EXPRESS: ASPECTS-based selection for late endovascular treatment: a retrospective two-site cohort study.

IntroductionThe DAWN trial demonstrated the effectiveness of late endovascular treatment (EVT) in acute ischemic stroke (AIS) patients selected on the basis of a clinical-core mismatch. We explored in a real-world sample of EVT patients if a clinical-ASPECTS (Alberta Stroke Program Early CT Score) mismatch was associated with an outcome benefit after late EVT. MethodsWe retrospectively analysed all consecutive AIS patients admitted 6-24 hours after last proof of good health in two stroke centres, with initial National Institutes of Health Stroke Scale (NIHSS) â¥10 and an internal carotid artery or M1 occlusion. We defined clinical-ASPECTS mismatch as NIHSSâ¥10 and ASPECTSâ¥7, or NIHSSâ¥20 and ASPECTSâ¥5. We assessed the interaction between clinical-ASPECTS mismatch positive and negative patients and late EVT, using ordinal shift analysis of the 3-month modified Rankin Scale and adjusting for multiple confounders.ResultsThe included 337 patients had a median age of 73 years (IQR=61-82), admission NIHSS of 18 (15-22) and baseline ASPECTS of 7 (5-9). Out of 196 (58.2%) patients showing clinical-ASPECTS mismatch, 146 (74.5%) underwent late EVT. Among 141 (41.8%) mismatch negative patients, late EVT was performed in 72 (51.1%) patients. In the adjusted analysis, late EVT was significantly associated with a better outcome in the presence of clinical-ASPECTS mismatch (adjusted Odd Ratio, aOR=2.83; 95% confidence interval, CI: 1.48-5.58) but not in its absence (aOR=1.32; 95%CI: 0.61-2.84). The p-value for the interaction term between clinical-ASPECTS mismatch and late EVT was 0.073. ConclusionsIn our retrospective two-site analysis, late EVT seemed effective in the presence of a clinical-ASPECTS mismatch, but not in its absence. If confirmed in randomized trials, this finding could support the use of an ASPECTS-based selection for late EVT decisions, obviating the need for advanced imaging.