Dose-dependent prophylactic effect of nicorandil, an ATP-sensitive potassium channel opener, on intra-operative myocardial ischaemia in patients undergoing major abdominal surgery

Nicorandil, a nicotinamide nitrate derivative, relaxes vascularsmooth muscle and reduces cardiac muscle contractility by increasingmembrane potassium conductance, probably by activating ATP-sensitivepotassium channels. In this prospective, randomized, double-blind,placebo-controlled clinical study, we examined the dose-dependentprophylactic effect of nicorandil on intra-operative myocardialischaemia in 248 patients who had pre-operative risk factorsfor ischaemic heart disease and were undergoing major abdominalsurgery. Patients in group HD (n=81) received a bolus dose ofnicorandil 0.08 mg kg^–1 and a continuous infusion of 0.08mg kg^–1 h^–1. Patients in group LD (n=87) receivednicorandil 0.04 mg kg^–1 and 0.04 mg kg^–1 h^–1.Patients in the placebo (P) group (n=80) received the same volumesof saline. The patients were monitored with a three-lead clinicalECG monitor with an ST trending device from arrival in the operatingtheatre to the end of anaesthesia. Intra-operative myocardialischaemia occurred significantly less frequently in the HD group(one patient, 1.2%) than in the LD (11 patients, 12.6%) andP groups (21 patients, 26.3%) (P<0.01), and in group LD significantlyless than in group P (P<0.05). Administration of nicorandilhad little effect on the patients’ heart rate or arterialpressure. Three patients in group P and none in either treatmentgroup developed myocardial infarction after surgery. Br J Anaesth 2001; 86: 332–7