Dr. Fifi said.
“This study stresses the importance of ‘time is brain,’ especially for patients in the early time window. Although the study is limited by the observational, retrospective design and was performed at a single integrated center, the findings are provocative,” said Louise McCullough, MD, of the University of Texas Health Science Center at Houston said in a statement to the American Heart Association. “The use of a MIST model highlights the potential benefit of early and urgent treatment for patients with large-vessel stroke. Stroke systems of care need to take advantage of any opportunity to treat patients early, wherever they are.”
The study was partly funded by a Stryker Foundation grant.
Having a mobile interventional stroke team (MIST) travel to treat stroke patients soon after stroke onset may improve patient outcomes, according to a new study. A retrospective analysis of a pilot program in New York found that
“The use of a Mobile Interventional Stroke Team (MIST) traveling to Thrombectomy Capable Stroke Centers to perform endovascular thrombectomy has been shown to be significantly faster with improved discharge outcomes,” wrote lead author Jacob Morey, a doctoral Candidate at Icahn School of Medicine at Mount Sinai in New York and coauthors in the paper. Prior to this study, “the effect of the MIST model stratified by time of presentation” had yet to be studied.
The findings were published online on Aug. 5 in Stroke.
MIST model versus drip-and-ship
The researchers analyzed 226 patients who underwent endovascular thrombectomy between January 2017 and February 2020 at four hospitals in the Mount Sinai health system using the NYC MIST Trial and a stroke database. At baseline, all patients were functionally independent as assessed by the modified Rankin Scale (mRS, score of 0-2). 106 patients were treated by a MIST team – staffed by a neurointerventionalist, a fellow or physician assistant, and radiologic technologist – that traveled to the patient’s location. A total of 120 patients were transferred to a comprehensive stroke center (CSC) or a hospital with endovascular thrombectomy expertise. The analysis was stratified based on whether the patient presented in the early time window (≤ 6 hours) or late time window (> 6 hours).
Patients treated in the early time window were significantly more likely to be mobile and able to perform daily tasks (mRS ≤ 2) 90 days after the procedure in the MIST group (54%), compared with the transferred group (28%, P < 0.01). Outcomes did not differ significantly between groups in the late time window (35% vs. 41%, P = 0.77).
Similarly, early-time-window patients in the MIST group were more likely to have higher functionality at discharge, compared with transferred patients, based on the on the National Institutes of Health Stroke Scale (median score of 5.0 vs. 12.0, P < 0.01). There was no significant difference between groups treated in the late time window (median score of 5.0 vs. 11.0, P = 0.11).
“Ischemic strokes often progress rapidly and can cause severe damage because brain tissue dies quickly without oxygen, resulting in serious long-term disabilities or death,“ said Johanna Fifi, MD, of Icahn School of Medicine, said in a statement to the American Heart Association. “Assessing and treating stroke patients in the early window means that a greater number of fast-progressing strokes are identified and treated.”
Time is brain
Endovascular thrombectomy is a time-sensitive surgical procedure to remove large blood clots in acute ischemic stroke that has “historically been limited to comprehensive stroke centers,” the authors wrote in their paper. It is considered the standard of care in ischemic strokes, which make up 90% of all strokes. “Less than 50% of Americans have direct access to endovascular thrombectomy, the others must be transferred to a thrombectomy-capable hospital for treatment, often losing over 2 hours of time to treatment,” said Dr. Fifi. “Every minute is precious in treating stroke, and getting to a center that offers thrombectomy is very important. The MIST model would address this by providing faster access to this potentially life-saving, disability-reducing procedure.”
Access to timely endovascular thrombectomy is gradually improving as “more institutions and cities have implemented the [MIST] model.” Dr. Fifi said.
“This study stresses the importance of ‘time is brain,’ especially for patients in the early time window. Although the study is limited by the observational, retrospective design and was performed at a single integrated center, the findings are provocative,” said Louise McCullough, MD, of the University of Texas Health Science Center at Houston said in a statement to the American Heart Association. “The use of a MIST model highlights the potential benefit of early and urgent treatment for patients with large-vessel stroke. Stroke systems of care need to take advantage of any opportunity to treat patients early, wherever they are.”
The study was partly funded by a Stryker Foundation grant.
FROM STROKE
Transporting stroke patients directly to thrombectomy boosts outcomes
LOS ANGELES – Evidence continues to mount that in the new era of thrombectomy treatment for selected acute ischemic stroke patients outcomes are better when patients go directly to the closest comprehensive stroke center that offers intravascular procedures rather than first being taken to a closer hospital and then needing transfer.
Nils H. Mueller-Kronast, MD, presented a modeled analysis of data collected in a registry on 236 real-world U.S. patients who underwent mechanical thrombectomy for an acute, large-vessel occlusion stroke following transfer from a hospital that could perform thrombolysis but couldn’t offer thrombectomy. The analysis showed that if the patients had instead gone directly to the closest thrombectomy center the result would have been a 16-percentage-point increase in patients with a modified Rankin Scale (mRS) score of 0-1 after 90 days, and a 9-percentage-point increase in mRS 0-2 outcomes, Dr. Mueller-Kronast said at the International Stroke Conference, sponsored by the American Heart Association.
The analysis he presented used data from the Systematic Evaluation of Patients Treated With Stroke Devices for Acute Ischemic Stroke (STRATIS) registry, which included 984 acute ischemic stroke patients who underwent mechanical thrombectomy at any one of 55 participating U.S. sites (Stroke. 2017 Oct;48[10]:2760-8). A previously-reported analysis of the STRATIS data showed that the 55% of patients taken directly to a center that performed thrombectomy had a 60% rate of mRS score 0-2 after 90 days, compared with 52% of patients taken first to a hospital unable to perform thrombectomy and then transferred (Circulation. 2017 Dec 12;136[24]:2311-21).
The current analysis focused on 236 of the transferred patients with complete information on their location at the time of their stroke and subsequent time intervals during their transport and treatment, including 117 patients with ground transfer from their first hospital to the thrombectomy site, 114 with air transfer, and 5 with an unreported means of transport.
Dr. Mueller-Kronast and his associates calculated the time it would have taken each of the 117 ground transported patients to have gone directly to the closest thrombectomy center (adjusted by traffic conditions at the time of the stroke), and modeled the likely outcomes of these patients based on the data collected in the registry. This projected a 47% rate of mRS scores 0-1 (good outcomes) after 90 days, and a 60% rate of mRS 0-2 scores with a direct-to-thrombectomy strategy, compared with actual rates of 31% and 51%, respectively, among the patients who were transferred from their initial hospital.
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“Bypass to an endovascular-capable center may be an option to improve rapid access to mechanical thrombectomy,” he concluded.
The STRATIS registry is sponsored by Medtronic. Dr. Mueller-Kronast has been a consultant to Medtronic.
SOURCE: Mueller-Kronast N et al. Abstract LB12.
LOS ANGELES – Evidence continues to mount that in the new era of thrombectomy treatment for selected acute ischemic stroke patients outcomes are better when patients go directly to the closest comprehensive stroke center that offers intravascular procedures rather than first being taken to a closer hospital and then needing transfer.
Nils H. Mueller-Kronast, MD, presented a modeled analysis of data collected in a registry on 236 real-world U.S. patients who underwent mechanical thrombectomy for an acute, large-vessel occlusion stroke following transfer from a hospital that could perform thrombolysis but couldn’t offer thrombectomy. The analysis showed that if the patients had instead gone directly to the closest thrombectomy center the result would have been a 16-percentage-point increase in patients with a modified Rankin Scale (mRS) score of 0-1 after 90 days, and a 9-percentage-point increase in mRS 0-2 outcomes, Dr. Mueller-Kronast said at the International Stroke Conference, sponsored by the American Heart Association.
The analysis he presented used data from the Systematic Evaluation of Patients Treated With Stroke Devices for Acute Ischemic Stroke (STRATIS) registry, which included 984 acute ischemic stroke patients who underwent mechanical thrombectomy at any one of 55 participating U.S. sites (Stroke. 2017 Oct;48[10]:2760-8). A previously-reported analysis of the STRATIS data showed that the 55% of patients taken directly to a center that performed thrombectomy had a 60% rate of mRS score 0-2 after 90 days, compared with 52% of patients taken first to a hospital unable to perform thrombectomy and then transferred (Circulation. 2017 Dec 12;136[24]:2311-21).
The current analysis focused on 236 of the transferred patients with complete information on their location at the time of their stroke and subsequent time intervals during their transport and treatment, including 117 patients with ground transfer from their first hospital to the thrombectomy site, 114 with air transfer, and 5 with an unreported means of transport.
Dr. Mueller-Kronast and his associates calculated the time it would have taken each of the 117 ground transported patients to have gone directly to the closest thrombectomy center (adjusted by traffic conditions at the time of the stroke), and modeled the likely outcomes of these patients based on the data collected in the registry. This projected a 47% rate of mRS scores 0-1 (good outcomes) after 90 days, and a 60% rate of mRS 0-2 scores with a direct-to-thrombectomy strategy, compared with actual rates of 31% and 51%, respectively, among the patients who were transferred from their initial hospital.
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“Bypass to an endovascular-capable center may be an option to improve rapid access to mechanical thrombectomy,” he concluded.
The STRATIS registry is sponsored by Medtronic. Dr. Mueller-Kronast has been a consultant to Medtronic.
SOURCE: Mueller-Kronast N et al. Abstract LB12.
LOS ANGELES – Evidence continues to mount that in the new era of thrombectomy treatment for selected acute ischemic stroke patients outcomes are better when patients go directly to the closest comprehensive stroke center that offers intravascular procedures rather than first being taken to a closer hospital and then needing transfer.
Nils H. Mueller-Kronast, MD, presented a modeled analysis of data collected in a registry on 236 real-world U.S. patients who underwent mechanical thrombectomy for an acute, large-vessel occlusion stroke following transfer from a hospital that could perform thrombolysis but couldn’t offer thrombectomy. The analysis showed that if the patients had instead gone directly to the closest thrombectomy center the result would have been a 16-percentage-point increase in patients with a modified Rankin Scale (mRS) score of 0-1 after 90 days, and a 9-percentage-point increase in mRS 0-2 outcomes, Dr. Mueller-Kronast said at the International Stroke Conference, sponsored by the American Heart Association.
The analysis he presented used data from the Systematic Evaluation of Patients Treated With Stroke Devices for Acute Ischemic Stroke (STRATIS) registry, which included 984 acute ischemic stroke patients who underwent mechanical thrombectomy at any one of 55 participating U.S. sites (Stroke. 2017 Oct;48[10]:2760-8). A previously-reported analysis of the STRATIS data showed that the 55% of patients taken directly to a center that performed thrombectomy had a 60% rate of mRS score 0-2 after 90 days, compared with 52% of patients taken first to a hospital unable to perform thrombectomy and then transferred (Circulation. 2017 Dec 12;136[24]:2311-21).
The current analysis focused on 236 of the transferred patients with complete information on their location at the time of their stroke and subsequent time intervals during their transport and treatment, including 117 patients with ground transfer from their first hospital to the thrombectomy site, 114 with air transfer, and 5 with an unreported means of transport.
Dr. Mueller-Kronast and his associates calculated the time it would have taken each of the 117 ground transported patients to have gone directly to the closest thrombectomy center (adjusted by traffic conditions at the time of the stroke), and modeled the likely outcomes of these patients based on the data collected in the registry. This projected a 47% rate of mRS scores 0-1 (good outcomes) after 90 days, and a 60% rate of mRS 0-2 scores with a direct-to-thrombectomy strategy, compared with actual rates of 31% and 51%, respectively, among the patients who were transferred from their initial hospital.
[embed:render:related:node:132691]
[embed:render:related:node:158309]
“Bypass to an endovascular-capable center may be an option to improve rapid access to mechanical thrombectomy,” he concluded.
The STRATIS registry is sponsored by Medtronic. Dr. Mueller-Kronast has been a consultant to Medtronic.
SOURCE: Mueller-Kronast N et al. Abstract LB12.
REPORTING FROM ISC 2018
Key clinical point: A direct-to-thrombectomy strategy maximizes good stroke outcomes.
Major finding: Modeling showed a 47% rate of good 90-day outcomes by taking patients to the closest thrombectomy center, compared with an actual 31% rate with transfers.
Study details: A simulation-model analysis of data collected by the STRATIS registry of acute stroke thrombectomies.
Disclosures: The STRATIS registry is sponsored by Medtronic. Dr. Mueller-Kronast has been a consultant to Medtronic.
Source: Mueller-Kronast N et al. Abstract LB12.
EMS stroke field triage improves outcomes
LOS ANGELES – An emergency medical services protocol to identify large vessel occlusions and deliver patients to a comprehensive stroke center if it is within 30 minutes of travel time reduced the time to recanalization when compared against a separate protocol that optimized transfer of such patients from primary to comprehensive stroke centers.
The findings, which come from a sequential study conducted in an urban Rhode Island region, offer evidence to resolve the controversy over whether field triage in emergency medical services (EMS) units will improve outcomes, because field stroke severity scores won’t always be accurate, and longer travel to a comprehensive stroke center (CSC) could delay treatment to a patient who doesn’t need thrombectomy.
The region where the study was carried out has one CSC and eight primary stroke centers (PSCs). The large vessel occlusions transfer protocol instructed PSCs to contact the CSC when a patient scored 4 or 5 on the Los Angeles Motor Scale (LAMS), followed by CT and CT angiography. They then shared the resulting images with the CSC, which could make a decision whether to transfer the patient.
The field-based protocol relied on a LAMS score assessment by EMS personnel. Patients scoring 4 or 5 would then be delivered to the CSC if it was within 30 minutes from their current location. Patients scoring less than 4 would be brought to the nearest facility. In cases when the field LAMS score was 4 or greater and the nearest CSC was more than 30 miles away, EMS personnel were instructed to travel to the closest PSC, but immediately send word of an inbound patient that might need a transfer to a CSC. In those cases, the PSC’s goal was to get images to the CSC for review within 45 minutes. The protocol was executed out to 24 hours after the patient was last known well.
Even in patients who were closer to a PSC than a CSC, process outcomes were better with the field triage protocol. “Despite 8 additional minutes of transport time, IV TPA was given 17 minutes earlier, and recanalization occurred almost an hour earlier,” said Dr. McTaggart. “That would indicate that perhaps even a 30-minute window is too conservative of a protocol, because the number needed to treat for mechanical thrombectomy is 2 or 3, so you have this tremendously powerful treatment effect for these patients. If you can get it to them an hour earlier, it’s a no-brainer to me that they need to go to the right place the first time,” he said.
Instituting the changes was no picnic. Dr. McTaggart spent thousands of hours working with EMS personnel and emergency department physicians at PSCs. “It’s a lot of work, but the downstream gains are huge, not only from a disability standpoint for patients but for the economics of the health care system. We’re potentially saving patients from disability health care costs,” he said.
The study population included consecutive stroke patients in the region whose first contact was with EMS personnel during three time periods: before either change was made: (pre PSC-CSC transfer optimization, pre field triage, July 2015 to January 2016), after PSC optimization but only voluntary field triage (January 2016 to January 2017), and when both PSC optimization and field triage were mandatory (January 2017 to January 2018).
The patients had an anterior large vessel occlusion and mild to moderate early ischemic change. Outcomes included time from hospital arrival (PSC or CSC) to alteplase treatment, arterial puncture, and recanalization. Clinical measures included favorable outcomes (modified Rankin scale score 0-2) at 90 days, or discharge with a National Institutes of Health Stroke Scale score of 4 or less, in cases where 90-day follow-up did not occur.
A total of 38 patients were seen before any change, 100 after PSC optimization, and 94 after both PSC optimization and field triage were implemented. A Google Maps analysis showed that the median additional time required to travel to a CSC instead of a PSC was 8 minutes (interquartile range 4-12).
The time to first use of IV alteplase dropped from 54 minutes before any change to 49 minutes after PSC optimization, and 36 minutes after both PSC optimization and field triage. Similar drops were seen in time to arterial puncture (105 minutes, 101 minutes, 88 minutes) and time to recanalization (156 minutes, 132 minutes, 116 minutes). These differences did not reach statistical significance.
The clinical outcomes also became more favorable: 58% had a favorable outcome at 90 days with both protocols in place, compared with 51% with only PSC optimization and 31% before any changes (P = .049 for 31% to 58% comparison).
The researchers conducted a subanalysis of 150 patients for whom the PSC was closest. Of these, 94 went to a CSC and 56 went to a PSC. The elapsed time between EMS leaving the scene with the patient aboard and IV TPA treatment was an average of 51 minutes in patients taken to the CSC, compared with 68 minutes in patients taken to PSCs (P = .012). The time to arterial puncture was also shorter (98 minutes versus 155 minutes; P less than .001), as was time to recanalization (131 minutes versus 174 minutes; P less than .001).
CSC patients were more likely to have a favorable outcome (65% versus 42%; P = .01).
The study received no external funding. Dr. McTaggart reported having no financial disclosures.
SOURCE: Jayaraman M et al. ISC 2018 Abstract 95 (Stroke. 2018 Jan;49[Suppl 1]:A95)
LOS ANGELES – An emergency medical services protocol to identify large vessel occlusions and deliver patients to a comprehensive stroke center if it is within 30 minutes of travel time reduced the time to recanalization when compared against a separate protocol that optimized transfer of such patients from primary to comprehensive stroke centers.
The findings, which come from a sequential study conducted in an urban Rhode Island region, offer evidence to resolve the controversy over whether field triage in emergency medical services (EMS) units will improve outcomes, because field stroke severity scores won’t always be accurate, and longer travel to a comprehensive stroke center (CSC) could delay treatment to a patient who doesn’t need thrombectomy.
The region where the study was carried out has one CSC and eight primary stroke centers (PSCs). The large vessel occlusions transfer protocol instructed PSCs to contact the CSC when a patient scored 4 or 5 on the Los Angeles Motor Scale (LAMS), followed by CT and CT angiography. They then shared the resulting images with the CSC, which could make a decision whether to transfer the patient.
The field-based protocol relied on a LAMS score assessment by EMS personnel. Patients scoring 4 or 5 would then be delivered to the CSC if it was within 30 minutes from their current location. Patients scoring less than 4 would be brought to the nearest facility. In cases when the field LAMS score was 4 or greater and the nearest CSC was more than 30 miles away, EMS personnel were instructed to travel to the closest PSC, but immediately send word of an inbound patient that might need a transfer to a CSC. In those cases, the PSC’s goal was to get images to the CSC for review within 45 minutes. The protocol was executed out to 24 hours after the patient was last known well.
Even in patients who were closer to a PSC than a CSC, process outcomes were better with the field triage protocol. “Despite 8 additional minutes of transport time, IV TPA was given 17 minutes earlier, and recanalization occurred almost an hour earlier,” said Dr. McTaggart. “That would indicate that perhaps even a 30-minute window is too conservative of a protocol, because the number needed to treat for mechanical thrombectomy is 2 or 3, so you have this tremendously powerful treatment effect for these patients. If you can get it to them an hour earlier, it’s a no-brainer to me that they need to go to the right place the first time,” he said.
Instituting the changes was no picnic. Dr. McTaggart spent thousands of hours working with EMS personnel and emergency department physicians at PSCs. “It’s a lot of work, but the downstream gains are huge, not only from a disability standpoint for patients but for the economics of the health care system. We’re potentially saving patients from disability health care costs,” he said.
The study population included consecutive stroke patients in the region whose first contact was with EMS personnel during three time periods: before either change was made: (pre PSC-CSC transfer optimization, pre field triage, July 2015 to January 2016), after PSC optimization but only voluntary field triage (January 2016 to January 2017), and when both PSC optimization and field triage were mandatory (January 2017 to January 2018).
The patients had an anterior large vessel occlusion and mild to moderate early ischemic change. Outcomes included time from hospital arrival (PSC or CSC) to alteplase treatment, arterial puncture, and recanalization. Clinical measures included favorable outcomes (modified Rankin scale score 0-2) at 90 days, or discharge with a National Institutes of Health Stroke Scale score of 4 or less, in cases where 90-day follow-up did not occur.
A total of 38 patients were seen before any change, 100 after PSC optimization, and 94 after both PSC optimization and field triage were implemented. A Google Maps analysis showed that the median additional time required to travel to a CSC instead of a PSC was 8 minutes (interquartile range 4-12).
The time to first use of IV alteplase dropped from 54 minutes before any change to 49 minutes after PSC optimization, and 36 minutes after both PSC optimization and field triage. Similar drops were seen in time to arterial puncture (105 minutes, 101 minutes, 88 minutes) and time to recanalization (156 minutes, 132 minutes, 116 minutes). These differences did not reach statistical significance.
The clinical outcomes also became more favorable: 58% had a favorable outcome at 90 days with both protocols in place, compared with 51% with only PSC optimization and 31% before any changes (P = .049 for 31% to 58% comparison).
The researchers conducted a subanalysis of 150 patients for whom the PSC was closest. Of these, 94 went to a CSC and 56 went to a PSC. The elapsed time between EMS leaving the scene with the patient aboard and IV TPA treatment was an average of 51 minutes in patients taken to the CSC, compared with 68 minutes in patients taken to PSCs (P = .012). The time to arterial puncture was also shorter (98 minutes versus 155 minutes; P less than .001), as was time to recanalization (131 minutes versus 174 minutes; P less than .001).
CSC patients were more likely to have a favorable outcome (65% versus 42%; P = .01).
The study received no external funding. Dr. McTaggart reported having no financial disclosures.
SOURCE: Jayaraman M et al. ISC 2018 Abstract 95 (Stroke. 2018 Jan;49[Suppl 1]:A95)
LOS ANGELES – An emergency medical services protocol to identify large vessel occlusions and deliver patients to a comprehensive stroke center if it is within 30 minutes of travel time reduced the time to recanalization when compared against a separate protocol that optimized transfer of such patients from primary to comprehensive stroke centers.
The findings, which come from a sequential study conducted in an urban Rhode Island region, offer evidence to resolve the controversy over whether field triage in emergency medical services (EMS) units will improve outcomes, because field stroke severity scores won’t always be accurate, and longer travel to a comprehensive stroke center (CSC) could delay treatment to a patient who doesn’t need thrombectomy.
The region where the study was carried out has one CSC and eight primary stroke centers (PSCs). The large vessel occlusions transfer protocol instructed PSCs to contact the CSC when a patient scored 4 or 5 on the Los Angeles Motor Scale (LAMS), followed by CT and CT angiography. They then shared the resulting images with the CSC, which could make a decision whether to transfer the patient.
The field-based protocol relied on a LAMS score assessment by EMS personnel. Patients scoring 4 or 5 would then be delivered to the CSC if it was within 30 minutes from their current location. Patients scoring less than 4 would be brought to the nearest facility. In cases when the field LAMS score was 4 or greater and the nearest CSC was more than 30 miles away, EMS personnel were instructed to travel to the closest PSC, but immediately send word of an inbound patient that might need a transfer to a CSC. In those cases, the PSC’s goal was to get images to the CSC for review within 45 minutes. The protocol was executed out to 24 hours after the patient was last known well.
Even in patients who were closer to a PSC than a CSC, process outcomes were better with the field triage protocol. “Despite 8 additional minutes of transport time, IV TPA was given 17 minutes earlier, and recanalization occurred almost an hour earlier,” said Dr. McTaggart. “That would indicate that perhaps even a 30-minute window is too conservative of a protocol, because the number needed to treat for mechanical thrombectomy is 2 or 3, so you have this tremendously powerful treatment effect for these patients. If you can get it to them an hour earlier, it’s a no-brainer to me that they need to go to the right place the first time,” he said.
Instituting the changes was no picnic. Dr. McTaggart spent thousands of hours working with EMS personnel and emergency department physicians at PSCs. “It’s a lot of work, but the downstream gains are huge, not only from a disability standpoint for patients but for the economics of the health care system. We’re potentially saving patients from disability health care costs,” he said.
The study population included consecutive stroke patients in the region whose first contact was with EMS personnel during three time periods: before either change was made: (pre PSC-CSC transfer optimization, pre field triage, July 2015 to January 2016), after PSC optimization but only voluntary field triage (January 2016 to January 2017), and when both PSC optimization and field triage were mandatory (January 2017 to January 2018).
The patients had an anterior large vessel occlusion and mild to moderate early ischemic change. Outcomes included time from hospital arrival (PSC or CSC) to alteplase treatment, arterial puncture, and recanalization. Clinical measures included favorable outcomes (modified Rankin scale score 0-2) at 90 days, or discharge with a National Institutes of Health Stroke Scale score of 4 or less, in cases where 90-day follow-up did not occur.
A total of 38 patients were seen before any change, 100 after PSC optimization, and 94 after both PSC optimization and field triage were implemented. A Google Maps analysis showed that the median additional time required to travel to a CSC instead of a PSC was 8 minutes (interquartile range 4-12).
The time to first use of IV alteplase dropped from 54 minutes before any change to 49 minutes after PSC optimization, and 36 minutes after both PSC optimization and field triage. Similar drops were seen in time to arterial puncture (105 minutes, 101 minutes, 88 minutes) and time to recanalization (156 minutes, 132 minutes, 116 minutes). These differences did not reach statistical significance.
The clinical outcomes also became more favorable: 58% had a favorable outcome at 90 days with both protocols in place, compared with 51% with only PSC optimization and 31% before any changes (P = .049 for 31% to 58% comparison).
The researchers conducted a subanalysis of 150 patients for whom the PSC was closest. Of these, 94 went to a CSC and 56 went to a PSC. The elapsed time between EMS leaving the scene with the patient aboard and IV TPA treatment was an average of 51 minutes in patients taken to the CSC, compared with 68 minutes in patients taken to PSCs (P = .012). The time to arterial puncture was also shorter (98 minutes versus 155 minutes; P less than .001), as was time to recanalization (131 minutes versus 174 minutes; P less than .001).
CSC patients were more likely to have a favorable outcome (65% versus 42%; P = .01).
The study received no external funding. Dr. McTaggart reported having no financial disclosures.
SOURCE: Jayaraman M et al. ISC 2018 Abstract 95 (Stroke. 2018 Jan;49[Suppl 1]:A95)
REPORTING FROM ISC 2018
Key clinical point: EMS field triage may improve stroke patient management.
Major finding: Even when a primary stroke center was closer, the time to recanalization was shortened by 43 minutes when patients were taken to a comprehensive stroke center instead.
Data source: Prospective study of 232 consecutive stroke patients.
Disclosures: The study received no external funding. Dr. McTaggart reported having no financial disclosures.
Source: Jayaraman M et al. ISC 2018 Abstract 95 (Stroke. 2018 Jan;49[Suppl 1]:A95)
First EDition: Mobile Stroke Units Becoming More Common, more
MITCHEL L. ZOLER
FRONTLINE MEDICAL NEWS
Mobile stroke units—specially equipped ambulances that bring a diagnostic computed tomography (CT) scanner and therapeutic thrombolysis directly to patients in the field—have begun to proliferate across the United States, although they remain investigational, with no clear proof of their incremental clinical value or cost-effectiveness.
The first US mobile stroke unit (MSU) launched in Houston, Texas in early 2014 (following the world’s first in Berlin, Germany, which began running in early 2011), and by early 2017, at least eight other US MSUs were in operation, most of them put into service during the prior 15 months. United States MSU locations now include Cleveland, Ohio; Denver, Colorado; Memphis, Tennessee; New York, New York; Toledo, Ohio; Trenton, New Jersey; and Northwestern Medicine and Rush University Medical Center in the western Chicago, Illinois region. A tenth MSU is slated to start operation at the University of California, Los Angeles later this year.
Early data collected at some of these sites show that initiating care of an acute ischemic stroke patient in an MSU shaves precious minutes off the time it takes to initiate thrombolytic therapy with tissue plasminogen activator (tPA), and findings from preliminary analyses suggest better functional outcomes for patients treated this way. However, leaders in the nascent field readily admit that the data needed to clearly prove the benefit patients receive from operating MSUs are still a few years off. This uncertainty about the added benefit to patients from MSUs couples with one clear fact: MSUs are expensive to start up, with a price tag of roughly $1 million to get an MSU on the road for the first time; they are also expensive to operate, with one estimate for the annual cost of keeping an MSU on the street at about $500,000 per year for staffing, supplies, and other expenses.
“Every US MSU I know of started with philanthropic gifts, but you need a business model” to keep the program running long-term, James C. Grotta, MD, said during a session focused on MSUs at the International Stroke Conference sponsored by the American Heart Association. “You can’t sustain an MSU with philanthropy,” said Dr Grotta, professor of neurology at the University of Texas Health Science Center in Houston, director and founder of the Houston MSU, and acknowledged “godfather” of all US MSUs.
“We believe that MSUs are very worthwhile and that the clinical and economic benefits of earlier stroke treatment [made possible with MSUs] could offset the costs, but we need to show this,” admitted May Nour, MD, a vascular and interventional neurologist at the University of California, Los Angeles (UCLA), and director of the soon-to-launch Los Angeles MSU.
The concept behind MSUs is simple: Each one carries a CT scanner on board so that once the vehicle’s staff identifies a patient with clinical signs of a significant-acute ischemic stroke in the field and confirms that the timing of the stroke onset suggests eligibility for tPA treatment, a CT scan can immediately be run on-site to finalize tPA eligibility. The MSU staff can then begin infusing the drug in the ambulance as it speeds the patient to an appropriate hospital.
In addition, many MSUs now carry a scanner that can perform a CT angiogram (CTA) to locate the occluding clot. If a large vessel occlusion is found, the crew can bring the patient directly to a comprehensive stroke center for a thrombectomy. If thrombectomy is not appropriate, the MSU crew may take the patient to a primary stroke center where thrombectomy is not available.
Another advantage to MSUs, in addition to quicker initiation of thrombolysis, is “getting patients to where they need to go faster and more directly,” said Dr Nour.
“Instead of bringing patients first to a hospital that’s unable to do thrombectomy and where treatment gets slowed down, with an MSU you can give tPA on the street and go straight to a thrombectomy center,” agreed Jeffrey L. Saver, MD, professor of neurology and director of the stroke unit at UCLA. “The MSU offers the tantalizing possibility that you can give tPA with no time hit because you can give it on the way directly to a comprehensive stroke center,” Dr Saver said during a session at the meeting.
Early Data on Effectiveness
Dr Nour reported some of the best evidence for the incremental clinical benefit of MSUs based on the reduced time for starting a tPA infusion. She used data the Berlin group published in September 2016 that compared the treatment courses and outcomes of patients managed with an MSU to similar patients managed by conventional ambulance transport for whom CT scan assessment and the start of tPA treatment did not begin until the patient reached a hospital. The German analysis showed that, in the observational Pre-hospital Acute Neurological Therapy and Optimization of Medical Care in Stroke Patients–Study (PHANTOM-S), among 353 patients treated by conventional transport, the median time from stroke onset to thrombolysis was 112 minutes, compared with a median of 73 minutes among 305 patients managed with an MSU, a statistically significant difference.1 However, the study found no significant difference for its primary endpoint: the percentage of patients with a modified Rankin Scale score of 1 or lower when measured 90 days after their respective strokes. This outcome occurred in 47% of the control patients managed conventionally and in 53% of those managed by an MSU, a difference that fell short of statistical significance
Dr Nour attributed the lack of statistical significance for this primary endpoint to the relatively small number of patients enrolled in PHANTOM-S. “The study was underpowered,” she said.
Dr Nour presented an analysis at the meeting that extrapolated the results out to 1,000 hypothetical patients and tallied the benefits that a larger number of patients could expect to receive if their outcomes paralleled those seen in the published results. It showed that among 1,000 stroke patients treated with an MSU, 58 were expected to be free from disability 90 days later, and an additional 124 patients would have some improvement in their 90-day clinical outcome based on their modified Rankin Scale scores when compared with patients undergoing conventional hospitalization.
“If this finding was confirmed in a larger, controlled study, it would suggest that MSU-based thrombolysis has substantial clinical benefit,” she concluded.
Another recent report looked at the first 100 stroke patients treated by the Cleveland MSU during 2014. Researchers at the Cleveland Clinic and Case Western Reserve University said that 16 of those 100 patients received tPA, and the median time from their emergency call to thrombolytic treatment was 38.5 minutes faster than for 53 stroke patients treated during the same period at EDs operated by the Cleveland Clinic, a statistically significant difference.2 However, this report included no data on clinical outcomes.
Running the Financial Numbers
Nailing down the incremental clinical benefit from MSUs is clearly a very important part of determining the value of this strategy, but another very practical concern is how much the service costs and whether it is financially sustainable.
“We did a cost-effectiveness analysis based on the PHANTOM-S data, and we were conservative by only looking at the benefit from early tPA treatment,” Heinrich J. Audebert, MD, professor of neurology at Charité Hospital in Berlin and head of the team running Berlin’s MSU, said during the MSU session at the meeting. “We did not take into account saving money by avoiding long-term stroke disability and just considered the cost of [immediate] care and the quality-adjusted life years. We calculated a cost of $35,000 per quality-adjusted life year, which is absolutely acceptable.”
He cautioned that this analysis was not based on actual outcomes but on the numbers needed to treat calculated from the PHANTOM-S results. “We need to now show this in controlled trials,” he admitted.
During his talk at the same session, Dr Grotta ran through the numbers for the Houston program. They spent $1.1 million to put their MSU into service in early 2014, and, based on the expenses accrued since then, he estimated an annual staffing cost of about $400,000 and an annual operating cost of about $100,000, for a total estimated 5-year cost of about $3.6 million. Staffing of the Houston MSU started with a registered nurse, CT technician, paramedic, and vascular neurologist, although, like most other US MSUs, the onboard neurologist has since been replaced by a second paramedic, and the neurological diagnostic consult is done via a telemedicine link.
Income from transport reimbursement, currently $500 per trip, and reimbursements of $17,000 above costs for administering tPA and of roughly $40,000 above costs for performing thrombectomy, are balancing these costs. Based on an estimated additional one thrombolysis case per month and one additional thrombectomy case per month, the MSU yields a potential incremental income to the hospital running the MSU of about $3.8 million over 5 years—enough to balance the operating cost, Dr Grotta said.
A key part of controlling costs is having the neurological consult done via a telemedicine link rather than by neurologist at the MSU. “Telemedicine reduces operational costs and improves efficiency,” noted M. Shazam Hussain, MD, interim director of the Cerebrovascular Center at the Cleveland Clinic. “Cost-effectiveness is a very important part of the concept” of MSUs, he said at the session.
The Houston group reported results from a study that directly compared the diagnostic performance of an onboard neurologist with that of a telemedicine neurologist linked-in remotely during MSU deployments for 174 patients. For these cases, the two neurologists each made an independent diagnosis that the researchers then compared. The two diagnoses concurred for 88% of the cases, Tzu-Ching Wu, MD, reported at the meeting. This rate of agreement matched the incidence of concordance between two neurologists who independently assessed the same patients at the hospital,3 said Dr Wu, a vascular neurologist and director of the telemedicine program at the University of Texas Health Science Center in Houston.
“The results support using telemedicine as the primary means of assessment on the MSU,” said Dr Wu. “This may enhance MSU efficiency and reduce costs.” His group’s next study of MSU telemedicine will compare the time needed to make a diagnostic decision using the two approaches, which Dr Wu reported was something not formally examined in the study.
However, telemedicine assessment of CT results gathered in an MSU has one major limitation: the time needed to transmit the huge amount of information from a CTA.
The MSU used by clinicians at the University of Tennessee, Memphis, incorporates an extremely powerful battery that enables “full CT scanner capability with a moving gantry,” said Andrei V. Alexandrov, MD, professor and chairman of neurology at the university. With this set up “we can do in-the-field multiphasic CT angiography from the aortic arch up within 4 minutes. The challenge of doing this is simple. It’s 1.7 gigabytes of data,” which would take a prohibitively long time to transmit from a remote site, he explained. As a result, the complete set of images from the field CTA is delivered on a memory stick to the attending hospital neurologist once the MSU returns.
Waiting for More Data
Despite these advances and the steady recent growth of MSUs, significant skepticism remains. “While mobile stroke units seem like a good idea and there is genuine hope that they will improve outcomes for selected stroke patients, there is not yet any evidence that this is the case,” wrote Bryan Bledsoe, DO, in a January 2017 editorial in the Journal of Emergency Medical Services. “They are expensive and financially nonsustainable. Without widespread deployment, they stand to benefit few, if any, patients. The money spent on these devices would be better spent on improving the current EMS system, including paramedic education, the availability of stroke centers, and on the early recognition of ELVO [emergent large vessel occlusion] strokes,” wrote Dr Bledsoe, professor of emergency medicine at the University of Nevada in Las Vegas.
Two other experts voiced concerns about MSUs in an editorial that accompanied a Cleveland Clinic report in March.4 “Even if MSUs meet an acceptable societal threshold for cost-effectiveness, cost-efficiency may prove a taller order to achieve return on investment for individual health systems and communities,” wrote Andrew M. Southerland, MD, and Ethan S. Brandler, MD. They cited the Cleveland report, which noted that the group’s first 100 MSU-treated patients came from a total of 317 MSU deployments and included 217 trips that were canceled prior to the MSU’s arrival at the patient’s location. In Berlin’s initial experience, more than 2,000 MSU deployments led to 200 tPA treatments and 349 cancellations before arrival, noted Dr Southerland, a neurologist at the University of Virginia in Charlottesville, and Dr Brandler, an emergency medicine physician at Stony Brook (NY) University.
“Hope remains that future trials may demonstrate the ultimate potential of mobile stroke units to improve long-term outcomes for more patients by treating them more quickly and effectively. In the meantime, ongoing efforts are needed to streamline MSU cost and efficiency,” they wrote.
Proponents of MSUs agree that what’s needed now are more data to prove efficacy and cost-effectiveness, as well as better integration into EMS programs. The first opportunity for documenting the clinical impact of MSUs on larger numbers of US patients may be from the BEnefits of Stroke Treatment Delivered using a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services (BEST-MSU) Study, funded by the Patient-Centered Outcomes Research Institute. This study is collecting data from the MSU programs in Denver, Houston, and Memphis. Although currently designed to enroll 697 patients, Dr Grotta said he hopes to bring the number up to 1,000 patients.
“We are following the health care use and its cost for every enrolled MSU and conventional patient for 1 year,” Dr Grotta explained in an interview. He hopes these results will provide the data needed to move MSUs from investigational status to routine and reimbursable care.
References
1. Kunz A, Ebinger M, Geisler F, et al. Functional outcomes of pre-hospital thrombolysis in a mobile stroke treatment unit compared with conventional care: an observational registry study. Lancet Neurol. 2016;15(10):1035-1043. doi:10.1016/S1474-4422(16)30129-6.
2. Taqui A, Cerejo R, Itrat A, et al; Cleveland Pre-Hospital Acute Stroke Treatment (PHAST) Group. Reduction in time to treatment in prehospital telemedicine evaluation and thrombolysis. Neurology. 2017 March 8. [Epub ahead of print]. doi:10.1212/WNL.0000000000003786.
3. Ramadan AR, Denny MC, Vahidy F, et al. Agreement among stroke faculty and fellows in treating ischemic stroke patients with tissue-type plasminogen activator and thrombectomy. Stroke. 2017;48(1):222-224. doi:10.1161/STROKEAHA.116.015214.
4. Southerland AM, Brandler ES. The cost-efficiency of mobile stroke units: Where the rubber meets the road. Neurology. 2017 Mar 8. [Epub ahead of print]. doi:10.1212/WNL.0000000000003833.
Pulmonary Embolism Common in Patients With Acute Exacerbations of COPD
JIM KLING
FRONTLINE MEDICAL NEWS
About 16% of patients with unexplained acute exacerbations of chronic obstructive pulmonary disease (AECOPD) had an accompanying pulmonary embolism (PE), usually in regions that could be targeted with anticoagulants, according to a new systematic review and meta-analysis.
Approximately 70% of AECOPD cases develop in response to an infection, but about 30% of the time, an AE has no clear cause, the authors said in a report on their research. There is a known biological link between inflammation and coagulation, which suggests that patients experiencing AECOPD may be at increased risk of PE.
The researchers reviewed and analyzed seven studies, comprising 880 patients. Among the authors’ reasons for conducting this research was to update the pooled prevalence of PE in AECOPD from a previous systematic review published in Chest in 2009.
The meta-analysis revealed that 16.1% of patients with AECOPD were also diagnosed with PE (95% confidence interval [CI], 8.3%-25.8%). There was a wide range of variation between individual studies (prevalence 3.3%-29.1%). In six studies that reported on deep vein thrombosis (DVT), the pooled prevalence of DVT was 10.5% (95% CI, 4.3%-19.0%).
Five of the studies identified the PE location. An analysis of those studies showed that 35% were in the main pulmonary artery, and 31.7% were in the lobar and interlobar arteries. Such findings “[suggest] that the majority of these embolisms have important clinical consequences,” the authors wrote.
The researchers also looked at clinical markers that accompanied AECOPD and found a potential signal with respect to pleuritic chest pain. One study found a strong association between pleuritic chest pain and AECOPD patients with PE (81% vs 40% in those without PE). A second study showed a similar association (24% in PE vs 11.5% in non-PE patients), and a third study found no significant difference.
The presence of PE was also linked to hypotension, syncope, and acute right failure on ultrasonography, suggesting that PE may be associated with heart failure.
Patients with PE were less likely to have symptoms consistent with a respiratory tract infection. They also tended to have higher mortality rates and longer hospitalization rates compared with those without PE.
The meta-analysis had some limitations, including the heterogeneity of findings in the included studies, as well as the potential for publication bias, since reports showing unusually low or high rates may be more likely to be published, the researchers noted. There was also a high proportion of male subjects in the included studies.
Overall, the researchers concluded that PE is more likely in patients with pleuritic chest pain and signs of heart failure, and less likely in patients with signs of a respiratory infection. That information “might add to the clinical decision-making in patients with an AECOPD, because it would be undesirable to perform [CT pulmonary angiography] in every patient with an AECOPD,” the researchers wrote.
Aleva FE, Voets LW, Simons SO, de Mast Q, van der Ven AJ, Heijdra YF. Prevalence and localization of pulmonary embolism in unexplained acute exacerbations of COPD: A systematic review and meta-analysis. Chest. 2017;151(3):544-554. doi:10.1016/j.chest.2016.07.034.
Norepinephrine Shortage Linked to Mortality in Patients With Septic Shock
AMY KARON
FRONTLINE MEDICAL NEWS
A national shortage of norepinephrine in the United States was associated with higher rates of mortality among patients hospitalized with septic shock, investigators reported.
Rates of in-hospital mortality in 2011 were 40% during quarters when hospitals were facing shortages and 36% when they were not, Emily Vail, MD, and her associates said at the International Symposium on Intensive Care and Emergency Medicine. The report was published simultaneously in JAMA.
The link between norepinephrine shortage and death from septic shock persisted even after the researchers accounted for numerous clinical and demographic factors (adjusted odds ratio, 1.2; 95% CI, 1.01 to 1.30; P = .03), wrote Dr Vail of Columbia University, New York.
Drug shortages are common in the United States, but few studies have explored their effects on patient outcomes. Investigators compared mortality rates among affected patients during 3-month intervals when hospitals were and were not using at least 20% less norepinephrine than baseline. The researchers used Premier Healthcare Database, which includes both standard claims and detailed, dated logs of all services billed to patients or insurance, with minimal missing data.
A total of 77% patients admitted with septic shock received norepinephrine before the shortage. During the lowest point of the shortage, 56% of patients received it, the researchers reported. Clinicians most often used phenylephrine instead, prescribing it to up to 54% of patients during the worst time of the shortage. The absolute increase in mortality during the quarters of shortage was 3.7% (95% CI, 1.5%-6.0%).
Several factors might explain the link between norepinephrine shortage and mortality, the investigators said. The vasopressors chosen to replace norepinephrine might result directly in worse outcomes, but a decrease in norepinephrine use also might be a proxy for relevant variables such as delayed use of vasopressors, lack of knowledge of how to optimally dose vasopressors besides norepinephrine, or the absence of a pharmacist dedicated to helping optimize the use of limited supplies.
The study did not uncover a dose-response association between greater decreases in norepinephrine use and increased mortality, the researchers noted. “This may be due to a threshold effect of vasopressor shortage on mortality, or lack of power due to relatively few hospital quarters at the extreme levels of vasopressor shortage,” they wrote.
Because the deaths captured included only those that occurred in-hospital, “the results may have underestimated mortality, particularly for hospitals that tend to transfer patients early to other skilled care facilities,” the researchers noted.
The cohort of patients was limited to those who received vasopressors for 2 or more days and excluded patients who died on the first day of vasopressor treatment, the researchers said.
Vail E, Gershengorn HB, Hua M, Walkey AJ, Rubenfeld G, Wunsch H. Association between US norepinephrine shortage and mortality among patients with septic shock. JAMA. 21 March 2017. [Epub ahead of print]. doi:10.1001/jama.2017.2841.
MITCHEL L. ZOLER
FRONTLINE MEDICAL NEWS
Mobile stroke units—specially equipped ambulances that bring a diagnostic computed tomography (CT) scanner and therapeutic thrombolysis directly to patients in the field—have begun to proliferate across the United States, although they remain investigational, with no clear proof of their incremental clinical value or cost-effectiveness.
The first US mobile stroke unit (MSU) launched in Houston, Texas in early 2014 (following the world’s first in Berlin, Germany, which began running in early 2011), and by early 2017, at least eight other US MSUs were in operation, most of them put into service during the prior 15 months. United States MSU locations now include Cleveland, Ohio; Denver, Colorado; Memphis, Tennessee; New York, New York; Toledo, Ohio; Trenton, New Jersey; and Northwestern Medicine and Rush University Medical Center in the western Chicago, Illinois region. A tenth MSU is slated to start operation at the University of California, Los Angeles later this year.
Early data collected at some of these sites show that initiating care of an acute ischemic stroke patient in an MSU shaves precious minutes off the time it takes to initiate thrombolytic therapy with tissue plasminogen activator (tPA), and findings from preliminary analyses suggest better functional outcomes for patients treated this way. However, leaders in the nascent field readily admit that the data needed to clearly prove the benefit patients receive from operating MSUs are still a few years off. This uncertainty about the added benefit to patients from MSUs couples with one clear fact: MSUs are expensive to start up, with a price tag of roughly $1 million to get an MSU on the road for the first time; they are also expensive to operate, with one estimate for the annual cost of keeping an MSU on the street at about $500,000 per year for staffing, supplies, and other expenses.
“Every US MSU I know of started with philanthropic gifts, but you need a business model” to keep the program running long-term, James C. Grotta, MD, said during a session focused on MSUs at the International Stroke Conference sponsored by the American Heart Association. “You can’t sustain an MSU with philanthropy,” said Dr Grotta, professor of neurology at the University of Texas Health Science Center in Houston, director and founder of the Houston MSU, and acknowledged “godfather” of all US MSUs.
“We believe that MSUs are very worthwhile and that the clinical and economic benefits of earlier stroke treatment [made possible with MSUs] could offset the costs, but we need to show this,” admitted May Nour, MD, a vascular and interventional neurologist at the University of California, Los Angeles (UCLA), and director of the soon-to-launch Los Angeles MSU.
The concept behind MSUs is simple: Each one carries a CT scanner on board so that once the vehicle’s staff identifies a patient with clinical signs of a significant-acute ischemic stroke in the field and confirms that the timing of the stroke onset suggests eligibility for tPA treatment, a CT scan can immediately be run on-site to finalize tPA eligibility. The MSU staff can then begin infusing the drug in the ambulance as it speeds the patient to an appropriate hospital.
In addition, many MSUs now carry a scanner that can perform a CT angiogram (CTA) to locate the occluding clot. If a large vessel occlusion is found, the crew can bring the patient directly to a comprehensive stroke center for a thrombectomy. If thrombectomy is not appropriate, the MSU crew may take the patient to a primary stroke center where thrombectomy is not available.
Another advantage to MSUs, in addition to quicker initiation of thrombolysis, is “getting patients to where they need to go faster and more directly,” said Dr Nour.
“Instead of bringing patients first to a hospital that’s unable to do thrombectomy and where treatment gets slowed down, with an MSU you can give tPA on the street and go straight to a thrombectomy center,” agreed Jeffrey L. Saver, MD, professor of neurology and director of the stroke unit at UCLA. “The MSU offers the tantalizing possibility that you can give tPA with no time hit because you can give it on the way directly to a comprehensive stroke center,” Dr Saver said during a session at the meeting.
Early Data on Effectiveness
Dr Nour reported some of the best evidence for the incremental clinical benefit of MSUs based on the reduced time for starting a tPA infusion. She used data the Berlin group published in September 2016 that compared the treatment courses and outcomes of patients managed with an MSU to similar patients managed by conventional ambulance transport for whom CT scan assessment and the start of tPA treatment did not begin until the patient reached a hospital. The German analysis showed that, in the observational Pre-hospital Acute Neurological Therapy and Optimization of Medical Care in Stroke Patients–Study (PHANTOM-S), among 353 patients treated by conventional transport, the median time from stroke onset to thrombolysis was 112 minutes, compared with a median of 73 minutes among 305 patients managed with an MSU, a statistically significant difference.1 However, the study found no significant difference for its primary endpoint: the percentage of patients with a modified Rankin Scale score of 1 or lower when measured 90 days after their respective strokes. This outcome occurred in 47% of the control patients managed conventionally and in 53% of those managed by an MSU, a difference that fell short of statistical significance
Dr Nour attributed the lack of statistical significance for this primary endpoint to the relatively small number of patients enrolled in PHANTOM-S. “The study was underpowered,” she said.
Dr Nour presented an analysis at the meeting that extrapolated the results out to 1,000 hypothetical patients and tallied the benefits that a larger number of patients could expect to receive if their outcomes paralleled those seen in the published results. It showed that among 1,000 stroke patients treated with an MSU, 58 were expected to be free from disability 90 days later, and an additional 124 patients would have some improvement in their 90-day clinical outcome based on their modified Rankin Scale scores when compared with patients undergoing conventional hospitalization.
“If this finding was confirmed in a larger, controlled study, it would suggest that MSU-based thrombolysis has substantial clinical benefit,” she concluded.
Another recent report looked at the first 100 stroke patients treated by the Cleveland MSU during 2014. Researchers at the Cleveland Clinic and Case Western Reserve University said that 16 of those 100 patients received tPA, and the median time from their emergency call to thrombolytic treatment was 38.5 minutes faster than for 53 stroke patients treated during the same period at EDs operated by the Cleveland Clinic, a statistically significant difference.2 However, this report included no data on clinical outcomes.
Running the Financial Numbers
Nailing down the incremental clinical benefit from MSUs is clearly a very important part of determining the value of this strategy, but another very practical concern is how much the service costs and whether it is financially sustainable.
“We did a cost-effectiveness analysis based on the PHANTOM-S data, and we were conservative by only looking at the benefit from early tPA treatment,” Heinrich J. Audebert, MD, professor of neurology at Charité Hospital in Berlin and head of the team running Berlin’s MSU, said during the MSU session at the meeting. “We did not take into account saving money by avoiding long-term stroke disability and just considered the cost of [immediate] care and the quality-adjusted life years. We calculated a cost of $35,000 per quality-adjusted life year, which is absolutely acceptable.”
He cautioned that this analysis was not based on actual outcomes but on the numbers needed to treat calculated from the PHANTOM-S results. “We need to now show this in controlled trials,” he admitted.
During his talk at the same session, Dr Grotta ran through the numbers for the Houston program. They spent $1.1 million to put their MSU into service in early 2014, and, based on the expenses accrued since then, he estimated an annual staffing cost of about $400,000 and an annual operating cost of about $100,000, for a total estimated 5-year cost of about $3.6 million. Staffing of the Houston MSU started with a registered nurse, CT technician, paramedic, and vascular neurologist, although, like most other US MSUs, the onboard neurologist has since been replaced by a second paramedic, and the neurological diagnostic consult is done via a telemedicine link.
Income from transport reimbursement, currently $500 per trip, and reimbursements of $17,000 above costs for administering tPA and of roughly $40,000 above costs for performing thrombectomy, are balancing these costs. Based on an estimated additional one thrombolysis case per month and one additional thrombectomy case per month, the MSU yields a potential incremental income to the hospital running the MSU of about $3.8 million over 5 years—enough to balance the operating cost, Dr Grotta said.
A key part of controlling costs is having the neurological consult done via a telemedicine link rather than by neurologist at the MSU. “Telemedicine reduces operational costs and improves efficiency,” noted M. Shazam Hussain, MD, interim director of the Cerebrovascular Center at the Cleveland Clinic. “Cost-effectiveness is a very important part of the concept” of MSUs, he said at the session.
The Houston group reported results from a study that directly compared the diagnostic performance of an onboard neurologist with that of a telemedicine neurologist linked-in remotely during MSU deployments for 174 patients. For these cases, the two neurologists each made an independent diagnosis that the researchers then compared. The two diagnoses concurred for 88% of the cases, Tzu-Ching Wu, MD, reported at the meeting. This rate of agreement matched the incidence of concordance between two neurologists who independently assessed the same patients at the hospital,3 said Dr Wu, a vascular neurologist and director of the telemedicine program at the University of Texas Health Science Center in Houston.
“The results support using telemedicine as the primary means of assessment on the MSU,” said Dr Wu. “This may enhance MSU efficiency and reduce costs.” His group’s next study of MSU telemedicine will compare the time needed to make a diagnostic decision using the two approaches, which Dr Wu reported was something not formally examined in the study.
However, telemedicine assessment of CT results gathered in an MSU has one major limitation: the time needed to transmit the huge amount of information from a CTA.
The MSU used by clinicians at the University of Tennessee, Memphis, incorporates an extremely powerful battery that enables “full CT scanner capability with a moving gantry,” said Andrei V. Alexandrov, MD, professor and chairman of neurology at the university. With this set up “we can do in-the-field multiphasic CT angiography from the aortic arch up within 4 minutes. The challenge of doing this is simple. It’s 1.7 gigabytes of data,” which would take a prohibitively long time to transmit from a remote site, he explained. As a result, the complete set of images from the field CTA is delivered on a memory stick to the attending hospital neurologist once the MSU returns.
Waiting for More Data
Despite these advances and the steady recent growth of MSUs, significant skepticism remains. “While mobile stroke units seem like a good idea and there is genuine hope that they will improve outcomes for selected stroke patients, there is not yet any evidence that this is the case,” wrote Bryan Bledsoe, DO, in a January 2017 editorial in the Journal of Emergency Medical Services. “They are expensive and financially nonsustainable. Without widespread deployment, they stand to benefit few, if any, patients. The money spent on these devices would be better spent on improving the current EMS system, including paramedic education, the availability of stroke centers, and on the early recognition of ELVO [emergent large vessel occlusion] strokes,” wrote Dr Bledsoe, professor of emergency medicine at the University of Nevada in Las Vegas.
Two other experts voiced concerns about MSUs in an editorial that accompanied a Cleveland Clinic report in March.4 “Even if MSUs meet an acceptable societal threshold for cost-effectiveness, cost-efficiency may prove a taller order to achieve return on investment for individual health systems and communities,” wrote Andrew M. Southerland, MD, and Ethan S. Brandler, MD. They cited the Cleveland report, which noted that the group’s first 100 MSU-treated patients came from a total of 317 MSU deployments and included 217 trips that were canceled prior to the MSU’s arrival at the patient’s location. In Berlin’s initial experience, more than 2,000 MSU deployments led to 200 tPA treatments and 349 cancellations before arrival, noted Dr Southerland, a neurologist at the University of Virginia in Charlottesville, and Dr Brandler, an emergency medicine physician at Stony Brook (NY) University.
“Hope remains that future trials may demonstrate the ultimate potential of mobile stroke units to improve long-term outcomes for more patients by treating them more quickly and effectively. In the meantime, ongoing efforts are needed to streamline MSU cost and efficiency,” they wrote.
Proponents of MSUs agree that what’s needed now are more data to prove efficacy and cost-effectiveness, as well as better integration into EMS programs. The first opportunity for documenting the clinical impact of MSUs on larger numbers of US patients may be from the BEnefits of Stroke Treatment Delivered using a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services (BEST-MSU) Study, funded by the Patient-Centered Outcomes Research Institute. This study is collecting data from the MSU programs in Denver, Houston, and Memphis. Although currently designed to enroll 697 patients, Dr Grotta said he hopes to bring the number up to 1,000 patients.
“We are following the health care use and its cost for every enrolled MSU and conventional patient for 1 year,” Dr Grotta explained in an interview. He hopes these results will provide the data needed to move MSUs from investigational status to routine and reimbursable care.
References
1. Kunz A, Ebinger M, Geisler F, et al. Functional outcomes of pre-hospital thrombolysis in a mobile stroke treatment unit compared with conventional care: an observational registry study. Lancet Neurol. 2016;15(10):1035-1043. doi:10.1016/S1474-4422(16)30129-6.
2. Taqui A, Cerejo R, Itrat A, et al; Cleveland Pre-Hospital Acute Stroke Treatment (PHAST) Group. Reduction in time to treatment in prehospital telemedicine evaluation and thrombolysis. Neurology. 2017 March 8. [Epub ahead of print]. doi:10.1212/WNL.0000000000003786.
3. Ramadan AR, Denny MC, Vahidy F, et al. Agreement among stroke faculty and fellows in treating ischemic stroke patients with tissue-type plasminogen activator and thrombectomy. Stroke. 2017;48(1):222-224. doi:10.1161/STROKEAHA.116.015214.
4. Southerland AM, Brandler ES. The cost-efficiency of mobile stroke units: Where the rubber meets the road. Neurology. 2017 Mar 8. [Epub ahead of print]. doi:10.1212/WNL.0000000000003833.
Pulmonary Embolism Common in Patients With Acute Exacerbations of COPD
JIM KLING
FRONTLINE MEDICAL NEWS
About 16% of patients with unexplained acute exacerbations of chronic obstructive pulmonary disease (AECOPD) had an accompanying pulmonary embolism (PE), usually in regions that could be targeted with anticoagulants, according to a new systematic review and meta-analysis.
Approximately 70% of AECOPD cases develop in response to an infection, but about 30% of the time, an AE has no clear cause, the authors said in a report on their research. There is a known biological link between inflammation and coagulation, which suggests that patients experiencing AECOPD may be at increased risk of PE.
The researchers reviewed and analyzed seven studies, comprising 880 patients. Among the authors’ reasons for conducting this research was to update the pooled prevalence of PE in AECOPD from a previous systematic review published in Chest in 2009.
The meta-analysis revealed that 16.1% of patients with AECOPD were also diagnosed with PE (95% confidence interval [CI], 8.3%-25.8%). There was a wide range of variation between individual studies (prevalence 3.3%-29.1%). In six studies that reported on deep vein thrombosis (DVT), the pooled prevalence of DVT was 10.5% (95% CI, 4.3%-19.0%).
Five of the studies identified the PE location. An analysis of those studies showed that 35% were in the main pulmonary artery, and 31.7% were in the lobar and interlobar arteries. Such findings “[suggest] that the majority of these embolisms have important clinical consequences,” the authors wrote.
The researchers also looked at clinical markers that accompanied AECOPD and found a potential signal with respect to pleuritic chest pain. One study found a strong association between pleuritic chest pain and AECOPD patients with PE (81% vs 40% in those without PE). A second study showed a similar association (24% in PE vs 11.5% in non-PE patients), and a third study found no significant difference.
The presence of PE was also linked to hypotension, syncope, and acute right failure on ultrasonography, suggesting that PE may be associated with heart failure.
Patients with PE were less likely to have symptoms consistent with a respiratory tract infection. They also tended to have higher mortality rates and longer hospitalization rates compared with those without PE.
The meta-analysis had some limitations, including the heterogeneity of findings in the included studies, as well as the potential for publication bias, since reports showing unusually low or high rates may be more likely to be published, the researchers noted. There was also a high proportion of male subjects in the included studies.
Overall, the researchers concluded that PE is more likely in patients with pleuritic chest pain and signs of heart failure, and less likely in patients with signs of a respiratory infection. That information “might add to the clinical decision-making in patients with an AECOPD, because it would be undesirable to perform [CT pulmonary angiography] in every patient with an AECOPD,” the researchers wrote.
Aleva FE, Voets LW, Simons SO, de Mast Q, van der Ven AJ, Heijdra YF. Prevalence and localization of pulmonary embolism in unexplained acute exacerbations of COPD: A systematic review and meta-analysis. Chest. 2017;151(3):544-554. doi:10.1016/j.chest.2016.07.034.
Norepinephrine Shortage Linked to Mortality in Patients With Septic Shock
AMY KARON
FRONTLINE MEDICAL NEWS
A national shortage of norepinephrine in the United States was associated with higher rates of mortality among patients hospitalized with septic shock, investigators reported.
Rates of in-hospital mortality in 2011 were 40% during quarters when hospitals were facing shortages and 36% when they were not, Emily Vail, MD, and her associates said at the International Symposium on Intensive Care and Emergency Medicine. The report was published simultaneously in JAMA.
The link between norepinephrine shortage and death from septic shock persisted even after the researchers accounted for numerous clinical and demographic factors (adjusted odds ratio, 1.2; 95% CI, 1.01 to 1.30; P = .03), wrote Dr Vail of Columbia University, New York.
Drug shortages are common in the United States, but few studies have explored their effects on patient outcomes. Investigators compared mortality rates among affected patients during 3-month intervals when hospitals were and were not using at least 20% less norepinephrine than baseline. The researchers used Premier Healthcare Database, which includes both standard claims and detailed, dated logs of all services billed to patients or insurance, with minimal missing data.
A total of 77% patients admitted with septic shock received norepinephrine before the shortage. During the lowest point of the shortage, 56% of patients received it, the researchers reported. Clinicians most often used phenylephrine instead, prescribing it to up to 54% of patients during the worst time of the shortage. The absolute increase in mortality during the quarters of shortage was 3.7% (95% CI, 1.5%-6.0%).
Several factors might explain the link between norepinephrine shortage and mortality, the investigators said. The vasopressors chosen to replace norepinephrine might result directly in worse outcomes, but a decrease in norepinephrine use also might be a proxy for relevant variables such as delayed use of vasopressors, lack of knowledge of how to optimally dose vasopressors besides norepinephrine, or the absence of a pharmacist dedicated to helping optimize the use of limited supplies.
The study did not uncover a dose-response association between greater decreases in norepinephrine use and increased mortality, the researchers noted. “This may be due to a threshold effect of vasopressor shortage on mortality, or lack of power due to relatively few hospital quarters at the extreme levels of vasopressor shortage,” they wrote.
Because the deaths captured included only those that occurred in-hospital, “the results may have underestimated mortality, particularly for hospitals that tend to transfer patients early to other skilled care facilities,” the researchers noted.
The cohort of patients was limited to those who received vasopressors for 2 or more days and excluded patients who died on the first day of vasopressor treatment, the researchers said.
Vail E, Gershengorn HB, Hua M, Walkey AJ, Rubenfeld G, Wunsch H. Association between US norepinephrine shortage and mortality among patients with septic shock. JAMA. 21 March 2017. [Epub ahead of print]. doi:10.1001/jama.2017.2841.
MITCHEL L. ZOLER
FRONTLINE MEDICAL NEWS
Mobile stroke units—specially equipped ambulances that bring a diagnostic computed tomography (CT) scanner and therapeutic thrombolysis directly to patients in the field—have begun to proliferate across the United States, although they remain investigational, with no clear proof of their incremental clinical value or cost-effectiveness.
The first US mobile stroke unit (MSU) launched in Houston, Texas in early 2014 (following the world’s first in Berlin, Germany, which began running in early 2011), and by early 2017, at least eight other US MSUs were in operation, most of them put into service during the prior 15 months. United States MSU locations now include Cleveland, Ohio; Denver, Colorado; Memphis, Tennessee; New York, New York; Toledo, Ohio; Trenton, New Jersey; and Northwestern Medicine and Rush University Medical Center in the western Chicago, Illinois region. A tenth MSU is slated to start operation at the University of California, Los Angeles later this year.
Early data collected at some of these sites show that initiating care of an acute ischemic stroke patient in an MSU shaves precious minutes off the time it takes to initiate thrombolytic therapy with tissue plasminogen activator (tPA), and findings from preliminary analyses suggest better functional outcomes for patients treated this way. However, leaders in the nascent field readily admit that the data needed to clearly prove the benefit patients receive from operating MSUs are still a few years off. This uncertainty about the added benefit to patients from MSUs couples with one clear fact: MSUs are expensive to start up, with a price tag of roughly $1 million to get an MSU on the road for the first time; they are also expensive to operate, with one estimate for the annual cost of keeping an MSU on the street at about $500,000 per year for staffing, supplies, and other expenses.
“Every US MSU I know of started with philanthropic gifts, but you need a business model” to keep the program running long-term, James C. Grotta, MD, said during a session focused on MSUs at the International Stroke Conference sponsored by the American Heart Association. “You can’t sustain an MSU with philanthropy,” said Dr Grotta, professor of neurology at the University of Texas Health Science Center in Houston, director and founder of the Houston MSU, and acknowledged “godfather” of all US MSUs.
“We believe that MSUs are very worthwhile and that the clinical and economic benefits of earlier stroke treatment [made possible with MSUs] could offset the costs, but we need to show this,” admitted May Nour, MD, a vascular and interventional neurologist at the University of California, Los Angeles (UCLA), and director of the soon-to-launch Los Angeles MSU.
The concept behind MSUs is simple: Each one carries a CT scanner on board so that once the vehicle’s staff identifies a patient with clinical signs of a significant-acute ischemic stroke in the field and confirms that the timing of the stroke onset suggests eligibility for tPA treatment, a CT scan can immediately be run on-site to finalize tPA eligibility. The MSU staff can then begin infusing the drug in the ambulance as it speeds the patient to an appropriate hospital.
In addition, many MSUs now carry a scanner that can perform a CT angiogram (CTA) to locate the occluding clot. If a large vessel occlusion is found, the crew can bring the patient directly to a comprehensive stroke center for a thrombectomy. If thrombectomy is not appropriate, the MSU crew may take the patient to a primary stroke center where thrombectomy is not available.
Another advantage to MSUs, in addition to quicker initiation of thrombolysis, is “getting patients to where they need to go faster and more directly,” said Dr Nour.
“Instead of bringing patients first to a hospital that’s unable to do thrombectomy and where treatment gets slowed down, with an MSU you can give tPA on the street and go straight to a thrombectomy center,” agreed Jeffrey L. Saver, MD, professor of neurology and director of the stroke unit at UCLA. “The MSU offers the tantalizing possibility that you can give tPA with no time hit because you can give it on the way directly to a comprehensive stroke center,” Dr Saver said during a session at the meeting.
Early Data on Effectiveness
Dr Nour reported some of the best evidence for the incremental clinical benefit of MSUs based on the reduced time for starting a tPA infusion. She used data the Berlin group published in September 2016 that compared the treatment courses and outcomes of patients managed with an MSU to similar patients managed by conventional ambulance transport for whom CT scan assessment and the start of tPA treatment did not begin until the patient reached a hospital. The German analysis showed that, in the observational Pre-hospital Acute Neurological Therapy and Optimization of Medical Care in Stroke Patients–Study (PHANTOM-S), among 353 patients treated by conventional transport, the median time from stroke onset to thrombolysis was 112 minutes, compared with a median of 73 minutes among 305 patients managed with an MSU, a statistically significant difference.1 However, the study found no significant difference for its primary endpoint: the percentage of patients with a modified Rankin Scale score of 1 or lower when measured 90 days after their respective strokes. This outcome occurred in 47% of the control patients managed conventionally and in 53% of those managed by an MSU, a difference that fell short of statistical significance
Dr Nour attributed the lack of statistical significance for this primary endpoint to the relatively small number of patients enrolled in PHANTOM-S. “The study was underpowered,” she said.
Dr Nour presented an analysis at the meeting that extrapolated the results out to 1,000 hypothetical patients and tallied the benefits that a larger number of patients could expect to receive if their outcomes paralleled those seen in the published results. It showed that among 1,000 stroke patients treated with an MSU, 58 were expected to be free from disability 90 days later, and an additional 124 patients would have some improvement in their 90-day clinical outcome based on their modified Rankin Scale scores when compared with patients undergoing conventional hospitalization.
“If this finding was confirmed in a larger, controlled study, it would suggest that MSU-based thrombolysis has substantial clinical benefit,” she concluded.
Another recent report looked at the first 100 stroke patients treated by the Cleveland MSU during 2014. Researchers at the Cleveland Clinic and Case Western Reserve University said that 16 of those 100 patients received tPA, and the median time from their emergency call to thrombolytic treatment was 38.5 minutes faster than for 53 stroke patients treated during the same period at EDs operated by the Cleveland Clinic, a statistically significant difference.2 However, this report included no data on clinical outcomes.
Running the Financial Numbers
Nailing down the incremental clinical benefit from MSUs is clearly a very important part of determining the value of this strategy, but another very practical concern is how much the service costs and whether it is financially sustainable.
“We did a cost-effectiveness analysis based on the PHANTOM-S data, and we were conservative by only looking at the benefit from early tPA treatment,” Heinrich J. Audebert, MD, professor of neurology at Charité Hospital in Berlin and head of the team running Berlin’s MSU, said during the MSU session at the meeting. “We did not take into account saving money by avoiding long-term stroke disability and just considered the cost of [immediate] care and the quality-adjusted life years. We calculated a cost of $35,000 per quality-adjusted life year, which is absolutely acceptable.”
He cautioned that this analysis was not based on actual outcomes but on the numbers needed to treat calculated from the PHANTOM-S results. “We need to now show this in controlled trials,” he admitted.
During his talk at the same session, Dr Grotta ran through the numbers for the Houston program. They spent $1.1 million to put their MSU into service in early 2014, and, based on the expenses accrued since then, he estimated an annual staffing cost of about $400,000 and an annual operating cost of about $100,000, for a total estimated 5-year cost of about $3.6 million. Staffing of the Houston MSU started with a registered nurse, CT technician, paramedic, and vascular neurologist, although, like most other US MSUs, the onboard neurologist has since been replaced by a second paramedic, and the neurological diagnostic consult is done via a telemedicine link.
Income from transport reimbursement, currently $500 per trip, and reimbursements of $17,000 above costs for administering tPA and of roughly $40,000 above costs for performing thrombectomy, are balancing these costs. Based on an estimated additional one thrombolysis case per month and one additional thrombectomy case per month, the MSU yields a potential incremental income to the hospital running the MSU of about $3.8 million over 5 years—enough to balance the operating cost, Dr Grotta said.
A key part of controlling costs is having the neurological consult done via a telemedicine link rather than by neurologist at the MSU. “Telemedicine reduces operational costs and improves efficiency,” noted M. Shazam Hussain, MD, interim director of the Cerebrovascular Center at the Cleveland Clinic. “Cost-effectiveness is a very important part of the concept” of MSUs, he said at the session.
The Houston group reported results from a study that directly compared the diagnostic performance of an onboard neurologist with that of a telemedicine neurologist linked-in remotely during MSU deployments for 174 patients. For these cases, the two neurologists each made an independent diagnosis that the researchers then compared. The two diagnoses concurred for 88% of the cases, Tzu-Ching Wu, MD, reported at the meeting. This rate of agreement matched the incidence of concordance between two neurologists who independently assessed the same patients at the hospital,3 said Dr Wu, a vascular neurologist and director of the telemedicine program at the University of Texas Health Science Center in Houston.
“The results support using telemedicine as the primary means of assessment on the MSU,” said Dr Wu. “This may enhance MSU efficiency and reduce costs.” His group’s next study of MSU telemedicine will compare the time needed to make a diagnostic decision using the two approaches, which Dr Wu reported was something not formally examined in the study.
However, telemedicine assessment of CT results gathered in an MSU has one major limitation: the time needed to transmit the huge amount of information from a CTA.
The MSU used by clinicians at the University of Tennessee, Memphis, incorporates an extremely powerful battery that enables “full CT scanner capability with a moving gantry,” said Andrei V. Alexandrov, MD, professor and chairman of neurology at the university. With this set up “we can do in-the-field multiphasic CT angiography from the aortic arch up within 4 minutes. The challenge of doing this is simple. It’s 1.7 gigabytes of data,” which would take a prohibitively long time to transmit from a remote site, he explained. As a result, the complete set of images from the field CTA is delivered on a memory stick to the attending hospital neurologist once the MSU returns.
Waiting for More Data
Despite these advances and the steady recent growth of MSUs, significant skepticism remains. “While mobile stroke units seem like a good idea and there is genuine hope that they will improve outcomes for selected stroke patients, there is not yet any evidence that this is the case,” wrote Bryan Bledsoe, DO, in a January 2017 editorial in the Journal of Emergency Medical Services. “They are expensive and financially nonsustainable. Without widespread deployment, they stand to benefit few, if any, patients. The money spent on these devices would be better spent on improving the current EMS system, including paramedic education, the availability of stroke centers, and on the early recognition of ELVO [emergent large vessel occlusion] strokes,” wrote Dr Bledsoe, professor of emergency medicine at the University of Nevada in Las Vegas.
Two other experts voiced concerns about MSUs in an editorial that accompanied a Cleveland Clinic report in March.4 “Even if MSUs meet an acceptable societal threshold for cost-effectiveness, cost-efficiency may prove a taller order to achieve return on investment for individual health systems and communities,” wrote Andrew M. Southerland, MD, and Ethan S. Brandler, MD. They cited the Cleveland report, which noted that the group’s first 100 MSU-treated patients came from a total of 317 MSU deployments and included 217 trips that were canceled prior to the MSU’s arrival at the patient’s location. In Berlin’s initial experience, more than 2,000 MSU deployments led to 200 tPA treatments and 349 cancellations before arrival, noted Dr Southerland, a neurologist at the University of Virginia in Charlottesville, and Dr Brandler, an emergency medicine physician at Stony Brook (NY) University.
“Hope remains that future trials may demonstrate the ultimate potential of mobile stroke units to improve long-term outcomes for more patients by treating them more quickly and effectively. In the meantime, ongoing efforts are needed to streamline MSU cost and efficiency,” they wrote.
Proponents of MSUs agree that what’s needed now are more data to prove efficacy and cost-effectiveness, as well as better integration into EMS programs. The first opportunity for documenting the clinical impact of MSUs on larger numbers of US patients may be from the BEnefits of Stroke Treatment Delivered using a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services (BEST-MSU) Study, funded by the Patient-Centered Outcomes Research Institute. This study is collecting data from the MSU programs in Denver, Houston, and Memphis. Although currently designed to enroll 697 patients, Dr Grotta said he hopes to bring the number up to 1,000 patients.
“We are following the health care use and its cost for every enrolled MSU and conventional patient for 1 year,” Dr Grotta explained in an interview. He hopes these results will provide the data needed to move MSUs from investigational status to routine and reimbursable care.
References
1. Kunz A, Ebinger M, Geisler F, et al. Functional outcomes of pre-hospital thrombolysis in a mobile stroke treatment unit compared with conventional care: an observational registry study. Lancet Neurol. 2016;15(10):1035-1043. doi:10.1016/S1474-4422(16)30129-6.
2. Taqui A, Cerejo R, Itrat A, et al; Cleveland Pre-Hospital Acute Stroke Treatment (PHAST) Group. Reduction in time to treatment in prehospital telemedicine evaluation and thrombolysis. Neurology. 2017 March 8. [Epub ahead of print]. doi:10.1212/WNL.0000000000003786.
3. Ramadan AR, Denny MC, Vahidy F, et al. Agreement among stroke faculty and fellows in treating ischemic stroke patients with tissue-type plasminogen activator and thrombectomy. Stroke. 2017;48(1):222-224. doi:10.1161/STROKEAHA.116.015214.
4. Southerland AM, Brandler ES. The cost-efficiency of mobile stroke units: Where the rubber meets the road. Neurology. 2017 Mar 8. [Epub ahead of print]. doi:10.1212/WNL.0000000000003833.
Pulmonary Embolism Common in Patients With Acute Exacerbations of COPD
JIM KLING
FRONTLINE MEDICAL NEWS
About 16% of patients with unexplained acute exacerbations of chronic obstructive pulmonary disease (AECOPD) had an accompanying pulmonary embolism (PE), usually in regions that could be targeted with anticoagulants, according to a new systematic review and meta-analysis.
Approximately 70% of AECOPD cases develop in response to an infection, but about 30% of the time, an AE has no clear cause, the authors said in a report on their research. There is a known biological link between inflammation and coagulation, which suggests that patients experiencing AECOPD may be at increased risk of PE.
The researchers reviewed and analyzed seven studies, comprising 880 patients. Among the authors’ reasons for conducting this research was to update the pooled prevalence of PE in AECOPD from a previous systematic review published in Chest in 2009.
The meta-analysis revealed that 16.1% of patients with AECOPD were also diagnosed with PE (95% confidence interval [CI], 8.3%-25.8%). There was a wide range of variation between individual studies (prevalence 3.3%-29.1%). In six studies that reported on deep vein thrombosis (DVT), the pooled prevalence of DVT was 10.5% (95% CI, 4.3%-19.0%).
Five of the studies identified the PE location. An analysis of those studies showed that 35% were in the main pulmonary artery, and 31.7% were in the lobar and interlobar arteries. Such findings “[suggest] that the majority of these embolisms have important clinical consequences,” the authors wrote.
The researchers also looked at clinical markers that accompanied AECOPD and found a potential signal with respect to pleuritic chest pain. One study found a strong association between pleuritic chest pain and AECOPD patients with PE (81% vs 40% in those without PE). A second study showed a similar association (24% in PE vs 11.5% in non-PE patients), and a third study found no significant difference.
The presence of PE was also linked to hypotension, syncope, and acute right failure on ultrasonography, suggesting that PE may be associated with heart failure.
Patients with PE were less likely to have symptoms consistent with a respiratory tract infection. They also tended to have higher mortality rates and longer hospitalization rates compared with those without PE.
The meta-analysis had some limitations, including the heterogeneity of findings in the included studies, as well as the potential for publication bias, since reports showing unusually low or high rates may be more likely to be published, the researchers noted. There was also a high proportion of male subjects in the included studies.
Overall, the researchers concluded that PE is more likely in patients with pleuritic chest pain and signs of heart failure, and less likely in patients with signs of a respiratory infection. That information “might add to the clinical decision-making in patients with an AECOPD, because it would be undesirable to perform [CT pulmonary angiography] in every patient with an AECOPD,” the researchers wrote.
Aleva FE, Voets LW, Simons SO, de Mast Q, van der Ven AJ, Heijdra YF. Prevalence and localization of pulmonary embolism in unexplained acute exacerbations of COPD: A systematic review and meta-analysis. Chest. 2017;151(3):544-554. doi:10.1016/j.chest.2016.07.034.
Norepinephrine Shortage Linked to Mortality in Patients With Septic Shock
AMY KARON
FRONTLINE MEDICAL NEWS
A national shortage of norepinephrine in the United States was associated with higher rates of mortality among patients hospitalized with septic shock, investigators reported.
Rates of in-hospital mortality in 2011 were 40% during quarters when hospitals were facing shortages and 36% when they were not, Emily Vail, MD, and her associates said at the International Symposium on Intensive Care and Emergency Medicine. The report was published simultaneously in JAMA.
The link between norepinephrine shortage and death from septic shock persisted even after the researchers accounted for numerous clinical and demographic factors (adjusted odds ratio, 1.2; 95% CI, 1.01 to 1.30; P = .03), wrote Dr Vail of Columbia University, New York.
Drug shortages are common in the United States, but few studies have explored their effects on patient outcomes. Investigators compared mortality rates among affected patients during 3-month intervals when hospitals were and were not using at least 20% less norepinephrine than baseline. The researchers used Premier Healthcare Database, which includes both standard claims and detailed, dated logs of all services billed to patients or insurance, with minimal missing data.
A total of 77% patients admitted with septic shock received norepinephrine before the shortage. During the lowest point of the shortage, 56% of patients received it, the researchers reported. Clinicians most often used phenylephrine instead, prescribing it to up to 54% of patients during the worst time of the shortage. The absolute increase in mortality during the quarters of shortage was 3.7% (95% CI, 1.5%-6.0%).
Several factors might explain the link between norepinephrine shortage and mortality, the investigators said. The vasopressors chosen to replace norepinephrine might result directly in worse outcomes, but a decrease in norepinephrine use also might be a proxy for relevant variables such as delayed use of vasopressors, lack of knowledge of how to optimally dose vasopressors besides norepinephrine, or the absence of a pharmacist dedicated to helping optimize the use of limited supplies.
The study did not uncover a dose-response association between greater decreases in norepinephrine use and increased mortality, the researchers noted. “This may be due to a threshold effect of vasopressor shortage on mortality, or lack of power due to relatively few hospital quarters at the extreme levels of vasopressor shortage,” they wrote.
Because the deaths captured included only those that occurred in-hospital, “the results may have underestimated mortality, particularly for hospitals that tend to transfer patients early to other skilled care facilities,” the researchers noted.
The cohort of patients was limited to those who received vasopressors for 2 or more days and excluded patients who died on the first day of vasopressor treatment, the researchers said.
Vail E, Gershengorn HB, Hua M, Walkey AJ, Rubenfeld G, Wunsch H. Association between US norepinephrine shortage and mortality among patients with septic shock. JAMA. 21 March 2017. [Epub ahead of print]. doi:10.1001/jama.2017.2841.
Patient transfer before thrombectomy worsens stroke outcomes
HOUSTON – Drip and ship may not be the most time-effective way to treat acute ischemic stroke patients who are candidates for endovascular thrombectomy.
Results from two separate real-world, observational studies showed that acute ischemic stroke patients with large vessel occlusions amenable to mechanical thrombectomy had significantly worse clinical outcomes when their management path included a stop at a primary stroke center followed by transfer to a comprehensive stroke center that had the capacity to perform thrombectomy, compared with going straight to the thrombectomy site.
The findings show “the system of care has room for improvement. Patients with large vessel occlusions clearly do better when we get them to mechanical thrombectomy as quickly as possible,” said Dr. Froehler, a vascular neurologist at Vanderbilt University in Nashville, Tenn. Thrombectomy “has a more powerful treatment effect than TPA [tissue plasminogen activator] and we need to adjust our standard of care to best deliver” thrombectomy, he said in an interview.
The study run by Dr. Froehler used data collected in the Systematic Evaluation of Patients Treated With Stroke Devices for Acute Ischemic Stroke (STRATIS) registry, which began in 2014 and has data for 984 acute ischemic stroke patients with large vessel occlusions treated by mechanical thrombectomy seen at any of 55 U.S. centers. The series included 445 (45%) patients first seen as a primary stroke center and then transferred to a comprehensive center and 539 (55%) who went directly to a comprehensive stroke center (direct patients). Prior to thrombectomy, 628 of all patients (64%) received TPA, with a roughly similar percentage in both the transferred and direct patients.
The data showed that the median time from symptom onset to revascularization was 202 minutes among the direct patients and 312 minutes among those first seen at a primary stroke center and then transferred, a statistically significant difference. The average time difference per patient between the two subgroups was 100 minutes, Dr. Froehler reported.
This difference in time to reperfusion led directly to significant differences in functional outcomes after 90 days measured on the modified Rankin Scale (mRS). The percentage of patients with a mRS score of 0 or 1 (an excellent functional outcome) was 38% for the patients first seen at primary stroke centers and 47% in direct patients, a 47% relative rise in excellent outcomes among the direct patients. The percentage of patients with a mRS score of 0-2, which identifies functional independence post stroke, was 52% among transferred patients and 60% in direct patients, a 38% relative improvement for this outcome among direct patients.
The second study of stroke transfer times and outcomes used data from 562 acute ischemic stroke patients with large vessel occlusions treated in the Providence Health & Services system in five western U.S. states during 2012-2016. Nearly half the patients required a transfer and the other half went directly to a center able to perform thrombectomy. The analysis used clinical outcomes scored on the mRS at the time of hospital discharge.
“Right now, the big delay at primary stroke centers is the door-in door-out time,” commented Ryan A. McTaggart, MD, an interventional neuroradiologist at Rhode Island Hospital in Providence, the only comprehensive stroke center in Rhode Island. He helped organize a partnership with 14 primary stroke centers in Rhode Island that uses a streamlined imaging, treatment (with TPA), and transfer protocol that hacked dozens of minutes off transfer times and produced a median time from onset of symptoms to revascularization by thrombectomy of 184 minutes in patients first seen at a primary stroke center. This clocking blows past the 202 minute median for stroke onset to revascularization in the direct patients from Dr. Froehler’s study.
Stroke transport and treatment networks are now undergoing refinement in Tennessee, said Dr. Froehler, based in part on the data he reported. Considerations in Tennessee include how EMS workers assess possible stroke patients, decisions by EMS on where to take patients, and how quality of care is measured at primary and comprehensive stroke centers.
The STRATIS registry is sponsored by Medtronic. Dr. Froehler is a consultant to Medtronic, Blockade, Stryker, and Control Medical. Dr. Smith, Dr. Tarpley, and Dr. McTaggart had no disclosures.
mzoler@frontlinemedcom.com
On Twitter @mitchelzoler
HOUSTON – Drip and ship may not be the most time-effective way to treat acute ischemic stroke patients who are candidates for endovascular thrombectomy.
Results from two separate real-world, observational studies showed that acute ischemic stroke patients with large vessel occlusions amenable to mechanical thrombectomy had significantly worse clinical outcomes when their management path included a stop at a primary stroke center followed by transfer to a comprehensive stroke center that had the capacity to perform thrombectomy, compared with going straight to the thrombectomy site.
The findings show “the system of care has room for improvement. Patients with large vessel occlusions clearly do better when we get them to mechanical thrombectomy as quickly as possible,” said Dr. Froehler, a vascular neurologist at Vanderbilt University in Nashville, Tenn. Thrombectomy “has a more powerful treatment effect than TPA [tissue plasminogen activator] and we need to adjust our standard of care to best deliver” thrombectomy, he said in an interview.
The study run by Dr. Froehler used data collected in the Systematic Evaluation of Patients Treated With Stroke Devices for Acute Ischemic Stroke (STRATIS) registry, which began in 2014 and has data for 984 acute ischemic stroke patients with large vessel occlusions treated by mechanical thrombectomy seen at any of 55 U.S. centers. The series included 445 (45%) patients first seen as a primary stroke center and then transferred to a comprehensive center and 539 (55%) who went directly to a comprehensive stroke center (direct patients). Prior to thrombectomy, 628 of all patients (64%) received TPA, with a roughly similar percentage in both the transferred and direct patients.
The data showed that the median time from symptom onset to revascularization was 202 minutes among the direct patients and 312 minutes among those first seen at a primary stroke center and then transferred, a statistically significant difference. The average time difference per patient between the two subgroups was 100 minutes, Dr. Froehler reported.
This difference in time to reperfusion led directly to significant differences in functional outcomes after 90 days measured on the modified Rankin Scale (mRS). The percentage of patients with a mRS score of 0 or 1 (an excellent functional outcome) was 38% for the patients first seen at primary stroke centers and 47% in direct patients, a 47% relative rise in excellent outcomes among the direct patients. The percentage of patients with a mRS score of 0-2, which identifies functional independence post stroke, was 52% among transferred patients and 60% in direct patients, a 38% relative improvement for this outcome among direct patients.
The second study of stroke transfer times and outcomes used data from 562 acute ischemic stroke patients with large vessel occlusions treated in the Providence Health & Services system in five western U.S. states during 2012-2016. Nearly half the patients required a transfer and the other half went directly to a center able to perform thrombectomy. The analysis used clinical outcomes scored on the mRS at the time of hospital discharge.
“Right now, the big delay at primary stroke centers is the door-in door-out time,” commented Ryan A. McTaggart, MD, an interventional neuroradiologist at Rhode Island Hospital in Providence, the only comprehensive stroke center in Rhode Island. He helped organize a partnership with 14 primary stroke centers in Rhode Island that uses a streamlined imaging, treatment (with TPA), and transfer protocol that hacked dozens of minutes off transfer times and produced a median time from onset of symptoms to revascularization by thrombectomy of 184 minutes in patients first seen at a primary stroke center. This clocking blows past the 202 minute median for stroke onset to revascularization in the direct patients from Dr. Froehler’s study.
Stroke transport and treatment networks are now undergoing refinement in Tennessee, said Dr. Froehler, based in part on the data he reported. Considerations in Tennessee include how EMS workers assess possible stroke patients, decisions by EMS on where to take patients, and how quality of care is measured at primary and comprehensive stroke centers.
The STRATIS registry is sponsored by Medtronic. Dr. Froehler is a consultant to Medtronic, Blockade, Stryker, and Control Medical. Dr. Smith, Dr. Tarpley, and Dr. McTaggart had no disclosures.
mzoler@frontlinemedcom.com
On Twitter @mitchelzoler
HOUSTON – Drip and ship may not be the most time-effective way to treat acute ischemic stroke patients who are candidates for endovascular thrombectomy.
Results from two separate real-world, observational studies showed that acute ischemic stroke patients with large vessel occlusions amenable to mechanical thrombectomy had significantly worse clinical outcomes when their management path included a stop at a primary stroke center followed by transfer to a comprehensive stroke center that had the capacity to perform thrombectomy, compared with going straight to the thrombectomy site.
The findings show “the system of care has room for improvement. Patients with large vessel occlusions clearly do better when we get them to mechanical thrombectomy as quickly as possible,” said Dr. Froehler, a vascular neurologist at Vanderbilt University in Nashville, Tenn. Thrombectomy “has a more powerful treatment effect than TPA [tissue plasminogen activator] and we need to adjust our standard of care to best deliver” thrombectomy, he said in an interview.
The study run by Dr. Froehler used data collected in the Systematic Evaluation of Patients Treated With Stroke Devices for Acute Ischemic Stroke (STRATIS) registry, which began in 2014 and has data for 984 acute ischemic stroke patients with large vessel occlusions treated by mechanical thrombectomy seen at any of 55 U.S. centers. The series included 445 (45%) patients first seen as a primary stroke center and then transferred to a comprehensive center and 539 (55%) who went directly to a comprehensive stroke center (direct patients). Prior to thrombectomy, 628 of all patients (64%) received TPA, with a roughly similar percentage in both the transferred and direct patients.
The data showed that the median time from symptom onset to revascularization was 202 minutes among the direct patients and 312 minutes among those first seen at a primary stroke center and then transferred, a statistically significant difference. The average time difference per patient between the two subgroups was 100 minutes, Dr. Froehler reported.
This difference in time to reperfusion led directly to significant differences in functional outcomes after 90 days measured on the modified Rankin Scale (mRS). The percentage of patients with a mRS score of 0 or 1 (an excellent functional outcome) was 38% for the patients first seen at primary stroke centers and 47% in direct patients, a 47% relative rise in excellent outcomes among the direct patients. The percentage of patients with a mRS score of 0-2, which identifies functional independence post stroke, was 52% among transferred patients and 60% in direct patients, a 38% relative improvement for this outcome among direct patients.
The second study of stroke transfer times and outcomes used data from 562 acute ischemic stroke patients with large vessel occlusions treated in the Providence Health & Services system in five western U.S. states during 2012-2016. Nearly half the patients required a transfer and the other half went directly to a center able to perform thrombectomy. The analysis used clinical outcomes scored on the mRS at the time of hospital discharge.
“Right now, the big delay at primary stroke centers is the door-in door-out time,” commented Ryan A. McTaggart, MD, an interventional neuroradiologist at Rhode Island Hospital in Providence, the only comprehensive stroke center in Rhode Island. He helped organize a partnership with 14 primary stroke centers in Rhode Island that uses a streamlined imaging, treatment (with TPA), and transfer protocol that hacked dozens of minutes off transfer times and produced a median time from onset of symptoms to revascularization by thrombectomy of 184 minutes in patients first seen at a primary stroke center. This clocking blows past the 202 minute median for stroke onset to revascularization in the direct patients from Dr. Froehler’s study.
Stroke transport and treatment networks are now undergoing refinement in Tennessee, said Dr. Froehler, based in part on the data he reported. Considerations in Tennessee include how EMS workers assess possible stroke patients, decisions by EMS on where to take patients, and how quality of care is measured at primary and comprehensive stroke centers.
The STRATIS registry is sponsored by Medtronic. Dr. Froehler is a consultant to Medtronic, Blockade, Stryker, and Control Medical. Dr. Smith, Dr. Tarpley, and Dr. McTaggart had no disclosures.
mzoler@frontlinemedcom.com
On Twitter @mitchelzoler
AT THE INTERNATIONAL STROKE CONFERENCE
<p><strong>Key clinical point: </strong><span class="tag metaDescription">Acute ischemic stroke patients who required mechanical thrombectomy had better outcomes when they went directly to a comprehensive stroke center, thereby avoiding a subsequent transfer.</span><br><br><strong>Major finding: </strong>In STRATIS, excellent outcomes occurred in 47% of patients sent directly to a thrombectomy hospital and in 38% of transferred patients.<br><br><strong>Data source: </strong>The STRATIS registry, with 984 U.S. acute ischemic stroke patients, and 562 U.S. acute ischemic stroke patients from the Providence Health & Services network.<br><br><strong>Disclosures:</strong> The STRATIS registry is sponsored by Medtronic. Dr. Froehler is a consultant to Medtronic, Blockade, Stryker, and Control Medical. Dr. Smith, Dr. Tarpley, and Dr. McTaggart had no disclosures.</p>
Hypotension ‘dose’ drives mortality in traumatic brain injury
NEW ORLEANS – The severity and duration of hypotension in traumatic brain injury patients during EMS transport to an emergency department has a tight and essentially linear relationship to their mortality rate during subsequent weeks of recovery, according to an analysis of more than 7,500 brain-injured patients.
For each doubling of the combined severity and duration of hypotension during the prehospital period, when systolic blood pressure was less than 90 mm Hg, patient mortality rose by 19%, Daniel W. Spaite, MD, reported at the American Heart Association scientific sessions.
However, the results do not address whether aggressive treatment of hypotension by EMS technicians in a patient with traumatic brain injury (TBI) leads to reduced mortality. That question is being assessed as part of the primary endpoint of the Excellence in Prehospital Injury Care-Traumatic Brain Injury (EPIC-TBI) study, which should have an answer by the end of 2017, said Dr. Spaite, professor of emergency medicine at the University of Arizona in Tuscon.
The innovation introduced by Dr. Spaite and his associates in their analysis of the EPIC-TBI data was to drill down into each patient’s hypotensive event, made possible by the 16,711 patients enrolled in EPIC-TBI.
The calculation they performed was limited to patients with EMS records of at least two blood pressure measurements during prehospital transport. These data allowed them to use both the extent to which systolic blood pressure dropped below 90 mm Hg and the amount of time pressure was below this threshold to better define the total hypotension exposure each patient received.
This meant that a TBI patient with a systolic pressure of 80 mm Hg for 10 minutes had twice the hypotension exposure of both a patient with a pressure of 85 mm Hg for 10 minutes, and a patient with a pressure of 80 mm Hg for 5 minutes.
Their analysis also adjusted the relationship of this total hypotensive dose and subsequent mortality based on several baseline demographic and clinical variables, including age, sex, injury severity, trauma type, and head-region severity score. After adjustment, the researchers found a “strikingly linear relationship” between hypotension dose and mortality, Dr. Spaite said, although a clear dose-response relationship was also evident in the unadjusted data.
EPIC-TBI enrolled TBI patients age 10 years or older during 2007-2014 through participation by dozens of EMS providers throughout Arizona. For the current analysis, the researchers identified 7,521 patients from the total group who had at least two blood pressure measurements taken during their prehospital EMS care and also met other inclusion criteria.
The best way to manage hypotension in TBI patients during the prehospital period remains unclear. Simply raising blood pressure with fluid infusion may not necessarily help, because it could exacerbate a patient’s bleeding, Dr. Spaite noted during an interview.
The primary goal of EPIC-TBI is to assess the impact of the third edition of the traumatic brain injury guidelines released in 2007 by the Brain Trauma Foundation. (The fourth edition of these guidelines came out in August 2016.) The new finding by Dr. Spaite and his associates will allow the full EPIC-TBI analysis to correlate patient outcomes with the impact that acute, prehospital treatment had on the hypotension dose received by each patient, he noted.
“What’s remarkable is that the single, prehospital parameter of hypotension for just a few minutes during transport can have such a strong impact on survival, given all the other factors that can influence outcomes” in TBI patients once they reach a hospital and during the period they remain hospitalized, Dr. Spaite said.
mzoler@frontlinemedcom.com On Twitter @mitchelzoler
NEW ORLEANS – The severity and duration of hypotension in traumatic brain injury patients during EMS transport to an emergency department has a tight and essentially linear relationship to their mortality rate during subsequent weeks of recovery, according to an analysis of more than 7,500 brain-injured patients.
For each doubling of the combined severity and duration of hypotension during the prehospital period, when systolic blood pressure was less than 90 mm Hg, patient mortality rose by 19%, Daniel W. Spaite, MD, reported at the American Heart Association scientific sessions.
However, the results do not address whether aggressive treatment of hypotension by EMS technicians in a patient with traumatic brain injury (TBI) leads to reduced mortality. That question is being assessed as part of the primary endpoint of the Excellence in Prehospital Injury Care-Traumatic Brain Injury (EPIC-TBI) study, which should have an answer by the end of 2017, said Dr. Spaite, professor of emergency medicine at the University of Arizona in Tuscon.
The innovation introduced by Dr. Spaite and his associates in their analysis of the EPIC-TBI data was to drill down into each patient’s hypotensive event, made possible by the 16,711 patients enrolled in EPIC-TBI.
The calculation they performed was limited to patients with EMS records of at least two blood pressure measurements during prehospital transport. These data allowed them to use both the extent to which systolic blood pressure dropped below 90 mm Hg and the amount of time pressure was below this threshold to better define the total hypotension exposure each patient received.
This meant that a TBI patient with a systolic pressure of 80 mm Hg for 10 minutes had twice the hypotension exposure of both a patient with a pressure of 85 mm Hg for 10 minutes, and a patient with a pressure of 80 mm Hg for 5 minutes.
Their analysis also adjusted the relationship of this total hypotensive dose and subsequent mortality based on several baseline demographic and clinical variables, including age, sex, injury severity, trauma type, and head-region severity score. After adjustment, the researchers found a “strikingly linear relationship” between hypotension dose and mortality, Dr. Spaite said, although a clear dose-response relationship was also evident in the unadjusted data.
EPIC-TBI enrolled TBI patients age 10 years or older during 2007-2014 through participation by dozens of EMS providers throughout Arizona. For the current analysis, the researchers identified 7,521 patients from the total group who had at least two blood pressure measurements taken during their prehospital EMS care and also met other inclusion criteria.
The best way to manage hypotension in TBI patients during the prehospital period remains unclear. Simply raising blood pressure with fluid infusion may not necessarily help, because it could exacerbate a patient’s bleeding, Dr. Spaite noted during an interview.
The primary goal of EPIC-TBI is to assess the impact of the third edition of the traumatic brain injury guidelines released in 2007 by the Brain Trauma Foundation. (The fourth edition of these guidelines came out in August 2016.) The new finding by Dr. Spaite and his associates will allow the full EPIC-TBI analysis to correlate patient outcomes with the impact that acute, prehospital treatment had on the hypotension dose received by each patient, he noted.
“What’s remarkable is that the single, prehospital parameter of hypotension for just a few minutes during transport can have such a strong impact on survival, given all the other factors that can influence outcomes” in TBI patients once they reach a hospital and during the period they remain hospitalized, Dr. Spaite said.
mzoler@frontlinemedcom.com On Twitter @mitchelzoler
NEW ORLEANS – The severity and duration of hypotension in traumatic brain injury patients during EMS transport to an emergency department has a tight and essentially linear relationship to their mortality rate during subsequent weeks of recovery, according to an analysis of more than 7,500 brain-injured patients.
For each doubling of the combined severity and duration of hypotension during the prehospital period, when systolic blood pressure was less than 90 mm Hg, patient mortality rose by 19%, Daniel W. Spaite, MD, reported at the American Heart Association scientific sessions.
However, the results do not address whether aggressive treatment of hypotension by EMS technicians in a patient with traumatic brain injury (TBI) leads to reduced mortality. That question is being assessed as part of the primary endpoint of the Excellence in Prehospital Injury Care-Traumatic Brain Injury (EPIC-TBI) study, which should have an answer by the end of 2017, said Dr. Spaite, professor of emergency medicine at the University of Arizona in Tuscon.
The innovation introduced by Dr. Spaite and his associates in their analysis of the EPIC-TBI data was to drill down into each patient’s hypotensive event, made possible by the 16,711 patients enrolled in EPIC-TBI.
The calculation they performed was limited to patients with EMS records of at least two blood pressure measurements during prehospital transport. These data allowed them to use both the extent to which systolic blood pressure dropped below 90 mm Hg and the amount of time pressure was below this threshold to better define the total hypotension exposure each patient received.
This meant that a TBI patient with a systolic pressure of 80 mm Hg for 10 minutes had twice the hypotension exposure of both a patient with a pressure of 85 mm Hg for 10 minutes, and a patient with a pressure of 80 mm Hg for 5 minutes.
Their analysis also adjusted the relationship of this total hypotensive dose and subsequent mortality based on several baseline demographic and clinical variables, including age, sex, injury severity, trauma type, and head-region severity score. After adjustment, the researchers found a “strikingly linear relationship” between hypotension dose and mortality, Dr. Spaite said, although a clear dose-response relationship was also evident in the unadjusted data.
EPIC-TBI enrolled TBI patients age 10 years or older during 2007-2014 through participation by dozens of EMS providers throughout Arizona. For the current analysis, the researchers identified 7,521 patients from the total group who had at least two blood pressure measurements taken during their prehospital EMS care and also met other inclusion criteria.
The best way to manage hypotension in TBI patients during the prehospital period remains unclear. Simply raising blood pressure with fluid infusion may not necessarily help, because it could exacerbate a patient’s bleeding, Dr. Spaite noted during an interview.
The primary goal of EPIC-TBI is to assess the impact of the third edition of the traumatic brain injury guidelines released in 2007 by the Brain Trauma Foundation. (The fourth edition of these guidelines came out in August 2016.) The new finding by Dr. Spaite and his associates will allow the full EPIC-TBI analysis to correlate patient outcomes with the impact that acute, prehospital treatment had on the hypotension dose received by each patient, he noted.
“What’s remarkable is that the single, prehospital parameter of hypotension for just a few minutes during transport can have such a strong impact on survival, given all the other factors that can influence outcomes” in TBI patients once they reach a hospital and during the period they remain hospitalized, Dr. Spaite said.
mzoler@frontlinemedcom.com On Twitter @mitchelzoler
<p> </p><p><strong>Key clinical point: </strong><span class="tag metaDescription">Both the duration and severity of hypotension a traumatic brain injury patient has during transport to an emergency department has a significant, linear impact on subsequent mortality.</span><br /><br /><strong>Major finding: </strong>For each doubling of the dose of prehospital hypotension (a function of severity and duration), mortality rose by 19%.<br /><br /><strong>Data source: </strong>EPIC-TBI, a multicenter study with 16,711 patients, including 7,521 who met inclusion criteria for the current analysis.<br /><br /><strong>Disclosures:</strong> Dr. Spaite had no disclosures.</p>
