Lp(a) (Lipoprotein [a]) and Risk for Incident Atrial Fibrillation

Abstract

Studies assessing associations between Lp(a) (lipoprotein [a]) and atrial fibrillation (AF) are limited to 2 prospective studies, neither reporting a significant relationship. We examined the association of circulating Lp(a) levels with incident AF in a community-based multi-ethnic prospective cohort. The MESA (Multi-Ethnic Study of Atherosclerosis) recruited 6814 adults across the United States aged 45 to 84 years and free of clinically recognized cardiovascular disease between 2000 and 2002. The study was approved by the institutional review board at each center, and all participants signed an informed consent. Standardized questionnaires were used at baseline to obtain demographic information, education level, household income, physical activity, alcohol consumption, smoking history, and medication usage. Total and high-density lipoprotein cholesterol, triglycerides, and glucose were measured from fasting blood samples. Lp(a) mass concentration was measured with a latex-enhanced turbidimetric immunoassay (Denka Seiken, Tokyo, Japan) at visit 1, and methods have been reported previously.1 This assay employed 5 independent calibrators to control for apo(a) size heterogeneity, and the total imprecision was found to be <5%. At a concentration of 4 mg/dL, the imprecision was 6%. Incident AF through December 2014 was identified from study ECGs verified for AF at visit 5 (2010–2012), International Classification of Diseases-Ninth Revision hospital discharge diagnoses consistent with AF (427.31 or 427.32), and for participants enrolled in fee-for-service Medicare, inpatient and outpatient AF claims data.