Plasma microRNAs reflecting cardiac and inflammatory injury in coronary artery bypass grafting surgery

Background Circulating microRNAs (miRs) may act as diagnostic and prognostic biomarkers for cardiovascular events in coronary artery bypass graft (CABG) surgery patients. This study measured changes in cardiac- and muscle-related miRs and cardiac and inflammatory biomarkers in acute coronary syndrome patients undergoing CABG surgery as well as investigated the correlations between these indicators. Methods Creatine kinase-MB (CK-MB), brain natriuretic peptide (BNP), cardiac troponin T (cTnT), interleukin-6 (IL-6), IL-8, IL-10, high-sensitivity C-reactive protein, and tumor necrosis factor-α were measured, and real-time quantitative polymerase chain reaction was performed to determine the plasma levels of miR-1, miR-133a, miR-208a, and miR-499 before and after surgery in 27 acute coronary syndrome patients. Left ventricular ejection fraction was also analyzed in a 3-month follow-up. Results miR-1, miR-133a, and miR-208a increased significantly (P = 0.0011; P = 0.0057; P = 0.0197, respectively) and the CK-MB, cTnT, BNP, and IL-6 levels were augmented after surgery. miR-133a, miR-208a, and miR-499 positively correlated with cTnT (r = 0.302, P = 0.027; r = 0.326, P = 0.016; r = 0.298, P = 0.029, respectively), but only miR-208a significantly correlated with CK-MB (r = 0.278, P = 0.041). miR-133a and miR-208a were significantly related to IL-6 (r = 0.287, P = 0.036; r = 0.292, P = 0.032, respectively). However, there were no significant associations between miRs and BNP or 3-month left ventricular ejection fraction. Conclusions CABG surgery–induced myocardial reperfusion damage and subsequent inflammation were related to changes in miR-1, miR-133a, and miR-208a. Notably, miR-208a was the only indicator associated with CK-MB, cTnT, and IL-6, which may reflect heart injury and inflammation in these patients.