Endovascular treatment in patients with acute ischemic stroke presenting beyond 6 h after symptom onset: An international multicenter cohort study of the EVA-TRISP collaboration.

Introduction: After positive findings in clinical trials the time window for endovascular thrombectomy (EVT) for patients with an acute ischemic stroke has been expanded up to 24 h from symptom onset or last seen well (LSW). We aimed to compare EVT patients' characteristics and outcomes in the early versus extended time window and to compare outcomes with the DAWN and DEFUSE 3 trial results.

Patients and methods: Consecutive EVT patients from 16 mostly European comprehensive stroke centers from the EVA-TRISP cohort were included. We compared rates of 90-day good functional outcomes (Modified Rankin Scale 0-2), symptomatic intracranial hemorrhage (sICH), and 90-day mortality between patients treated in the early (<6 h after onset or LSW) versus extended (6-24 h after onset or LSW) time windows.

Results: We included 9313 patients, of which 6876 were treated in the early and 2437 in the extended time window. National Institutes of Health Stroke Scale (NIHSS) score at presentation was lower in patients treated in the extended time window (median 13 [IQR 7-18] vs 15 [IQR 9-19], p < 0.001). The percentage of patients with good functional outcome was slightly lower in the extended time window (37.4% vs 42.2%, p < 0.001). However, rates of successful recanalization, sICH, and mortality were similar. Good functional outcome rates after EVT were slightly lower for patients in the extended window in the EVA-TRISP cohort as compared to DAWN and DEFUSE 3.

Discussion and conclusion: According to this large multicenter cohort study reflecting daily clinical practice, EVT use in the extended time window appears safe and effective.