AT1 receptor blockade for the prevention of cardiovascular events after myocardial infarction

Abstract

Myocardial infarction is associated with high morbidity and mortality. Multiple therapeutic modalities have been shown to be effective in reducing adverse postmyocardial infarction outcomes. The most prominent drugs that have been used in this group of patients are those that oppose the effects of the renin-angiotensin-aldosterone system. These drugs include beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and aldosterone blockers. Following initial success with angiotensin-converting enzyme inhibitors in reducing mortality and cardiac remodeling in postmyocardial infarction patients, recent focus has been on adjunctive or alternative use of angiotensin II-receptor antagonists. Multiple large-scale, randomized trials have been conducted in order to compare angiotensin II-receptor antagonists with a combination of angiotensin II-receptor antagonists and angiotensin-converting enzyme inhibitors, and with angiotensin-converting enzyme inhibitors alone in postmyocardial infarction patients and also in heart failure. Although some results are conflicting, the weight of evidence is towards equivalency of these two groups of medicines, provided that the maximum effective dose of the angiotensin II-receptor antagonists is used. The combination of an angiotensin-converting enzyme inhibitor and an angiotensin II-receptor antagonist may have additional benefits for some, but not all, patients; for example, reducing morbidity and mortality in patients with chronic heart failure but not in postmyocardial infarction patients. Indeed, in the postmyocardial infarction setting, the combination appears simply to increase the side effects, without conferring additional benefits. Use of aldosterone antagonists as adjunctive therapy in postmyocardial infarction patients is associated with added benefits in terms of mortality reduction and will become the standard of care in this group of patients.