Factors associated with unfavorable outcome in minor ischemic stroke

Objectives: 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. Methods: 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. Results: 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). Conclusions: 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.