Aspirin's Efficacy in Primary Prevention Examined: Study Shows Varied Impact on Adults with Elevated Lipoprotein(a)

The study found a significantly lower atherosclerotic cardiovascular disease (ASCVD) mortality in adults without clinical ASCVD with elevated Lp(a). Given the high prevalence of predominantly genetically determined elevated Lp(a), the findings may have public and clinical health implications for aspirin utilization in primary prevention.

Analyzing more than 2900 people with a median follow-up of 26 years, the researchers found that regular aspirin use in those aged 40 to 70 years cut the risk of ASCVD mortality in half among those with Lp(a) levels of 50 mg/dL or more but had no benefit among those with reduced Lp(a).

Lipoprotein(a) is an atherogenic and prothrombotic lipoprotein associated with ASCVD. Alexander C. Razavi, Emory Clinical Cardiovascular Research Institute, Emory University School of Medicine, Atlanta, GA, and colleagues aimed to assess the association between regular aspirin use and ASCVD mortality among individuals with versus without elevated Lp(a) in a nationally representative US cohort.

Eligible participants were aged 40–70 years without clinical ASCVD, reported on aspirin use, and had Lp(a) measurements from the Third National Health and Nutrition Examination Survey (NHANES III, 1988–1994), the only cycle of this nationally representative US cohort to measure Lp(a).

Regular aspirin use was defined as aspirin intake ≥30 times in the previous month. Over a median 26-year follow-up, using NHANES III linked mortality records and weighted Cox proportional hazards regression, the association between regular use of aspirin and ASCVD mortality was observed in those with and without elevated Lp(a) (≥50 versus <50 mg/dL).

The study revealed the following findings:

• Among 2,990 persons meeting inclusion criteria (∼73 million US adults), the mean age was 50 years; 53% were female, and 7% reported regular aspirin use.
• The median Lp(a) was 14 mg/dL, and the proportion with elevated Lp(a) was similar among those with versus without regular aspirin use (15.1% versus 21.9%).
• Among individuals with elevated Lp(a), the incidence of ASCVD mortality per 1,000 person-years was lower for those with versus without regular aspirin use (1.2 versus 3.9).
• In multivariable modeling, regular aspirin use was associated with a 52% lower risk of ASCVD mortality among individuals with elevated Lp(a) (HR=0.48) but not for those without elevated Lp(a) (HR=1.01).

"Regular aspirin use was associated with a 52% lower risk of ASCVD mortality among adults without clinical ASCVD who had elevated Lp(a)," the researchers wrote. "These findings suggest that Lp(a) measurement may help identify individuals who benefit from aspirin therapy for primary prevention."

Reference:

Razavi, A. C., Richardson, L. C., Coronado, F., Dzaye, O., Bhatia, H. S., Mehta, A., Quyyumi, A. A., Vaccarino, V., Budoff, M. J., Nasir, K., Tsimikas, S., Whelton, S. P., Blaha, M. J., Blumenthal, R. S., & Sperling, L. S. (2024). Aspirin Use for Primary Prevention Among US Adults With and Without Elevated Lipoprotein(a). American Journal of Preventive Cardiology, 100674. https://doi.org/10.1016/j.ajpc.2024.100674