Reappraisal of beta-blocker therapy in the acute and chronic post-myocardial infarction period.

In patients presenting with acute myocardial infarction (MI), the early use of intravenous beta-blockade followed by short-term oral administration in the absence of reperfusion therapy has shown a modest reduction in mortality. In contrast, major reductions in mortality and reinfarction have been shown when beta-blockers have been used soon after an acute MI and continued long-term. These benefits were observed in trials conducted in the 1970s and 1980s, prior to the widespread use of reperfusion therapies, antiplatelet agents, and angiotensin-converting enzyme inhibitors; those trials excluded patients with postischemic heart failure. Recently, the CAPRICORN trial has shown a significant reduction in all-cause mortality and reinfarction in post-MI patients with systolic dysfunction, in response to carvedilol. In spite of compelling evidence supporting the use of beta-blockers in the post-MI setting, data published by the National Cooperative Cardiovascular Project have shown that fewer than half of all post-MI patients receive beta-blockers as long-term therapy. It appears that post-MI patients with perceived contraindications, such as advanced age, diabetes, heart failure, peripheral vascular disease, and/or chronic pulmonary obstructive disease, may derive a substantial benefit from the use of beta-blockers. Given the considerable evidence from randomized clinical trials, the use of beta-blockers is recommended in all post-MI patients without a contraindication, particularly in those with left ventricular systolic dysfunction.