Mechanical Thrombectomy 24 to 72 Hours after Large-Vessel Ischemic Stroke

BACKGROUND: Endovascular thrombectomy is an established treatment for acute ischemic stroke. Whether the benefit extends to patients with salvageable brain tissue in the infarct who present more than 24 hours after symptom onset or the time when they were last known to be well is uncertain. METHODS: We conducted an open-label, randomized trial with blinded outcome assessment at comprehensive stroke centers in China. Patients with acute ischemic stroke from large-vessel occlusion of the anterior circulation and imaging-identified salvageable brain tissue at 24 to 72 hours were assigned to receive endovascular therapy plus standard medical care (intervention group) or standard medical care alone (control group). The primary outcome was functional status, defined by the score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death) at 90 days, with results assessed as the distribution of scores in each group. Secondary outcomes included disability, neurologic impairment, and safety. RESULTS: A total of 336 patients were included in the intention-to-treat population, with 168 assigned to each group. The median time from symptom onset or from the point when the patient was last known to be well to randomization was 38.5 hours. Endovascular therapy resulted in a more favorable distribution of modified Rankin scale scores at 90 days than standard medical care alone (common odds ratio for a better functional outcome, 1.74; 95% confidence interval, 1.19 to 2.55). Symptomatic intracranial hemorrhage occurred in 4.8% of the patients in the intervention group and in no patients in the control group, and the 90-day case fatality rate was 6.0% and 1.8%, respectively. CONCLUSIONS: Among patients who presented 24 to 72 hours after an acute ischemic stroke from large-vessel occlusion of the anterior circulation and had imaging-identified salvageable tissue, endovascular therapy resulted in better functional outcomes than standard care but led to a higher risk of intracranial hemorrhage and death. (Funded by the National Health Commission Capacity Building and Continuing Education Center and others; LATE-MT ClinicalTrials.gov number, NCT05326932.).