Abstract
BACKGROUND: In previous analyses in ALLHAT, blacks had a significantly lower risk of coronary heart disease (CHD) in the pravastatin group compared to the usual care group, whereas non-blacks had no benefit from pravastatin. No previous statin trial has reported results separately in blacks. OBJECTIVES: The study aimed to determine if apparent racial differences in CHD in ALLHAT are explained by differences in baseline characteristics, adherence during the trial, or achieved blood pressure and lipid lowering. METHODS: This was a prespecified subgroup analysis of a randomized controlled trial. Hypertensive, moderately hypercholesterolemic participants were assigned to open-label pravastatin (40 mg/d) or usual care. The outcome was a composite of nonfatal myocardial infarction and fatal CHD. We performed intention-to-treat survival analyses using Cox proportional hazards models, adjusting for baseline covariates (age, sex, aspirin use, history of CHD and diabetes, and baseline hypertension treatment) and time-varying levels of blood pressure and total cholesterol. RESULTS: After adjustment for baseline characteristics, there remained a significant interaction between race and treatment group (P = .02). In stratified models, blacks in the pravastatin group had a 29% lower risk of CHD (hazard ratio [HR] 0.71, 95% CI 0.57-0.90, P = .005) compared to those in the usual care group, whereas non-blacks had no benefit (HR 1.00, 95% CI 0.85-1.19, P = .95). With further adjustment for achieved blood pressure and total cholesterol, the HR in blacks was 0.65 (95% CI 0.45-0.96, P = .03) and in non-blacks was 1.07 (95% CI 0.81-1.41, P = .65). CONCLUSIONS: Our results suggest that pravastatin is effective in preventing CHD in blacks.