New research into puzzling racial differences in medicine found that one widely prescribed heart drug works relatively poorly in Blacks, while another such drug is just as effective in Blacks as it is in people of other races.
The two drugs, an ACE inhibitor and a beta blocker, are standard treatment for heart failure, a condition in which the heart is weak and cannot pump enough blood. Previous studies suggested that Blacks get less benefit from these drugs, though the reasons are not clear.
An estimated 4.8 million Americans have congestive heart failure, about 25 percent more Blacks than Whites.
In a report in Thursday's New England Journal of Medicine, researchers said the beta blocker Coreg, also known as carvedilol, was equally effective in reducing the risk of death and hospitalization in Blacks and non-Blacks with chronic heart failure. The non-Black group included people of European, Asian and American Indian descent.
Coreg lowered the risk of death or hospitalization by 48 percent among Black patients, and 30 percent among non-Blacks. The researchers said that when other factors were taken into account, there was no difference between the two groups.
"The big question has been all along, does anything work?'' said one of the researchers, Dr. Clyde W. Yancy of the University of Texas Southwestern Medical Center in Dallas. "I think we can not only say, yes, something does work, but we can say it works in a very striking way and is equally similar.''
A second report looked at the ACE inhibitor Vasotec, or enalapril. The researchers found the drug reduced the risk of hospitalization 44 percent among Whites with damage to their left ventricles. There was no significant reduction among similar Black patients. The study matched 800 Black patients with 1,196 White patients.
The lead researcher, Dr. Derek V. Exner of the University of Calgary, said Blacks should not stop taking the drug but may need a higher dose.
"Based on the information we have, these drugs should still be used as standard treatment for heart failure,'' Exner said.
Yancy noted that the 217 Blacks and 877 non-Blacks in the Coreg study were also taking an ACE inhibitor. The combination, Yancy said, appears to be very effective treatment for heart failure in Black patients with mild to moderate disease.
In both studies, researchers analyzed data from previous tests of the drugs. The study of Coreg was sponsored by its makers, SmithKline Beecham Pharmaceuticals and Roche Laboratories, and some of the researchers have been consultants to or employed by Glaxo SmithKline.
In an accompanying editorial, Dr. Alastair J.J. Wood of Vanderbilt University School of Medicine said the reports will be a "great help to physicians in their attempt to choose the best therapy for heart failure in patients of different races.''