Abstract 16133: Lipoprotein(a) Screening Practices in a Large US Healthcare Dataset

Introduction/Background: Elevated Lipoprotein(a) [Lp(a)] is an independent, genetically determined, causal risk factor for atherosclerotic cardiovascular disease (ASCVD). European and Canadian guidelines recommend Lp(a) screening in all adults, while US guidelines recognize elevated Lp(a) as a risk enhancer.

Research Hypothesis: Although elevated Lp(a) is an important ASCVD risk factor with a high prevalence, testing is infrequent.

Aims: To characterize adults screened for Lp(a) and their clinicians using real-world data from the Family Heart Database of >324M US individuals with medical and/or lab data from 2012-2021.

Methods: In this retrospective cohort study of > 44 million adults with lab data and medical claims one year before and after initial Lp(a) measurement, screening rates, demographics, ASCVD status, comorbidities, Lp(a) level (median; IQR) and ordering clinician are described.

Results: Lp(a) screening rates were 1.1% (n=500,899 of 44,857,734) and 2.0% (n=218,331 of 10,658,820) in all and in those with ASCVD respectively. Among those with any Lp(a) test, median age was 60 (IQR 50-69) years, 55.0% were female,43.6%, 33.0%, 33.9%, and 13.9% had prior ASCVD, hypertension, hyperlipidemia and diabetes respectively. 20% had an Lp(a) level

139 nmol/L. Lp(a) level was higher in females than males 36 (IQR 11-118) versus 28 (IQR 10-95) nmol/L, and in Blacks versus White and Hispanic populations 73 (IQR 24-170), 29 (IQR 10-102) and 28 (IQR 10-85) nmol/L. A small number of clinicians (n=687 of 41,976; 1.6%) ordered 50% of Lp(a) tests.

Conclusions: Measurement of Lp(a) in US adults with and without ASCVD was rare but increased substantially after 2018. Individuals who had Lp(a) assessed were older and frequently had ASCVD and comorbidities. A small number of clinicians were responsible for most Lp(a) orders. Additional research into barriers and facilitators of Lp(a) screening is needed.