Angiotensin-converting enzyme inhibitors in heart failure: a role after myocardial infarction

The prognosis for clinical congestive heart failure remains poor even with modern treatment as severe ventricular dysfunction is often present at the time of clinical presentation. A substantial improvement in prognosis might be achieved through earlier intervention and a preventive approach to treatment following myocardial infarction to delay progressive ventricular dilation and the occurrence of clinical heart failure. The rationale for treatment of left ventricular dysfunction following myocardial infarction is further supported by the prognostic importance of ventricular dilation and by experimental animal studies that demonstrate that converting enzyme inhibition can improve ventricular function and survival following myocardial infarction. Similarly, clinical studies have demonstrated that converting enzyme inhibition can improve ventricular function during the year following transmural myocardial infarction. Possible mechanisms of action that require further understanding include ventricular afterload reduction and direct coronary and tissue effects of angiotensin II blockade. The further benefit to be obtained from very early intervention following myocardial infarction is currently being addressed in several studies. Large-scale studies also in progress should determine the mortality benefit of such treatment. Further questions that remain include the optimal timing of intervention, comparison with other treatments such as nitrates and beta-blockade, and also the use of appropriate combination treatments.