Exclusion of Isolated Cortical Swelling Can Increase Efficacy of Baseline Alberta Stroke Program Early CT Score in the Prediction of Prognosis in Acute Ischemic Stroke Patients Treated with Thrombolysis

Abstract

The accuracy of the Alberta Stroke Program Early CT Score (ASPECTS) as a prognostic indicator in the treatment of cerebral infarction with thrombolysis remains controversial. We hypothesized that ASPECTS can more accurately predict treatment outcomes by excluding isolated cortical swelling (ICS) from ASPECTS and retrospectively tested patients treated with thrombolysis. This retrospective cohort study included 106 patients treated with intravenous thrombolysis for cerebral infarction in our hospital. We included only patients with middle cerebral artery infarction. For the modification of ASPECTS, we removed each ICS from the ASPECTS system. We compared the correlation coefficients between the ASPECTS and modified ASPECTS with regard to treatment outcome, and performed a multivariate logistic regression analysis to evaluate the association between modified ASPECTS and outcomes. The primary outcome was a modified Rankin Scale score equal to or less than 2 on discharge and the secondary outcomes included an improvement of National Institutes of Health Stroke Scale (NIHSS) score of 4 or greater within 24 hours. Seventy-two patients were included in this study. The correlation coefficient of modified ASPECTS was significantly higher than that of ASPECTS in the primary outcome (r = .249 versus r = .363, P < .001) and in the improvement of NIHSS score (r = .303 versus r = .443, P < .001). Multivariate analysis revealed that a modified ASPECTS greater than 7 was significantly associated with the primary outcome (odds ratio [OR] = 1.334, 95% confidence interval [CI] = 1.071-1.661, P = .012) and the improvement of the NIHSS score (OR = 1.555, 95% CI = 1.208-2.003, P = .001). The present study reveals that ASPECTS may be more strongly associated with outcome by excluding ICS.