Factors associated with unfavorable outcome in minor ischemic stroke

Abstract

The purpose of this study was to elucidate the factors that correlate with unfavorable outcomes and to develop a simple validated model for assessing risk of unfavorable outcomes in patients with minor ischemic stroke. The derivation cohort included 1,313 patients hospitalized within 72 hours after onset with an initial NIH Stroke Scale score of 0 to 3 enrolled in a prospective, multicenter, observational study. Unfavorable outcome was defined as dependency (modified Rankin Scale score of 3-5) or death at 90 days. The predictive values of factors related to unfavorable outcome were evaluated. External validation was performed in 879 patients from a single-center stroke registry. In the derivation cohort, a total of 203 patients (15%) had unfavorable outcomes. On multivariable analysis, women (odds ratio [OR] 1.95, 95% confidence interval [CI] 1.30-2.94), age ≥72 years (OR 2.80, 95% CI 1.83-4.36), intra/extracranial vascular occlusive lesion (OR 2.80, 95% CI 1.82-4.28), leg weakness (OR 1.72, 95% CI 1.06-2.82), and extinction/inattention (OR 5.55, 95% CI 1.30-21.71) were independently associated with unfavorable outcome. Patients having both a vascular lesion and either leg weakness or extinction/inattention showed 4.63 (95% CI 2.23-9.33) times the risk of unfavorable outcome compared with those having neither. In the validation cohort, the risk was similar, at 3.77 (95% CI 1.64-8.37). Intra- and extracranial vascular imaging, NIH Stroke Scale items such as leg weakness and extinction/inattention, and their combination, as well as female sex and advanced age, may be useful for predicting unfavorable outcomes in patients with minor stroke.