Elevated lipoprotein(a) [Lp(a)] levels and coronary artery calcium scores are independently associated with an increased risk for atherosclerotic cardiovascular disease; however, they have not been evaluated in combination. These findings were published in the Journal of the American College of Cardiology.
Researchers sought to explore both the independent and joint associations of Lp(a) and coronary artery calcium score with an individual’s risk for atherosclerotic cardiovascular disease (ASCVD). At study enrollment, plasma Lp(a) levels and coronary artery calcium scores were obtained from patients in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort (n=4512) and patients in the Dallas Heart Study (DHS) cohort (n=2078). Elevated Lp(a) was defined as the highest race-specific quintile. For coronary artery calcium, 3 score categories were analyzed: 0, 1 to 99, and 100 or higher.
In the MESA cohort, 52.5% of the participants were women. Overall, 36.8% of patients in this cohort were White, 29.3% were Black, 22.2% were Hispanic, and 11.7% were Chinese. Patients were mean aged 61.9±10.4 years. During the 13.2-year follow-up, a total of 476 incident ASCVD events were reported.
Elevated Lp(a) level (hazard ratio [HR], 1.29; 95% CI, 1.04-1.61), coronary artery calcium score category of 1 to 99 (HR, 1.68; 95% CI, 1.30-2.16), and coronary artery calcium score category of 100 or higher (HR, 2.66; 95% CI, 2.07-3.43) all were independently associated with the risk for ASCVD. Further, Lp(a) by coronary artery calcium interaction was not observed.
Compared with individuals without elevated Lp(a) and a coronary artery calcium score category of 0, participants with elevated Lp(a) and a coronary artery calcium score category of 100 or higher were at the highest risk for ASCVD (HR, 4.71; 95% CI, 3.01-7.40), whereas patients with elevated Lp(a) and a coronary artery calcium score category of 0 were at a similar risk for ASCVD (HR, 1.31; 95% CI, 0.73-2.35).
Similar findings were reported when guideline-recommended Lp(a) and coronary artery calcium thresholds were taken into account. The findings from the MESA cohort were replicated in the DHS cohort.
Limitations of the study include the fact that it did not take into consideration prospective changes in coronary artery calcium, risk factors, and CV risk reduction treatment, such as statin therapy. Additionally, although the study was conducted in 2 American multiethnic, contemporary, population-based cohorts who were free of ASCVD at baseline, study results may not be applicable to those ethnic groups that were not represented.
“Lp(a) and [coronary artery calcium] are independently associated with ASCVD risk and may be useful concurrently for guiding primary prevention therapy decisions,” the study authors wrote. Additional research is warranted, to define algorithms that utilize these quantitative assays optimally for cardiovascular risk stratification.
Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Mehta A, Vasquez N, Ayers CR, et al. Independent association of lipoprotein(a) and coronary artery calcification with atherosclerotic cardiovascular risk. J Am Coll Cardiol. Published online February 21, 2022. doi:10.1016/j.jacc.2021.11.058