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Is there a need for tPA before thrombectomy in patients with stroke?
In a new randomized trial that investigated the question of whether thrombolysis can be omitted for patients with stroke who are undergoing endovascular thrombectomy for a large-vessel occlusion, results were similar for both approaches.
and functional outcomes were not significantly different. In addition, hemorrhage rates with or without intravenous alteplase administration before endovascular treatment were similar.
“From the MR CLEAN NO IV results, we cannot change standard practice, as we failed to show superiority of the direct endovascular approach, and we also didn’t meet the noninferiority criteria. So, the standard practice of giving tPA to those eligible still holds,” said co–lead investigator Yvo Roos, MD.
“But I think we can say that these results suggest that there may also not be such a need for tPA in patients who can go straight for endovascular therapy,” said Dr. Roos, who is professor of neurology at Amsterdam Medical Center.
“If we are not sure whether a patient is suitable for tPA because they have a higher bleeding risk, I think we can be reassured about missing the tPA out and going straight to endovascular treatment. So, if in doubt, leave it out,” he added.
Results of the MR CLEAN NO IV trial were presented at the International Stroke Conference sponsored by the American Heart Association.
“If in doubt, leave it out”
Dr. Roos noted that three trials have investigated the question regarding dropping thrombolysis for patients who can receive thrombectomy quickly. These are the DIRECT MT, SKIP, and DEVT studies. All of these trials were conducted in Asian countries, and none found differences in functional outcomes between the two approaches.
The largest of these studies – the DIRECT-MT trial, from China, which was a sister study to MR CLEAN NO IV – did show noninferiority of the direct endovascular approach to tPA plus endovascular treatment.
But because of differences in health care logistics and trial populations, the benefits and risks of dropping thrombolysis in Western countries are not known, explained Charles Majoie, MD, who is co–lead investigator of the current trial and is chair of neuroradiology at Amsterdam Medical Center.
The MR CLEAN NO IV trial was designed to show superiority of the direct endovascular approach with noninferiority for hemorrhage. It enrolled 540 European patients who were eligible for both thrombolysis and thrombectomy and who presented to a thrombectomy-capable center. They were randomly assigned to receive thrombolysis plus endovascular therapy or direct endovascular therapy alone.
The mean time from stroke onset to groin puncture (the start of endovascular therapy) was very fast in both groups – 130 minutes in the direct group, and 135 minutes in the tPA group.
The primary outcome was a shift analysis of the Modified Rankin Scale (mRS). On that outcome, the trial failed to show significant superiority of the direct approach (odds ratio, 0.88; 95% confidence interval, 0.65-1.19).
A good functional outcome (mRS, 0-2) was achieved in 49% of the direct thrombectomy group and in 51% of the tPA group (OR, 0.95; 95% CI, 0.65-1.40).
Safety results showed no difference in any of the hemorrhage endpoints between the two groups. The rate of symptomatic intracranial hemorrhage was actually numerically higher in the direct thrombectomy group (5.9% vs. 5.3%).
“One of the most intriguing results of this study is that there was no increase in hemorrhage in the tPA group,” Dr. Roos commented. “This is very surprising, as we have always thought thrombolysis causes an increased bleeding risk. But after these results, we may have to rethink that idea – perhaps it is not the tPA itself that causes bleeding risk but rather the opening up of the vessel.”
On the failure to show noninferiority of the direct approach, Dr. Roos suggested that the trial may have been underpowered in this respect.
“Our sister trial, DIRECT-MT, was a noninferiority study. They had 650 patients, and they just reached noninferiority,” he said. “In MR CLEAN NO IV, we were aiming for superiority, and we had fewer patients – 540. We didn’t show superiority, and we didn’t have quite enough patients to show noninferiority.”
He added that, considering all the four studies together, the results look very similar and suggest no difference between the two approaches.
Individualized approach probable
Dr. Majoie suggested that different patients may be suitable for the different approaches.
“I think we are heading for individualized treatment. If we have a young patient and the angiography suite is ready, we could probably skip tPA, but it would be for the neurologist/neuroradiologist to make individualized decisions on this,” he said. “We need to look at subgroups for more information.”
Another large trial that investigated this issue, SWIFT-DIRECT, is expected to be presented later this year. An Australian trial, DIRECT-SAFE, is ongoing and is at an early stage of recruitment.
Dr. Roos said that the data from all the trials will be combined for a more comprehensive analysis of the benefits and risks of the two approaches in various subgroups.
Commenting on the study was cochair of the ISC session at which it was presented, Tudor Jovin, MD, chair of neurology at Cooper University Hospital, Cherry Hill, N.J.
“Putting these results together with the previous Asian studies, I think we can say that direct thrombectomy without tPA is clearly not superior to the combined approach of tPA plus thrombectomy,” he said.
Dr. Jovin explained that, in theory, direct thrombectomy could be faster than the combined approach and that the risk for symptomatic intracerebral hemorrhage could be lower. But neither of these two possible benefits were seen in this study.
He agreed with Dr. Roos that MR CLEAN NO IV could have failed to show noninferiority of the direct strategy because the sample was not large enough.
“The results of the two approaches are very similar in this study and in the Asian studies, so it doesn’t appear that tPA adds very much, and it is associated with a significant increase in costs,” he said.
“The answer will probably be that there is not a ‘one-size-fits-all’ strategy, and we may end up using different approaches for different patient groups,” Dr. Jovin added. “Information on this will come from subgroups analyses from these trials.”
MR CLEAN NO-IV trial was part of the CONTRAST consortium, which is supported by the Netherlands Cardiovascular Research Initiative (an initiative of the Dutch Heart Foundation), the Brain Foundation Netherlands, Medtronic, Health-Holland, and Top Sector Life Sciences. The study received additional unrestricted funding from Stryker European Operations. Dr. Roos and Dr. Majoie are shareholders of Nico Lab.
A version of this article first appeared on Medscape.com.
In a new randomized trial that investigated the question of whether thrombolysis can be omitted for patients with stroke who are undergoing endovascular thrombectomy for a large-vessel occlusion, results were similar for both approaches.
and functional outcomes were not significantly different. In addition, hemorrhage rates with or without intravenous alteplase administration before endovascular treatment were similar.
“From the MR CLEAN NO IV results, we cannot change standard practice, as we failed to show superiority of the direct endovascular approach, and we also didn’t meet the noninferiority criteria. So, the standard practice of giving tPA to those eligible still holds,” said co–lead investigator Yvo Roos, MD.
“But I think we can say that these results suggest that there may also not be such a need for tPA in patients who can go straight for endovascular therapy,” said Dr. Roos, who is professor of neurology at Amsterdam Medical Center.
“If we are not sure whether a patient is suitable for tPA because they have a higher bleeding risk, I think we can be reassured about missing the tPA out and going straight to endovascular treatment. So, if in doubt, leave it out,” he added.
Results of the MR CLEAN NO IV trial were presented at the International Stroke Conference sponsored by the American Heart Association.
“If in doubt, leave it out”
Dr. Roos noted that three trials have investigated the question regarding dropping thrombolysis for patients who can receive thrombectomy quickly. These are the DIRECT MT, SKIP, and DEVT studies. All of these trials were conducted in Asian countries, and none found differences in functional outcomes between the two approaches.
The largest of these studies – the DIRECT-MT trial, from China, which was a sister study to MR CLEAN NO IV – did show noninferiority of the direct endovascular approach to tPA plus endovascular treatment.
But because of differences in health care logistics and trial populations, the benefits and risks of dropping thrombolysis in Western countries are not known, explained Charles Majoie, MD, who is co–lead investigator of the current trial and is chair of neuroradiology at Amsterdam Medical Center.
The MR CLEAN NO IV trial was designed to show superiority of the direct endovascular approach with noninferiority for hemorrhage. It enrolled 540 European patients who were eligible for both thrombolysis and thrombectomy and who presented to a thrombectomy-capable center. They were randomly assigned to receive thrombolysis plus endovascular therapy or direct endovascular therapy alone.
The mean time from stroke onset to groin puncture (the start of endovascular therapy) was very fast in both groups – 130 minutes in the direct group, and 135 minutes in the tPA group.
The primary outcome was a shift analysis of the Modified Rankin Scale (mRS). On that outcome, the trial failed to show significant superiority of the direct approach (odds ratio, 0.88; 95% confidence interval, 0.65-1.19).
A good functional outcome (mRS, 0-2) was achieved in 49% of the direct thrombectomy group and in 51% of the tPA group (OR, 0.95; 95% CI, 0.65-1.40).
Safety results showed no difference in any of the hemorrhage endpoints between the two groups. The rate of symptomatic intracranial hemorrhage was actually numerically higher in the direct thrombectomy group (5.9% vs. 5.3%).
“One of the most intriguing results of this study is that there was no increase in hemorrhage in the tPA group,” Dr. Roos commented. “This is very surprising, as we have always thought thrombolysis causes an increased bleeding risk. But after these results, we may have to rethink that idea – perhaps it is not the tPA itself that causes bleeding risk but rather the opening up of the vessel.”
On the failure to show noninferiority of the direct approach, Dr. Roos suggested that the trial may have been underpowered in this respect.
“Our sister trial, DIRECT-MT, was a noninferiority study. They had 650 patients, and they just reached noninferiority,” he said. “In MR CLEAN NO IV, we were aiming for superiority, and we had fewer patients – 540. We didn’t show superiority, and we didn’t have quite enough patients to show noninferiority.”
He added that, considering all the four studies together, the results look very similar and suggest no difference between the two approaches.
Individualized approach probable
Dr. Majoie suggested that different patients may be suitable for the different approaches.
“I think we are heading for individualized treatment. If we have a young patient and the angiography suite is ready, we could probably skip tPA, but it would be for the neurologist/neuroradiologist to make individualized decisions on this,” he said. “We need to look at subgroups for more information.”
Another large trial that investigated this issue, SWIFT-DIRECT, is expected to be presented later this year. An Australian trial, DIRECT-SAFE, is ongoing and is at an early stage of recruitment.
Dr. Roos said that the data from all the trials will be combined for a more comprehensive analysis of the benefits and risks of the two approaches in various subgroups.
Commenting on the study was cochair of the ISC session at which it was presented, Tudor Jovin, MD, chair of neurology at Cooper University Hospital, Cherry Hill, N.J.
“Putting these results together with the previous Asian studies, I think we can say that direct thrombectomy without tPA is clearly not superior to the combined approach of tPA plus thrombectomy,” he said.
Dr. Jovin explained that, in theory, direct thrombectomy could be faster than the combined approach and that the risk for symptomatic intracerebral hemorrhage could be lower. But neither of these two possible benefits were seen in this study.
He agreed with Dr. Roos that MR CLEAN NO IV could have failed to show noninferiority of the direct strategy because the sample was not large enough.
“The results of the two approaches are very similar in this study and in the Asian studies, so it doesn’t appear that tPA adds very much, and it is associated with a significant increase in costs,” he said.
“The answer will probably be that there is not a ‘one-size-fits-all’ strategy, and we may end up using different approaches for different patient groups,” Dr. Jovin added. “Information on this will come from subgroups analyses from these trials.”
MR CLEAN NO-IV trial was part of the CONTRAST consortium, which is supported by the Netherlands Cardiovascular Research Initiative (an initiative of the Dutch Heart Foundation), the Brain Foundation Netherlands, Medtronic, Health-Holland, and Top Sector Life Sciences. The study received additional unrestricted funding from Stryker European Operations. Dr. Roos and Dr. Majoie are shareholders of Nico Lab.
A version of this article first appeared on Medscape.com.
In a new randomized trial that investigated the question of whether thrombolysis can be omitted for patients with stroke who are undergoing endovascular thrombectomy for a large-vessel occlusion, results were similar for both approaches.
and functional outcomes were not significantly different. In addition, hemorrhage rates with or without intravenous alteplase administration before endovascular treatment were similar.
“From the MR CLEAN NO IV results, we cannot change standard practice, as we failed to show superiority of the direct endovascular approach, and we also didn’t meet the noninferiority criteria. So, the standard practice of giving tPA to those eligible still holds,” said co–lead investigator Yvo Roos, MD.
“But I think we can say that these results suggest that there may also not be such a need for tPA in patients who can go straight for endovascular therapy,” said Dr. Roos, who is professor of neurology at Amsterdam Medical Center.
“If we are not sure whether a patient is suitable for tPA because they have a higher bleeding risk, I think we can be reassured about missing the tPA out and going straight to endovascular treatment. So, if in doubt, leave it out,” he added.
Results of the MR CLEAN NO IV trial were presented at the International Stroke Conference sponsored by the American Heart Association.
“If in doubt, leave it out”
Dr. Roos noted that three trials have investigated the question regarding dropping thrombolysis for patients who can receive thrombectomy quickly. These are the DIRECT MT, SKIP, and DEVT studies. All of these trials were conducted in Asian countries, and none found differences in functional outcomes between the two approaches.
The largest of these studies – the DIRECT-MT trial, from China, which was a sister study to MR CLEAN NO IV – did show noninferiority of the direct endovascular approach to tPA plus endovascular treatment.
But because of differences in health care logistics and trial populations, the benefits and risks of dropping thrombolysis in Western countries are not known, explained Charles Majoie, MD, who is co–lead investigator of the current trial and is chair of neuroradiology at Amsterdam Medical Center.
The MR CLEAN NO IV trial was designed to show superiority of the direct endovascular approach with noninferiority for hemorrhage. It enrolled 540 European patients who were eligible for both thrombolysis and thrombectomy and who presented to a thrombectomy-capable center. They were randomly assigned to receive thrombolysis plus endovascular therapy or direct endovascular therapy alone.
The mean time from stroke onset to groin puncture (the start of endovascular therapy) was very fast in both groups – 130 minutes in the direct group, and 135 minutes in the tPA group.
The primary outcome was a shift analysis of the Modified Rankin Scale (mRS). On that outcome, the trial failed to show significant superiority of the direct approach (odds ratio, 0.88; 95% confidence interval, 0.65-1.19).
A good functional outcome (mRS, 0-2) was achieved in 49% of the direct thrombectomy group and in 51% of the tPA group (OR, 0.95; 95% CI, 0.65-1.40).
Safety results showed no difference in any of the hemorrhage endpoints between the two groups. The rate of symptomatic intracranial hemorrhage was actually numerically higher in the direct thrombectomy group (5.9% vs. 5.3%).
“One of the most intriguing results of this study is that there was no increase in hemorrhage in the tPA group,” Dr. Roos commented. “This is very surprising, as we have always thought thrombolysis causes an increased bleeding risk. But after these results, we may have to rethink that idea – perhaps it is not the tPA itself that causes bleeding risk but rather the opening up of the vessel.”
On the failure to show noninferiority of the direct approach, Dr. Roos suggested that the trial may have been underpowered in this respect.
“Our sister trial, DIRECT-MT, was a noninferiority study. They had 650 patients, and they just reached noninferiority,” he said. “In MR CLEAN NO IV, we were aiming for superiority, and we had fewer patients – 540. We didn’t show superiority, and we didn’t have quite enough patients to show noninferiority.”
He added that, considering all the four studies together, the results look very similar and suggest no difference between the two approaches.
Individualized approach probable
Dr. Majoie suggested that different patients may be suitable for the different approaches.
“I think we are heading for individualized treatment. If we have a young patient and the angiography suite is ready, we could probably skip tPA, but it would be for the neurologist/neuroradiologist to make individualized decisions on this,” he said. “We need to look at subgroups for more information.”
Another large trial that investigated this issue, SWIFT-DIRECT, is expected to be presented later this year. An Australian trial, DIRECT-SAFE, is ongoing and is at an early stage of recruitment.
Dr. Roos said that the data from all the trials will be combined for a more comprehensive analysis of the benefits and risks of the two approaches in various subgroups.
Commenting on the study was cochair of the ISC session at which it was presented, Tudor Jovin, MD, chair of neurology at Cooper University Hospital, Cherry Hill, N.J.
“Putting these results together with the previous Asian studies, I think we can say that direct thrombectomy without tPA is clearly not superior to the combined approach of tPA plus thrombectomy,” he said.
Dr. Jovin explained that, in theory, direct thrombectomy could be faster than the combined approach and that the risk for symptomatic intracerebral hemorrhage could be lower. But neither of these two possible benefits were seen in this study.
He agreed with Dr. Roos that MR CLEAN NO IV could have failed to show noninferiority of the direct strategy because the sample was not large enough.
“The results of the two approaches are very similar in this study and in the Asian studies, so it doesn’t appear that tPA adds very much, and it is associated with a significant increase in costs,” he said.
“The answer will probably be that there is not a ‘one-size-fits-all’ strategy, and we may end up using different approaches for different patient groups,” Dr. Jovin added. “Information on this will come from subgroups analyses from these trials.”
MR CLEAN NO-IV trial was part of the CONTRAST consortium, which is supported by the Netherlands Cardiovascular Research Initiative (an initiative of the Dutch Heart Foundation), the Brain Foundation Netherlands, Medtronic, Health-Holland, and Top Sector Life Sciences. The study received additional unrestricted funding from Stryker European Operations. Dr. Roos and Dr. Majoie are shareholders of Nico Lab.
A version of this article first appeared on Medscape.com.
FROM ISC 2021
Meta-analysis supports late thrombectomy in selected stroke patients
of data from six clinical trials.
Results of the AURORA analysis showed that for every 100 patients treated with thrombectomy, 33 patients will have less disability, and 27 patients will achieve an independent level of functioning compared with patients who receive only standard medical care.
The benefit of mechanical removal of the clot for selected patients who may have salvageable brain tissue, as identified through the use of various imaging modalities, was maintained whether the patient had a “wake-up stroke” or the onset of symptoms was witnessed, regardless of the point in time within the late window. In fact, the benefit of intervention was greater for patients who presented in the latter part of the late time window.
Never too late for urgent medical care
“While the findings of this analysis do not contradict the mantra that the earlier treatment is instituted, the higher the chance of a good outcome, they highlight the fact that it is never too late to seek urgent medical care,” said lead investigator Tudor Jovin, MD, chair of neurology at Cooper University Hospital, Cherry Hill, New Jersey.
“The implications of the findings from AURORA are that they could lead to a change in guidelines from endorsement of thrombectomy as level 1a recommendation in eligible patients presenting in the 6- to 16-hour time window to a 6- to 24-hour time window,” said Dr. Jovin.
“Furthermore, there are strong signals of benefit of thrombectomy in patients who are not selected based on volumetric analysis of baseline infarct (core) or extent of tissue at risk (penumbra), such that when those imaging modalities are not available or contraindicated, selection based on noncontrast CT and clinical information only may be acceptable,” he added. “Finally, the possibility of benefit from thrombectomy performed beyond 24 hours from last seen well is real and should be explored in future studies.”
The AURORA findings were presented at the virtual International Stroke Conference (ISC) 2021.
The objective of the study was to provide a more precise estimate of the benefit of thrombectomy for patients with stroke when performed within 6-24 hours after the patient was last seen well, Dr. Jovin explained.
He said the 6-hour cutoff was chosen somewhat arbitrarily, but added, “It is highly consequential, as it marks the point of demarcation between the early and late time window, and virtually all guidelines recommend different approaches, dependent on whether patients present before or after 6 hours from symptom onset.”
The 6+ hour window
Dr. Jovin pointed out that for patients who present beyond 6 hours, treatment options are more restricted, because the data on thrombectomy in this later period come mainly from two North American trials (DEFUSE 3 and DAWN) that had very stringent imaging criteria for enrollment.
“We wanted to create a heterogeneous dataset with regard to geography and selection criteria by forming the AURORA collaboration,” he commented. Their study involved an individual-level pooled analysis of all patients who underwent randomization after 6 hours from the time that they were last seen well. Patients were randomly assigned to receive either best medical therapy alone or best medical therapy plus thrombectomy (either with stent retrievers or aspiration) for anterior circulation proximal large-vessel occlusion stroke.
The data came from six trials: DAWN (which enrolled patients 6-24 hours from stroke onset), DEFUSE 3 (6-16 hours), ESCAPE (0-12 hours), REVASCAT (0-8 hours), RESILIENT (0-8 hours), and POSITIVE (0-12 hours). In total, 505 patients were included in the meta-analysis, 266 in the intervention group, and 239 in the control group.
“By pooling data on patients presenting after 6 hours from all these trails, we achieve greater precision for treatment effect estimation and increased the power for subgroup analysis,” Dr. Jovin noted.
Although the majority of the patients were in the DAWN and DIFFUSE 3 trials (n = 388), “there are still a good number from the other four trials (n = 117),” Dr. Jovin reported.
Most of the trials used Modified Rankin Scale (mRS) ordinal or shift analysis as their primary endpoint, which was the also the endpoint chosen for this meta-analysis.
Imaging selection criteria ranged from fully automated software-generated quantitative volumetric analysis of baseline infarct (core) or tissue at risk to CT perfusion and plain CT/CTA. The minimum ASPECTS score was 5 or 6.
There were no imbalances in baseline characteristics. The median NIH Stroke Scale score was 16, and the median ASPECTS score was 8. The median time to randomization was 10.5 hours.
With regard to safety, there was no significant difference in rates of symptomatic intracerebral hemorrhage (5.3% in the intervention group vs. 3.3% in the control group; P = .23) or in mortality at 90 days (16.5% vs. 19.3%; P = .87). Jovin noted that these results are very similar to those from the HERMES meta-analysis of patients treated in the early time window.
The primary outcome – ordinal analysis of the mRS distribution – showed an adjusted odds ratio of 2.54 (P < .0001) for benefit in the intervention group. The number needed to treat to reduce disability was 3. “This is again very similar to the HERMES meta-analysis of patients in the early window,” Dr. Jovin said.
The P value for heterogeneity of treatment effect across the six studies was nonsignificant.
Secondary outcome analysis showed an “almost 27%” difference in good functional outcome (MRS, 0-2) between the two groups (45.9% in the intervention group vs. 19.3% in the control group), which translates into a number needed to treat of 3.8, Dr. Jovin reported.
Subgroup analysis showed a treatment effect favoring intervention across all prespecified subgroup factors, including age, sex, occlusion location, mode of presentation (wake-up vs. witnessed), and ASPECTS score, with the caveat that most of the patients were enrolled with ASPECTS scores of 7 or greater.
Early versus late
Surprisingly, although thrombectomy was found to be beneficial in both the 6- to 12-hour and 12- to 24-hour time window, the magnitude of benefit was significantly higher in the later rather than the earlier time window. The odds ratio of a better outcome with thrombectomy on the mRS shift analysis in those presenting in the 6- to 12-hour period was 1.78, compared with 5.86 in the 12- to 24-hour time window.
“This should not be interpreted as a higher chance of a good outcome if treated late. In fact, the rate of good outcomes were numerically higher in the earlier treated patients, but the difference comes from the control group, which did much worse in patients randomized in the later time period,” Dr. Jovin said.
“Aurora was the goddess of dawn [in ancient Roman mythology], so this is a very fitting name, as it reminds us that we are in the dawn of a new era where patients are selected based on physiological data rather than on time, and we certainly hope that this work has brought us closer to this reality,” Dr. Jovin concluded.
Commenting on the study, Michael Hill, MD, University of Calgary (Alta.), said: “The work provides pooled empiric data to support the concept that time to treatment is no longer the sole threshold variable to be used in treatment decision-making. Instead, time is now simply another variable to consider in the context of clinical and imaging factors.”
Dr. Hill, who headed up the ESCAPE trial and was also involved in the current meta-analysis, added: “This meta-analysis supports the concept of patient selection using the ‘good scan’ model, rather than using a time-based concept of patient eligibility for endovascular therapy. It will further push changes in care, because the implication is that all patients with more severe acute stroke presentations need emergency neurovascular imaging to decide if they are eligible for treatment.”
The AURORA meta-analysis was funded by Stryker Neurovascular. Dr. Jovin reports stock holdings in Anaconda, Route 92, VizAi, FreeOx, Blockade Medical, Methinks, and Corindus; personal fees from Cerenovus and Contego Medical; travel support from Fundacio Ictus; and grant support from Medtronic and Stryker Neurovascular.
A version of this article first appeared on Medscape.com.
of data from six clinical trials.
Results of the AURORA analysis showed that for every 100 patients treated with thrombectomy, 33 patients will have less disability, and 27 patients will achieve an independent level of functioning compared with patients who receive only standard medical care.
The benefit of mechanical removal of the clot for selected patients who may have salvageable brain tissue, as identified through the use of various imaging modalities, was maintained whether the patient had a “wake-up stroke” or the onset of symptoms was witnessed, regardless of the point in time within the late window. In fact, the benefit of intervention was greater for patients who presented in the latter part of the late time window.
Never too late for urgent medical care
“While the findings of this analysis do not contradict the mantra that the earlier treatment is instituted, the higher the chance of a good outcome, they highlight the fact that it is never too late to seek urgent medical care,” said lead investigator Tudor Jovin, MD, chair of neurology at Cooper University Hospital, Cherry Hill, New Jersey.
“The implications of the findings from AURORA are that they could lead to a change in guidelines from endorsement of thrombectomy as level 1a recommendation in eligible patients presenting in the 6- to 16-hour time window to a 6- to 24-hour time window,” said Dr. Jovin.
“Furthermore, there are strong signals of benefit of thrombectomy in patients who are not selected based on volumetric analysis of baseline infarct (core) or extent of tissue at risk (penumbra), such that when those imaging modalities are not available or contraindicated, selection based on noncontrast CT and clinical information only may be acceptable,” he added. “Finally, the possibility of benefit from thrombectomy performed beyond 24 hours from last seen well is real and should be explored in future studies.”
The AURORA findings were presented at the virtual International Stroke Conference (ISC) 2021.
The objective of the study was to provide a more precise estimate of the benefit of thrombectomy for patients with stroke when performed within 6-24 hours after the patient was last seen well, Dr. Jovin explained.
He said the 6-hour cutoff was chosen somewhat arbitrarily, but added, “It is highly consequential, as it marks the point of demarcation between the early and late time window, and virtually all guidelines recommend different approaches, dependent on whether patients present before or after 6 hours from symptom onset.”
The 6+ hour window
Dr. Jovin pointed out that for patients who present beyond 6 hours, treatment options are more restricted, because the data on thrombectomy in this later period come mainly from two North American trials (DEFUSE 3 and DAWN) that had very stringent imaging criteria for enrollment.
“We wanted to create a heterogeneous dataset with regard to geography and selection criteria by forming the AURORA collaboration,” he commented. Their study involved an individual-level pooled analysis of all patients who underwent randomization after 6 hours from the time that they were last seen well. Patients were randomly assigned to receive either best medical therapy alone or best medical therapy plus thrombectomy (either with stent retrievers or aspiration) for anterior circulation proximal large-vessel occlusion stroke.
The data came from six trials: DAWN (which enrolled patients 6-24 hours from stroke onset), DEFUSE 3 (6-16 hours), ESCAPE (0-12 hours), REVASCAT (0-8 hours), RESILIENT (0-8 hours), and POSITIVE (0-12 hours). In total, 505 patients were included in the meta-analysis, 266 in the intervention group, and 239 in the control group.
“By pooling data on patients presenting after 6 hours from all these trails, we achieve greater precision for treatment effect estimation and increased the power for subgroup analysis,” Dr. Jovin noted.
Although the majority of the patients were in the DAWN and DIFFUSE 3 trials (n = 388), “there are still a good number from the other four trials (n = 117),” Dr. Jovin reported.
Most of the trials used Modified Rankin Scale (mRS) ordinal or shift analysis as their primary endpoint, which was the also the endpoint chosen for this meta-analysis.
Imaging selection criteria ranged from fully automated software-generated quantitative volumetric analysis of baseline infarct (core) or tissue at risk to CT perfusion and plain CT/CTA. The minimum ASPECTS score was 5 or 6.
There were no imbalances in baseline characteristics. The median NIH Stroke Scale score was 16, and the median ASPECTS score was 8. The median time to randomization was 10.5 hours.
With regard to safety, there was no significant difference in rates of symptomatic intracerebral hemorrhage (5.3% in the intervention group vs. 3.3% in the control group; P = .23) or in mortality at 90 days (16.5% vs. 19.3%; P = .87). Jovin noted that these results are very similar to those from the HERMES meta-analysis of patients treated in the early time window.
The primary outcome – ordinal analysis of the mRS distribution – showed an adjusted odds ratio of 2.54 (P < .0001) for benefit in the intervention group. The number needed to treat to reduce disability was 3. “This is again very similar to the HERMES meta-analysis of patients in the early window,” Dr. Jovin said.
The P value for heterogeneity of treatment effect across the six studies was nonsignificant.
Secondary outcome analysis showed an “almost 27%” difference in good functional outcome (MRS, 0-2) between the two groups (45.9% in the intervention group vs. 19.3% in the control group), which translates into a number needed to treat of 3.8, Dr. Jovin reported.
Subgroup analysis showed a treatment effect favoring intervention across all prespecified subgroup factors, including age, sex, occlusion location, mode of presentation (wake-up vs. witnessed), and ASPECTS score, with the caveat that most of the patients were enrolled with ASPECTS scores of 7 or greater.
Early versus late
Surprisingly, although thrombectomy was found to be beneficial in both the 6- to 12-hour and 12- to 24-hour time window, the magnitude of benefit was significantly higher in the later rather than the earlier time window. The odds ratio of a better outcome with thrombectomy on the mRS shift analysis in those presenting in the 6- to 12-hour period was 1.78, compared with 5.86 in the 12- to 24-hour time window.
“This should not be interpreted as a higher chance of a good outcome if treated late. In fact, the rate of good outcomes were numerically higher in the earlier treated patients, but the difference comes from the control group, which did much worse in patients randomized in the later time period,” Dr. Jovin said.
“Aurora was the goddess of dawn [in ancient Roman mythology], so this is a very fitting name, as it reminds us that we are in the dawn of a new era where patients are selected based on physiological data rather than on time, and we certainly hope that this work has brought us closer to this reality,” Dr. Jovin concluded.
Commenting on the study, Michael Hill, MD, University of Calgary (Alta.), said: “The work provides pooled empiric data to support the concept that time to treatment is no longer the sole threshold variable to be used in treatment decision-making. Instead, time is now simply another variable to consider in the context of clinical and imaging factors.”
Dr. Hill, who headed up the ESCAPE trial and was also involved in the current meta-analysis, added: “This meta-analysis supports the concept of patient selection using the ‘good scan’ model, rather than using a time-based concept of patient eligibility for endovascular therapy. It will further push changes in care, because the implication is that all patients with more severe acute stroke presentations need emergency neurovascular imaging to decide if they are eligible for treatment.”
The AURORA meta-analysis was funded by Stryker Neurovascular. Dr. Jovin reports stock holdings in Anaconda, Route 92, VizAi, FreeOx, Blockade Medical, Methinks, and Corindus; personal fees from Cerenovus and Contego Medical; travel support from Fundacio Ictus; and grant support from Medtronic and Stryker Neurovascular.
A version of this article first appeared on Medscape.com.
of data from six clinical trials.
Results of the AURORA analysis showed that for every 100 patients treated with thrombectomy, 33 patients will have less disability, and 27 patients will achieve an independent level of functioning compared with patients who receive only standard medical care.
The benefit of mechanical removal of the clot for selected patients who may have salvageable brain tissue, as identified through the use of various imaging modalities, was maintained whether the patient had a “wake-up stroke” or the onset of symptoms was witnessed, regardless of the point in time within the late window. In fact, the benefit of intervention was greater for patients who presented in the latter part of the late time window.
Never too late for urgent medical care
“While the findings of this analysis do not contradict the mantra that the earlier treatment is instituted, the higher the chance of a good outcome, they highlight the fact that it is never too late to seek urgent medical care,” said lead investigator Tudor Jovin, MD, chair of neurology at Cooper University Hospital, Cherry Hill, New Jersey.
“The implications of the findings from AURORA are that they could lead to a change in guidelines from endorsement of thrombectomy as level 1a recommendation in eligible patients presenting in the 6- to 16-hour time window to a 6- to 24-hour time window,” said Dr. Jovin.
“Furthermore, there are strong signals of benefit of thrombectomy in patients who are not selected based on volumetric analysis of baseline infarct (core) or extent of tissue at risk (penumbra), such that when those imaging modalities are not available or contraindicated, selection based on noncontrast CT and clinical information only may be acceptable,” he added. “Finally, the possibility of benefit from thrombectomy performed beyond 24 hours from last seen well is real and should be explored in future studies.”
The AURORA findings were presented at the virtual International Stroke Conference (ISC) 2021.
The objective of the study was to provide a more precise estimate of the benefit of thrombectomy for patients with stroke when performed within 6-24 hours after the patient was last seen well, Dr. Jovin explained.
He said the 6-hour cutoff was chosen somewhat arbitrarily, but added, “It is highly consequential, as it marks the point of demarcation between the early and late time window, and virtually all guidelines recommend different approaches, dependent on whether patients present before or after 6 hours from symptom onset.”
The 6+ hour window
Dr. Jovin pointed out that for patients who present beyond 6 hours, treatment options are more restricted, because the data on thrombectomy in this later period come mainly from two North American trials (DEFUSE 3 and DAWN) that had very stringent imaging criteria for enrollment.
“We wanted to create a heterogeneous dataset with regard to geography and selection criteria by forming the AURORA collaboration,” he commented. Their study involved an individual-level pooled analysis of all patients who underwent randomization after 6 hours from the time that they were last seen well. Patients were randomly assigned to receive either best medical therapy alone or best medical therapy plus thrombectomy (either with stent retrievers or aspiration) for anterior circulation proximal large-vessel occlusion stroke.
The data came from six trials: DAWN (which enrolled patients 6-24 hours from stroke onset), DEFUSE 3 (6-16 hours), ESCAPE (0-12 hours), REVASCAT (0-8 hours), RESILIENT (0-8 hours), and POSITIVE (0-12 hours). In total, 505 patients were included in the meta-analysis, 266 in the intervention group, and 239 in the control group.
“By pooling data on patients presenting after 6 hours from all these trails, we achieve greater precision for treatment effect estimation and increased the power for subgroup analysis,” Dr. Jovin noted.
Although the majority of the patients were in the DAWN and DIFFUSE 3 trials (n = 388), “there are still a good number from the other four trials (n = 117),” Dr. Jovin reported.
Most of the trials used Modified Rankin Scale (mRS) ordinal or shift analysis as their primary endpoint, which was the also the endpoint chosen for this meta-analysis.
Imaging selection criteria ranged from fully automated software-generated quantitative volumetric analysis of baseline infarct (core) or tissue at risk to CT perfusion and plain CT/CTA. The minimum ASPECTS score was 5 or 6.
There were no imbalances in baseline characteristics. The median NIH Stroke Scale score was 16, and the median ASPECTS score was 8. The median time to randomization was 10.5 hours.
With regard to safety, there was no significant difference in rates of symptomatic intracerebral hemorrhage (5.3% in the intervention group vs. 3.3% in the control group; P = .23) or in mortality at 90 days (16.5% vs. 19.3%; P = .87). Jovin noted that these results are very similar to those from the HERMES meta-analysis of patients treated in the early time window.
The primary outcome – ordinal analysis of the mRS distribution – showed an adjusted odds ratio of 2.54 (P < .0001) for benefit in the intervention group. The number needed to treat to reduce disability was 3. “This is again very similar to the HERMES meta-analysis of patients in the early window,” Dr. Jovin said.
The P value for heterogeneity of treatment effect across the six studies was nonsignificant.
Secondary outcome analysis showed an “almost 27%” difference in good functional outcome (MRS, 0-2) between the two groups (45.9% in the intervention group vs. 19.3% in the control group), which translates into a number needed to treat of 3.8, Dr. Jovin reported.
Subgroup analysis showed a treatment effect favoring intervention across all prespecified subgroup factors, including age, sex, occlusion location, mode of presentation (wake-up vs. witnessed), and ASPECTS score, with the caveat that most of the patients were enrolled with ASPECTS scores of 7 or greater.
Early versus late
Surprisingly, although thrombectomy was found to be beneficial in both the 6- to 12-hour and 12- to 24-hour time window, the magnitude of benefit was significantly higher in the later rather than the earlier time window. The odds ratio of a better outcome with thrombectomy on the mRS shift analysis in those presenting in the 6- to 12-hour period was 1.78, compared with 5.86 in the 12- to 24-hour time window.
“This should not be interpreted as a higher chance of a good outcome if treated late. In fact, the rate of good outcomes were numerically higher in the earlier treated patients, but the difference comes from the control group, which did much worse in patients randomized in the later time period,” Dr. Jovin said.
“Aurora was the goddess of dawn [in ancient Roman mythology], so this is a very fitting name, as it reminds us that we are in the dawn of a new era where patients are selected based on physiological data rather than on time, and we certainly hope that this work has brought us closer to this reality,” Dr. Jovin concluded.
Commenting on the study, Michael Hill, MD, University of Calgary (Alta.), said: “The work provides pooled empiric data to support the concept that time to treatment is no longer the sole threshold variable to be used in treatment decision-making. Instead, time is now simply another variable to consider in the context of clinical and imaging factors.”
Dr. Hill, who headed up the ESCAPE trial and was also involved in the current meta-analysis, added: “This meta-analysis supports the concept of patient selection using the ‘good scan’ model, rather than using a time-based concept of patient eligibility for endovascular therapy. It will further push changes in care, because the implication is that all patients with more severe acute stroke presentations need emergency neurovascular imaging to decide if they are eligible for treatment.”
The AURORA meta-analysis was funded by Stryker Neurovascular. Dr. Jovin reports stock holdings in Anaconda, Route 92, VizAi, FreeOx, Blockade Medical, Methinks, and Corindus; personal fees from Cerenovus and Contego Medical; travel support from Fundacio Ictus; and grant support from Medtronic and Stryker Neurovascular.
A version of this article first appeared on Medscape.com.
FROM ISC 2021
Radially adjustable ‘Tigertriever’ safe, effective in stroke
in a new study. The novel device may increase the options for endovascular therapy, researchers say.
In this study, the Tigertriever (Rapid Medical) was noninferior to a prespecified performance goal and superior to established devices, as determined from historical rates derived from trials. The device achieved first-pass successful reperfusion in approximately 6 of 10 patients and final successful reperfusion in more than 9 of 10 patients.
“The Tigertriever is a highly effective and safe device to remove thrombus in patients with large-vessel occlusion who are eligible for mechanical thrombectomy,” Rishi Gupta, MD, a vascular neurologist at Wellstar Health System Kennestone Hospital, Marietta, Ga., said during his presentation.
Results of the TIGER trial were presented at the International Stroke Conference, sponsored by the American Heart Association, and were published online March 19, 2021, in Stroke.
Endovascular therapy significantly improves outcomes of acute ischemic stroke resulting from large-vessel occlusion. However, current devices fail to achieve successful reperfusion in approximately 27% of patients, the researchers noted. In addition, the devices are associated with complications such as embolization to a new territory and symptomatic intracranial hemorrhage.
The Tigertriever is a radially adjustable, fully visible stent retriever. The operator controls the device’s radial expansion and force, enabling the operator to minimize vessel tension. The Tigertriever is available in Europe.
Effective revascularization
Dr. Gupta and colleagues conducted the prospective, single-arm TIGER study to evaluate the safety and efficacy of the Tigertriever in restoring blood flow by removing clots for patients with ischemic stroke resulting from large-vessel occlusion. The investigators compared the performance of the Tigertriever with a composite performance goal criterion derived from six pivotal trials of the Solitaire and Trevo devices.
The researchers enrolled patients at 16 U.S. sites and one site in Israel. Eligible participants had acute ischemic stroke resulting from large-vessel occlusion and moderate to severe neurologic deficits within 8 hours of symptom onset.
The study’s primary efficacy endpoint was successful revascularization within three Tigertriever passes. The investigators defined successful revascularization as achieving a modified Thrombolysis in Cerebral Ischemia score of 2b-3. Secondary efficacy endpoints were first-pass successful revascularization and good clinical outcome, which was defined as a Modified Rankin Scale score of 0-2.
The primary safety endpoint was the composite of symptomatic intracranial hemorrhage at 24 hours and all-cause mortality at 3 months.
The researchers enrolled 160 patients between May 2018 and March 2020. The mean age of the patients was 65 years, and 61.5% were men. The median National Institutes of Health Stroke Scale score was 17. Approximately 66% of patients received tissue plasminogen activator, and the median time to tPA administration was 95 minutes.
Most occlusions were in the M1 segment of the middle cerebral artery (57.3%) or the M2 segment of the MCA (19.7%). Approximately 21% of occlusions were in the internal carotid artery.
Successful revascularization was achieved in 84.6% of participants within three passes of the Tigertriever device. This rate surpassed the 63.4% performance goal and the 73.4% historical rate.
Successful revascularization was achieved in 57.8% of cases on first pass. After three passes, the rate was 84.6%. The rate of good clinical outcome at 90 days was 58% with the Tigertriever and 43% with the historical control.
The rate of symptomatic intracranial hemorrhage at 24 hours and mortality at 90 days was 18.1% with the Tigertriever and 20.4% with the historical control.
The rates of symptomatic hemorrhage and of embolization to a new territory with the Tigertriever were lower than with other devices, despite the relatively infrequent use of balloon guide catheters in the study, said Dr. Gupta.
Unmeasured confounding
“I congratulate the TIGER investigators for an interesting study that looked at a novel stentriever with adjustable radial size and force,” said Adam de Havenon, MD, assistant professor of neurology at the University of Utah, Salt Lake City, who was asked to comment on the study. “This intuitive concept shows promise in comparison to historical controls, and I look forward to hearing more about this exciting technology.”
The major advantage of the use of a composite historical control in the study is that fewer patients are needed for a trial, said Dr. de Havenon. This design makes the trial more economical and enables it to be completed more quickly.
“The impact is that a real-world patient could receive a beneficial treatment even sooner if it was shown to be beneficial with this study design,” he added. “The disadvantage is that there is unmeasured confounding because the historical controls come from trials during different time periods and at different centers and countries, with unique demographics that may not match well with your cohort.”
Statistical methodology helps mitigate this unmeasured confounding, but it remains a concern in the quest for a high level of evidence, Dr. de Havenon added.
The data suggest that the Tigertriever is a viable alternative to other stent retrievers, but they do not support its preferential use. “If the goal is to have the Tigertriever be considered a viable treatment option for large-vessel occlusion stroke, then [the researchers] have accomplished that with this study, which provides the needed data for FDA approval of the device,” said Dr. de Havenon.
“However, these data introduce the possibility of superiority but do not definitely show that,” he concluded. “To do so, they would need a randomized trial with a comparator device or devices and, as a result, a larger sample size.”
The study was funded by Rapid Medical. Dr. Gupta was one of the principal investigators for this study and for studies sponsored by Stryker Neurovascular, Zoll, and Vesalio. He served on the clinical events committee of a trial sponsored by Penumbra and has acted as a consultant for Cerenovous. Dr de Havenon disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
in a new study. The novel device may increase the options for endovascular therapy, researchers say.
In this study, the Tigertriever (Rapid Medical) was noninferior to a prespecified performance goal and superior to established devices, as determined from historical rates derived from trials. The device achieved first-pass successful reperfusion in approximately 6 of 10 patients and final successful reperfusion in more than 9 of 10 patients.
“The Tigertriever is a highly effective and safe device to remove thrombus in patients with large-vessel occlusion who are eligible for mechanical thrombectomy,” Rishi Gupta, MD, a vascular neurologist at Wellstar Health System Kennestone Hospital, Marietta, Ga., said during his presentation.
Results of the TIGER trial were presented at the International Stroke Conference, sponsored by the American Heart Association, and were published online March 19, 2021, in Stroke.
Endovascular therapy significantly improves outcomes of acute ischemic stroke resulting from large-vessel occlusion. However, current devices fail to achieve successful reperfusion in approximately 27% of patients, the researchers noted. In addition, the devices are associated with complications such as embolization to a new territory and symptomatic intracranial hemorrhage.
The Tigertriever is a radially adjustable, fully visible stent retriever. The operator controls the device’s radial expansion and force, enabling the operator to minimize vessel tension. The Tigertriever is available in Europe.
Effective revascularization
Dr. Gupta and colleagues conducted the prospective, single-arm TIGER study to evaluate the safety and efficacy of the Tigertriever in restoring blood flow by removing clots for patients with ischemic stroke resulting from large-vessel occlusion. The investigators compared the performance of the Tigertriever with a composite performance goal criterion derived from six pivotal trials of the Solitaire and Trevo devices.
The researchers enrolled patients at 16 U.S. sites and one site in Israel. Eligible participants had acute ischemic stroke resulting from large-vessel occlusion and moderate to severe neurologic deficits within 8 hours of symptom onset.
The study’s primary efficacy endpoint was successful revascularization within three Tigertriever passes. The investigators defined successful revascularization as achieving a modified Thrombolysis in Cerebral Ischemia score of 2b-3. Secondary efficacy endpoints were first-pass successful revascularization and good clinical outcome, which was defined as a Modified Rankin Scale score of 0-2.
The primary safety endpoint was the composite of symptomatic intracranial hemorrhage at 24 hours and all-cause mortality at 3 months.
The researchers enrolled 160 patients between May 2018 and March 2020. The mean age of the patients was 65 years, and 61.5% were men. The median National Institutes of Health Stroke Scale score was 17. Approximately 66% of patients received tissue plasminogen activator, and the median time to tPA administration was 95 minutes.
Most occlusions were in the M1 segment of the middle cerebral artery (57.3%) or the M2 segment of the MCA (19.7%). Approximately 21% of occlusions were in the internal carotid artery.
Successful revascularization was achieved in 84.6% of participants within three passes of the Tigertriever device. This rate surpassed the 63.4% performance goal and the 73.4% historical rate.
Successful revascularization was achieved in 57.8% of cases on first pass. After three passes, the rate was 84.6%. The rate of good clinical outcome at 90 days was 58% with the Tigertriever and 43% with the historical control.
The rate of symptomatic intracranial hemorrhage at 24 hours and mortality at 90 days was 18.1% with the Tigertriever and 20.4% with the historical control.
The rates of symptomatic hemorrhage and of embolization to a new territory with the Tigertriever were lower than with other devices, despite the relatively infrequent use of balloon guide catheters in the study, said Dr. Gupta.
Unmeasured confounding
“I congratulate the TIGER investigators for an interesting study that looked at a novel stentriever with adjustable radial size and force,” said Adam de Havenon, MD, assistant professor of neurology at the University of Utah, Salt Lake City, who was asked to comment on the study. “This intuitive concept shows promise in comparison to historical controls, and I look forward to hearing more about this exciting technology.”
The major advantage of the use of a composite historical control in the study is that fewer patients are needed for a trial, said Dr. de Havenon. This design makes the trial more economical and enables it to be completed more quickly.
“The impact is that a real-world patient could receive a beneficial treatment even sooner if it was shown to be beneficial with this study design,” he added. “The disadvantage is that there is unmeasured confounding because the historical controls come from trials during different time periods and at different centers and countries, with unique demographics that may not match well with your cohort.”
Statistical methodology helps mitigate this unmeasured confounding, but it remains a concern in the quest for a high level of evidence, Dr. de Havenon added.
The data suggest that the Tigertriever is a viable alternative to other stent retrievers, but they do not support its preferential use. “If the goal is to have the Tigertriever be considered a viable treatment option for large-vessel occlusion stroke, then [the researchers] have accomplished that with this study, which provides the needed data for FDA approval of the device,” said Dr. de Havenon.
“However, these data introduce the possibility of superiority but do not definitely show that,” he concluded. “To do so, they would need a randomized trial with a comparator device or devices and, as a result, a larger sample size.”
The study was funded by Rapid Medical. Dr. Gupta was one of the principal investigators for this study and for studies sponsored by Stryker Neurovascular, Zoll, and Vesalio. He served on the clinical events committee of a trial sponsored by Penumbra and has acted as a consultant for Cerenovous. Dr de Havenon disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
in a new study. The novel device may increase the options for endovascular therapy, researchers say.
In this study, the Tigertriever (Rapid Medical) was noninferior to a prespecified performance goal and superior to established devices, as determined from historical rates derived from trials. The device achieved first-pass successful reperfusion in approximately 6 of 10 patients and final successful reperfusion in more than 9 of 10 patients.
“The Tigertriever is a highly effective and safe device to remove thrombus in patients with large-vessel occlusion who are eligible for mechanical thrombectomy,” Rishi Gupta, MD, a vascular neurologist at Wellstar Health System Kennestone Hospital, Marietta, Ga., said during his presentation.
Results of the TIGER trial were presented at the International Stroke Conference, sponsored by the American Heart Association, and were published online March 19, 2021, in Stroke.
Endovascular therapy significantly improves outcomes of acute ischemic stroke resulting from large-vessel occlusion. However, current devices fail to achieve successful reperfusion in approximately 27% of patients, the researchers noted. In addition, the devices are associated with complications such as embolization to a new territory and symptomatic intracranial hemorrhage.
The Tigertriever is a radially adjustable, fully visible stent retriever. The operator controls the device’s radial expansion and force, enabling the operator to minimize vessel tension. The Tigertriever is available in Europe.
Effective revascularization
Dr. Gupta and colleagues conducted the prospective, single-arm TIGER study to evaluate the safety and efficacy of the Tigertriever in restoring blood flow by removing clots for patients with ischemic stroke resulting from large-vessel occlusion. The investigators compared the performance of the Tigertriever with a composite performance goal criterion derived from six pivotal trials of the Solitaire and Trevo devices.
The researchers enrolled patients at 16 U.S. sites and one site in Israel. Eligible participants had acute ischemic stroke resulting from large-vessel occlusion and moderate to severe neurologic deficits within 8 hours of symptom onset.
The study’s primary efficacy endpoint was successful revascularization within three Tigertriever passes. The investigators defined successful revascularization as achieving a modified Thrombolysis in Cerebral Ischemia score of 2b-3. Secondary efficacy endpoints were first-pass successful revascularization and good clinical outcome, which was defined as a Modified Rankin Scale score of 0-2.
The primary safety endpoint was the composite of symptomatic intracranial hemorrhage at 24 hours and all-cause mortality at 3 months.
The researchers enrolled 160 patients between May 2018 and March 2020. The mean age of the patients was 65 years, and 61.5% were men. The median National Institutes of Health Stroke Scale score was 17. Approximately 66% of patients received tissue plasminogen activator, and the median time to tPA administration was 95 minutes.
Most occlusions were in the M1 segment of the middle cerebral artery (57.3%) or the M2 segment of the MCA (19.7%). Approximately 21% of occlusions were in the internal carotid artery.
Successful revascularization was achieved in 84.6% of participants within three passes of the Tigertriever device. This rate surpassed the 63.4% performance goal and the 73.4% historical rate.
Successful revascularization was achieved in 57.8% of cases on first pass. After three passes, the rate was 84.6%. The rate of good clinical outcome at 90 days was 58% with the Tigertriever and 43% with the historical control.
The rate of symptomatic intracranial hemorrhage at 24 hours and mortality at 90 days was 18.1% with the Tigertriever and 20.4% with the historical control.
The rates of symptomatic hemorrhage and of embolization to a new territory with the Tigertriever were lower than with other devices, despite the relatively infrequent use of balloon guide catheters in the study, said Dr. Gupta.
Unmeasured confounding
“I congratulate the TIGER investigators for an interesting study that looked at a novel stentriever with adjustable radial size and force,” said Adam de Havenon, MD, assistant professor of neurology at the University of Utah, Salt Lake City, who was asked to comment on the study. “This intuitive concept shows promise in comparison to historical controls, and I look forward to hearing more about this exciting technology.”
The major advantage of the use of a composite historical control in the study is that fewer patients are needed for a trial, said Dr. de Havenon. This design makes the trial more economical and enables it to be completed more quickly.
“The impact is that a real-world patient could receive a beneficial treatment even sooner if it was shown to be beneficial with this study design,” he added. “The disadvantage is that there is unmeasured confounding because the historical controls come from trials during different time periods and at different centers and countries, with unique demographics that may not match well with your cohort.”
Statistical methodology helps mitigate this unmeasured confounding, but it remains a concern in the quest for a high level of evidence, Dr. de Havenon added.
The data suggest that the Tigertriever is a viable alternative to other stent retrievers, but they do not support its preferential use. “If the goal is to have the Tigertriever be considered a viable treatment option for large-vessel occlusion stroke, then [the researchers] have accomplished that with this study, which provides the needed data for FDA approval of the device,” said Dr. de Havenon.
“However, these data introduce the possibility of superiority but do not definitely show that,” he concluded. “To do so, they would need a randomized trial with a comparator device or devices and, as a result, a larger sample size.”
The study was funded by Rapid Medical. Dr. Gupta was one of the principal investigators for this study and for studies sponsored by Stryker Neurovascular, Zoll, and Vesalio. He served on the clinical events committee of a trial sponsored by Penumbra and has acted as a consultant for Cerenovous. Dr de Havenon disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
Direct transfer to angiography improves outcome in large-vessel stroke
in a new study.
Results of the ANGIO-CAT trial were presented at the International Stroke Conference sponsored by the American Heart Association.
The study involved patients suspected of having a large-vessel occlusion, as assessed in the prehospital setting by paramedics using the Rapid Arterial Occlusion Evaluation (RACE) score.
In his presentation, Manuel Requena, PhD, a neurologist and neurointerventionalist fellow at Vall d’Hebron Hospital, Barcelona, explained that, if patients were within 6 hours of symptom onset with a RACE scale score greater than 4, paramedics called ahead to a stroke neurologist, who met the patient directly at the hospital.
If on clinical examination the National Institutes of Health Stroke Scale (NIHSS) score was greater than 10, patients could be enrolled into the study. Upon enrollment, they were randomly assigned either to be taken directly to the angiography suite or to receive standard care.
Bypassing the emergency department
Dr. Requena noted that, at his center, patients who receive standard care are transferred to the CT imaging suite, where they are evaluated with noncontrast CT and CT angiography. CT perfusion is also performed if the treating physician deems it necessary.
If a large-vessel occlusion is confirmed, patients are then transferred to the angiography suite for endovascular treatment. He added that in many centers, patients are evaluated in the ED before undergoing CT scanning.
Patients in the direct angiography group received a “flat-panel” noncontrast CT in the angiography suite to rule out intracranial hemorrhage or a large, established infarct. The large-vessel occlusion would be confirmed by arteriography before the endovascular procedure was performed.
After CT scanning, patients received thrombolysis as recommended in the guidelines.
The current interim analysis includes the 174 patients who have been enrolled so far in the study. The median RACE score for these patients was 7, and the median NIHSS score was 17. Large-vessel occlusion was confirmed in 84% of patients, and 8% had an intracerebral hemorrhage.
Results showed that of the 147 patients who received endovascular therapy, puncture time was shorter for those who were taken directly to angiography (median, 18 min vs. 42 min), as was time to reperfusion (median, 57 min vs. 84 min).
The primary outcome was a shift analysis of the Modified Rankin Scale functional outcome scale at 90 days (odds of 1-point improvement or more). In the direct angiography group, the adjusted odds ratio for an improved functional outcome was 2.2 (95% confidence interval, 1.2-.1).
There were no significant differences in safety endpoints. There was a trend toward more procedural complications in those receiving endovascular therapy in the direct angiography group (8.1% vs. 2.7%; P = .6), but there was also a trend toward lower 90-day mortality in this group (20.2% vs. 32.9%; P = .07)
Dr. Requena reported no significant difference in safety outcomes among those with a hemorrhagic stroke.
“Our study is the first clinical trial that shows the superiority of direct transfer to an angiography suite,” said Dr. Requena. “Our findings were close to what we expected, and we were surprised that they occurred so early in the study. We trust that they will be confirmed in ongoing, multicenter, international trials.”
Stroke patients who were transferred directly to an angiography suite were also less likely to be dependent on assistance with daily activities than were those who received the current standard of care, Dr. Requena said. “More frequent and more rapid treatment can help improve outcomes for our stroke patients.”
A limitation of this study is that the hospital had extensive experience with immediate angiography, so findings may differ at hospitals or care centers with less angiography expertise or experience, Dr. Requena said.
He added that retrospective studies conducted in hospitals in the United States, Germany, and Switzerland show that this kind of protocol can be developed in any high-volume stroke center, although multicenter, international trials are needed.
The cost of speed
Commenting on the ANGIO-CAT study, Michael Hill, MD, a professor at the University of Calgary (Alta.), said the 27-minute improvement in door-to-reperfusion time achieved in the study was meaningful and correlates with the degree of improved outcomes observed. “So, the improvement in speed of treatment resulting in better outcomes makes sense,” he added.
He cautioned that this strategy would only be feasible in certain centers with selected patients and that cost will be a fundamental issue.
“If you identify patients at angiography, you risk having some patients with no target large-vessel occlusion,” Dr. Hill added. “The real question is, how many of these patients without a large-vessel occlusion can the system tolerate before it becomes uneconomical and not fruitful or harmful, given that groin puncture is not totally harmless?”
The moderator of the ISC news conference on the study, Mitchell Elkind, MD, professor of neurology at Columbia University, New York, who is also president of the American Stroke Association, said the study reflects the growing recognition of the importance of speed when treating stroke. “If we can shorten time to treatment using rapid evaluation and imaging protocols, this will help save brain,” he said.
Also commenting on the study, Louisa McCullough, MD, PhD, chief of neurology at Memorial Hermann Hospital–Texas Medical Center, Houston, who is the ISC meeting chair, said she thought the study would be relevant to the United States. “Speed is really of the essence. Whenever we can reduce delays, that will make a big difference to patients.”
Referring to this study on improving hospital systems, as well as a second study that was presented at the meeting that showed benefits from delivery of prehospital thrombolysis via a mobile stroke unit, Dr. McCullough added that “we need to set up models so we can get the best of both these worlds. These studies are really leading the way on how we can change the stroke systems of care.”
The study was funded by Vall d’Hebron Research Institute. Dr. Requena disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
in a new study.
Results of the ANGIO-CAT trial were presented at the International Stroke Conference sponsored by the American Heart Association.
The study involved patients suspected of having a large-vessel occlusion, as assessed in the prehospital setting by paramedics using the Rapid Arterial Occlusion Evaluation (RACE) score.
In his presentation, Manuel Requena, PhD, a neurologist and neurointerventionalist fellow at Vall d’Hebron Hospital, Barcelona, explained that, if patients were within 6 hours of symptom onset with a RACE scale score greater than 4, paramedics called ahead to a stroke neurologist, who met the patient directly at the hospital.
If on clinical examination the National Institutes of Health Stroke Scale (NIHSS) score was greater than 10, patients could be enrolled into the study. Upon enrollment, they were randomly assigned either to be taken directly to the angiography suite or to receive standard care.
Bypassing the emergency department
Dr. Requena noted that, at his center, patients who receive standard care are transferred to the CT imaging suite, where they are evaluated with noncontrast CT and CT angiography. CT perfusion is also performed if the treating physician deems it necessary.
If a large-vessel occlusion is confirmed, patients are then transferred to the angiography suite for endovascular treatment. He added that in many centers, patients are evaluated in the ED before undergoing CT scanning.
Patients in the direct angiography group received a “flat-panel” noncontrast CT in the angiography suite to rule out intracranial hemorrhage or a large, established infarct. The large-vessel occlusion would be confirmed by arteriography before the endovascular procedure was performed.
After CT scanning, patients received thrombolysis as recommended in the guidelines.
The current interim analysis includes the 174 patients who have been enrolled so far in the study. The median RACE score for these patients was 7, and the median NIHSS score was 17. Large-vessel occlusion was confirmed in 84% of patients, and 8% had an intracerebral hemorrhage.
Results showed that of the 147 patients who received endovascular therapy, puncture time was shorter for those who were taken directly to angiography (median, 18 min vs. 42 min), as was time to reperfusion (median, 57 min vs. 84 min).
The primary outcome was a shift analysis of the Modified Rankin Scale functional outcome scale at 90 days (odds of 1-point improvement or more). In the direct angiography group, the adjusted odds ratio for an improved functional outcome was 2.2 (95% confidence interval, 1.2-.1).
There were no significant differences in safety endpoints. There was a trend toward more procedural complications in those receiving endovascular therapy in the direct angiography group (8.1% vs. 2.7%; P = .6), but there was also a trend toward lower 90-day mortality in this group (20.2% vs. 32.9%; P = .07)
Dr. Requena reported no significant difference in safety outcomes among those with a hemorrhagic stroke.
“Our study is the first clinical trial that shows the superiority of direct transfer to an angiography suite,” said Dr. Requena. “Our findings were close to what we expected, and we were surprised that they occurred so early in the study. We trust that they will be confirmed in ongoing, multicenter, international trials.”
Stroke patients who were transferred directly to an angiography suite were also less likely to be dependent on assistance with daily activities than were those who received the current standard of care, Dr. Requena said. “More frequent and more rapid treatment can help improve outcomes for our stroke patients.”
A limitation of this study is that the hospital had extensive experience with immediate angiography, so findings may differ at hospitals or care centers with less angiography expertise or experience, Dr. Requena said.
He added that retrospective studies conducted in hospitals in the United States, Germany, and Switzerland show that this kind of protocol can be developed in any high-volume stroke center, although multicenter, international trials are needed.
The cost of speed
Commenting on the ANGIO-CAT study, Michael Hill, MD, a professor at the University of Calgary (Alta.), said the 27-minute improvement in door-to-reperfusion time achieved in the study was meaningful and correlates with the degree of improved outcomes observed. “So, the improvement in speed of treatment resulting in better outcomes makes sense,” he added.
He cautioned that this strategy would only be feasible in certain centers with selected patients and that cost will be a fundamental issue.
“If you identify patients at angiography, you risk having some patients with no target large-vessel occlusion,” Dr. Hill added. “The real question is, how many of these patients without a large-vessel occlusion can the system tolerate before it becomes uneconomical and not fruitful or harmful, given that groin puncture is not totally harmless?”
The moderator of the ISC news conference on the study, Mitchell Elkind, MD, professor of neurology at Columbia University, New York, who is also president of the American Stroke Association, said the study reflects the growing recognition of the importance of speed when treating stroke. “If we can shorten time to treatment using rapid evaluation and imaging protocols, this will help save brain,” he said.
Also commenting on the study, Louisa McCullough, MD, PhD, chief of neurology at Memorial Hermann Hospital–Texas Medical Center, Houston, who is the ISC meeting chair, said she thought the study would be relevant to the United States. “Speed is really of the essence. Whenever we can reduce delays, that will make a big difference to patients.”
Referring to this study on improving hospital systems, as well as a second study that was presented at the meeting that showed benefits from delivery of prehospital thrombolysis via a mobile stroke unit, Dr. McCullough added that “we need to set up models so we can get the best of both these worlds. These studies are really leading the way on how we can change the stroke systems of care.”
The study was funded by Vall d’Hebron Research Institute. Dr. Requena disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
in a new study.
Results of the ANGIO-CAT trial were presented at the International Stroke Conference sponsored by the American Heart Association.
The study involved patients suspected of having a large-vessel occlusion, as assessed in the prehospital setting by paramedics using the Rapid Arterial Occlusion Evaluation (RACE) score.
In his presentation, Manuel Requena, PhD, a neurologist and neurointerventionalist fellow at Vall d’Hebron Hospital, Barcelona, explained that, if patients were within 6 hours of symptom onset with a RACE scale score greater than 4, paramedics called ahead to a stroke neurologist, who met the patient directly at the hospital.
If on clinical examination the National Institutes of Health Stroke Scale (NIHSS) score was greater than 10, patients could be enrolled into the study. Upon enrollment, they were randomly assigned either to be taken directly to the angiography suite or to receive standard care.
Bypassing the emergency department
Dr. Requena noted that, at his center, patients who receive standard care are transferred to the CT imaging suite, where they are evaluated with noncontrast CT and CT angiography. CT perfusion is also performed if the treating physician deems it necessary.
If a large-vessel occlusion is confirmed, patients are then transferred to the angiography suite for endovascular treatment. He added that in many centers, patients are evaluated in the ED before undergoing CT scanning.
Patients in the direct angiography group received a “flat-panel” noncontrast CT in the angiography suite to rule out intracranial hemorrhage or a large, established infarct. The large-vessel occlusion would be confirmed by arteriography before the endovascular procedure was performed.
After CT scanning, patients received thrombolysis as recommended in the guidelines.
The current interim analysis includes the 174 patients who have been enrolled so far in the study. The median RACE score for these patients was 7, and the median NIHSS score was 17. Large-vessel occlusion was confirmed in 84% of patients, and 8% had an intracerebral hemorrhage.
Results showed that of the 147 patients who received endovascular therapy, puncture time was shorter for those who were taken directly to angiography (median, 18 min vs. 42 min), as was time to reperfusion (median, 57 min vs. 84 min).
The primary outcome was a shift analysis of the Modified Rankin Scale functional outcome scale at 90 days (odds of 1-point improvement or more). In the direct angiography group, the adjusted odds ratio for an improved functional outcome was 2.2 (95% confidence interval, 1.2-.1).
There were no significant differences in safety endpoints. There was a trend toward more procedural complications in those receiving endovascular therapy in the direct angiography group (8.1% vs. 2.7%; P = .6), but there was also a trend toward lower 90-day mortality in this group (20.2% vs. 32.9%; P = .07)
Dr. Requena reported no significant difference in safety outcomes among those with a hemorrhagic stroke.
“Our study is the first clinical trial that shows the superiority of direct transfer to an angiography suite,” said Dr. Requena. “Our findings were close to what we expected, and we were surprised that they occurred so early in the study. We trust that they will be confirmed in ongoing, multicenter, international trials.”
Stroke patients who were transferred directly to an angiography suite were also less likely to be dependent on assistance with daily activities than were those who received the current standard of care, Dr. Requena said. “More frequent and more rapid treatment can help improve outcomes for our stroke patients.”
A limitation of this study is that the hospital had extensive experience with immediate angiography, so findings may differ at hospitals or care centers with less angiography expertise or experience, Dr. Requena said.
He added that retrospective studies conducted in hospitals in the United States, Germany, and Switzerland show that this kind of protocol can be developed in any high-volume stroke center, although multicenter, international trials are needed.
The cost of speed
Commenting on the ANGIO-CAT study, Michael Hill, MD, a professor at the University of Calgary (Alta.), said the 27-minute improvement in door-to-reperfusion time achieved in the study was meaningful and correlates with the degree of improved outcomes observed. “So, the improvement in speed of treatment resulting in better outcomes makes sense,” he added.
He cautioned that this strategy would only be feasible in certain centers with selected patients and that cost will be a fundamental issue.
“If you identify patients at angiography, you risk having some patients with no target large-vessel occlusion,” Dr. Hill added. “The real question is, how many of these patients without a large-vessel occlusion can the system tolerate before it becomes uneconomical and not fruitful or harmful, given that groin puncture is not totally harmless?”
The moderator of the ISC news conference on the study, Mitchell Elkind, MD, professor of neurology at Columbia University, New York, who is also president of the American Stroke Association, said the study reflects the growing recognition of the importance of speed when treating stroke. “If we can shorten time to treatment using rapid evaluation and imaging protocols, this will help save brain,” he said.
Also commenting on the study, Louisa McCullough, MD, PhD, chief of neurology at Memorial Hermann Hospital–Texas Medical Center, Houston, who is the ISC meeting chair, said she thought the study would be relevant to the United States. “Speed is really of the essence. Whenever we can reduce delays, that will make a big difference to patients.”
Referring to this study on improving hospital systems, as well as a second study that was presented at the meeting that showed benefits from delivery of prehospital thrombolysis via a mobile stroke unit, Dr. McCullough added that “we need to set up models so we can get the best of both these worlds. These studies are really leading the way on how we can change the stroke systems of care.”
The study was funded by Vall d’Hebron Research Institute. Dr. Requena disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
FROM ISC 2021