A new study performed at 41 tertiary-care centers in China shows that endovascular thrombectomy alone is not inferior to intravenous alteplase plus endovascular thrombectomy in treating acute ischemic stroke.
Pengfei Yang, MD, and colleagues of Naval Medical University Changhai Hospital, Shanghai, China, reported these results in a paper published in the May 21 issue of The New England Journal of Medicine.
Endovascular thrombectomy is the standard treatment for patients who have acute ischemic stroke due to large vessel occlusion. However, the role of thrombolytics, i.e., alteplase before and during thrombectomy is uncertain. While alteplase can lyse the thrombus, there is a serious risk of cerebral hemorrhage. Multiple observational studies have shown that endovascular thrombectomy alone has acceptable clinical outcomes; however, to date there had been no randomized trials performed.
To answer this study question, Yang and colleagues conducted an investigator-initiated, multicenter, prospective, randomized, open-label trial with blinded outcome assessment. A total of 1,586 patients were assessed for eligibility, and 656 were enrolled in the study. Of those enrolled, 327 patients underwent endovascular thrombectomy alone and 329 underwent combination therapy of intravenous alteplase and endovascular thrombectomy.
Baseline characteristics were well-balanced between the groups. The median age was 69 years and 56% were men. The median National Institutes of Health Stroke Scale score was 17. The median time from stroke onset to randomization was 167 minutes in the thrombectomy-alone group and 177 minutes in the combination-therapy group. Stent retrievers were used in 96% of the cases. Major protocol violations were seen in 25 patients, 17 patients did not undergo endovascular treatment, and four patients crossed over to the other group. One patient in each group was lost to follow-up.
At 90 days, the primary endpoint of modified Rankin Scale score was similar between both the groups (endovascular thrombectomy and combination therapy both 3 [interquartile range, 2-5)], odds ratio, 1.07; 95% confidence interval, 0.81-1.40; p=0.04 for non-inferiority). Reperfusion success was also similar between both the groups. The composite safety endpoint of death, any intracranial hemorrhage or infarction in new territory also was not different between both the groups.
The authors noted some limitations to this study. The study was designed in accordance with the 2015 American Heart Association/American Stroke Association guidelines, in which stent retrievers were recommended. However, newer thrombectomy devices, such as aspiration catheters and new thrombolytic drugs are currently being used. Other limitations are a wide noninferiority margin and short time for alteplase to act before endovascular treatment.
Yang and colleagues concluded that in patients with acute ischemic stroke with a large vessel occlusion in the anterior circulation, endovascular thrombectomy alone is non-inferior to thrombectomy preceded by alteplase administered within 4.5 hours after symptom onset. The authors recommend larger trials in other populations.
The study was funded by the Stroke Prevention Project of the National Health Commission of the People’s Republic of China and the Wu Jieping Medical Foundation.
Yang P, Zhang Y, Zhang L, et al. Endovascular Thrombectomy with or without Intravenous Alteplase in Acute Stroke. N Engl J Med 2020;382:1981-1993. https://www.nejm.org/doi/full/10.1056/NEJMoa2001123