Aspirin in the secondary prevention of cardiovascular disease: an update of the APTC meta‐analysis

Abstract

We updated the 2002 Antiplatelet Trialists' Collaboration meta-analysis of antiplatelet therapy to assess the effects of aspirin alone in the secondary prevention of different types of thrombotic arterial disease. Results of randomized, placebo-controlled trials of aspirin in patients with confirmed cardiovascular disease were abstracted and synthesized by the Mantel-Haenszel method. We defined three cardiovascular disease groups according to the qualifying disease at entry: coronary artery disease (CAD), cerebrovascular disease (CRVD), and peripheral arterial disease (PAD). Results are given as odds ratios (OR) and 95% confidence intervals (95% CI). Compared with placebo, aspirin decreased significantly the risk of all-cause death in CAD and CRVD (OR = 0.80, 95% CI 0.75-0.86 and 0.91, 95% CI 0.85-0.98, respectively), and of vascular events in CAD, CRVD, and PAD (OR = 0.71, 95% CI 0.67-0.76, 0.87, 95% CI 0.82-0.93, and 0.50, 95% CI 0.29-0.88, respectively). The risk of non-fatal stroke was decreased in the CAD, CRVD, and PAD (OR = 0.64, 95% CI 0.50-0.83, 0.81, 95% CI 0.74-0.89, and 0.26, 95% CI 0.07-0.94, respectively). The risk of non-fatal myocardial infarction was decreased significantly in the CAD and CRVD (OR = 0.59, 95% CI 0.53-0.67, and 0.63, 95% CI 0.48-0.84, respectively), but not in the PAD (OR = 0.43, 95% CI 0.15-1.25). Aspirin nearly doubled the risk of major bleeds (OR = 1.87, 95% CI 1.51-2.32 for all clinical conditions). This meta-analysis confirms that aspirin decreases the risk of thrombotic events in patients with confirmed disease of the coronary, cerebrovascular, or peripheral artery beds.