BackgroundTo compare the benefit of endovascular treatment(EVT) in acute ischemic stroke(AIS) patients with large vessel occlusion(LVO) presenting > 6 h from last known well outside a clinical trial setting to best medical management and to EVT in a randomized trial setting.MethodsData from a retrospective multicenter cohort study (ESCAPE-LATE) of AIS-LVO patients treated with EVT beyond 6 hours from last known well at former ESCAPE trial sites were pooled with historical data from ESCAPE trial late time window patients. Unadjusted and adjusted 90-day modified Rankin Scale (mRS) score was compared between ESCAPE-LATE patients, ESCAPE late time window EVT arm and control arm patients.ResultsA total of 249 patients were included in the analysis: 200 ESCAPE-LATE patients (for 141 of whom 90-day clinical outcomes were available) and 49 ESCAPE patients, for all of whom clinical outcome data were available (control arm: 20 and EVT arm: 29). Good clinical outcome (mRS 0-2 at 90 days) was nominally, albeit not significantly, lower in patients not treated with EVT (5/19[26.3%]) as compared to ESCAPE EVT arm patients (13/29[44.8%] and ESCAPE-LATE patients (66/141[46.8%]). After adjustment, a graded mRS pattern was seen, whereby patients treated with EVT did better as compared to non-treated patients, and those who underwent EVT in the ESCAPE trial had better mRS as compared to those included in ESCAPE-LATE who underwent EVT in clinical routine.ConclusionPatients presenting beyond 6 hours from last known well who are treated with EVT in a real-world setting show comparable benefit to patients treated in a clinical trial setting.