BACKGROUND: We examined whether a fixed dose of both isosorbide dinitrate and hydralazine provides additional benefit in blacks with advanced heart failure, a subgroup previously noted to have a favorable response to this therapy. METHODS : A total of 1050 black patients who had New York Heart Association class III or IV heart failure with dilated ventricles were randomly assigned to receive a fi xed dose of isosorbide dinitrate plus hydralazine or placebo in addition to stan dard therapy for heart failure. The primary end point was a composite score made up of weighted values for death from any cause, a first hospitalization for hea rt failure, and change in the quality of life. RESULTS: The study was terminated early owing to a significantly higher mortality rate in the placebo group than in the group given isosorbide dinitrate plus hydralazine (10.2 percent vs. 6.2 p ercent, P=0.02). The mean primary composite score was significantly better in th e group given isosorbide dinitrate plus hydralazine than in the placebo group(- 0.1±1.9 vs. -0.5±2.0, P=0.01; range of possible values, -6 to +2), as were its individual components(43 percent reduction in the rate of death from any cau se[hazard ratio, 0.57; P=0.01] 33 percent relative reduction in the rate of firs t hospitalization for heart failure[16.4 percent vs. 22.4 percent, P=0.001], and an improvement in the quality of life [change in score, -5.6±20.6 vs. -2.7± 21.2, with lower scores indicating better quality of life; P=0.02; range of poss ible values, 0 to 105]). CONCLUSIONS: The addition of a fixed dose of isosorbide dinitrate plus hydralazine to standard therapy for heart failure including neur ohormonal blockers is efficacious and increases survival among black patients wi th advanced heart failure. BACKGROUND: We examined whether a fixed dose of both isosorbide dinitrate and hydralazine provides additional benefit in blacks with advanced heart failure, a subgroup previously noted to have favorable response to this therapy. A total of 1050 black patients who had New York Heart Association class III or IV heart failure with dilated ventricles were randomly assigned to receive a fi xed dose of isosorbide dinitrate plus hydralazine or placebo in addition to stan dard therapy for heart failure. The primary end point was a composite score made up of weighted values ​​for death from any cause, a first hospitalization for hea rt failure, and change in the quality of life. RESULTS: The study was terminated early due to a significantly higher mortality rate in the placebo group than in the group given isosorbide dinitrate plus hydralazine (10.2 percent vs. 6.2 p ercent, P = 0.02). The mean primary composite score was significantly better in th e group given isosorbide dinitrate p lus hydralazine than in the placebo group (-0.1 ± 1.9 vs. -0.5 ± 2.0, P = 0.01; range of possible values, -6 to +2), as were its individual components (43 percent reduction in the rate of death from any cau se [hazard ratio, 0.57; P = 0.01] 33 percent relative reduction in the rate of firs t hospitalization for heart failure [16.4 percent vs. 22.4 percent, P = 0.001], and an improvement in the quality of life [change in score, -5.6 ± 20.6 vs. -2.7 ± 21.2, with lower scores indicating better quality of life; P = 0.02; range of poss ible values, 0 to 105]). CONCLUSIONS: The addition of a fixed dose of isosorbide dinitrate plus hydralazine to standard therapy for heart failure including neurohormonal blockers is efficacious and increases surviving among black patients wi th advanced heart failure.