Low-dose aspirin for primary prevention of cardiovascular disease.

Progressive atherosclerosis followed by plaque rupture is the leading cause of acute cardiovascular events. Inhibition of platelet aggregation by acetylsalicylic acid (aspirin) reduces recurrent cardiovascular events in secondary prevention trials. By extracting data from available randomized trials that examined aspirin prevention in persons without previously known cardiovascular disease, we evaluated the use of aspirin as a primary prevention measure. Using the raw data presented in the source publication on death, fatal and nonfatal myocardial infarctions, and cerebrovascular accidents, all relative and absolute risk reductions were recalculated with confidence intervals. In healthy men above 45 years of age, men with an increased cardiovascular risk profile, and persons with diabetes mellitus or hypertension, the use of aspirin reduces the incidence of myocardial infarction and has a neutral effect on cerebrovascular events. The protective effect of aspirin is apparently most prominent in those persons with an increased risk of manifest atherosclerotic vascular disease. Notwithstanding these results, for each patient it remains essential to balance the cardiovascular risk profile against the small increased risk of bleeding complications when prescribing aspirin.