Perioperative glycemic control and its outcome in patients following open heart surgery

Background: Diabetes is not uncommon in patients requiring cardiac surgery. These patients have a higher incidence of morbidity and mortality. Subsequently, diabetes represents a major medico-economic problem in both developed and developing countries. This study was designed to observe the association between glycemic control and outcome of patients after open heart surgery in adult population. Materials and Methods: Data was collected retrospectively in all patients who underwent open cardiac surgery (coronary artery bypass grafting, valve, or bypass grafting with valve surgery) and survived 72 hours postoperatively and had diabetes. The study was conducted from January 2015 to December 2016. Results: Of the 129 patients included in the study, male dominated 101 (78.3%). Most frequent surgery was coronary artery bypass grafting (CABG) 123 (95.3%), CABG plus aortic valve replacement 4 (3.1%), and CABG plus mitral valve replacement 2 (1.6%). Considering diabetes, only 3 (2.3%) were on diet control, 112 (86.8%) on oral hypoglycemic agents (OHA), whereas 9 (7%) had control on both insulin and OHA. Only 5 (3.9%) had type I diabetes. The mean fasting blood sugar (FBS) was 154.58 g/dl, and the mean duration of diabetic mellitus was observed 12.32 years. Microvascular and macrovascular complications were 26/129 (20.16%) and 17/129 (13.17%), respectively. Total 75 (58.1%) patients did not require insulin and 54 (41.9%) were treated with insulin intraoperatively to keep the blood glucose level less than 200 g/dl. Cardiac arrhythmias were frequent in the insulin group (P < 0.05), which was also associated with increased stay in the cardiac intensive care unit. Conclusion: Inadequate glycemic control during open cardiac surgery can possibly lead to increased perioperative morbidity and mortality and with decreased long-term survival and recurrent ischemic events. Therefore, aiming for blood glucose levels around 140 mg/dl appears reasonable. Further studies are required to define specific glucose ranges for a clearer definition of recommended blood glucose goals in postoperative cardiac patients for the best outcomes in patients with diabetes mellitus.