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Assessing lipoprotein(a) (Lp[a]) levels in US adults, both with and without atherosclerotic cardiovascular disease (ASCVD), was previously an uncommon practice but exhibited a notable surge post-2018, according to McGowan and colleagues.1 The findings were presented as, “Lipoprotein(a) Screening Practices in a Large US Health Care Dataset,” at the American Heart Association Scientific Sessions 2023, which ran from November 11 to 13, 2023, in Philadelphia, Pennsylvania.1
Elevated Lp(a) is an independent and genetically determined risk factor for ASCVD, affecting approximately 20% of the general population.2 Although European and Canadian guidelines advocate for Lp(a) screening across patients with an intermediate or high risk of cardiovascular disease or strong family history of premature atherothrombotic disease, the American College of Cardiology/American Heart Association Task Force guideline describes Lp(a) as a risk enhancer.3-5
Despite its high prevalence and role as a crucial ASCVD risk factor, testing for elevated Lp(a) is not commonly performed. Using a comprehensive real-world US database, McGowan and colleagues aimed to provide insight into the demographic and clinical profiles individuals undergoing Lp(a) assessment, as well as the patterns and attributes associated with health care professionals (HCPs) ordering these tests.1
The Family Heart Database is a comprehensive repository of data of medical claims, including diagnostic, procedural, and prescription data, along with laboratory information for more than 324 million individuals in the US. Data were collected from May 2012 to December 2021. Within this database, the investigators focused on a subset of 44 million adults with available laboratory data, predominantly lipid labs, and medical claims recorded 1 year before and after their initial lab date. Patients who underwent screening for Lp(a) were identified to calculate screening rates. Additionally, various patient characteristics, including demographics, ASCVD status, comorbidities, distributions of Lp(a) levels, and the clinicians responsible for ordering Lp(a) tests were examined.1
Analysis of real-world data extracted from the Family Heart Database revealed that Lp(a) screening among US adults, including those with a history of ASCVD, was infrequent. Specifically, only 1.1% of the overall adult population (500,899/44,857,734 individuals) underwent Lp(a) screening between 2012 and 2021. In the subgroup of adults with ASCVD, the screening rate marginally increased to 2.0% (218,331/10,658,820 individuals) over the same period.1
The cohort of adults who underwent Lp(a) testing exhibited specific demographic and health characteristics. The median age of these individuals was 60 years (IQR, 50-69 years). A slight majority, accounting for 55%, were female. A notable portion of this cohort, comprising 43.6% of individuals, had a history of ASCVD. Hypertension was prevalent among those tested for Lp(a) levels, affecting 33% of the group, and 34% had hyperlipidemia. Additionally, 14% of the adults with Lp(a) tests had diabetes.1
Notable variations in Lp(a) testing were observed according to sex, race, and the clinicians placing orders. Women who underwent Lp(a) testing showed a higher median Lp(a) level of 36 nmol/L (IQR, 11-118) compared with that in men, who had a median level of 28 nmol/L (IQR, 10-95). Distinct racial disparities were observed, with the Black population demonstrating a median Lp(a) level that was 2-fold higher than those of the White and Hispanic populations, with values of 73 nmol/L (IQR, 24-170) for Black individuals, 29 nmol/L (IQR, 10-102) for White individuals, and 28 nmol/L (IQR, 10-85) for Hispanic individuals. Also, Lp(a) testing orders were concentrated, as only 1.6% of clinicians (687/41,976) were responsible for half of all Lp(a) tests.1
A notable surge in Lp(a) testing occurred in 2019, likely resulting from heightened awareness regarding Lp(a) and the introduction of an International Classification of Diseases–Tenth Edition code (E78.41) for elevated Lp(a) in 2018, according to the investigators.1,6 Conversely, the reduction in Lp(a) testing after 2019 may be attributed to the influence of COVID-19 policies on health care practices, causing a shift in priorities and resource allocation away from routine screenings during the pandemic.1,7
Although Lp(a) testing is rare, patients who underwent Lp(a) assessment frequently presented with ASCVD and associated comorbidities. Furthermore, a limited number of HCPs were accountable for the majority of Lp(a) testing orders. Overcoming barriers and leveraging facilitators for Lp(a) screening necessitates dedicated research and strategic efforts.1