International beta-blocker review in acute and postmyocardial infarction

The benefits of beta blockade in acute and postmyocardial infarction are well documented. More than 50 placebo-controlled trials have been performed, involving more than 40,000 patients with short- or long-term follow-up. In long-term follow-up studies in approximately 20,000 patients, mortality was reduced by 21% and reinfarction by 24%. When high-risk patients were assessed separately, the reduction in mortality after early intervention was significantly greater than in low-risk patients. The trial medication was withdrawn in approximately 24% and 28% of patients in the placebo and beta-blocker groups, respectively, in the major trials. In addition to reduction of mortality and reinfarction rates, benefits have clearly been demonstrated in prevention of arrhythmias and thromboatherosclerotic complications. Significantly more patients had hypotension and bradycardia with beta-blocker treatment than with placebo; no clear-cut difference between the placebo and beta-blocker groups was found for atrioventricular block or congestive heart failure when patients with these conditions were excluded. In the Stockholm Metoprolol Trial, 3 years of metoprolol treatment in about 300 patients after myocardial infarction prolonged both survival and time spent completely asymptomatic, in an optimal functional state, or both. Patients receiving metoprolol spent less time disabled after serious atherosclerotic complications, including bypass surgery. Long-term beta blockade after myocardial infarction reduces mortality and morbidity in 80% of patients by 21% and 24%, respectively, but causes adverse reactions in approximately 10%. With proper selection of patients and the type and dose of beta blocker, survival without atherosclerotic complications or adverse effects can be prolonged.