Angiotensin receptor blockers versus ACE inhibitors: Prevention of death and myocardial infarction in high-risk populations

OBJECTIVE: To determine, through a review of the medical literature, whether there is adequate evidence to support the use of angiotensin receptor blockers (ARBs) in place of angiotensin-converting enzyme (ACE) inhibitors in high-risk populations, focusing on the prevention of death and myocardial infarction (MI). DATA SOURCES: Original investigations, reviews, and meta-analyses were identified from the biomedical literature via a MEDLINE search (1966-August 2004). Published articles were also cross-referenced for pertinent citations, and recent meeting abstracts were searched for relevant data. STUDY SELECTION AND DATA EXTRACTION: All articles identified during the search were evaluated. Preference was given to prospective, randomized, controlled trials that evaluated major cardiovascular endpoints and compared ARBs with ACE inhibitors, active controls, or placebo. DATA SYNTHESIS: The renin-angiotensin system plays a pivotal role in the continuum of cardiovascular disease and represents a major therapeutic target in the treatment of patients at risk for vascular events. While ACE inhibitors have been definitively shown to prevent death and MI, studies with ARBs in similar populations have not reduced these endpoints. In clinical trials that enrolled patients with heart failure, post-MI, diabetes, and hypertension, ARBs did not prevent MI or prolong survival compared with ACE inhibitors, other anti hypertensives, or placebo. CONCLUSIONS: ACE inhibitors and ARBs should not be considered interchangeable, even among patients with a documented history of ACE inhibitor intolerance. ARBs can be considered a second-line alternative in such patients with the realization that they have not been shown to prevent MI or prolong survival.