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.