Racial differences in outcome and treatment effect in congestive heart failure

BACKGROUND: In congestive heart failure (CHF), it is unknown whether race affects mortality and whether the effect of treatments differs by race. METHODS: This study was a post hoc analysis of data from the DIG study that evaluated the effect of digoxin on morbidity and mortality in CHF. RESULTS: Investigators followed 897 black and 6660 white participants for a mean of 37 months. Compared with whites, blacks were younger (60 +/- 13 vs 65 +/- 11 years). Total mortality was 34.2% in blacks and 33.6% in whites; hospitalization for worsening CHF occurred in 39% of blacks and 28% of whites. Cox regressions with race as the only covariate showed no effect of race on risk for death (relative risk = 1.04, 95% CI 0.93-1.18, P = .49) but an increase in CHF hospitalization in blacks (relative risk = 1.52, 95% CI 1.35-1.70, P = .0001). Multivariate Cox regression showed no difference by race in risk for death or death/hospitalization for CHF and no difference in the effect of digoxin on either end point. CONCLUSION: Race is not an independent predictor of mortality in CHF. The effect of digoxin on morbidity and mortality in CHF does not differ in blacks and whites.