Efficacy of Dexmedetomidine in Coronary Artery Bypass Graft Surgery under Cardiopulmonary Bypass: A Randomized, Double-Blind Clinical Trial

Background: In patients undergoing Cardiopulmonary Bypass (CPB) with extracorporeal circulation, the rapid restoration of blood flow to the ischemic tissue induces cardiac damage termed as myocardial Ischemic Reperfusion (I/R) injury. Objectives: In the current study, the researchers hypothesized that Dexmedetomidine (DEX) modulates I/R injury in Coronary Artery Bypass Graft Surgery (CABG) with Cardiopulmonary Bypass (CPB). Methods: This randomized, double-blind, clinical trial took place in a university affiliated Hospital, Gilan, Iran. From April 2016 to March 2017, 114 eligible patients undergoing elective and isolated CABG were randomized to receive either DEX infusion 0.3 to 0.5 g/kg/hour before induction of anesthesia till 12 hours postoperatively (group D) or normal saline as placebo (group C). The endpoints were used to assess creatinine phosphokinase-MB (CKMB) and cardiac troponin I (CTnI) levels at four measurement time points, including baseline (T0) and 6, 12, 24, and 48 hours after the operation (T0 - T4). Results: Overall, 114 patients’ data were analyzed; group D (n = 58) and group C (n = 56). No significant differences were found between the two groups, in view of baseline characteristics. Following CPB, a marked increase in CKMB and CTnI plasma levels was observed in both groups compared with baseline (P = 0.0001). Serum CKMB levels increased from 2.270.59 to 7.811.39, and 2.22 0.64 to 7.46 1.25 and CTnI levels from 10.22 0.17 to 4.89 1.1, and 0.27 0.28 to 4.5 1.4 in groups C and D, respectively (P = 0.0001). According to CKMB, there was a significant difference between the two groups at T2 (P = 0.002) and T3 (P = 0.0001), and based on CTnI at T2 (P = 0.004) and T3 (P = 0.0001). However, no significant difference was observed at the other measurement point times. No adverse effect was recorded due to this intervention. Conclusions: Perioperative DEX in cardiac surgery appears safe, with properties to alleviate I/R injury. Obviously, future standard trials are required to find optimal intervention strategies.