Abstract 3371: Glucagon Like Peptide-1 Improves Post Bypass Cardiac Function in High Risk Patients With Low Left Ventricular Ejection Fraction
Patients without prior diabetes develop insulin resistance and stress hyperglycemia after coronary artery bypass surgery (CABG) in the postoperative period. The magnitude of hyperglycemia, influences post surgical recovery. However, aggressive insulin protocols are associated with hypoglycemia which mitigates the benefits. Glucagon like peptide -1 (GLP-1) has insulinotropic and insulinomimetic properties resulting in euglycemia without the risks of hypoglycemia. Accordingly, we studied the effects of GLP-1 on recovery of LV function and glycemic control in patients undergoing CABG with severe left ventricular dysfunction (LVEF <35%). Twelve patients were randomized prospectively, in a double-blind fashion, to saline or continuous GLP-1 infusion (1.5 pmol/kg/min IV) for 48 hours. Those who were scheduled for valvular, redo bypass and, emergency aortic surgeries, were excluded from the study. The respective infusions were started 12 hours prior to surgery, continued throughout the surgery until 48 hours after surgery. Echocardiogram was performed at baseline prior to infusions, 48 hours after the surgery and on seventh or discharge day, whichever was earlier. Perioperative hemodynamic, LVEF, plasma glucose, and requirements for insulin drips and inotropic support were monitored. The results were evaluated by two-tailed unpaired student-t test for each time point for statistical significance. Hemodynamic indices including heart rate, blood pressure, cardiac output, and index were not statistically significant between groups. However, GLP-1 patients had higher LVEF after 48 hours (40+7%) compared to control (29+10%, p=0.049). The improved LVEF occurred despite greater inotrope and pressor support in the control group. GLP-1 had lower peri-op glucose (100±31 mg/dL) compared to controls (145±28 mg/dL, p=0.026) and remained lower. Despite receiving more dextrose, the GLP-1 group required less insulin. In patients with low LVEF following CABG surgery, GLP-1 effectively controls glucose with reduced requirements for insulin and improves LVEF recovery with less requirements for inotropic and pressor support compared to control. GLP-1 may be a safer and more effective alternative to insulin in the peri-op period following CABG surgery.