Testing practices and clinical management of lipoprotein(a) levels: A 5-year retrospective analysis from the Johns Hopkins Hospital

Abstract

Elevated lipoprotein(a) [Lp(a)] is an independent, genetically determined risk factor for atherosclerotic cardiovascular disease (ASCVD). We evaluated the frequency of testing for elevated Lp(a) and subsequent management at the Johns Hopkins Hospital, a large academic medical center, over a 5-year period. The Johns Hopkins Hospital (JHH) electronic medical record was queried to identify patients with an encounter between 2017-2021, either with established ASCVD or at increased risk, defined as being on any lipid lowering medication or having LDL-C ≥190 mg/dL. The frequency of Lp(a) testing and of elevated levels (≥75 nmol/L) were identified for each year. Among 111,350 unique adult patients, 2,785 (2.5%) had at least one Lp(a) test. Patients with Lp(a) testing, compared to those without testing, were younger (mean age 56 years vs. 66), more often female (49% vs. 44%), Black (24.7% vs. 24.6%) or "other" race/ethnicity (12% vs 10%), and had higher LDL-C levels (median 118 vs. 91 mg/dL; p<0.001). The number and frequency of Lp(a) testing increased from 167 (0.57%) in 2017 to 1155 (5.67%) in 2021. Lp(a) levels were elevated in 43.4% of patients (moderate [75-125]: 10.3%, high [125-600]: 32.2%, severe [>600]: 0.9%). Among 920 patients with high or severe Lp(a) levels, 200 (22%) had a subsequent referral to cardiology or lipid specialist, and 180 (20%) had a subsequent lipid-lowering medication prescribed in the subsequent 18 months. Based on a single-center experience, the frequency of incident Lp(a) testing among increased-risk patients was low but increased significantly over 5-years, likely largely due to Lipid Clinic referrals with reflex Lp(a) testing and greater awareness about this risk factor. Future work should target appropriate population based Lp(a) testing strategies and clinical decision-making regarding risk management once Lp(a) elevation is diagnosed.