Relation between aspirin dose, all-cause mortality, and bleeding in patients with recent cerebrovascular or coronary ischemic events (from the BRAVO Trial).

Overview

Despite aspirin's established role in the treatment of atherosclerotic vascular disease, considerable controversy exists regarding its most effective dosing strategy. In a retrospective observational study, we examined the relation between prescribed aspirin dose (<162 mg vs > or =162 mg/day aspirin) and clinical outcome in 4,589 placebo-treated patients enrolled in the Blockage of the Glycoprotein IIb/IIIa Receptor to Avoid Vascular Occlusion (BRAVO) trial over a median follow-up of 366 days. Standard Cox regression analysis was employed because propensity analysis was not feasible. Compared with lower aspirin doses, higher doses were associated with lower unadjusted all-cause mortality (2.9 vs 1.6%, respectively; log rank chi-square 8.6, p = 0.0034). Higher aspirin dose remained independently predictive of lower all-cause mortality in a multivariable Cox proportional hazards model (hazard ratio 0.64, 95% confidence interval 0.42 to 0.97, p = 0.037). However, there was no significant difference in the incidence of the composite endpoint death, nonfatal myocardial infarction, or nonfatal stroke (6.1% vs 6.2%, p = 0.74). Higher aspirin dose was a significant independent predictor of any (hazard ratio 1.32, 95% confidence interval 1.12 to 1.55, p = 0.001) but not serious bleeding. In conclusion, our findings suggest that aspirin doses of > or =162 mg/day may be more beneficial than those <162 mg/day at preventing death.