Relevance of stroke subtype in vascular risk prediction

Abstract

OBJECTIVE: To ascertain the risk of a new vascular event (NVE) occurring after ischemic stroke and evaluate differences in risk based on stroke subtype. METHODS: This was a prospective observational study of consecutive patients with nonfatal stroke recruited at a single tertiary stroke center with follow-up ranging from 2 to 5 years (average, 31 ± 15.9 months). An NVE (vascular death, nonfatal stroke or myocardial infarction, and hospitalization for other atherothrombotic events) was defined according to criteria used in a previously developed large multicenter register of atherothrombotic patients (Reduction of Atherothrombosis for Continued Health Registry [REACH]). We analyzed age, sex, and atherosclerotic burden (AB) based on a number of vascular risk factors, affected vascular areas, and stroke subtype according to Stop Stroke Study Trial of Org 10172 in acute stroke treatment (SSS-TOAST) criteria in cardioaortic, large artery atherosclerosis (LAA), unclassified (more than one causal mechanism), small-artery disease (SAD), and undetermined (without cause) stroke categories. RESULTS: The final cohort consisted of 748 patients. An NVE occurred in 162 patients (21.7%), equivalent to a rate of 0.084 events per patient/year. Multivariate analysis revealed that higher NVE risk was associated with AB and 3 stroke subtypes, namely cardioaortic (hazard ratio [HR] = 2.58; 95% confidence interval [CI] 1.27-5.22), LAA (HR = 4.17; 95% CI 2.03-8.56), and unclassified (HR = 5.70; 95% CI 2.49-13.08). Patients with SAD or stroke of undetermined cause had lower NVE risk. CONCLUSIONS: Patients who survive stroke are at increased risk for NVEs. The risk for NVE varies according to stroke subtype.