Abstract Body (Do not enter title and authors here): Introduction: There is an active debate about who may benefit from taking aspirin to reduce their incidence of cardiovascular disease (CVD). Some prior cohort studies with small sample size suggest that aspirin use may be associated with a lower incidence of CVD or coronary heart disease (CHD) in adults with Lp(a) ≥50 mg/dL but not in those with Lp(a) <50 mg/dL, a hypothesis that needs confirmation.
Research question: Does the association of aspirin use with incident CVD or CHD vary by Lp(a) among US adults?
Methods: We analyzed publicly available data from adults without CVD at baseline in the ARIC (n=13,085, mean age 54 years), CHS (n=3,956, mean age 72 years), and MESA (n=6,324, mean age 62 years) studies. Lp(a) ≥50 mg/dL was defined as high. Participants were followed for incident CVD (myocardial infarction, stroke, or CVD death) and CHD (myocardial infarction or CHD death; median follow-up: ARIC 26 years, CHS 12 years, MESA 14 years). Hazard ratios associated with aspirin use were calculated after propensity score matching (primary analysis) and in all participants using multivariable adjustment (secondary analysis). Mixed-effects models were used to obtain pooled hazard ratios.
Results: Aspirin use was 25.1% in ARIC, 29.6% in CHS, and 19.9% in MESA. In MESA, adults taking aspirin were older, had higher blood pressure, and were more likely to have diabetes and a low estimated glomerular filtration rate and to be taking antihypertensive medication and a statin versus those not taking aspirin. These differences were attenuated or not present in ARIC and CHS. The CVD incidence rate per 1,000 person-years (95%CI) was higher in adults with versus without high Lp(a): 16.3 (15.3-17.4) and 12.5 (12.1-13.0), respectively, in ARIC, 35.8 (31.5-40.1) and 32.3 (30.6-34.0) in CHS, and 10.8 (9.1-12.4) and 8.2 (7.5-8.9) in MESA. Aspirin use was not associated with CVD or CHD incidence in adults with or without high Lp(a) in the primary analysis (Figure). No association between aspirin use and CVD or CHD incidence was present in the secondary analysis using multivariable adjustment (data not shown).
Conclusion: The association of aspirin use with CVD and CHD incidence did not differ by Lp(a) in this multi-cohort study.