Real world evaluation of lipoprotein (a) testing and impact on LDL-C management in atherosclerotic cardiovascular disease patients: findings from the CVMOBIUS2 registry

Background Current guidelines recommend testing Lp(a) to identify adults with elevated levels who may need further intensification of treatments to manage other cardiovascular risk factors, such as low density lipoprotein cholesterol (LDL-C) levels. Despite the rising knowledge of Lp(a), it is unclear whether this has translated to increased Lp(a) testing and how testing impacts contemporary LDL-C management in patients with ASCVD in clinical practice. Purpose To understand trends in testing of Lp(a) in patients with ASCVD in the United States and changes in LDL-C management in those who are identified to have elevated Lp(a) levels. Methods Electronic health record (EHR) data from 17 US health systems between 1/1/2021-12/31/2024 were analyzed to determine the prevalence of Lp(a) testing among adults with ASCVD. Lp(a) levels in mg/dL were approximated to nmol/L using the formula 2.18*Lp(a) (in mg/dL) – 3.821. The percent of ASCVD patients who underwent Lp(a) testing each year was evaluated overall and stratified by age, sex, race, and ethnicity. Of those tested, the proportions with elevated Lp(a) levels were also assessed. Changes in LDL-C lowering therapy after Lp(a) testing were evaluated overall and stratified by Lp(a) levels. Results A total of 2,378,652 patients with ASCVD were included in the study, of which only 36,410 (1.5%) ever had an Lp(a) test. Most (73.0%) tests were performed as molar assays (nmol/L) while 28.0% were mass-based assays (mg/dL). A small incremental increase in testing was observed from 2021 through 2024 (0.2% in 2021, 0.3% in 2022, 0.5% in 2023, and 0.7% in 2024). Testing was more common in younger individuals: 3.1% of those age 18-40 and 3.0% of those 41-60 years underwent testing, while only 1.4% of those age 61-80 and 0.4% of those >80 years ever had a test. No major differences in testing patterns were seen by sex, race, or ethnicity. Of those tested, 29.9% had an Lp(a) > 125 nmol/L, and 17% had Lp(a) ≥ 200 nmol/L. Non-Hispanic Black patients had the highest proportion of elevated Lp(a) (51.8% with ≥ 125 nmol/L and 31.1% ≥ 200 nmol/L.). LDL-C lowering therapy was more frequently intensified in those with higher Lp(a) levels (Table), with LDL-C lowering therapeutic intensification occurring in 50.1% of those with Lp(a) ≥200 nmol/L compared to 36.8% in those with <125 nmol/L (p <0.001). Conclusion Despite rising evidence and guideline support to modify risk associated with elevated Lp(a), testing rates remain low. When tested, those with elevated Lp(a) levels were more likely to undergo intensification of LDL-C lowering therapy.