Trends in lipoprotein(a) testing and impact on clinical care: A contemporary systemwide analysis

: Elevated lipoprotein(a) [Lp(a)] is an independent, causal risk factor for atherosclerotic cardiovascular disease (ASCVD), yet testing remains low. As our health system has expanded its efforts to increase Lp(a) awareness, we evaluated testing rates and their impact on care. : Lp(a) testing rates were collected through electronic health record queries between 1/1/2022 to 12/31/2024. Baseline demographics, ASCVD status, Lp(a) testing rates by specialty, lipid lowering therapy (LLT) prescriptions and number of cardiology referrals were collected. : 450,412 outpatients had ≥1 lipid panel order and 3.7% (N=16,476) had Lp(a) tested. Of those who had Lp(a) measured, 50.5% were female and 61.8% identified as White. Most Lp(a) orders were for patients without established ASCVD (68.9%). Between 2022-2024, Lp(a) orders increased from 3,052 to 8,425. Most orders were placed by cardiologists although their proportion decreased (75.5% in 2022 vs. 62.9% in 2024) as orders from other specialties increased. We found 67.0% of patients with normal Lp(a) (<75 nmol/L), 12.2% were intermediate risk (75 ≥ Lp(a) < 125 nmol/L), 11.3% were high risk (125 ≥ Lp(a) < 200 nmol/L) and 9.4% had very high-risk values (≥200 nmol/L). Across the same Lp(a) categories, LLT initiation/escalation rates were 12.8%, 17.5%, 20.2% and 22.1%. There was a positive association between LLT initiation/escalation and Lp(a) range (p<0.0001). : While Lp(a) testing was low, it increased substantially over time. High risk Lp(a) levels were found irrespective of ASCVD status and were associated with more aggressive treatment. Systematic strategies to increase Lp(a) awareness and testing are warranted to mitigate cardiovascular risk.