Impact of intravenous exenatide infusion for perioperative blood glucose control on myocardial ischemia-reperfusion injuries after coronary artery bypass graft surgery: sub study of the phase II/III ExSTRESS randomized trial.

BACKGROUND: The aim of the study was to investigate whether intravenous (iv) infusion of exenatide, a synthetic GLP-1 receptor agonist, could provide a protective effect against myocardial ischemia-reperfusion injury after coronary artery bypass graft (CABG) surgery. METHODS: A sub study analysis of patients > 18 years admitted for elective CABG and included in the ExSTRESS trial was conducted. Patients were randomized to receive either iv exenatide (1-h bolus of 0.05 µg min-1 followed by a constant infusion of 0.025 µg min-1) (exenatide group) or iv insulin therapy (control group) for blood glucose control (target range 100-139 mg dl-1) during the first 48 h after surgical incision. All serum levels of troponin I measured during routine care in the Cardiac Surgery ICU were recorded. The primary outcome was the highest value of plasma concentration of troponin I measured between 12 and 24 h after ICU admission. The proportion of patients presenting an echocardiographic left ventricular ejection fraction (LVEF) > 50% at the follow-up consultation was compared between the two groups. RESULTS: Finally, 43 and 49 patients were analyzed in the control and exenatide groups, respectively {age: 69 [61-76] versus 71 [63-75] years; baseline LVEF < 50%: 6 (14%) versus 16 (32%) patients; on-pump surgery: 29 (67%) versus 33 (67%) patients}. The primary outcome did not significantly differ between the two groups (3.34 [1.06-6.19] µg l-1 versus 2.64 [1.29-3.85] µg l-1 in the control and exenatide groups, respectively; mean difference (MD) [95% confidence interval (95% CI)] 0.16 [- 0.25; 0.57], p = 0.54). The highest troponin value measured during the first 72 h in the ICU was 6.34 [1.36-10.90] versus 5.04 [2.39-7.18] µg l-1, in the control and exenatide groups respectively (MD [95% CI] 0.20 [- 0.22; 0.61], p = 0.39). At the follow-up consultation, 5 (12%) versus 8 (16%) patients presented a LVEF < 50% in the control and in the exenatide groups respectively (relative risk [95% CI] 0.68 [0.16; 2.59], p = 0.56). CONCLUSIONS: Postoperative iv exenatide did not provide any additional cardioprotective effect compared to iv insulin in low-risk patients undergoing scheduled CABG surgery. Trial registration ClinicalTrials.gov Identifier NCT01969149, date of registration: January 7th, 2015; EudraCT No. 2009-009254-25 A, date of registration: January 6th, 2009.

Clinical Effectiveness of Intravenous Exenatide Infusion in Perioperative Glycemic Control after Coronary Artery Bypass Graft Surgery: A Phase II/III Randomized Trial.

BACKGROUND: We aimed to assess the clinical effectiveness of intravenous exenatide compared to insulin in perioperative blood glucose control in coronary artery bypass grafting surgery patients. METHODS: Patients more than 18 yr old admitted for elective coronary artery bypass grafting were included in a phase II/III nonblinded randomized superiority trial. Current insulin use and creatinine clearance of less than 60 ml/min were exclusion criteria. Two groups were compared: the exenatide group, receiving exenatide (1-h bolus of 0.05 µg/min followed by a constant infusion of 0.025 µg/min), and the control group, receiving insulin therapy. The blood glucose target range was 100 to 139 mg/dl. The primary outcome was the proportion of patients who spent at least 50% of the study period within the target range. The consumption of insulin (Cinsulin) and the time to start insulin (Tinsulin) were compared between the two groups. RESULTS: In total, 53 and 51 patients were included and analyzed in the exenatide and control groups, respectively (age: 70 ± 9 vs. 68 ± 11 yr; diabetes mellitus: 12 [23%] vs. 10 [20%]). The primary outcome was observed in 38 (72%) patients in the exenatide group and in 41 (80%) patients in the control group (odds ratio [95% CI] = 0.85 [0.34 to 2.11]; P = 0.30). Cinsulin was significantly lower (60 [40 to 80] vs. 92 [63 to 121] U, P < 0.001), and Tinsulin was significantly longer (12 [7 to 16] vs. 7 [5 to 10] h, P = 0.02) in the exenatide group. CONCLUSIONS: Exenatide alone at the dose used was not enough to achieve adequate blood glucose control in coronary artery bypass grafting patients, but it reduces overall consumption of insulin and increases the time to initiation of insulin.