Purpose: Information regarding the use of aspirin for patients with no known cardiovascular disease remains conflicting. We performed an updated meta-analysis to evaluate the efficacy and safety of aspirin for primary prevention of cardiovascular disease.
Patients and methods: PubMed, MEDLINE, and Cochrane library databases were searched for randomized controlled trials comparing aspirin with placebos or no treatment published up until November 1, 2018. The primary efficacy endpoint was all-cause death. The secondary endpoints included cardiovascular death, myocardial infarction, and stroke. The safety endpoints included major bleeding, gastrointestinal bleeding, and hemorrhagic stroke.
Results: Fourteen studies were included. Aspirin use was associated with a lower risk of myocardial infarction than placebo use or no treatment (risk ratio [RR], 0.83, 95% confidence interval [CI]: 0.73–0.95, P = 0.005). Additionally, compared with the control groups, aspirin use was not associated with a lower risk of all-cause mortality or cardiovascular mortality. In terms of safety, aspirin use was associated with a higher risk of major bleeding (RR, 1.40, 95% CI: 1.25–1.57, P = 0.000), gastrointestinal bleeding (RR, 1.58, 95% CI: 1.25–1.99, P = 0.000), and hemorrhagic stroke (RR, 1.30, 95% CI: 1.06–1.60, P = 0.011). Furthermore, the treatment effect was not significantly modified by patients’ clinical characteristics. No publication bias was present.
Conclusion: Aspirin use reduced the myocardial infarction risk in patients without known cardiovascular disease, but had no effect in terms of reducing the risk of all-cause death, cardiovascular death, and stroke, and increased the risk of major bleeding, gastrointestinal bleeding, and hemorrhagic stroke.
Keywords: aspirin, primary prevention, cardiovascular disease, meta-analysis