Black people who survived strokes caused by bleeding in the brain were more likely than whites to have high blood pressure a year later increasing their risk of another stroke, according to a study in the American Heart Association journal Stroke.
The study examined racial and ethnic differences in these strokes, called intracranial hemorrhage or ICH. They account for only 10 percent of all strokes but have a death rate of about 40 percent in the first month, much higher than other types of stroke. High blood pressure is the most important modifiable risk factor associated with bleeding stroke.
"If you have already had a stroke, blood pressure treatment can reduce your chance of having another stroke by between 25 and 50 percent," said Darin B. Zahuranec, M.D., M.S., lead author of the study and assistant professor of neurology at the University of Michigan Cardiovascular Center in Ann Arbor.
However, more than half of patients in the study still had high blood pressure a year after the stroke, despite taking one or more anti-hypertensive medications. There were no significant racial differences 30 days after ICH. But a year later, 63 percent of blacks had hypertension, compared with 38 percent of whites, despite taking more blood pressure medications.
The study was conducted at Georgetown University Medical Center and included 162 patients (average age 59, 77 percent black, 53 percent male) in Washington, D.C.
The study was too small to identify which factors may explain the racial differences. However, Zahuranec said two social factors were the only independent predictors of lower blood pressure at follow-up: patients who were married rather than single, and those that lived in a facility rather than a private residence had lower blood pressure.
"Blood pressure is not just about taking medications," Zahuranec said. "Patients can have a very large impact on blood pressure control by making changes to diet and exercise habits, and with weight loss. We need to do more for our patients to help them get their blood pressure under control."
Zahuranec said he hopes this study will help to underscore that environmental and social factors may be very important to blood pressure control in stroke survivors. He added that additional studies should also be done to further investigate underlying reasons for racial differences in blood pressure.