TEMPORAL TRENDS IN LIPOPROTEIN(A) TESTING AMONG UNITED STATES VETERANS FROM 2014-2023

Abstract

Therapeutic Area

Novel Biomarkers

Background

Elevated lipoprotein(a) [Lp(a)] is a genetically-determined, independent, causal risk factor for atherosclerotic cardiovascular disease (ASCVD). Multiple contemporary clinical practice guidelines endorse Lp(a) testing to refine risk stratification for ASCVD and guide clinical decision-making among high-risk patients. Changes in rates of testing and detection of elevated Lp(a) over time have not been well described.

Methods

We performed a retrospective cohort study using Veterans Affairs electronic health record data to evaluate temporal trends in Lp(a) testing from January 1, 2014 to December 31, 2023 among United States Veterans. We identified Veterans in each year who had a primary care or cardiology visit, an active medication filled, and no prior Lp(a) testing. We stratified testing rates based on demographic and clinical factors: age, sex, race and ethnicity, history of ASCVD, and neighborhood social vulnerability index (SVI) scores as defined by the Centers for Disease Control. The SVI incorporates variables such as employment, income, crowding, and education, with higher scores suggesting greater vulnerability. We classified elevated Lp(a) levels using three clinically meaningful thresholds: 50 mg/dL, 70 mg/dL and 90 mg/dL.

Results

Lp(a) testing increased nationally from 1 test per 10,000 eligible Veterans (558 tests) in 2014 to 9 tests per 10,000 (4,440 tests) in 2023. While testing increased across all groups, prevalent ASCVD was strongly associated with an increase in Lp(a) testing over time (Figure). Rates of testing increased less among those residing in neighborhoods with high social vulnerability compared with low social vulnerability. Rates of testing increased most among Asian Veterans but similarly across other racial and ethnic groups. The percent of elevated tests across clinically meaningful thresholds has remained stable over time.

Conclusions

We found a 9-fold increase in Lp(a) testing among US Veterans over the last decade, particularly among those with ASCVD, but the overall rate remains extremely low. The proportion of Veterans with elevated Lp(a) has remained steady, supporting the clinical utility of testing expansion. Efforts to increase testing among Veterans living in neighborhoods with high social vulnerability will be important to reduce emerging disparities as novel therapeutics to target Lp(a) become available.