Assessment of Levels of Apelinergic System Peptides in Serum and Epicardial Adipose Tissue in Patients with Multivessel Coronary Artery Disease Who Underwent Myocardial Revascularisation

<b>Background:</b> Peptides of the apelinergic system may participate in the development of atherosclerosis, but their role in atherogenesis is unclear. 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. <b>Methods:</b> The participants comprised 51 CAD patients and 34 healthy adults. Concentrations of Ela, AP-13, AP-17 and APJ were determined by ELISA kits. We analysed the demographics, and clinical and laboratory parameters of the CAD patients. <b>Results:</b> We showed that the serum Ela and AP-17 levels significantly decreased, and APJ significantly increased, in the CAD patients in comparison to the healthy control. A significant relationship between the serum and EAT concentrations of Ela and APJ (<i>p</i> < 0.05) was observed. Positive correlations were found between the serum levels of AP-13 and AP-17, and between AP-17 and APJ. There was a positive correlation between the tissue levels of AP-17 and APJ. The tissue Ela concentration negatively correlated with the BMI, TCH and LDL levels. AP-13 in EAT was negatively associated with the glucose level. In contrast, the tissue APJ showed a positive correlation with TCH concentration. Good diagnostic potential of ELA, AP-17 and APJ was observed for CAD prediction (<i>p</i> < 0.001 for all). <b>Conclusions:</b> The results indicate that the levels of apelinergic peptides are altered in patients with CAD, which may be a potential diagnostic indicator.