Polygenic risk, aspirin and primary prevention of coronary artery disease

Aims: Recent aspirin primary prevention trials failed to identify a net benefit of aspirin for preventing cardiovascular disease versus the harms of bleeding. This study aimed to investigate whether a high-risk subgroup, individuals with elevated genetic predisposition to coronary artery disease (CAD), might derive more benefit than harm with aspirin, compared to those with lower genetic risk.

Methods and results: We performed genetic risk stratification of the Aspirin in Reducing Events in the Elderly (ASPREE) randomized controlled trial using a CAD polygenic risk score (GPSMult). For 12,031 genotyped participants (5,974 aspirin, 6,057 placebo) overall, we stratified them by GPSMult quintiles (q1-5), then examined risk of CAD (composite of myocardial infarction and coronary heart disease death) and bleeding events using Cox models. During a median 4.6 years of follow-up with randomization to 100 mg/day aspirin versus placebo, 234 (1.9%) participants had CAD and 373 (3.1%) had bleeding events. In the overall cohort, aspirin resulted in higher bleeding risk (adjusted Hazard Ratio [aHR]=1.30 [1.06-1.61], P=0.01) but no significant CAD reduction (aHR=0.84 [0.64-1.09], P=0.19). However, among the highest quintile of polygenic risk (q5, top 20% of the GPSMult distribution), there was a 47% reduction in risk of CAD events with aspirin (aHR=0.53 [0.31-0.90], P=0.02) without increased bleeding risk (aHR=1.05 [0.60-1.82], P=0.88). Interaction between the GPSMult and aspirin was significant for CAD (q5 versus q1, P=0.02) but not bleeding (P=0.80).

Conclusion: The balance between net benefit and harm on aspirin in the primary prevention setting shifts favourably in individuals with an elevated genetic predisposition.