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.

Figures

Figure 1. Risk for new vascular events (hazard function) by stroke subtypes adjusted for age, sex, and atherosclerotic burden

SSS-TOAST= Stop Stroke Study Trial of Org 10172 in Acute Stroke Treatment (evidence-based causative classification system for ischemic stroke).