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.