Alteplase for Posterior Circulation Ischemic Stroke at 4.5 to 24 Hours

BACKGROUND: The effects and risks of the use of intravenous thrombolysis between 4.5 and 24 hours after the onset of a posterior circulation ischemic stroke are not well studied. METHODS: In a trial conducted in China, we randomly assigned patients with posterior circulation stroke, without extensive early hypodensity on computed tomography and with no planned thrombectomy, to receive alteplase (0.9 mg per kilogram of body weight; maximum dose, 90 mg) or standard medical treatment 4.5 to 24 hours after the onset of symptoms. The primary outcome was functional independence (defined as a score of 0 to 2 on the modified Rankin scale; scores range from 0 to 6, with higher scores indicating greater disability) at 90 days. The key safety outcomes were symptomatic intracranial hemorrhage and death. RESULTS: A total of 234 patients were enrolled; 117 were assigned to the alteplase group and 117 to the standard-treatment group. The median score on the National Institutes of Health Stroke Scale was 3 (interquartile range, 2 to 6) (scores range from 0 to 42, with higher scores indicating greater neurologic deficit). A higher percentage of patients in the alteplase group than in the standard-treatment group had functional independence at 90 days (89.6% vs. 72.6%; adjusted risk ratio, 1.16; 95% confidence interval [CI], 1.03 to 1.30; P = 0.01). The incidence of symptomatic intracranial hemorrhage within 36 hours was 1.7% in the alteplase group and 0.9% in the standard-treatment group. At 90 days, 5.2% of the patients in the alteplase group and 8.5% of those in the standard-treatment group had died. CONCLUSIONS: Among Chinese patients with mainly mild posterior circulation stroke who did not receive thrombectomy, alteplase administered 4.5 to 24 hours after stroke onset resulted in a higher frequency of functional independence at 90 days than standard medical care. (Funded by the National Natural Science Foundation of China; EXPECTS ClinicalTrials.gov number, NCT05429476.).