Race and Ethnicity, Socioeconomic Status Influence Lp(a) Testing Rates

Gissette Reyes-Soffer, MD

Credit: LinkedIn

Assessment of lipoprotein (a) [Lp(a)] is low among patients with or at risk for atherosclerotic cardiovascular disease (ASCVD), particularly those who are non-Hispanic Black and Hispanic or reside in a socioeconomically deprived neighborhood, according to a new retrospective analysis.¹

This single-center study, evaluating electronic medical record (EMR) data between February 2020 and June 2023, revealed only 0.32% of patients in the general population had an Lp(a) order. Among those with or at risk for ASCVD, only 4.0% had an Lp(a) order, with an upward trend during the study period.

“Although literature consistently shows the correlation between high Lp(a), myocardial infarction and calcific aortic valve stenosis, our data suggest that patients with these two diagnoses were not the most likely to be tested for high Lp(a),” wrote the investigative team, led by Gissette Reyes-Soffer, MD, department of medicine, Columbia University Vagelos College of Physicians and Surgeons.

Lp(a) is typically modified by genetics, with high levels marking the most common genetic dyslipidemia.² Well-described mechanisms have linked high Lp(a) levels to atherosclerosis, including complement activation, and coagulation pathways.

Recommendations from the American Heart Association (AHA) advocate for early identification of patients with high Lp(a) levels,³ while updates from the National Lipid Association (NLA) recommend all adults be screened for Lp(a) once in a lifetime.⁴ However, screening for Lp(a) has remained low in clinical practice, despite the available data and guideline recommendations.

In this analysis, Reyes-Soffer and colleagues examined the impact of race and ethnicity, and socioeconomic status on the likelihood of Lp(a) ordering. The retrospective study used EMR data on adults with ≥1 personal International Classifications of Disease (ICD-10) diagnosis of ASCVD, aortic valve stenosis, and resistant hypercholesterolemia (LDL-C >160 mg/dL on statin therapy).

Family history was also searched, including family history of ASCVD or elevated Lp(a) levels, and additional data on race and ethnicity, sex, and socioeconomic status, including Medicaid coverage, were collected. Investigators then determined whether patients had completed a signed laboratory order for Lp(a) and underwent an Lp(a) test.

The general adult patient population included 1,265,646 patients, of whom 0.32% had Lp(a) ordered, with a 74.8% completion rate. From this population, investigators obtained data on 56,833 adults diagnosed with ASCVD or at risk for ASCVD, based on family history or the presence of comorbidities. Lp(a) ordering in this study cohort was higher (4.0%), but achieved a similar rate of test completion (73.9%).

Patients with a diagnosis of familial hypercholesterolemia had the highest rate of Lp(a) orders (14.9%), followed by carotid stenosis (8.7%) and myocardial infarction (5.1%). Those with a greater number of diagnoses were significantly more likely to have an Lp(a) order, compared with a single diagnosis (P <.001).

Upon further analysis, non-Hispanic Black (0.17%) and Hispanic (0.28%) patients were less likely to have an Lp(a) order, compared with non-Hispanic White (2.35%) patients (P <.001). However, these patient populations experienced the highest mean Lp(a) levels (P <.001).

Neighborhoods with greater deprivation were less likely to have an Lp(a) order, compared with more affluent neighborhoods (incidence rate ratio [IRR], 0.39; P <.001). Meanwhile, those with Medicaid were significantly less likely to have an Lp(a) order compared to those without Medicaid (IRR, 0.40; P <.001).

Reyes-Soffer and colleagues noted that non-Hispanic Black and Hispanic patients, who experienced higher Lp(a) levels, also represented the majority of residents on Medicaid and living in lower-income neighborhoods.

“While one might hypothesize that observed differences in levels are the result of selection bias from differences in testing frequency, one cannot explain the differences in testing frequency,” they wrote. “If one wishes to improve equity in cardiovascular outcomes, we need to provide equitable care, and this begins with implementing similar screening and diagnosis practices.”

References

1. _{Pavlyha M, Li Y, Crook S, Anderson BR, Reyes-Soffer G. Race/ethnicity and socioeconomic status affect the assessment of lipoprotein(a) levels in clinical practice. Preprint. medRxiv. 2024;2024.05.14.24307362. Published 2024 May 14. doi:10.1101/2024.05.14.24307362}
2. _{Tsimikas S. A Test in Context: Lipoprotein(a): Diagnosis, Prognosis, Controversies, and Emerging Therapies. J Am Coll Cardiol. 2017;69(6):692-711. doi:10.1016/j.jacc.2016.11.042}
3. _{Reyes-Soffer G, Ginsberg HN, Berglund L, et al. Lipoprotein(a): A Genetically Determined, Causal, and Prevalent Risk Factor for Atherosclerotic Cardiovascular Disease: A Scientific Statement From the American Heart Association. Arterioscler Thromb Vasc Biol. 2022;42(1):e48-e60. doi:10.1161/ATV.0000000000000147}
4. _{Koschinsky ML, Bajaj A, Boffa MB, et al. A focused update to the 2019 NLA scientific statement on use of lipoprotein(a) in clinical practice. J Clin Lipidol. 2024;18(3):e308-e319. doi:10.1016/j.jacl.2024.03.001}