A Closer Look at Aspirin for Primary Prevention

Many consider aspirin to be a miracle drug, but its use for primary prevention of cardiovascular events remains controversial. To synthesize the existing evidence, these investigators pooled patient-level data from major prevention trials comparing aspirin with no aspirin (control).

Six primary-prevention trials involving 95,000 subjects were included in the analysis. During 330,000 person-years, 1671 vascular events occurred in the aspirin group and 1883 in the control group (0.51% and 0.57% per year, respectively; relative risk, 0.88; 95% confidence interval, 0.82–0.94). Aspirin was associated with an 18% proportional reduction in coronary events, with an absolute reduction of 0.06% per year. Stroke incidence was not significantly reduced …