Predicting final infarct size and clinical outcomes in patients with acute ischemic stroke after endovascular thrombectomy using the Alberta Stroke Program early CT score on venous-phase CT.

Background: The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is a semi-quantitative tool for evaluating the extent and distribution of early ischemic changes.

Objective: To assess the value of ASPECTS on non-contrast CT (NCCT), arterial-phase CT (APCT), or venous-phase CT (VPCT) in predicting the final infarct core (IC) on follow-up diffusion-weighted imaging (DWI) and the clinical outcomes of patients with acute ischemic stroke (AIS) after endovascular thrombectomy (EVT).

Methods: In total, 120 patients with AIS who underwent EVT in our center were retrospectively enrolled. Correlations between CT-ASPECTS and follow-up DWI-ASPECTS were analyzed using Spearman's rank correlation coefficient. Mean differences and limit of agreement (LoA) between CT-ASPECTS and follow-up DWI-ASPECTS were assessed using the Bland-Altman plots. Multivariate logistic regression and receiver operating characteristic curve analyses were used to identify independent factors and evaluate their performances in predicting the clinical outcomes.

Results: VPCT-ASPECTS exhibited the highest correlation with follow-up DWI-ASPECTS (r = 0.846, P < 0.001), followed by APCT-ASPECTS (r = 0.613, P < 0.001) and NCCT-ASPECTS (r = 0.557, P < 0.001). The mean difference between VPCT-ASPECTS and follow-up DWI-ASPECTS was 0.0 (limit of agreement = -2.1 to 2.1). National Institute of Health Stroke Scale (NIHSS) scores at admission (NIHSSpre) (odds ratio [OR]=1.162, 95% confidence interval [CI]=1.063-1.270; P = 0.001) and VPCT-ASPECTS (OR=0.728, 95% CI=0.535-0.991; P = 0.044) were the independent factors associated with clinical outcomes. The combined model integrating NIHSSpre and VPCT-ASPECTS exhibited an excellent performance in predicting good clinical outcomes (area under curve [AUC]=0.807; sensitivity=75.0%; specificity=72.3%).

Conclusions: VPCT-ASPECTS may be a promising imaging biomarker to predict the final IC and the clinical outcome of the patients with AIS after EVT.