Clinical Trial of Propranolol in Acute Myocardial Infarction

BETA-ADRENERGIC blocking agents have been used with success in angina pectoris (Alleyne et al, 1963; Hamer et al, 1964; Keelan, 1965); and in various cardiac arrthymias (Besterman and Friedlander, 1965). Snow (1965) administered 10-20 mg. of propranolol (Inderal-I.C.I.) eight-hourly to 45 patients with myocardial infarction and found that the mortality in the treated cases was 16 per cent. compared with 35 per cent. in the controls. Snow's results have been challenged by Balcon et al (1966) and by Clausen et al (1966). Agents of this type can reduce the cardiac output and may therefore predispose to heart failure. It was felt that this risk was acceptable if they would prolong the survival time after acute myocardial infarction.