APLNR and coronary artery disorder: The aim of the study was to evaluate the levels of apelinergic system peptides, such as Elabela (Ela), apelin-13 (AP-13), apelin-17 (AP-17) and apelin receptor (APJ) in the serum and epicardial adipose tissue (EAT) of patients with multivessel coronary artery disease (CAD) who underwent myocardial revascularisation surgery.