beta-Blockade in acute myocardial infarction. Inability of relatively late administration to influence infarct size and arrhythmias.

The effects of orally administered timolol maleate (10 mg twice a day) were assessed in 88 patients entered into a double-blind study within 10.74 +/- 5.07 hours of onset of myocardial infarction. Timolol maleate produced no significant change in crude mortality rate, infarct size, incidence of arrhythmias or significant left ventricular failure. Withdrawals from study because of recurrent angina or hypertension were confined to the placebo group. The results of this study suggested that, when given relatively late after infarction, timolol maleate does not reduce either infarct size or incidence of arrhythmias, despite production of a safe and effective beta-blockade.