It could be the first medication for a specific race to win government approval.
The two-drug combination pill, BiDil, dramatically reduces deaths among blacks with heart failure. The condition affects five million Americans, but blacks are two and a-half times more likely to develop it.
Earlier research suggested standard heart failure drugs called ACE inhibitors don't work as well in blacks, unless taken with two other chemicals.
The NitroMed company combined those into the BiDil pill that, in tests, cut the heart failure death rate by 43 percent among blacks who had the condition.
Experts say genetic differences among ethnic groups are so small the drug should probably help whites, too.
The findings, reported at an American Heart Association meeting, will be published Thursday in the New England Journal of Medicine.