Race and association of angiotensin converting enzyme/angiotensin receptor blocker exposure with outcome in heart failure.

Abstract

Angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) have been established as a mainstay of heart failure treatment. Current data are limited and conflicting regarding the consistency of ACE/ARB benefit across race groups in heart failure. This study aims to clarify this point. This was a retrospective study of insured patients with a documented ejection fraction of less than 50%, hospitalized for heart failure between January 2000 and June 2008. Pharmacy claims data were used to estimate ACE/ARB exposure over 6-month rolling windows. The association between ACE/ARB exposure and all-cause hospitalization or death was assessed by proportional hazards regression, with adjustment for baseline covariates and β-blocker exposure. Further analyses were stratified by race, and included an ACE/ARB × Race interaction term. A total of 1095 patients met inclusion criteria (619 African-American individuals). Median follow-up was 2.1 years. In adjusted models, ACE/ARB exposure was associated with lower risk of death or hospitalization in both groups (African-Americans hazard ratio 0.47, P < 0.001; whites hazard ratio 0.55, P < 0.001). A formal test for interaction was consistent with similar effects in each group (P = 0.861, β = 0.04). ACE/ARB exposure was equally associated with a protective effect in preventing death or rehospitalization among heart failure patients with systolic dysfunction in both African-American patients and whites.