Late time window endovascular treatment for acute ischemic stroke: rethinking the role of simplified imaging

OBJECTIVE: To assess safety and efficacy of endovascular treatment (EVT) in acute ischemic stroke (AIS)patients selected by ASPECTS within 6-24 h after onset. METHODS: Patients were divided into early and late time window groups. Primary outcome was 90-day mRS 0-2, safety outcomes were 90-day any intracranial hemorrhage (ICH) and mortality. Univariate and multivariate analyses were conducted for the prediction of good outcome. RESULTS: Of the 296 patients screened, 242 patients fulfilled the study criteria. Patients in the late time window group were younger, had lower baseline NIHSS scores and ASPECTS, a lower proportion of atrial fibrillation, a higher proportion of large-artery atherosclerosis, less received intravenous thrombolysis, and had a longer time from symptom onset to treatment. No difference in primary and safety outcomes: good outcome (42% vs. 50.5%, p = 0.188), ICH (26.1% vs. 20.6%, p = 0.311), and mortality (18% vs. 9.9%, p = 0.067). Multivariate analysis showed that age (OR = 0.977, 95%CI 0.955-0.999, p = 0.039), NIHSS score (OR = 0.905, 95%CI 0.858-0.953, p = 0.001), ASPECTS (OR = 1.242, 95%CI 1.004-1.538, p = 0.046), glucose (OR = 0.817, 95%CI 0.720-0.926, p = 0.002), platelet (OR = 1.005, 95% CI 1.000 -1.010, p = 0.031) and successful recanalization (OR = 5.037, 95%CI 1.137-22.318, p = 0.033) were independent predictors of good outcomes. CONCLUSIONS: For late-window acute anterior-circulation LVO patients, those selected based on the ASPECTS exhibited comparable 90-day good outcomes and safety profiles to those in the early time window. This finding implies that ASPECTS could serve as a screening tool for patients in the late time window when undergoing EVT. CLINICAL TRIAL: This is a clinical retrospective study. However, at the time when the study was initiated, clinical trial registration was not a mandatory requirement. Therefore, this trial was not registered.