Chronic beta blockade therapy in patients after myocardial infarction

This report is a review of >18 years of experience with clinical trials that have examined the effect of beta blockers on mortality after acute myocardial infarction (MI). Despite inadequate sample size, a substantial number of the early randomized trials demonstrated a trend toward reduction in mortality after MI using a number of beta blockers. This review highlights the larger prospective randomized trials, especially the Multicenter International Trial of practolol, the Norwegian Multicenter Study of timolol and the Beta-Blocker Heart Attack Trial (BHAT) of propranolol. The combined strength of these longterm trials, comprising > 8,000 patients, demonstrates a consistent and statistically significant reduction in mortality after MI. Both the Norwegian timolol study and BHAT further document a substantial reduction in mortality in patients stratified according to risk groups, with a reduction in mortality after complicated or uncomplicated first MI or in patients with prior MI. These 2 studies also document a reduction in sudden death mortality in the first year after MI. Data regarding subendocardial MI is more variable, but the Norwegian timolol study documents a substantial reduction in mortality after subendocardial MI. Based on this review, we recommend treatment of all patients who can tolerate beta blockade after acute MI, beginning in the late hospitalization phase and continuing for at least 2 years.