Abstract
BACKGROUND The cardioprotective protein SIRT1 is elevated in patients with coronary artery disease (CAD) to compensate for the disease-related adverse effects, but less is known about the prognostic role of SIRT 1 regulating microRNAs in patients after coronary artery bypass graft (CABG) surgery. MATERIAL AND METHODS The expression of the SIRT 1-specific microRNAs miR-199a and miR-195 was analyzed using real-time PCR in 68 patients referred for CABG surgery and 34 control patients undergoing heart valve surgery. In CABG patients, major adverse cardiac and cerebrovascular events (MACCEs), including all-cause death, myocardial infarction (MI), re-vascularization, heart failure symptoms ≥NYHA II, re-hospitalization for any cardiovascular reason, and stroke, were analyzed at a median follow-up (FU) of 3.2 years (range: 3.0-3.6). RESULTS The level of miR-199a in patients with CAD was significantly reduced compared to the control group (relative expression: 0.89±0.49 vs. 1.90±0.90, p=0.001), while SIRT 1 protein was markedly enhanced (p<0.001). In patients undergoing CABG who had MACCEs, miR-199a was significantly lower compared to patients with an uneventful FU (0.71±0.25 vs. 0.98±0.53, p=0.007). Heart failure status, death, and total MACCEs rate were inversely correlated with the amount of miR-199a (p=0.039) at 3-year FU. CONCLUSIONS Altered expression of miR-199a in myocardial tissue was found to be associated with SIRT 1 upregulation in patients with CAD undergoing CABG and was associated with an increased MACCEs rate at mid-term follow-up.