Association of black race with recurrent stroke risk

The significantly higher risk of primary stroke in Black vs. Whites is very well established. However, very few studies have specifically examined the presence of this racial disparity in recurrent stroke risk.

We conducted an analysis of a clinical trial dataset comprising 3470 recent non-cardioembolic stroke patients aged ≥35years and followed for 2years. Subjects were categorized by race into Whites and Blacks. Cox regression analysis was used to evaluate the associations between Black (vs. White) and ischemic stroke (primary outcome); and stroke/coronary heart disease (CHD)/vascular death as major vascular events (secondary outcome) with and without adjustment for comorbid conditions associated with stroke.

Among participants (2925 Whites and 545 Blacks), a total of 287 (8.3%) incident stroke and 582 (16.8%) major vascular events occurred. Compared with Whites, Blacks had higher frequencies of prior stroke, hypertension, diabetes mellitus, and smoking; but were younger with lower prevalence of CHD. Frequency of stroke was higher in Blacks vs. Whites (11.4% vs. 7.7%; P=0.004), but there was no difference in major vascular events (16.9% vs. 16.8%). Compared with Whites, Blacks experienced a significantly higher risk of recurrent stroke (HR 1.58; 95% CI, 1.19-2.09), but the stroke risk was not significant after multivariable adjustment (1.13; 0.81-1.59).

Blacks are ~60% more likely to experience a recurrent stroke within 2years than their Whites, but this risk is likely mediated via stroke risk factors. These results underscore a need to optimize and sustain risk factor control in Black stroke populations.