Endovascular thrombectomy for acute ischemic stroke caused by medium-vessel occlusion may not improve functional outcomes at 90 days compared with usual care, according to a new study.

In the multicenter, prospective, randomized, open-label the ESCAPE-MeVO trial with blinded outcome evaluation, published in the The New England Journal of Medicine, researchers enrolled 530 patients from 5 countries between April 2022 and June 2024. The patients presented within 12 hours of symptom onset with favorable baseline imaging and were randomly assigned to receive endovascular thrombectomy (EVT) plus usual care (n = 255) or usual care alone (n = 275). At 90 days, a modified Rankin Scale (mRS) score of 0 or 1 occurred in 41.6% of patients in the EVT group and 43.1% of the usual care group.

Mortality at 90 days was higher in the EVT group (13.3%) compared with in the usual-care group (8.4%). Symptomatic intracranial hemorrhage occurred in 5.4% of the patients who received EVT vs 2.2% of those who received usual care. Other serious adverse events were also more frequent in the EVT group (33.9% vs 25.7%).

Among the patients in the EVT group, successful reperfusion (MeVO-eTICI score ≥ 2b) was achieved in 75.1%, with a median time from symptom onset to recanalization of 359 minutes. Despite this, infarct volumes at 18 to 54 hours poststroke were comparable between the two groups (31.9 mL for EVT vs 29.1 mL for usual care).

"The results of our trial do not support routine endovascular treatment of acute ischemic stroke due to medium-vessel occlusion," said Mayank Goyal, MD, PhD, of the Department of Radiology at the University of Calgary Cumming School of Medicine, and colleagues.

Further research may be needed to refine patient selection criteria and EVT techniques for medium-vessel occlusions. The trial was funded by the Canadian Institutes for Health Research and Medtronic.

No competing interests were disclosed in the study.