Efficacy of Glucose-Insulin-Potassium Infusion on Left Ventricular Performance in Diabetic TypeII Diabetic Patients Undergoing Elective Coronary Artery Bypass Graft

Glucose-insulin-potassium (GIK) may improve cardiovascular performance after coronary artery bypass graft surgery(CABG). Our study investigated whether an infusion of glucose, insulin and potassium (GIK) during elective coronary artery bypass surgery in diabetic type II patients improved left ventricular performance.Methods. We measured left ventricular ejection fraction and troponin (Tn), a myofibrillar structural protein. In this clinical trial study, after ethics committee approval, 50 Patients with type 2 DM were enrolled into a randomized simple sampling, prospective, double-blinded study.(In the case group,500cc Dextrose water 5%+80 IU regular insulin and40 Meq KCL was infused at the rate of 30 cc/hr). (Patients in control group were put 5% dextrose solution at the rate of 30cc/hr). Venous blood sample were taken before induction of anesthesia, after removal of the aortic clamp and before discharging from hospital. The Mann–Whitney-test was used to test for differences in Tn concentration between groups at each time point. Fisher’s exact test was used to determine whether there was a significant difference in the proportion of patients with a low ejection fraction (<45%) in the case group compared with the control group. Changes in potassium and glucose concentrations over time within groups were examined by ANOVA and paired t-tests. P<0.05 was regarded as significant for all tests.Results.In the study 50 patients with type 2 DM were evaluated in case and control groups. The mean age ±S.D in the case group was 57.7 ±9.9 years and the other group was 61.2 ±8.4 years. The groups were well matched for age, sex and number of bypass grafts. Randomization did not give an equal distribution of male and female patients. There wasn’t any significant difference between ejection fraction in case and control groups before and after CABG (P>0.05). Tn concentration in the case group were 3.3 ±5.0 and mean of Tn concentration in the control group were 3.9 ±5.1.There was not a significant difference in Tn between the two groups before and after CABG (P>0.05). There was not a significant difference in hospitalization time between the two groupsConclusion. The results suggest that GIK does not improved left ventricular performance in routine coronaryartery bypass surgery.