Researchers from London, United Kingdom, conducted a meta-analysis of 13 randomized clinical trials to determine the effects of aspirin for primary prevention of cardiovascular events. The main cardiovascular outcome was the combination of cardiovascular mortality, nonfatal myocardial infarction, and nonfatal stroke. The main bleeding outcome was any major bleeding as defined by each study.

The use of aspirin in individuals without cardiovascular disease (CVD) was found to be linked to a reduced risk of cardiovascular events and an increased risk for major bleeding, according to a study published in JAMA.

Eligible studies in the meta-analysis compared aspirin use with either placebo or no treatment; follow-up of ≥12 months was required, and participants could not have known CVD.

A total of 164,225 individuals (median age, 62 years; 53% women) with 1,050,511 participant-years of follow-up were included in the analysis; 19% of participants had diabetes. The risk of the primary cardiovascular outcome ranged from 2.6% to 15.9%, with a median baseline of 9.2%.

Aspirin use was found to be significantly associated with a reduced risk of composite cardiovascular outcomes compared with no aspirin use (hazard ratio [HR], 0.89; absolute risk reduction, 0.38%). In addition, aspirin use was linked to an increased risk of major bleeding events compared with no aspirin use (HR, 1.43; absolute risk increase, 0.47%).

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“The current study demonstrates that the absolute risk reduction for cardiovascular events and absolute risk increase for major bleeding associated with aspirin use were of similar magnitude,” the authors noted. “Aspirin use was not associated with a reduction in cardiovascular mortality, and deaths due to bleeding were rare,” they continued. “Consequently, the decision to use aspirin for primary prevention may need to be made on an individual basis, accounting for the patient’s risk of bleeding and their views on the balance of risk vs benefit.”

Reference

Zheng SL, Roddick AJ. Association of aspirin use for primary prevention with cardiovascular events and bleeding events:  a systematic review and meta-analysis. JAMA. 2019;321(3):277-287.