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New stroke risk score developed for COVID patients
Researchers have developed a quick and easy scoring system to predict which hospitalized COVID-19 patients are more at risk for stroke.
“The system is simple. You can calculate the points in 5 seconds and then predict the chances the patient will have a stroke,” Alexander E. Merkler, MD, assistant professor of neurology at Weill Cornell Medical College/NewYork-Presbyterian Hospital, and lead author of a study of the system, told this news organization.
The new system will allow clinicians to stratify patients and lead to closer monitoring of those at highest risk for stroke, said Dr. Merkler.
The study was presented during the International Stroke Conference, presented by the American Stroke Association, a division of the American Heart Association.
Some, but not all, studies suggest COVID-19 increases the risk of stroke and worsens stroke outcomes, and the association isn’t clear, investigators note.
Researchers used the American Heart Association Get With the Guidelines COVID-19 cardiovascular disease registry for this analysis. They evaluated 21,420 adult patients (mean age 61 years, 54% men), who were hospitalized with COVID-19 at 122 centers from March 2020 to March 2021.
Investigators tapped into the vast amounts of data in this registry on different variables, including demographics, comorbidities, and lab values.
The outcome was a cerebrovascular event, defined as any ischemic or hemorrhagic stroke, transient ischemic attack (TIA), or cerebral vein thrombosis. Of the total hospitalized COVID-19 population, 312 (1.5%) had a cerebrovascular event.
Researchers first used standard statistical models to determine which risk factors are most associated with the development of stroke. They identified six such factors:
- history of stroke
- no fever at the time of hospital admission
- no history of pulmonary disease
- high white blood cell count
- history of hypertension
- high systolic blood pressure at the time of hospital admission
That the list of risk factors included absence of fever and no history of pulmonary disease was somewhat surprising, said Dr. Merkler, but there may be possible explanations, he added.
A high fever is an inflammatory response, and perhaps patients who aren’t responding appropriately “could be sicker in general and have a poor immune system, and thereby be at increased risk for stroke,” said Dr. Merkler.
In the case of pulmonary disease, patients without a history who are admitted for COVID “may have an extremely high burden of COVID, or are extremely sick, and that’s why they’re at higher risk for stroke.”
The scoring system assigns points for each variable, with more points conferring a higher risk of stroke. For example, someone who has 0-1 points has 0.2% risk of having a stroke, and someone with 4-6 points has 2% to 3% risk, said Dr. Merkler.
“So, we’re talking about a 10- to 15-fold increased risk of having a stroke with 4 to 6 versus 0 to 1 variables.”
The accuracy of the risk stratification score (C-statistic of 0.66; 95% confidence interval, 0.60-0.72) is “fairly good or modestly good,” said Dr. Merkler.
A patient with a score of 5 or 6 may need more vigilant monitoring to make sure symptoms are caught early and therapies such as thrombolytics and thrombectomy are readily available, he added.
Researchers also used a sophisticated machine-learning approach where a computer takes all the variables and identifies the best algorithm to predict stroke.
“The machine-learning algorithm was basically just as good as our standard model; it was almost identical,” said Dr. Merkler.
Outside of COVID, other scoring systems are used to predict stroke. For example, the ABCD2 score uses various factors to predict risk of recurrent stroke.
Philip B. Gorelick, MD, adjunct professor, Northwestern University Feinberg School of Medicine, Chicago, said the results are promising, as they may lead to identifying modifiable factors to prevent stroke.
Dr. Gorelick noted that the authors identified risk factors to predict risk of stroke “after an extensive analysis of baseline factors that included an internal validation process.”
The finding that no fever and no history of pulmonary disease were included in those risk factors was “unexpected,” said Dr. Gorelick, who is also medical director of the Hauenstein Neuroscience Center in Grand Rapids, Michigan. “This may reflect the baseline timing of data collection.”
He added further validation of the results in other data sets “will be useful to determine the consistency of the predictive model and its potential value in general practice.”
Louise D. McCullough, MD, PhD, professor and chair of neurology, McGovern Medical School, The University of Texas Health Science Center, Houston, said the association between stroke risk and COVID exposure “has been very unclear.”
“Some people find a very strong association between stroke and COVID, some do not,” said Dr. McCullough, who served as the chair of the ISC 2022 meeting.
This new study looking at a risk stratification model for COVID patients was “very nicely done,” she added.
“They used the American Heart Association Get With The Guidelines COVID registry, which was an amazing feat that was done very quickly by the AHA to establish COVID reporting in the Get With The Guidelines data, allowing us to really look at other factors related to stroke that are in this unique database.”
The study received funding support from the American Stroke Association. Dr. Merkler has received funding from the American Heart Association and the Leon Levy Foundation. Dr. Gorelick was not involved in the study and has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
Researchers have developed a quick and easy scoring system to predict which hospitalized COVID-19 patients are more at risk for stroke.
“The system is simple. You can calculate the points in 5 seconds and then predict the chances the patient will have a stroke,” Alexander E. Merkler, MD, assistant professor of neurology at Weill Cornell Medical College/NewYork-Presbyterian Hospital, and lead author of a study of the system, told this news organization.
The new system will allow clinicians to stratify patients and lead to closer monitoring of those at highest risk for stroke, said Dr. Merkler.
The study was presented during the International Stroke Conference, presented by the American Stroke Association, a division of the American Heart Association.
Some, but not all, studies suggest COVID-19 increases the risk of stroke and worsens stroke outcomes, and the association isn’t clear, investigators note.
Researchers used the American Heart Association Get With the Guidelines COVID-19 cardiovascular disease registry for this analysis. They evaluated 21,420 adult patients (mean age 61 years, 54% men), who were hospitalized with COVID-19 at 122 centers from March 2020 to March 2021.
Investigators tapped into the vast amounts of data in this registry on different variables, including demographics, comorbidities, and lab values.
The outcome was a cerebrovascular event, defined as any ischemic or hemorrhagic stroke, transient ischemic attack (TIA), or cerebral vein thrombosis. Of the total hospitalized COVID-19 population, 312 (1.5%) had a cerebrovascular event.
Researchers first used standard statistical models to determine which risk factors are most associated with the development of stroke. They identified six such factors:
- history of stroke
- no fever at the time of hospital admission
- no history of pulmonary disease
- high white blood cell count
- history of hypertension
- high systolic blood pressure at the time of hospital admission
That the list of risk factors included absence of fever and no history of pulmonary disease was somewhat surprising, said Dr. Merkler, but there may be possible explanations, he added.
A high fever is an inflammatory response, and perhaps patients who aren’t responding appropriately “could be sicker in general and have a poor immune system, and thereby be at increased risk for stroke,” said Dr. Merkler.
In the case of pulmonary disease, patients without a history who are admitted for COVID “may have an extremely high burden of COVID, or are extremely sick, and that’s why they’re at higher risk for stroke.”
The scoring system assigns points for each variable, with more points conferring a higher risk of stroke. For example, someone who has 0-1 points has 0.2% risk of having a stroke, and someone with 4-6 points has 2% to 3% risk, said Dr. Merkler.
“So, we’re talking about a 10- to 15-fold increased risk of having a stroke with 4 to 6 versus 0 to 1 variables.”
The accuracy of the risk stratification score (C-statistic of 0.66; 95% confidence interval, 0.60-0.72) is “fairly good or modestly good,” said Dr. Merkler.
A patient with a score of 5 or 6 may need more vigilant monitoring to make sure symptoms are caught early and therapies such as thrombolytics and thrombectomy are readily available, he added.
Researchers also used a sophisticated machine-learning approach where a computer takes all the variables and identifies the best algorithm to predict stroke.
“The machine-learning algorithm was basically just as good as our standard model; it was almost identical,” said Dr. Merkler.
Outside of COVID, other scoring systems are used to predict stroke. For example, the ABCD2 score uses various factors to predict risk of recurrent stroke.
Philip B. Gorelick, MD, adjunct professor, Northwestern University Feinberg School of Medicine, Chicago, said the results are promising, as they may lead to identifying modifiable factors to prevent stroke.
Dr. Gorelick noted that the authors identified risk factors to predict risk of stroke “after an extensive analysis of baseline factors that included an internal validation process.”
The finding that no fever and no history of pulmonary disease were included in those risk factors was “unexpected,” said Dr. Gorelick, who is also medical director of the Hauenstein Neuroscience Center in Grand Rapids, Michigan. “This may reflect the baseline timing of data collection.”
He added further validation of the results in other data sets “will be useful to determine the consistency of the predictive model and its potential value in general practice.”
Louise D. McCullough, MD, PhD, professor and chair of neurology, McGovern Medical School, The University of Texas Health Science Center, Houston, said the association between stroke risk and COVID exposure “has been very unclear.”
“Some people find a very strong association between stroke and COVID, some do not,” said Dr. McCullough, who served as the chair of the ISC 2022 meeting.
This new study looking at a risk stratification model for COVID patients was “very nicely done,” she added.
“They used the American Heart Association Get With The Guidelines COVID registry, which was an amazing feat that was done very quickly by the AHA to establish COVID reporting in the Get With The Guidelines data, allowing us to really look at other factors related to stroke that are in this unique database.”
The study received funding support from the American Stroke Association. Dr. Merkler has received funding from the American Heart Association and the Leon Levy Foundation. Dr. Gorelick was not involved in the study and has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
Researchers have developed a quick and easy scoring system to predict which hospitalized COVID-19 patients are more at risk for stroke.
“The system is simple. You can calculate the points in 5 seconds and then predict the chances the patient will have a stroke,” Alexander E. Merkler, MD, assistant professor of neurology at Weill Cornell Medical College/NewYork-Presbyterian Hospital, and lead author of a study of the system, told this news organization.
The new system will allow clinicians to stratify patients and lead to closer monitoring of those at highest risk for stroke, said Dr. Merkler.
The study was presented during the International Stroke Conference, presented by the American Stroke Association, a division of the American Heart Association.
Some, but not all, studies suggest COVID-19 increases the risk of stroke and worsens stroke outcomes, and the association isn’t clear, investigators note.
Researchers used the American Heart Association Get With the Guidelines COVID-19 cardiovascular disease registry for this analysis. They evaluated 21,420 adult patients (mean age 61 years, 54% men), who were hospitalized with COVID-19 at 122 centers from March 2020 to March 2021.
Investigators tapped into the vast amounts of data in this registry on different variables, including demographics, comorbidities, and lab values.
The outcome was a cerebrovascular event, defined as any ischemic or hemorrhagic stroke, transient ischemic attack (TIA), or cerebral vein thrombosis. Of the total hospitalized COVID-19 population, 312 (1.5%) had a cerebrovascular event.
Researchers first used standard statistical models to determine which risk factors are most associated with the development of stroke. They identified six such factors:
- history of stroke
- no fever at the time of hospital admission
- no history of pulmonary disease
- high white blood cell count
- history of hypertension
- high systolic blood pressure at the time of hospital admission
That the list of risk factors included absence of fever and no history of pulmonary disease was somewhat surprising, said Dr. Merkler, but there may be possible explanations, he added.
A high fever is an inflammatory response, and perhaps patients who aren’t responding appropriately “could be sicker in general and have a poor immune system, and thereby be at increased risk for stroke,” said Dr. Merkler.
In the case of pulmonary disease, patients without a history who are admitted for COVID “may have an extremely high burden of COVID, or are extremely sick, and that’s why they’re at higher risk for stroke.”
The scoring system assigns points for each variable, with more points conferring a higher risk of stroke. For example, someone who has 0-1 points has 0.2% risk of having a stroke, and someone with 4-6 points has 2% to 3% risk, said Dr. Merkler.
“So, we’re talking about a 10- to 15-fold increased risk of having a stroke with 4 to 6 versus 0 to 1 variables.”
The accuracy of the risk stratification score (C-statistic of 0.66; 95% confidence interval, 0.60-0.72) is “fairly good or modestly good,” said Dr. Merkler.
A patient with a score of 5 or 6 may need more vigilant monitoring to make sure symptoms are caught early and therapies such as thrombolytics and thrombectomy are readily available, he added.
Researchers also used a sophisticated machine-learning approach where a computer takes all the variables and identifies the best algorithm to predict stroke.
“The machine-learning algorithm was basically just as good as our standard model; it was almost identical,” said Dr. Merkler.
Outside of COVID, other scoring systems are used to predict stroke. For example, the ABCD2 score uses various factors to predict risk of recurrent stroke.
Philip B. Gorelick, MD, adjunct professor, Northwestern University Feinberg School of Medicine, Chicago, said the results are promising, as they may lead to identifying modifiable factors to prevent stroke.
Dr. Gorelick noted that the authors identified risk factors to predict risk of stroke “after an extensive analysis of baseline factors that included an internal validation process.”
The finding that no fever and no history of pulmonary disease were included in those risk factors was “unexpected,” said Dr. Gorelick, who is also medical director of the Hauenstein Neuroscience Center in Grand Rapids, Michigan. “This may reflect the baseline timing of data collection.”
He added further validation of the results in other data sets “will be useful to determine the consistency of the predictive model and its potential value in general practice.”
Louise D. McCullough, MD, PhD, professor and chair of neurology, McGovern Medical School, The University of Texas Health Science Center, Houston, said the association between stroke risk and COVID exposure “has been very unclear.”
“Some people find a very strong association between stroke and COVID, some do not,” said Dr. McCullough, who served as the chair of the ISC 2022 meeting.
This new study looking at a risk stratification model for COVID patients was “very nicely done,” she added.
“They used the American Heart Association Get With The Guidelines COVID registry, which was an amazing feat that was done very quickly by the AHA to establish COVID reporting in the Get With The Guidelines data, allowing us to really look at other factors related to stroke that are in this unique database.”
The study received funding support from the American Stroke Association. Dr. Merkler has received funding from the American Heart Association and the Leon Levy Foundation. Dr. Gorelick was not involved in the study and has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
FROM ISC 2022
Does endovascular therapy benefit strokes with larger ischemic cores?
The RESCUE-JAPAN LIMIT trial was presented at the International Stroke Conference by Shinichi Yoshimura, MD, Hyogo College of Medicine, Nishinomiya, Japan. The study was also published online in the New England Journal of Medicine to coincide with its presentation at the ISC meeting.
The trial showed that among patients with acute stroke and a large ischemic brain region, functional outcomes at 90 days were better with endovascular therapy and medical care than with medical care alone.
Patients who received endovascular therapy were more than twice as likely to have a good functional outcome, defined as a modified Rankin scale (mRS) score of 0-3 at 90 days, than those who received medical care alone.
While the rate of intracranial hemorrhage increased with endovascular therapy, authors of the study and outside commentators suggested that the benefit appeared to outweigh the risk. “Our results provide strong evidence that endovascular therapy improves patient outcomes when the infarct area is large,” Dr. Yoshimura concluded at the meeting, presented by the American Stroke Association, a division of the American Heart Association.
Commenting on the study at an ISC press conference, Tudor Jovin, MD, chair of neurology at Cooper University Hospital, Cherry Hill, New Jersey, said: “The question of strokes with a large core stroke being an exclusion criteria for endovascular therapy is arguably one of the hottest topics the field is facing at this time. There are several randomized trials ongoing aiming to answer this question.”
“The RESCUE-JAPAN trial is the first of these trials to report and shed some light on this issue,” Dr. Jovin added. “The results appear to show that these patients with large core infarcts have just as much benefit from endovascular therapy as patients with smaller infarcts.”
Dr. Jovin described these findings as encouraging but also surprising. “When these large core randomized trials were planned, there was a belief that there would be benefit at some level. But what is surprising to me is that in this trial the benefit was similar to that seen in trials in patients with moderate or small core infarcts. This begs the question of whether we should care about the size of the infarct when we are considering taking these patients for thrombectomy,” he said.
Confirmation needed
On whether this will change practice, Dr. Jovin cautioned that this was just one study with a relatively small number of patients. “I think it is important that all the other randomized trials ongoing should continue so that we have a definitive answer to this question,” he said.
In his presentation, Dr. Yoshimura explained that current guidelines recommended endovascular therapy for patients with large cerebral vessel occlusion and a small or moderate infarct size – an ASPECTS score (Alberta Stroke Program Early Computed Tomographic Score) of 6 or higher. The ASPECTS score has a scale of 1-10, with lower values indicating larger infarction.
The RESCUE-JAPAN LIMIT study included 203 patients with occlusion of large cerebral vessels and sizable strokes on imaging, as indicated by an ASPECTS score of 3 to 5.
Patients were randomly assigned to receive endovascular therapy with medical care (endovascular-therapy group) or medical therapy alone (medical-care group) within 6 hours after they were last known to be well or within 24 hours if there was no early change on fluid-attenuated inversion recovery images indicating that the infarction was recent.
The percentage of patients with a good outcome as defined by an mRS score of 0 to 3 at 90 days, the primary outcome, was 31.0% in the endovascular-therapy group and 12.7% in the medical-care group (relative risk, 2.43; 95% confidence interval, 1.35 to 4.37; P = .002).
Secondary outcomes were mRS scores of 0 to 2 and 0 to 1, an ordinal shift across the range of mRS scores toward a better outcome at 90 days, and an improvement of at least 8 points in the National Institutes of Health Stroke Scale (NIHSS) score (range, 0 to 42, with higher scores indicating greater deficit) at 48 hours.
An mRS score of 0 to 2 was seen in 14% of patients in the endovascular-therapy group and 6.9% in the medical-care group (RR, 2.04; 95% CI, 0.86 to 4.84), and an mRS score of 0 to 1 was reported in 5% of the endovascular group versus 2.9% of the medical group (RR, 1.70; 95% CI, 0.42 to 6.93).
The ordinal shift across the range of mRS scores also favored endovascular therapy (common odds ratio, 2.42; 95% CI, 1.46 to 4.01).
An improvement of at least 8 points on the NIHSS score at 48 hours was observed in 31.0% of the patients in the endovascular-therapy group and 8.8% of those in the medical-care group (RR, 3.51; 95% CI, 1.76 to 7.00).
In terms of safety, any intracranial hemorrhage occurred in 58.0% of patients in the endovascular group and 31.4% of those in the medical therapy group (RR, 1.85; 95% CI, 1.33 to 2.58; P < .001).
There was also a trend toward an increase in symptomatic intracranial hemorrhage in the endovascular group (9% vs. 4.9%), but this did not reach significance (RR, 1.84; 95% CI, 0.64 to 5.29; P = .25).
In the NEJM paper, the authors pointed out that the ASPECTS value in most of the patients in this study was determined with the use of diffusion-weighted MRI, as MRI is widely used in Japan for the diagnosis of acute ischemic stroke. They noted that differences between ASPECTS values based on CT results and those based on diffusion-weighted MRI results should be considered in the interpretation of the results and that previous studies have suggested that an ASPECTS value determined with the use of diffusion-weighted MRI may be one level lower than that determined with the use of CT.
They also noted that there was a relatively low use of thrombolysis in the trial (27% to 29%), which may have altered the outcomes in both groups and disadvantaged the medical-care group. However, they add that most guidelines recommend against the use of thrombolysis when there is extensive ischemic change on imaging.
Risk/benefit trade-off
Commenting on the trade-off between benefits and risks in the study, Dr. Jovin said the increase in intracranial hemorrhage seen in the endovascular group was similar to that seen in other situations.
“This is not really any different from what is seen when giving tPA [tissue plasminogen activator] to stroke patients or when performing thrombectomy in small or moderate core strokes – we know that intracranial hemorrhage is the price to pay,” he stated.
“While the increase in symptomatic intracranial hemorrhage was nonsignificant, the trend is very clear, and I believe it is real,” Dr. Jovin said. “But I think what matters – and what matters to patients – is that there is a much higher chance of having a good outcome with endovascular therapy. I think most patients will accept the extra risk of intracranial hemorrhage if there is an even higher chance of having a better neurological outcome. This is no different to the approach that we take when we treat patients with IV tPA.”
Dr. Jovin pointed out that the RESCUE-JAPAN study did not include the largest core infarcts (ASPECTS score 0-1), but he added that these very large core infarcts are quite rare – especially in patients in the early time window.
He concluded that the study provided important information but cautioned that, with just 200 patients, the findings needed confirmation from other randomized trials that are ongoing.
Also speaking at the ISC press conference, Mitchell Elkind, MD, immediate past president of the American Heart Association/American Stroke Association, and professor of neurology at Columbia University, New York, said previous trials had established endovascular therapy for patients with large cerebral artery occlusions who have primarily preserved brain tissue and small infarct cores.
“We have picked off the low-lying fruit – the patients with small areas of infarcted brain. But perhaps most patients do not fit into this category and now we are seeing trials addressing these groups,” he said. “This initial study suggests that these patients with larger core infarcts can indeed still benefit from this therapy tremendously.”
The RESCUE-JAPAN LIMIT study was supported in part by the Mihara Cerebrovascular Disorder Research Promotion Fund and the Japanese Society for Neuroendovascular Therapy. There was no industry involvement. Dr. Yoshimura reported research grants from Stryker, Siemens Healthineers, Bristol-Myers Squibb, Sanofi, Eisai, Daiichi Sankyo, Teijin Pharma, Chugai Pharmaceutical, HEALIOS, Asahi Kasei Medical, Kowa, and CSL Behring; and lecturer fees from Stryker, Medtronic, Johnson & Johnson, Kaneka, Terumo, Biomedical Solutions, Boehringer-Ingelheim, Daiichi Sankyo, Bayer, and Bristol-Meyers Squibb.
A version of this article first appeared on Medscape.com.
The RESCUE-JAPAN LIMIT trial was presented at the International Stroke Conference by Shinichi Yoshimura, MD, Hyogo College of Medicine, Nishinomiya, Japan. The study was also published online in the New England Journal of Medicine to coincide with its presentation at the ISC meeting.
The trial showed that among patients with acute stroke and a large ischemic brain region, functional outcomes at 90 days were better with endovascular therapy and medical care than with medical care alone.
Patients who received endovascular therapy were more than twice as likely to have a good functional outcome, defined as a modified Rankin scale (mRS) score of 0-3 at 90 days, than those who received medical care alone.
While the rate of intracranial hemorrhage increased with endovascular therapy, authors of the study and outside commentators suggested that the benefit appeared to outweigh the risk. “Our results provide strong evidence that endovascular therapy improves patient outcomes when the infarct area is large,” Dr. Yoshimura concluded at the meeting, presented by the American Stroke Association, a division of the American Heart Association.
Commenting on the study at an ISC press conference, Tudor Jovin, MD, chair of neurology at Cooper University Hospital, Cherry Hill, New Jersey, said: “The question of strokes with a large core stroke being an exclusion criteria for endovascular therapy is arguably one of the hottest topics the field is facing at this time. There are several randomized trials ongoing aiming to answer this question.”
“The RESCUE-JAPAN trial is the first of these trials to report and shed some light on this issue,” Dr. Jovin added. “The results appear to show that these patients with large core infarcts have just as much benefit from endovascular therapy as patients with smaller infarcts.”
Dr. Jovin described these findings as encouraging but also surprising. “When these large core randomized trials were planned, there was a belief that there would be benefit at some level. But what is surprising to me is that in this trial the benefit was similar to that seen in trials in patients with moderate or small core infarcts. This begs the question of whether we should care about the size of the infarct when we are considering taking these patients for thrombectomy,” he said.
Confirmation needed
On whether this will change practice, Dr. Jovin cautioned that this was just one study with a relatively small number of patients. “I think it is important that all the other randomized trials ongoing should continue so that we have a definitive answer to this question,” he said.
In his presentation, Dr. Yoshimura explained that current guidelines recommended endovascular therapy for patients with large cerebral vessel occlusion and a small or moderate infarct size – an ASPECTS score (Alberta Stroke Program Early Computed Tomographic Score) of 6 or higher. The ASPECTS score has a scale of 1-10, with lower values indicating larger infarction.
The RESCUE-JAPAN LIMIT study included 203 patients with occlusion of large cerebral vessels and sizable strokes on imaging, as indicated by an ASPECTS score of 3 to 5.
Patients were randomly assigned to receive endovascular therapy with medical care (endovascular-therapy group) or medical therapy alone (medical-care group) within 6 hours after they were last known to be well or within 24 hours if there was no early change on fluid-attenuated inversion recovery images indicating that the infarction was recent.
The percentage of patients with a good outcome as defined by an mRS score of 0 to 3 at 90 days, the primary outcome, was 31.0% in the endovascular-therapy group and 12.7% in the medical-care group (relative risk, 2.43; 95% confidence interval, 1.35 to 4.37; P = .002).
Secondary outcomes were mRS scores of 0 to 2 and 0 to 1, an ordinal shift across the range of mRS scores toward a better outcome at 90 days, and an improvement of at least 8 points in the National Institutes of Health Stroke Scale (NIHSS) score (range, 0 to 42, with higher scores indicating greater deficit) at 48 hours.
An mRS score of 0 to 2 was seen in 14% of patients in the endovascular-therapy group and 6.9% in the medical-care group (RR, 2.04; 95% CI, 0.86 to 4.84), and an mRS score of 0 to 1 was reported in 5% of the endovascular group versus 2.9% of the medical group (RR, 1.70; 95% CI, 0.42 to 6.93).
The ordinal shift across the range of mRS scores also favored endovascular therapy (common odds ratio, 2.42; 95% CI, 1.46 to 4.01).
An improvement of at least 8 points on the NIHSS score at 48 hours was observed in 31.0% of the patients in the endovascular-therapy group and 8.8% of those in the medical-care group (RR, 3.51; 95% CI, 1.76 to 7.00).
In terms of safety, any intracranial hemorrhage occurred in 58.0% of patients in the endovascular group and 31.4% of those in the medical therapy group (RR, 1.85; 95% CI, 1.33 to 2.58; P < .001).
There was also a trend toward an increase in symptomatic intracranial hemorrhage in the endovascular group (9% vs. 4.9%), but this did not reach significance (RR, 1.84; 95% CI, 0.64 to 5.29; P = .25).
In the NEJM paper, the authors pointed out that the ASPECTS value in most of the patients in this study was determined with the use of diffusion-weighted MRI, as MRI is widely used in Japan for the diagnosis of acute ischemic stroke. They noted that differences between ASPECTS values based on CT results and those based on diffusion-weighted MRI results should be considered in the interpretation of the results and that previous studies have suggested that an ASPECTS value determined with the use of diffusion-weighted MRI may be one level lower than that determined with the use of CT.
They also noted that there was a relatively low use of thrombolysis in the trial (27% to 29%), which may have altered the outcomes in both groups and disadvantaged the medical-care group. However, they add that most guidelines recommend against the use of thrombolysis when there is extensive ischemic change on imaging.
Risk/benefit trade-off
Commenting on the trade-off between benefits and risks in the study, Dr. Jovin said the increase in intracranial hemorrhage seen in the endovascular group was similar to that seen in other situations.
“This is not really any different from what is seen when giving tPA [tissue plasminogen activator] to stroke patients or when performing thrombectomy in small or moderate core strokes – we know that intracranial hemorrhage is the price to pay,” he stated.
“While the increase in symptomatic intracranial hemorrhage was nonsignificant, the trend is very clear, and I believe it is real,” Dr. Jovin said. “But I think what matters – and what matters to patients – is that there is a much higher chance of having a good outcome with endovascular therapy. I think most patients will accept the extra risk of intracranial hemorrhage if there is an even higher chance of having a better neurological outcome. This is no different to the approach that we take when we treat patients with IV tPA.”
Dr. Jovin pointed out that the RESCUE-JAPAN study did not include the largest core infarcts (ASPECTS score 0-1), but he added that these very large core infarcts are quite rare – especially in patients in the early time window.
He concluded that the study provided important information but cautioned that, with just 200 patients, the findings needed confirmation from other randomized trials that are ongoing.
Also speaking at the ISC press conference, Mitchell Elkind, MD, immediate past president of the American Heart Association/American Stroke Association, and professor of neurology at Columbia University, New York, said previous trials had established endovascular therapy for patients with large cerebral artery occlusions who have primarily preserved brain tissue and small infarct cores.
“We have picked off the low-lying fruit – the patients with small areas of infarcted brain. But perhaps most patients do not fit into this category and now we are seeing trials addressing these groups,” he said. “This initial study suggests that these patients with larger core infarcts can indeed still benefit from this therapy tremendously.”
The RESCUE-JAPAN LIMIT study was supported in part by the Mihara Cerebrovascular Disorder Research Promotion Fund and the Japanese Society for Neuroendovascular Therapy. There was no industry involvement. Dr. Yoshimura reported research grants from Stryker, Siemens Healthineers, Bristol-Myers Squibb, Sanofi, Eisai, Daiichi Sankyo, Teijin Pharma, Chugai Pharmaceutical, HEALIOS, Asahi Kasei Medical, Kowa, and CSL Behring; and lecturer fees from Stryker, Medtronic, Johnson & Johnson, Kaneka, Terumo, Biomedical Solutions, Boehringer-Ingelheim, Daiichi Sankyo, Bayer, and Bristol-Meyers Squibb.
A version of this article first appeared on Medscape.com.
The RESCUE-JAPAN LIMIT trial was presented at the International Stroke Conference by Shinichi Yoshimura, MD, Hyogo College of Medicine, Nishinomiya, Japan. The study was also published online in the New England Journal of Medicine to coincide with its presentation at the ISC meeting.
The trial showed that among patients with acute stroke and a large ischemic brain region, functional outcomes at 90 days were better with endovascular therapy and medical care than with medical care alone.
Patients who received endovascular therapy were more than twice as likely to have a good functional outcome, defined as a modified Rankin scale (mRS) score of 0-3 at 90 days, than those who received medical care alone.
While the rate of intracranial hemorrhage increased with endovascular therapy, authors of the study and outside commentators suggested that the benefit appeared to outweigh the risk. “Our results provide strong evidence that endovascular therapy improves patient outcomes when the infarct area is large,” Dr. Yoshimura concluded at the meeting, presented by the American Stroke Association, a division of the American Heart Association.
Commenting on the study at an ISC press conference, Tudor Jovin, MD, chair of neurology at Cooper University Hospital, Cherry Hill, New Jersey, said: “The question of strokes with a large core stroke being an exclusion criteria for endovascular therapy is arguably one of the hottest topics the field is facing at this time. There are several randomized trials ongoing aiming to answer this question.”
“The RESCUE-JAPAN trial is the first of these trials to report and shed some light on this issue,” Dr. Jovin added. “The results appear to show that these patients with large core infarcts have just as much benefit from endovascular therapy as patients with smaller infarcts.”
Dr. Jovin described these findings as encouraging but also surprising. “When these large core randomized trials were planned, there was a belief that there would be benefit at some level. But what is surprising to me is that in this trial the benefit was similar to that seen in trials in patients with moderate or small core infarcts. This begs the question of whether we should care about the size of the infarct when we are considering taking these patients for thrombectomy,” he said.
Confirmation needed
On whether this will change practice, Dr. Jovin cautioned that this was just one study with a relatively small number of patients. “I think it is important that all the other randomized trials ongoing should continue so that we have a definitive answer to this question,” he said.
In his presentation, Dr. Yoshimura explained that current guidelines recommended endovascular therapy for patients with large cerebral vessel occlusion and a small or moderate infarct size – an ASPECTS score (Alberta Stroke Program Early Computed Tomographic Score) of 6 or higher. The ASPECTS score has a scale of 1-10, with lower values indicating larger infarction.
The RESCUE-JAPAN LIMIT study included 203 patients with occlusion of large cerebral vessels and sizable strokes on imaging, as indicated by an ASPECTS score of 3 to 5.
Patients were randomly assigned to receive endovascular therapy with medical care (endovascular-therapy group) or medical therapy alone (medical-care group) within 6 hours after they were last known to be well or within 24 hours if there was no early change on fluid-attenuated inversion recovery images indicating that the infarction was recent.
The percentage of patients with a good outcome as defined by an mRS score of 0 to 3 at 90 days, the primary outcome, was 31.0% in the endovascular-therapy group and 12.7% in the medical-care group (relative risk, 2.43; 95% confidence interval, 1.35 to 4.37; P = .002).
Secondary outcomes were mRS scores of 0 to 2 and 0 to 1, an ordinal shift across the range of mRS scores toward a better outcome at 90 days, and an improvement of at least 8 points in the National Institutes of Health Stroke Scale (NIHSS) score (range, 0 to 42, with higher scores indicating greater deficit) at 48 hours.
An mRS score of 0 to 2 was seen in 14% of patients in the endovascular-therapy group and 6.9% in the medical-care group (RR, 2.04; 95% CI, 0.86 to 4.84), and an mRS score of 0 to 1 was reported in 5% of the endovascular group versus 2.9% of the medical group (RR, 1.70; 95% CI, 0.42 to 6.93).
The ordinal shift across the range of mRS scores also favored endovascular therapy (common odds ratio, 2.42; 95% CI, 1.46 to 4.01).
An improvement of at least 8 points on the NIHSS score at 48 hours was observed in 31.0% of the patients in the endovascular-therapy group and 8.8% of those in the medical-care group (RR, 3.51; 95% CI, 1.76 to 7.00).
In terms of safety, any intracranial hemorrhage occurred in 58.0% of patients in the endovascular group and 31.4% of those in the medical therapy group (RR, 1.85; 95% CI, 1.33 to 2.58; P < .001).
There was also a trend toward an increase in symptomatic intracranial hemorrhage in the endovascular group (9% vs. 4.9%), but this did not reach significance (RR, 1.84; 95% CI, 0.64 to 5.29; P = .25).
In the NEJM paper, the authors pointed out that the ASPECTS value in most of the patients in this study was determined with the use of diffusion-weighted MRI, as MRI is widely used in Japan for the diagnosis of acute ischemic stroke. They noted that differences between ASPECTS values based on CT results and those based on diffusion-weighted MRI results should be considered in the interpretation of the results and that previous studies have suggested that an ASPECTS value determined with the use of diffusion-weighted MRI may be one level lower than that determined with the use of CT.
They also noted that there was a relatively low use of thrombolysis in the trial (27% to 29%), which may have altered the outcomes in both groups and disadvantaged the medical-care group. However, they add that most guidelines recommend against the use of thrombolysis when there is extensive ischemic change on imaging.
Risk/benefit trade-off
Commenting on the trade-off between benefits and risks in the study, Dr. Jovin said the increase in intracranial hemorrhage seen in the endovascular group was similar to that seen in other situations.
“This is not really any different from what is seen when giving tPA [tissue plasminogen activator] to stroke patients or when performing thrombectomy in small or moderate core strokes – we know that intracranial hemorrhage is the price to pay,” he stated.
“While the increase in symptomatic intracranial hemorrhage was nonsignificant, the trend is very clear, and I believe it is real,” Dr. Jovin said. “But I think what matters – and what matters to patients – is that there is a much higher chance of having a good outcome with endovascular therapy. I think most patients will accept the extra risk of intracranial hemorrhage if there is an even higher chance of having a better neurological outcome. This is no different to the approach that we take when we treat patients with IV tPA.”
Dr. Jovin pointed out that the RESCUE-JAPAN study did not include the largest core infarcts (ASPECTS score 0-1), but he added that these very large core infarcts are quite rare – especially in patients in the early time window.
He concluded that the study provided important information but cautioned that, with just 200 patients, the findings needed confirmation from other randomized trials that are ongoing.
Also speaking at the ISC press conference, Mitchell Elkind, MD, immediate past president of the American Heart Association/American Stroke Association, and professor of neurology at Columbia University, New York, said previous trials had established endovascular therapy for patients with large cerebral artery occlusions who have primarily preserved brain tissue and small infarct cores.
“We have picked off the low-lying fruit – the patients with small areas of infarcted brain. But perhaps most patients do not fit into this category and now we are seeing trials addressing these groups,” he said. “This initial study suggests that these patients with larger core infarcts can indeed still benefit from this therapy tremendously.”
The RESCUE-JAPAN LIMIT study was supported in part by the Mihara Cerebrovascular Disorder Research Promotion Fund and the Japanese Society for Neuroendovascular Therapy. There was no industry involvement. Dr. Yoshimura reported research grants from Stryker, Siemens Healthineers, Bristol-Myers Squibb, Sanofi, Eisai, Daiichi Sankyo, Teijin Pharma, Chugai Pharmaceutical, HEALIOS, Asahi Kasei Medical, Kowa, and CSL Behring; and lecturer fees from Stryker, Medtronic, Johnson & Johnson, Kaneka, Terumo, Biomedical Solutions, Boehringer-Ingelheim, Daiichi Sankyo, Bayer, and Bristol-Meyers Squibb.
A version of this article first appeared on Medscape.com.
FROM ISC 2022
Chronic marijuana use linked to recurrent stroke
, new observational research suggests. “Our analysis shows young marijuana users with a history of stroke or transient ischemic attack remain at significantly high risk for future strokes,” said lead study author Akhil Jain, MD, a resident physician at Mercy Fitzgerald Hospital in Darby, Pennsylvania.
“It’s essential to raise awareness among young adults about the impact of chronic habitual use of marijuana, especially if they have established cardiovascular risk factors or previous stroke.”
The study will be presented during the International Stroke Conference, presented by the American Stroke Association, a division of the American Heart Association.
An increasing number of jurisdictions are allowing marijuana use. To date, 18 states and the District of Columbia have legalized recreational cannabis use, the investigators noted.
Research suggests cannabis use disorder – defined as the chronic habitual use of cannabis – is more prevalent in the young adult population. But Dr. Jain said the population of marijuana users is “a changing dynamic.”
Cannabis use has been linked to an increased risk for first-time stroke or transient ischemic attack (TIA). Traditional stroke risk factors include hypertension, diabetes, and diseases related to blood vessels or blood circulation, including atherosclerosis.
Young adults might have additional stroke risk factors, such as behavioral habits like substance abuse, low physical activity, and smoking, oral contraceptives use among females, and brain infections, especially in the immunocompromised, said Dr. Jain.
Research from the American Heart Association shows stroke rates are increasing among adults 18 to 45 years of age. Each year, young adults account for up to 15% of strokes in the United States.
Prevalence and risk for recurrent stroke in patients with previous stroke or TIA in cannabis users have not been clearly established, the researchers pointed out.
A higher rate of recurrent stroke
For this new study, Dr. Jain and colleagues used data from the National Inpatient Sample from October 2015 to December 2017. They identified hospitalizations among young adults 18 to 45 years of age with a previous history of stroke or TIA.
They then grouped these patients into those with cannabis use disorder (4,690) and those without cannabis use disorder (156,700). The median age in both cohorts was 37 years.
The analysis did not include those who were considered in remission from cannabis use disorder.
Results showed that 6.9% of those with cannabis use disorder were hospitalized for a recurrent stroke, compared with 5.4% of those without cannabis use disorder (P < .001).
After adjustment for demographic factors (age, sex, race, household income), and pre-existing conditions, patients with cannabis use disorder were 48% more likely to be hospitalized for recurrent stroke than those without cannabis use disorder (odds ratio, 1.48; 95% confidence interval, 1.28-1.71; P < .001).
Compared with the group without cannabis use disorder, the cannabis use disorder group had more men (55.2% vs. 40.2%), more African American people (44.6% vs. 37.2%), and more use of tobacco (73.9% vs. 39.6%) and alcohol (16.5% vs. 3.6%). They also had a greater percentage of chronic obstructive pulmonary disease, depression, and psychoses.
But a smaller percentage of those with cannabis use disorder had hypertension (51.3% vs. 55.6%; P = .001) and diabetes (16.3% vs. 22.7%; P < .001), which is an “interesting” finding, said Dr. Jain.
“We observed that even with a lower rate of cardiovascular risk factors, after controlling for all the risk factors, we still found the cannabis users had a higher rate of recurrent stroke.”
He noted this was a retrospective study without a control group. “If both groups had comparable hypertension, then this risk might actually be more evident,” said Dr. Jain. “We need a prospective study with comparable groups.”
Living in low-income neighborhoods and in northeast and southern regions of the United States was also more common in the cannabis use disorder group.
Hypothesis-generating research
The study did not investigate the possible mechanisms by which marijuana use might increase stroke risk, but Dr. Jain speculated that these could include factors such as impaired blood vessel function, changes in blood supply, an increased tendency of blood clotting, impaired energy production in brain cells, and an imbalance between molecules that harm healthy tissue and the antioxidant defenses that neutralize them.
As cannabis use may pose a different risk for a new stroke, as opposed a previous stroke, Dr. Jain said it would be interesting to study the amount of “residual function deficit” experienced with the first stroke.
The new study represents “foundational research” upon which other research teams can build, said Dr. Jain. “Our study is hypothesis-generating research for a future prospective randomized controlled trial.”
A limitation of the study is that it did not consider the effect of various doses, duration, and forms of cannabis abuse, or use of medicinal cannabis or other drugs.
Robert L. Page II, PharmD, professor, departments of clinical pharmacy and physical medicine/rehabilitation, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, provided a comment on this new research.
A cannabis use disorder diagnosis provides “specific criteria” with regard to chronicity of use and reflects “more of a physical and psychological dependence upon cannabis,” said Dr. Page, who chaired the writing group for the AHA 2020 cannabis and cardiovascular disease scientific statement.
He explained what sets people with cannabis use disorder apart from “run-of-the-mill” recreational cannabis users is that “these are individuals who use a cannabis product, whether it’s smoking it, vaping it, or consuming it via an edible, and are using it on a regular basis, in a chronic fashion.”
The study received no outside funding. The authors report no relevant disclosures.
A version of this article first appeared on Medscape.com.
, new observational research suggests. “Our analysis shows young marijuana users with a history of stroke or transient ischemic attack remain at significantly high risk for future strokes,” said lead study author Akhil Jain, MD, a resident physician at Mercy Fitzgerald Hospital in Darby, Pennsylvania.
“It’s essential to raise awareness among young adults about the impact of chronic habitual use of marijuana, especially if they have established cardiovascular risk factors or previous stroke.”
The study will be presented during the International Stroke Conference, presented by the American Stroke Association, a division of the American Heart Association.
An increasing number of jurisdictions are allowing marijuana use. To date, 18 states and the District of Columbia have legalized recreational cannabis use, the investigators noted.
Research suggests cannabis use disorder – defined as the chronic habitual use of cannabis – is more prevalent in the young adult population. But Dr. Jain said the population of marijuana users is “a changing dynamic.”
Cannabis use has been linked to an increased risk for first-time stroke or transient ischemic attack (TIA). Traditional stroke risk factors include hypertension, diabetes, and diseases related to blood vessels or blood circulation, including atherosclerosis.
Young adults might have additional stroke risk factors, such as behavioral habits like substance abuse, low physical activity, and smoking, oral contraceptives use among females, and brain infections, especially in the immunocompromised, said Dr. Jain.
Research from the American Heart Association shows stroke rates are increasing among adults 18 to 45 years of age. Each year, young adults account for up to 15% of strokes in the United States.
Prevalence and risk for recurrent stroke in patients with previous stroke or TIA in cannabis users have not been clearly established, the researchers pointed out.
A higher rate of recurrent stroke
For this new study, Dr. Jain and colleagues used data from the National Inpatient Sample from October 2015 to December 2017. They identified hospitalizations among young adults 18 to 45 years of age with a previous history of stroke or TIA.
They then grouped these patients into those with cannabis use disorder (4,690) and those without cannabis use disorder (156,700). The median age in both cohorts was 37 years.
The analysis did not include those who were considered in remission from cannabis use disorder.
Results showed that 6.9% of those with cannabis use disorder were hospitalized for a recurrent stroke, compared with 5.4% of those without cannabis use disorder (P < .001).
After adjustment for demographic factors (age, sex, race, household income), and pre-existing conditions, patients with cannabis use disorder were 48% more likely to be hospitalized for recurrent stroke than those without cannabis use disorder (odds ratio, 1.48; 95% confidence interval, 1.28-1.71; P < .001).
Compared with the group without cannabis use disorder, the cannabis use disorder group had more men (55.2% vs. 40.2%), more African American people (44.6% vs. 37.2%), and more use of tobacco (73.9% vs. 39.6%) and alcohol (16.5% vs. 3.6%). They also had a greater percentage of chronic obstructive pulmonary disease, depression, and psychoses.
But a smaller percentage of those with cannabis use disorder had hypertension (51.3% vs. 55.6%; P = .001) and diabetes (16.3% vs. 22.7%; P < .001), which is an “interesting” finding, said Dr. Jain.
“We observed that even with a lower rate of cardiovascular risk factors, after controlling for all the risk factors, we still found the cannabis users had a higher rate of recurrent stroke.”
He noted this was a retrospective study without a control group. “If both groups had comparable hypertension, then this risk might actually be more evident,” said Dr. Jain. “We need a prospective study with comparable groups.”
Living in low-income neighborhoods and in northeast and southern regions of the United States was also more common in the cannabis use disorder group.
Hypothesis-generating research
The study did not investigate the possible mechanisms by which marijuana use might increase stroke risk, but Dr. Jain speculated that these could include factors such as impaired blood vessel function, changes in blood supply, an increased tendency of blood clotting, impaired energy production in brain cells, and an imbalance between molecules that harm healthy tissue and the antioxidant defenses that neutralize them.
As cannabis use may pose a different risk for a new stroke, as opposed a previous stroke, Dr. Jain said it would be interesting to study the amount of “residual function deficit” experienced with the first stroke.
The new study represents “foundational research” upon which other research teams can build, said Dr. Jain. “Our study is hypothesis-generating research for a future prospective randomized controlled trial.”
A limitation of the study is that it did not consider the effect of various doses, duration, and forms of cannabis abuse, or use of medicinal cannabis or other drugs.
Robert L. Page II, PharmD, professor, departments of clinical pharmacy and physical medicine/rehabilitation, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, provided a comment on this new research.
A cannabis use disorder diagnosis provides “specific criteria” with regard to chronicity of use and reflects “more of a physical and psychological dependence upon cannabis,” said Dr. Page, who chaired the writing group for the AHA 2020 cannabis and cardiovascular disease scientific statement.
He explained what sets people with cannabis use disorder apart from “run-of-the-mill” recreational cannabis users is that “these are individuals who use a cannabis product, whether it’s smoking it, vaping it, or consuming it via an edible, and are using it on a regular basis, in a chronic fashion.”
The study received no outside funding. The authors report no relevant disclosures.
A version of this article first appeared on Medscape.com.
, new observational research suggests. “Our analysis shows young marijuana users with a history of stroke or transient ischemic attack remain at significantly high risk for future strokes,” said lead study author Akhil Jain, MD, a resident physician at Mercy Fitzgerald Hospital in Darby, Pennsylvania.
“It’s essential to raise awareness among young adults about the impact of chronic habitual use of marijuana, especially if they have established cardiovascular risk factors or previous stroke.”
The study will be presented during the International Stroke Conference, presented by the American Stroke Association, a division of the American Heart Association.
An increasing number of jurisdictions are allowing marijuana use. To date, 18 states and the District of Columbia have legalized recreational cannabis use, the investigators noted.
Research suggests cannabis use disorder – defined as the chronic habitual use of cannabis – is more prevalent in the young adult population. But Dr. Jain said the population of marijuana users is “a changing dynamic.”
Cannabis use has been linked to an increased risk for first-time stroke or transient ischemic attack (TIA). Traditional stroke risk factors include hypertension, diabetes, and diseases related to blood vessels or blood circulation, including atherosclerosis.
Young adults might have additional stroke risk factors, such as behavioral habits like substance abuse, low physical activity, and smoking, oral contraceptives use among females, and brain infections, especially in the immunocompromised, said Dr. Jain.
Research from the American Heart Association shows stroke rates are increasing among adults 18 to 45 years of age. Each year, young adults account for up to 15% of strokes in the United States.
Prevalence and risk for recurrent stroke in patients with previous stroke or TIA in cannabis users have not been clearly established, the researchers pointed out.
A higher rate of recurrent stroke
For this new study, Dr. Jain and colleagues used data from the National Inpatient Sample from October 2015 to December 2017. They identified hospitalizations among young adults 18 to 45 years of age with a previous history of stroke or TIA.
They then grouped these patients into those with cannabis use disorder (4,690) and those without cannabis use disorder (156,700). The median age in both cohorts was 37 years.
The analysis did not include those who were considered in remission from cannabis use disorder.
Results showed that 6.9% of those with cannabis use disorder were hospitalized for a recurrent stroke, compared with 5.4% of those without cannabis use disorder (P < .001).
After adjustment for demographic factors (age, sex, race, household income), and pre-existing conditions, patients with cannabis use disorder were 48% more likely to be hospitalized for recurrent stroke than those without cannabis use disorder (odds ratio, 1.48; 95% confidence interval, 1.28-1.71; P < .001).
Compared with the group without cannabis use disorder, the cannabis use disorder group had more men (55.2% vs. 40.2%), more African American people (44.6% vs. 37.2%), and more use of tobacco (73.9% vs. 39.6%) and alcohol (16.5% vs. 3.6%). They also had a greater percentage of chronic obstructive pulmonary disease, depression, and psychoses.
But a smaller percentage of those with cannabis use disorder had hypertension (51.3% vs. 55.6%; P = .001) and diabetes (16.3% vs. 22.7%; P < .001), which is an “interesting” finding, said Dr. Jain.
“We observed that even with a lower rate of cardiovascular risk factors, after controlling for all the risk factors, we still found the cannabis users had a higher rate of recurrent stroke.”
He noted this was a retrospective study without a control group. “If both groups had comparable hypertension, then this risk might actually be more evident,” said Dr. Jain. “We need a prospective study with comparable groups.”
Living in low-income neighborhoods and in northeast and southern regions of the United States was also more common in the cannabis use disorder group.
Hypothesis-generating research
The study did not investigate the possible mechanisms by which marijuana use might increase stroke risk, but Dr. Jain speculated that these could include factors such as impaired blood vessel function, changes in blood supply, an increased tendency of blood clotting, impaired energy production in brain cells, and an imbalance between molecules that harm healthy tissue and the antioxidant defenses that neutralize them.
As cannabis use may pose a different risk for a new stroke, as opposed a previous stroke, Dr. Jain said it would be interesting to study the amount of “residual function deficit” experienced with the first stroke.
The new study represents “foundational research” upon which other research teams can build, said Dr. Jain. “Our study is hypothesis-generating research for a future prospective randomized controlled trial.”
A limitation of the study is that it did not consider the effect of various doses, duration, and forms of cannabis abuse, or use of medicinal cannabis or other drugs.
Robert L. Page II, PharmD, professor, departments of clinical pharmacy and physical medicine/rehabilitation, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, provided a comment on this new research.
A cannabis use disorder diagnosis provides “specific criteria” with regard to chronicity of use and reflects “more of a physical and psychological dependence upon cannabis,” said Dr. Page, who chaired the writing group for the AHA 2020 cannabis and cardiovascular disease scientific statement.
He explained what sets people with cannabis use disorder apart from “run-of-the-mill” recreational cannabis users is that “these are individuals who use a cannabis product, whether it’s smoking it, vaping it, or consuming it via an edible, and are using it on a regular basis, in a chronic fashion.”
The study received no outside funding. The authors report no relevant disclosures.
A version of this article first appeared on Medscape.com.
FROM ISC 2022