Background: Aspirin is beneficial in secondary prevention of stroke and MI. There is no consensus on its role in primary prevention of the same.
Study design: Systematic review and meta-analysis.
Setting: PubMed and Embase search on Cochrane from the earliest publication available through Nov. 1, 2018.
Synopsis: This meta-analysis included randomized, controlled trials that compared aspirin use versus no aspirin use in more than 1,000 participants without known cardiovascular (CV) disease. The primary CV outcome was a composite of CV mortality, nonfatal MI, and nonfatal stroke. The primary bleeding outcome was major bleeding (defined by individual studies). Thirteen studies enrolling 164,225 participants and including 1,050,511 participant-years were included. Compared with no aspirin use, aspirin use showed a reduction in composite CV outcomes (hazard ratio, 0.89; 95% confidence interval, 0.84-0.95; number needed to treat, 265) and an increased risk of major bleeding (HR, 1.43; 95% CI, 1.30-1.56; number needed to harm, 210). Limitations of the study include variations in data quality, outcome definitions, and aspirin doses among trials. The study authors advocate for including the lower risk of CV events and increased risk of major bleeding as part of discussions with patients about the use of aspirin for primary prevention.
Bottom line: Aspirin for primary prevention lowers risk of CV events and increases risk of major bleeding. Health care providers should include this as part of informed decision-making discussions with patients about the use of aspirin for primary prevention.
Citation: Zheng S et al. Association of aspirin use for primary prevention with cardiovascular events and bleeding events: A systematic review and meta-analysis. JAMA. 2019 Jan 22;321(3):277-87.
Dr. Radhakrishnan is a hospitalist at Beth Israel Deaconess Medical Center.
