Effects of beta blockers on ventricular dysfunction after myocardial infarction: tolerability and survival effects.

At least 44 randomized trials of beta blockade in acute myocardial infarction have been reported. All of these trials excluded patients with moderate-to-severe clinical signs of acute left ventricular dysfunction (LVD). Several of the larger trials did include high-risk patients with a history of compensated heart failure or with symptoms and signs suggesting mild LVD. Data from these trials indicate that beta-blocker treatment was well tolerated by patients with LVD, both in the acute phase of myocardial infarction and during long-term follow-up treatment. Further, data for LVD patients indicate that mortality in the beta-blocker group was reduced by 20-30% when compared with the placebo group. A similar mortality reduction was obtained for the entire patient population in the trials. Because of the high mortality among patients with mild LVD, the absolute gain in numbers of lives saved per 100 patients treated with beta blockers is even larger than that in patients without LVD. Data from two long-term trials indicate marked (47% and 43%) reductions in the likelihood of sudden death among LVD patients treated with beta blockers. These results suggest that all patients with LVD who can tolerate beta blockade may benefit from treatment with these agents.