The risk of having another stroke among African Americans is associated with ongoing high blood pressure (hypertension), according to results of a study published in the journal Neurology. Researchers also report that recurrent stroke leads to disability in nearly half of previously nondisabled patients.

“Stroke incidence and mortality are generally disproportionately higher among African Americans than among whites,” Dr. Sean Ruland, of the University of Illinois at Chicago, and colleagues write. Part of this risk may be explained by a greater vascular risk among African Americans, the researchers suggest.

In the current study, the researchers followed 1,809 patients in the African-American Antiplatelet Stroke Prevention Study and documented recurrent stroke, recurrent stroke type and disability.

During follow-up, there were 191 (10.6 percent) recurrent strokes, which occurred within a year after the previous stroke.

Of the recurrent strokes, 39.0 percent were possibly or probably caused by blockage of a small blood vessel; 16.1 percent were caused by blockage of a large blood vessel; and 36.8 percent were from an unidentified blockage or unknown cause. Nine (4.7 percent) of the recurrent strokes were caused by bleeding in the brain.

In 57 percent of patients, the type of recurrent stroke differed from the original stroke type.

Recurrent stroke led to greater neurologic impairment and function compared with that sustained after the previous stroke. Forty-eight percent of previously non-disabled subjects became disabled or died after a stroke recurrence.

Overall, the researchers determined that the most significant predictors of stroke recurrence were greater disability, diabetes and hypertension at study entry.

“Hypertension is the most predictive modifiable risk factor,” the team points out, noting that recent clinical trial data support “the beneficial effects of blood pressure lowering on recurrent stroke risk.”

SOURCE: Neurology, August 2006.