Abstract 14093: High-Sensitivity C-reactive Protein Modifies the Effect of Lipoprotein (a) on Cardiovascular Risk: The Multi-Ethnic Study of Atherosclerosis (MESA)

Abstract

Introduction: Lipoprotein (a) (Lp(a)) and inflammation, as represented by elevated high-sensitivity C-reactive protein (hsCRP) concentration, are both considered as risk-enhancers in the 2018 AHA/ACC Cholesterol guidelines. However, little is known as to whether the association of Lp(a) with atherosclerotic cardiovascular disease (ASCVD) risk is modified by inflammation. Objective: We assessed whether hsCRP modifies the association of Lp(a) with ASCVD risk. Methods: MESA participants with baseline hsCRP and Lp(a) levels were included. Incident ASCVD events were ascertained from baseline through 2017. Time to incident ASCVD was analyzed using Kaplan Meir curves. Cox proportional hazards models were used to assess the association between Lp(a), hsCRP, and time to ASCVD events adjusting for covariates. Results: The study included 4,654 participants with mean age of 62 and 52.5% females (1,702 Caucasians, 557 Chinese Americans, 1,336 African Americans and 1,059 Hispanics). With a mean 13.6-year follow-up, 676 ASCVD events occurred among 4,609 participants (Figure 1). In participants with hsCRP <2mg/L, the association of Lp(a) (per 1 Log unit increase) and risk for ASCVD as represented by hazard ratio (HR) and 95%CI was 1.01 (0.79, 1.28). In subjects with hsCRP ≥2mg/L, the risk increased to 1.26 (1.01, 1.58). When compared to the reference group with Lp(a) <50mg/dL and hsCRP <2mg/L, the risk for ASCVD in participants with Lp(a) ≥50mg/dL and hsCRP <2mg/L was 1.13 (0.85, 1.50) and in those with Lp(a) <50mg/dL and hsCRP ≥2mg/L was 1.09 (0.92, 1.31). The risk increased significantly to 1.62 (1.26, 2.07) in participants with Lp(a) ≥50mg/dL and hsCRP ≥2mg/L. Conclusions: Lp(a)-related ASCVD risk is modified by hsCRP levels. The findings of this analysis suggest that Lp(a) may serve as a risk enhancing factor in individuals with hsCRP level ≥2mg/L. Future studies are needed to determine whether Lp(a) is associated with risk of ASCVD in the absence of subclinical inflammation.