Secondary prevention of myocardial infarction with drugs.

Clinical trials in the field of secondary prevention of myocardial infarctions are reviewed, with emphasis on those studies that were randomized and included at least 100 patients. Standardized total mortality data, when available, are provided. Five groups of drugs are reviewed: 1) antiarrhythmic drugs, including studies of phenytoin, tocainide, mexiletine and aprindine. Important, commonly used drugs in this group, which apparently have not been submitted to clinical trials, include procainamide and lidocaine; 2) lipid-lowering drugs, including estradiol, conjugated equine estrogen, dextrothyroxine, clofibrate and nicotinic acid; 3) anticoagulant drugs, the oldest and most controversial preventive drug measure. In this group, only the oral drug derivatives of indandione or coumarin have been tested, and no appropriate studies of parenteral heparin were found; 4) platelet-active drugs--six studies dealing with aspirin alone, one combining aspirin and dipyridamole, and one study of sulfinpyrazone are reviewed; and 5) beta-adrenergic blocking drugs, including practolol and timolol.