Aspirin use for primary prevention among US adults with and without elevated Lipoprotein(a)

Area of Science:

• Cardiovascular Medicine
• Epidemiology
• Pharmacology

Background:

• Lipoprotein(a) [Lp(a)] is a key risk factor for atherosclerotic cardiovascular disease (ASCVD), contributing to both atherosclerosis and thrombosis.
• Understanding the interplay between Lp(a) levels and the benefits of aspirin therapy is crucial for personalized cardiovascular risk management.

Purpose of the Study:

• To investigate the association between regular aspirin use and ASCVD mortality in a US population stratified by Lipoprotein(a) [Lp(a)] levels.
• To determine if elevated Lp(a) modifies the effect of aspirin on ASCVD mortality.

Main Methods:

• Analysis of a nationally representative US cohort (NHANES III, 1988-1994) with linked mortality data.
• Participants (aged 40-70, no clinical ASCVD) were categorized based on Lp(a) levels (≥50 mg/dL vs. <50 mg/dL) and regular aspirin use (≥30 times/month).
• Weighted Cox proportional hazards regression models were used to assess ASCVD mortality over a median 26-year follow-up.

Main Results:

• Among approximately 73 million US adults, regular aspirin use was associated with a 52% lower risk of ASCVD mortality in individuals with elevated Lp(a) (Hazard Ratio=0.48).
• No significant association between regular aspirin use and ASCVD mortality was observed in individuals without elevated Lp(a) (Hazard Ratio=1.01).
• A significant interaction (p=0.001) indicated that the benefit of aspirin on ASCVD mortality was confined to those with elevated Lp(a).

Conclusions:

• Regular aspirin use demonstrates a significant protective effect against ASCVD mortality in individuals with elevated Lipoprotein(a) [Lp(a)] and no prior clinical ASCVD.
• These findings suggest that Lp(a) status may be an important consideration for primary prevention strategies involving aspirin.