Acetylsalicylic Acid (Aspirin) for Primary Prevention of CardiovascularEvents in Patients with Diabetes: A Systematic Review and Meta-Analysisof Randomized Controlled Trials

BACKGROUND: Evidence regarding using acetylsalicylic acid (aspirin) for the prevention of cardiovascular (CV) events in patients with diabetes mellitus (DM) is inconsistent. Therefore, we performed a meta-analysis. METHODS: A literature search was performed (January 1990 to February 2022) and publications meeting the inclusion criteria were reviewed, and a meta-analysis was performed using RevMan software. The primary outcome was a composite of CV death, non-fatal myocardial infarction (MI) and stroke. Secondary outcomes included all-cause mortality, individual components of the primary outcome and major bleeding. RESULTS: The study cohort comprised 33525 diabetic patients from 9 randomized controlled trials. The primary outcome was significantly lower for aspirin vs. placebo (7.9 vs. 8.6, RR (risk ratio) 0.92, 95% CI (confidence interval) 0.86-0.99). All-cause mortality (10 vs. 10.3%, RR 0.97, 95% CI 0.90-1.03), CV death (4.4 vs. 4.7%, RR 0.93, 95% CI 0.83-1.04), non-fatal MI (4.6 vs. 4.8% RR 0.97, 95% CI 0.83- 1.15) and stroke (3.2 vs. 3.5%, RR 0.89, 95% CI 0.75-1.06) were similar between the two treatment groups. Major bleeding was significantly higher for aspirin compared with placebo (3.4 vs. 2.8%, RR 1.18, 95% CI 1.01-1.39). CONCLUSION: Aspirin use in patients with DM reduces the composite endpoint of CV death, non-fatal MI and stroke compared with a placebo. However, routine use of aspirin for primary prevention among diabetic patients cannot be advised due to the increased risk of major bleeding. These findings suggest careful risk assessment of individual patients.