Abstract
The effects of white matter hyperintensity volume and subclinical brain infarcts on the risk of incident stroke, its ischemic subtypes, and mortality require further study in diverse samples.
Stroke-free participants in the Northern Manhattan Study underwent magnetic resonance imaging (N=1287; mean age 71±9 years, 60% women, 15% non-Hispanic white, 17% non-Hispanic black, 68% Hispanic) and were followed for a median of 8 years (interquartile range: 6-9 years). Cox models estimated proportional hazards of incident stroke of all types, ischemic stroke (and its subtypes), and mortality and stratified by race/ethnicity. In total 72 participants (6%) had incident strokes and 244 died (19%). In fully adjusted models, those with larger white matter hyperintensity volume had greater risk of all stroke types (hazard ratio [HR]: 1.4; 95% CI, 1.1-1.9), ischemic stroke (HR: 1.3; 95% CI, 1.0-1.8), and cryptogenic stroke (HR: 2.2; 95% CI, 1.1-4.4). White and black but not Hispanic participants had increased stroke risk (
<0.05 for heterogeneity for all and ischemic stroke). Those with subclinical brain infarct had greater risk for all stroke types (HR: 1.9; 95% CI, 1.1-3.3), ischemic stroke (HR: 2.2; 95% CI, 1.3-3.8), lacunar (HR: 4.0; 95% CI, 1.3-12.3), and cryptogenic stroke (HR: 3.6; 95% CI, 1.0-12.7), without significant heterogeneity across race/ethnic groups. Greater white matter hyperintensity volume increased both vascular (HR: 1.3; 95% CI, 1.1-1.7) and nonvascular (HR: 1.2; 95% CI, 1.0-1.5) mortality among Hispanic and white but not black participants (
=0.040 for heterogeneity). Subclinical brain infarct was associated with increased vascular mortality among Hispanic participants only (HR: 2.9; 95% CI, 1.4-5.8).
In this urban US sample, subclinical cerebrovascular lesions increased the risk of clinical stroke and vascular mortality and varied by race/ethnicity and lesion type.
