AHA Scientific Sessions 2026 Abstract · Nov 2, 2026
Impact of Lipoprotein(a) Testing on Lipid-Lowering Therapy Use and LDL-C Goal Attainment in Patients with Atherosclerotic Cardiovascular Disease: A Difference-in-Differences Analysis
By Dai D, Hu X, Khakwani A et al.
Background: Elevated lipoprotein(a) [Lp(a)] is an independent, genetically determined causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and can refine risk assessment and, in the absence of targeted therapies, inform lipid lowering therapy (LLT) decisions. Although clinical guidelines recommend measuring Lp(a) at least once in all adults, the association between Lp(a) testing and subsequent changes in lipid management in routine clinical practice remains uncertain. Methods: A retrospective cohort study was conducted using a large U.S. health claims database. Patients with ASCVD, with or without Lp(a) testing, were identified between January 1, 2017, and June 30, 2024. LLT adherence was assessed using the proportion of days covered (PDC); PDC ≥80% was considered adherent. To address confounding and strengthen causal inference, propensity score matching (PSM) was used to balance baseline characteristics, followed by difference-in-differences (DiD) analyses to compare changes in outcomes over time between tested and non-tested patients while accounting for secular trends. Outcomes included LLT use and attainment of the low-density lipoprotein cholesterol (LDL-C) goal (<70 mg/dL) during the 12 months before and after Lp(a) testing. Results: The matched cohort included 32,466 patients with ASCVD (16,233 with Lp(a) testing and 16,233 without testing), of whom 14,619 (45%) were female, with a mean (SD) age of 68.2 (11.7) years. In DiD analyses, Lp(a) testing was associated with greater increases in LLT use compared with the matched control group (6.56% [95% CI, 5.83%-7.29%]), including statins (5.73% [95% CI, 4.98%-6.48%]), ezetimibe (5.44% [95% CI, 4.91%-5.98%]), and PCSK9 inhibitors (3.07% [95% CI, 2.72%-3.42%]), as well as greater improvement in LLT adherence (6.51% [95% CI, 5.45%-7.57%]) with all P-values <0.001. Among patients with available LDL-C measurements, those receiving Lp(a) testing experienced greater reductions in LDL-C (–4.43 mg/dL [95% CI, –5.51 to –3.35 mg/dL]) and a higher relative increase in the proportion achieving LDL-C <70 mg/dL (3.18% [95% CI, 2.39%-3.96%]) relative to contemporaneous changes observed in controls (Table 1). Conclusions: In this large real-world study, Lp(a) testing was associated with greater increases in LLT utilization, medication adherence, and LDL-C goal attainment among patients with ASCVD relative to matched controls. These findings suggest that broader implementation of guideline-recommended Lp(a) testing may support more effective lipid management strategies in high-risk populations, with potential implications for managed care quality metrics and cardiovascular risk reduction.