Beneficial effect of long-term beta blockade after acute myocardial infarction in patients without anterograde flow in the infarct artery.

Previous studies have shown that long-term survival after acute myocardial infarction (AMI) is improved by beta-adrenergic blockade and anterograde flow in the infarct artery. This study was done to assess the influence of beta blockade on mortality in survivors of AMI without anterograde flow. Over 9.5 years, 113 subjects (87 men and 26 women, aged 26 to 66 years) with AMI and no anterograde flow in the infarct artery and no disease of the other arteries were medically treated for 48 +/- 28 (mean +/- standard deviation) months. Forty-six patients received long-term beta blockade (group I), whereas 67 did not (group II). The groups were similar in age, sex, cardioactive medications, left ventricular performance and infarct artery. Of the 46 group I subjects, 1 (2%) died of cardiac causes; in contrast, 20 (30%) of the group II patients died of cardiac causes (p = 0.007 compared with group I). Thus, in survivors of AMI without anterograde flow in the infarct artery, mortality is markedly reduced by long-term beta blockade.