Alberta Stroke Program Early CT Score Versus Computed Tomographic Perfusion to Predict Functional Outcome After Successful Reperfusion in Acute Ischemic Stroke

Abstract

Background and Purpose— We aimed to compare the ability of conventional Alberta Stroke Program Early CT Score (ASPECTS), automated ASPECTS, and ischemic core volume on computed tomographic perfusion to predict clinical outcome in ischemic stroke because of large vessel occlusion ≤18 hours after symptom onset. Methods— We selected patients with acute ischemic stroke from the CRISP study (Computed Tomographic Perfusion to Predict Response to Recanalization in Ischemic Stroke Project) with successful reperfusion (modified treatment in cerebral ischemia score 2b or 3). We used e-ASPECTS software to calculate automated ASPECTS and RAPID software to estimate ischemic core volumes. We studied associations between these imaging characteristics and good outcome (modified Rankin Scale score, 0–2) or poor outcome (modified Rankin Scale score, 4–6) in univariable and multivariable analysis, after adjustment for relevant clinical confounders. Results— We included 156 patients. Conventional and automated ASPECTS was not associated with good or poor outcome in univariable analysis ( P =nonsignificant for all). Automated ASPECTS was associated with good outcome in multivariable analysis ( P =0.02) but not with poor outcome. Ischemic core volume was associated with good ( P <0.01) and poor outcome ( P =0.04) in univariable and multivariable analysis ( P =0.03 and P =0.02, respectively). Computed tomographic perfusion predicted good outcome with an area under the curve of 0.62 (95% CI, 0.53–0.71) and optimal cutoff core volume of 15 mL. Conclusions— Ischemic core volume assessed on computed tomographic perfusion is a predictor of clinical outcome among patients in whom endovascular reperfusion is achieved ≤18 hours after symptom onset. In this population, conventional or automated ASPECTS did not predict outcome.