Abstract 9121: Lipoprotein(a) and the Risk for Coronary Heart Disease and Ischemic Stroke Events Among Black and White Adults with Cardiovascular Disease

Abstract

Introduction: Lp(a) is a risk marker for incident coronary heart disease (CHD) and ischemic stroke. It is unclear if Lp(a) is associated with CHD and stroke events among adults with prevalent cardiovascular disease (CVD), particularly in non-White populations. Hypothesis: Higher Lp(a) levels are associated with an increased risk for both CHD and ischemic stroke events in Black and White adults with prevalent CVD. Methods: We conducted a case-cohort analysis including Black and White adults ≥45 years of age enrolled in the nationwide REasons for Geographic and Racial Differences in Stroke (REGARDS) study between 2003 and 2007 who had prevalent CVD at baseline. REGARDS study participants were followed for CHD and ischemic stroke events, which were expert adjudicated. Lp(a) molar concentration was measured using a particle-enhanced turbidimetric immunoassay from blood samples collected at baseline in a random subcohort of participants with prevalent CVD (n=1,948), and in all those with prevalent CVD who experienced a CHD event by December 31, 2017 (n=1,166), or an ischemic stroke by September 30, 2019 (n=492). Results: The median [25 th , 75 th percentile] Lp(a) concentration was 100 nmol/L [48, 186] among Black participants and 23 nmol/L [8, 113] among White participants (p-value <0.001). Higher Lp(a) was associated with an increased risk for CHD events among both Black and White participants, but it was not associated with the risk for ischemic stroke (Table). At baseline, 49% of Black participants and 59% of White participants with prevalent CVD were taking a statin. Among Black and White participants taking a statin, the hazard ratio [95% CI] associated with 1 SD higher log-Lp(a) was 1.69 [0.98, 2.93] and 1.38 [1.03, 1.85], respectively, for CHD, and 1.29 [0.70, 2.40] and 1.18 [0.81, 1.72], respectively, for stroke. Conclusion: Higher Lp(a) is a risk marker for CHD but not for ischemic stroke events in Black and White adults with prevalent CVD, including those taking a statin.