Clinical Outcomes of Posterior Versus Anterior Circulation Infarction With Low National Institutes of Health Stroke Scale Scores

Abstract

Background and Purpose— We compared baseline characteristics and outcomes at 3 months between patients with minor anterior circulation infarction (ACI) versus minor posterior circulation infarction (PCI), including the influence of large vessel disease on outcomes. Methods— This study is an analysis of a prospective multicenter registry database in South Korea. Eligibility criteria were patients with ischemic stroke admitted within 7 days of stroke onset, lesions in either anterior or posterior circulation, and National Institutes of Health Stroke Scale score of ≤4 at baseline. Patients were divided into 4 groups for further analysis: minor ACI with and without internal carotid artery/middle cerebral artery large vessel disease and minor PCI with and without vertebrobasilar large vessel disease. Results— A total of 7178 patients (65.2±12.6 years) were analyzed in this study, and 2233 patients (31.1%) had disability (modified Rankin Scale score 2–6) at 3 months. Disability was 32.3% in minor PCI and 30.3% in minor ACI ( P =0.07), and death was 1.3% and 1.5%, respectively ( P =0.82). In a multivariable logistic regression analysis, minor PCI was significantly associated with disability at 3 months when compared with minor ACI (odds ratio, 1.23; 95% confidence interval, 1.09–1.37; P <0.001). In pairwise comparisons, minor PCI with vertebrobasilar large vessel disease was independently associated with disability at 3 months, compared with the other 3 groups. Conclusions— Our study showed that minor PCI exhibited more frequent disability at 3 months than minor ACI. Especially, the presence of vertebrobasilar large vessel disease in minor PCI had a substantially higher risk of disability. Our results suggest that minor PCI with vertebrobasilar large vessel disease could require more meticulous care and are important targets for further study.