Association of Lipoprotein(a) Levels with Incidence of Major Adverse Limb Events

Abstract

Importance: High lipoprotein(a) (Lp[a]) levels are involved in the development of cardiovascular events, particularly in myocardial infarction, stroke, and peripheral artery disease. Studies assessing the Lp(a) levels associated with adverse lower-limb events are lacking. Objective: To assess the association between Lp(a) levels and incidence of major adverse limb events in unselected hospitalized patients. Design, Setting, and Participants: This large retrospective monocentric cohort study was conducted from January 1, 2000, to December 31, 2020. Data were derived from the clinical information system of the Hôpital Européen Georges-Pompidou, a Paris-based university hospital. Patients who underwent at least 1 Lp(a) measurement at the center during the study period were included. Patients who had no follow-up data or who had the first Lp(a) measurement after the study outcome had occurred were excluded. Data analyses were performed from May 2021 to January 2022. Main Outcomes and Measures: The primary outcome was the first inpatient major adverse limb event, defined as a major amputation, peripheral endovascular revascularization, or peripheral surgical revascularization, during follow-up. Secondary outcomes included individual components of the primary outcome. Lipoprotein(a) levels were categorized as follows: normal (<50 mg/dL), high (50 to <134 mg/dL), and very high (≥134 mg/dL); to convert Lp(a) values to milligrams per liter, multiply by 0.1. Results: A total of 16513 patients (median [IQR] age, 58.2 [49.0-66.7] years; 9774 men [59.2%]) were included in the cohort. The median (IQR) Lp(a) level was 24 (10.0-60.0) mg/dL. The 1-year incidence of major adverse limb event was 2.44% in the overall population and 4.54% among patients with very high Lp(a) levels. High (adjusted accelerated failure time [AFT] exponential estimate: 0.43; 95% CI, 0.24-0.78; Benjamini-Hochberg-corrected P =.01) and very high (adjusted AFT exponential estimate: 0.17; 95% CI, 0.07-0.40; Benjamini-Hochberg-corrected P