Secondary prevention trials after acute myocardial infarction.

Of those patients who reach the hospital after an acute myocardial infarction, 18% die during their stay and 85% to 90% of the remainder will eventually die of coronary artery disease. Several secondary preventive approaches have been made to prolong life in these patients. Long-term controlled trials involving nonsurgical measures and at least 100 patients will be reviewed. Lipid-lowering regimens have shown no demonstrable effect on survival over a 4- to 6-year period but show some benefit with respect to nonfatal infarction. Survival was not improved essentially by anticoagulants, antiarrhythmic agents or calcium channel blockers, although new trials are underway that might clarify their role. Platelet-active drugs achieved little reduction in mortality but showed benefit in nonfatal infarction (30% reduction with aspirin). Pooled data on physical exercise programs demonstrated a 15% benefit on mortality but larger trials are required to confirm this. The data on beta blockers (particularly those without intrinsic sympathomimetic activity) show that these drugs improve long-term survival after myocardial infarction, reducing all-cause mortality by as much as 25% to 30%. Larger trials are necessary to detect statistically significant reductions in mortality both overall and in selected subgroups of patients.