From University of Texas Southwestern Medical Center at Dallas
UT Southwestern researcher finds beta-blocking drug reduces heart failure in blacks
DALLAS - May 3, 2001 - The beta-blocking drug carvedilol reduces the risk of death and the symptoms of mild to moderate heart failure in black patients as well as it does in nonblack patients, according to results from the U.S. Carvedilol Heart Failure Trials Program led by a researcher at UT Southwestern Medical Center at Dallas.
Beta-blockers previously have been shown to be less effective in blacks than in nonblacks. This is the first study to evaluate whether race influences the response to the relatively new beta-blocker carvedilol, which also has alpha-blocking properties, as a treatment for heart failure, a disease that affects 3 percent of all black adults in the United States.
The researchers reported a 54 percent reduction in both death and hospitalization due to progression of heart failure in the black patients enrolled in the study. Similar results also were reported in nonblack patients. Their findings are reported in today's issue of The New England Journal of Medicine.
"For a long time, we've had a group of people (blacks) with a bad disease. It affects them worse than anyone else, and we've never really known if there is any therapeutic strategy that makes a difference," said Dr. Clyde Yancy, medical director of the UT Southwestern/St. Paul heart transplant program and lead author of the study.
"We have shown that carvedilol drastically reduces death and the progression of heart failure by 50 percent in this patient population. It's nice to know that risk can be cut in half by taking these medicines," said Yancy.
Several factors account for the high incidence of heart failure among blacks, Yancy said, including hypertension, which is prevalent in blacks, and appears to more aggressively affect other organs in the body. Blacks also have more strokes and kidney failure, Yancy said.
"We've always had concerns that even though we have come up with treatments for heart failure that appear to be very effective, we've never had sufficient data to know if they are effective, according to gender, race and age," he said.
In addition to blocking the b1 receptor, carvedilol also inhibits b2- and a1-adrenergic receptors, which may make this treatment particularly suitable for blacks, Yancy said.
These three receptors are believed to be the main receptors involved in the progression of heart failure.
Of the 1,094 patients involved in the study, 217 were black and 877 were of European, Asian or Native American descent. Ninety of the black study participants received a placebo and 127 received carvedilol.
The study participants were randomly assigned to receive a placebo or 6.25 milligrams to 50 mg of carvedilol twice daily for up to 15 months, in addition to conventional angiotensin-converting-enzyme (ACE) inhibitors, which are also used to treat heart failure.
The combined therapy lowered the risk of death from any cause by 48 percent in blacks and by 30 percent in nonblacks.
"It's incredibly reassuring and very much pertinent for contemporary medicine to be able to say with emphasis that this regimen works in African-American patients. It represents a new standard that we are able to prescribe in a positive way. This is a therapeutic strategy that is effective in an at-risk population," Yancy said.
Others involved in the study included Dr. Eric Eichhorn, professor of internal medicine at UT Southwestern and director of the cardiac catheterization lab at the Dallas Veterans Affairs Medical Center, and researchers from Stanford University School of Medicine, Boston University School of Medicine, the University of Utah School of Medicine, the University of Colorado School of Medicine, the University of Minnesota Medical School - Minneapolis, Columbia University College of Physicians and Surgeons, and GlaxoSmithKline.
The study was funded by grants from GlaxoSmithKline and Roche Laboratories.