The effects of nicorandil on perioperative hemodynamics in CABG patients

Reversible contractile dysfunction may persist for hours or days after cardiopulmonary bypass ('myocardial stunning'). Nicorandil, a relatively new antiischemic drug, activates K(ATP) channels, and exerts cardioprotective effects in dogs. In this study, we evaluated the effects of nicorandil on perioperative hemodynamics in coronary artery bypass graft (CABG) patients. Twenty patients undergoing elective CABG surgery were studied. Patients were randomly allocated to nicorandil group (n=10) or control group (n=10). Anesthesia was induced with fentanyl and vecuronium, and maintained with morphine and isoflurane. All patients received nitroglycerin i.v. infusion (0.5-1.5 μg/kg/min) and underwent cardiopulmonary bypass (CPB) at 28°C. In nicorandil group, nicorandil i.v. (loading dose 4 mg, infusion 4 mg/hr during CPB and 2 mg/hr after CPB) was started upon initiation of CPB and continued into the postoperative period. Patient characteristics and hemodynamic data were recorded. p<0.05 was considered significant. Demographic data, preoperative cardiac status and medications were similar between the groups. After CPB and in the first 12 hour of postoperative period, control group required epinephrine infusion to maintain hemodynamics more often than nicorandil group (7/10 vs 0/10, p<0.01). No patients had episodes of postoperative myocardial infarction. In conclusion, nicorandil improved perioperative hemodynamics in CABG patients. Further studies are needed to elucidate the mechanism.