Compared With t-PA, Endovascular Thrombectomy May Yield Better Function

Endovascular mechanical thrombectomy yields better function and revascularization rates, and similar mortality and intracranial hemorrhage rates, compared with standard medical therapy using t-PA, according to a meta-analysis published November 3 in JAMA. The meta-analysis included eight high-quality randomized clinical trials that compared the two approaches for acute ischemic stroke.

This meta-analysis included only large multicenter trials published between 2013 and the present. Previous trials and meta-analyses “had several well-recognized limitations,” including inconsistent use of vascular imaging to confirm vessel occlusion before randomization, variable use of t-PA in patients who eventually were assigned to endovascular therapy, and reliance on less effective and now outdated mechanical devices, said Jetan H. Badhiwala, MD, of the Division of Neurosurgery at the University of Toronto, and his associates.

The eight trials included 2,423 patients (mean age, 67.4); 46.7% of participants were women. A total of 1,313 patients underwent endovascular therapy, defined as the intra-arterial use of a microcatheter or other device for mechanical thrombectomy, with or without the local use of a chemical thrombolytic agent. The remaining 1,110 participants received standard medical therapy (ie, t-PA). The upper limit of time between stroke onset and endovascular treatment varied from five to 12 hours across these studies, and the mean time was 3.8 hours.

Patients who received endovascular thrombectomy had significantly higher rates of functional independence at 90 days (44.6%) than did those who received t-PA (31.8%, odds ratio [OR], 1.71). The rate of angiographic revascularization at 24 hours also was markedly higher for endovascular thrombectomy (75.8% vs 34.1%, OR, 6.49), the investigators said.

However, there were no significant differences between the two study groups in rates of symptomatic intracranial hemorrhage at 90 days (5.7% vs 5.1%) or all-cause mortality at 90 days (15.8% vs 17.8%). Overall morbidity, including in-hospital rates of deep venous thrombosis, myocardial infarction, and pneumonia, also was similar between the groups.

“It is important to note some limitations with this well-conducted meta-analysis,” said Joanna M. Wardlaw, MD, Chair of Applied Neuroimaging and Head of Neuroimaging Sciences, and Martin S. Dennis, MD, Head of the Brain Vascular Disease Section, both at the Centre for Clinical Brain Sciences at the University of Edinburgh, in an accompanying editorial. “First, functional outcomes showed significant heterogeneity, which the authors attributed to variations in patient-, treatment-, and study-related factors. Second, the confidence intervals for mortality and intracranial hemorrhage were wide, indicating that more data are necessary to fully inform these outcomes. Third, five of the eight trials were halted early because of the evident superiority of endovascular thrombectomy, which means they fell substantially short (by up to 74%) of their planned sample sizes. This [situation] tends to cause overestimation of treatment effects. Fourth, nearly all these strokes involved carotid territory, nearly all the patients were on the young end of the age spectrum, and very few participants had comorbidities such as [atrial fibrillation] or diabetes. Such favorable characteristics do not reflect real-world experience with ischemic stroke.”

—Mary Ann Moon

Endovascular mechanical thrombectomy yields better function and revascularization rates, and similar mortality and intracranial hemorrhage rates, compared with standard medical therapy using t-PA, according to a meta-analysis published November 3 in JAMA. The meta-analysis included eight high-quality randomized clinical trials that compared the two approaches for acute ischemic stroke.

This meta-analysis included only large multicenter trials published between 2013 and the present. Previous trials and meta-analyses “had several well-recognized limitations,” including inconsistent use of vascular imaging to confirm vessel occlusion before randomization, variable use of t-PA in patients who eventually were assigned to endovascular therapy, and reliance on less effective and now outdated mechanical devices, said Jetan H. Badhiwala, MD, of the Division of Neurosurgery at the University of Toronto, and his associates.

The eight trials included 2,423 patients (mean age, 67.4); 46.7% of participants were women. A total of 1,313 patients underwent endovascular therapy, defined as the intra-arterial use of a microcatheter or other device for mechanical thrombectomy, with or without the local use of a chemical thrombolytic agent. The remaining 1,110 participants received standard medical therapy (ie, t-PA). The upper limit of time between stroke onset and endovascular treatment varied from five to 12 hours across these studies, and the mean time was 3.8 hours.

Patients who received endovascular thrombectomy had significantly higher rates of functional independence at 90 days (44.6%) than did those who received t-PA (31.8%, odds ratio [OR], 1.71). The rate of angiographic revascularization at 24 hours also was markedly higher for endovascular thrombectomy (75.8% vs 34.1%, OR, 6.49), the investigators said.

However, there were no significant differences between the two study groups in rates of symptomatic intracranial hemorrhage at 90 days (5.7% vs 5.1%) or all-cause mortality at 90 days (15.8% vs 17.8%). Overall morbidity, including in-hospital rates of deep venous thrombosis, myocardial infarction, and pneumonia, also was similar between the groups.

“It is important to note some limitations with this well-conducted meta-analysis,” said Joanna M. Wardlaw, MD, Chair of Applied Neuroimaging and Head of Neuroimaging Sciences, and Martin S. Dennis, MD, Head of the Brain Vascular Disease Section, both at the Centre for Clinical Brain Sciences at the University of Edinburgh, in an accompanying editorial. “First, functional outcomes showed significant heterogeneity, which the authors attributed to variations in patient-, treatment-, and study-related factors. Second, the confidence intervals for mortality and intracranial hemorrhage were wide, indicating that more data are necessary to fully inform these outcomes. Third, five of the eight trials were halted early because of the evident superiority of endovascular thrombectomy, which means they fell substantially short (by up to 74%) of their planned sample sizes. This [situation] tends to cause overestimation of treatment effects. Fourth, nearly all these strokes involved carotid territory, nearly all the patients were on the young end of the age spectrum, and very few participants had comorbidities such as [atrial fibrillation] or diabetes. Such favorable characteristics do not reflect real-world experience with ischemic stroke.”

—Mary Ann Moon

Endovascular mechanical thrombectomy yields better function and revascularization rates, and similar mortality and intracranial hemorrhage rates, compared with standard medical therapy using t-PA, according to a meta-analysis published November 3 in JAMA. The meta-analysis included eight high-quality randomized clinical trials that compared the two approaches for acute ischemic stroke.

This meta-analysis included only large multicenter trials published between 2013 and the present. Previous trials and meta-analyses “had several well-recognized limitations,” including inconsistent use of vascular imaging to confirm vessel occlusion before randomization, variable use of t-PA in patients who eventually were assigned to endovascular therapy, and reliance on less effective and now outdated mechanical devices, said Jetan H. Badhiwala, MD, of the Division of Neurosurgery at the University of Toronto, and his associates.

The eight trials included 2,423 patients (mean age, 67.4); 46.7% of participants were women. A total of 1,313 patients underwent endovascular therapy, defined as the intra-arterial use of a microcatheter or other device for mechanical thrombectomy, with or without the local use of a chemical thrombolytic agent. The remaining 1,110 participants received standard medical therapy (ie, t-PA). The upper limit of time between stroke onset and endovascular treatment varied from five to 12 hours across these studies, and the mean time was 3.8 hours.

Patients who received endovascular thrombectomy had significantly higher rates of functional independence at 90 days (44.6%) than did those who received t-PA (31.8%, odds ratio [OR], 1.71). The rate of angiographic revascularization at 24 hours also was markedly higher for endovascular thrombectomy (75.8% vs 34.1%, OR, 6.49), the investigators said.

However, there were no significant differences between the two study groups in rates of symptomatic intracranial hemorrhage at 90 days (5.7% vs 5.1%) or all-cause mortality at 90 days (15.8% vs 17.8%). Overall morbidity, including in-hospital rates of deep venous thrombosis, myocardial infarction, and pneumonia, also was similar between the groups.

“It is important to note some limitations with this well-conducted meta-analysis,” said Joanna M. Wardlaw, MD, Chair of Applied Neuroimaging and Head of Neuroimaging Sciences, and Martin S. Dennis, MD, Head of the Brain Vascular Disease Section, both at the Centre for Clinical Brain Sciences at the University of Edinburgh, in an accompanying editorial. “First, functional outcomes showed significant heterogeneity, which the authors attributed to variations in patient-, treatment-, and study-related factors. Second, the confidence intervals for mortality and intracranial hemorrhage were wide, indicating that more data are necessary to fully inform these outcomes. Third, five of the eight trials were halted early because of the evident superiority of endovascular thrombectomy, which means they fell substantially short (by up to 74%) of their planned sample sizes. This [situation] tends to cause overestimation of treatment effects. Fourth, nearly all these strokes involved carotid territory, nearly all the patients were on the young end of the age spectrum, and very few participants had comorbidities such as [atrial fibrillation] or diabetes. Such favorable characteristics do not reflect real-world experience with ischemic stroke.”

—Mary Ann Moon