A genetic variation common in African-Americans naturally protects heart failure patients as effectively as popular heart medications, researchers reported today.
Scientists at the University of Maryland and other institutions tracked more than 300 heart failure patients for up to eight years and found that variations of a particular gene extended the lives of many of them for several years - just as if they were on beta blockers.
Researchers found the variation in 40 percent of blacks but only 2 percent of Caucasians. The finding could help explain why beta blockers seem to provide less benefit to African-Americans than other groups: Many of them already have nature working for them.
"It's a genetic mechanism that mimics the effects of the drugs," said Dr. Stephen Liggett, a co-author of the study and a professor of medicine and physiology at the University of Maryland School of Medicine.
The study, published today in the journal Nature Medicine, could eventually lead to genetic testing for heart failure patients, with the goal of tailoring therapies based on the results, experts say.
"This is cool stuff," Dr. David Kass, an expert on beta blockers at the Johns Hopkins School of Medicine, said of the report. "I've never seen anything like that."
The study showed how beta blockers affect long-term survival rates among heart failure patients with different genetic markers - adding to a growing body of evidence focused on the role genes play in how we respond to drugs.
"We're just at a point of understanding the genetics that put us at increased risk of common diseases and the differences in how we respond to a lot of the medications we use for them," said Dr. Maren T. Scheuner, a researcher at the Rand Corp. and the UCLA Center for Health Policy Research.
Black people suffer disproportionately from heart problems, scientists say. They have higher rates of hypertension and Type 2 diabetes and nearly twice the risk of developing heart failure as Caucasians. They're also at greater risk for high blood pressure, which can damage the heart if left untreated.
An estimated 750,000 African-Americans have been diagnosed with heart failure, and the number is expected to increase to 900,000 by 2010, according to the federal Centers for Disease Control and Prevention.
The genetic underpinnings of response to heart failure medication is worth studying, Liggett said, because the illness is so insidious.
