Therefore, we conducted this cross-sectional study in AF patients to investigate the relationship between the extent of the progression in LA structural remodeling and HDL functionality, which was measured in terms of three types of cholesterol efflux capacity (CEC), ie, Global CEC, ATP binding cassette transporter A1 (ABCA1) mediated CEC, and Non-ABCA1 mediated (Non-ABCA1) CEC. This evidence concerns the gene ABCA1 and atrial fibrillation.