Angiotensin-converting enzyme inhibition in myocardial infarction--Part 2: Clinical issues and controversies.

Over the past 10 years, several clinical studies have concluded that, in patients already receiving conventional therapies, angiotensin-converting enzyme (ACE) inhibitors further reduce the risk of death following myocardial infarction (MI). Post-MI ACE inhibitors have proven to be effective as long term therapy in high risk patients as well as when used for much shorter periods in a broad patient population. However, while considerable mortality data have been collected, the effects of ACE inhibitors post-MI on other cardiovascular outcomes have not been as well documented. In addition, a number of issues regarding the most effective use of these agents remain unresolved. This paper, the second of two parts, focuses on the clinical issues and controversies surrounding the use of ACE inhibitors following acute MI. The effects of ACE inhibitors on the outcomes of sudden death, nonsudden death, recurrent angina, mitral regurgitation and left ventricular dysfunction are reviewed and potential mechanisms of action are proposed. In addition, ACE inhibitor therapy is discussed in terms of patient selection criteria, choice of agent, optimal dosing regimen, concomitant use of other therapies and relative costs of treatment. Finally, potential mechanisms of action of ACE inhibitors are proposed for each of the outcomes examined.