Dynamics of myocardial necrosis biomarkers and acid-base balance parameters after coronary artery bypass grafting on beating-heart depending on the perioperative glucose-lowering treatment regimen in patients with type II diabetes

Abstract

The study included 71 patient with ischemic coronary disease (ICD) with type II diabetes mellitus (DM) treated by oral hypoglycemic agents undergoing off-pump coronary artery bypass grafting (CABG). The mean age was 59 (56-64) years. Before the surgery the patients were randomized to continuing of oral hypoglycemic agents (n = 34) or to switching to rapid-acting insulin (n = 37). In the studied groups we compared glycemic parameters, markers of myocardial necrosis (troponin T and creatinine phosphokinase-MB (CPK-MB)) and acid-base balance, as well as their dynamics during the perioperative period. The relationships of myocardial necrosis markers dynamics with glucose metabolism and acid-base balance parameters were investigated. Before the surgery in switched to rapid-acting insulin patients serum glucose, its daily variability and the proportion of blood glucose values less than recommended perioperative range (6,1-10,0 mmol/l) were higher than in those at oral hypoglycemic agents. The myocardial necrosis markers at the day before and 24 h after surgery as well as lactate level and blood acidity during and at 24 hours after surgery were higher in the insulin-group. The insulin-group was characterized by greater increase of troponin T during 24 h after surgery (0,36 [0,25-0,40] vs 0,2 [0,1-0,25] ng/ml; p < 0,001) and CPK-MB (14 [8,0-17,0] vs 7,3 [1,5-8,7] U/L; p < 0,001). Troponin T and CPK-MB dynamics correlated with serum glucose during surgery (r = +0,81 and r = +0,66 respectively), daily serum glucose variability at the day before surgery (r = +0,71 and r = +0,63) and the first day of admission to hospital (r = +0,37 and r = +0,31).