Myocardial protection by nicorandil during open-heart surgery under cardiopulmonary bypass.
BACKGROUND
To evaluate the myocardial protective effect of nicorandil when used as an adjuvant to cold hyperkalaemic cardioplegia in open-heart surgery.


METHODS
Patients who underwent surgery under cardiopulmonary bypass (CPB) for mitral valve replacement (MVR, 23 patients) or coronary artery bypass grafting (CABG, 24 patients) were entered in a double-blind study. The patients were randomized to a nicorandil Group (N) or placebo Group (P). Nicorandil 0.1 mg kg-1 (Group N), or normal saline (Group P), were administered at three time points: (1) after aortic cannulation, but prior to going on CPB, (2) 5 min before aortic cross-clamping and (3) 5 min before reperfusion. The following variables were studied: (a) time until electromechanical arrest after cardioplegia administration (Tarrest), (b) time until return of electromechanical activity after aortic cross-clamp removal (Trecovery), (c) incidence of postoperative myocardial infarction or low output syndromes (d) dysrhythmias requiring intervention after aortic cross-clamp removal and (e) haemodynamic changes after nicorandil administration.


RESULTS
The Tarrest after cardioplegia administration was significantly faster in nicorandil group in both MVR and CABG patients (P 75 IU L-1 in MVR patients was significantly lower in the Group N than in placebo patients (P < 0.05). However, in CABG patients there was no such significant difference. The incidence of dysrhythmias requiring intervention after aortic cross-clamp removal was also less in Group N. Administration of 0.1 mg kg-1 boluses of nicorandil did not cause significant haemodynamic changes or precipitate dysrhythmias in any patient.


CONCLUSIONS
Nicorandil enhances the myocardial protective effect of cold hyperkalaemic cardioplegia in cardiac surgery patients.
Chinnan
N K
NK
Post Graduate Institute of Medical Education and Research, Department of Anaesthesia and Intensive Care, Chandigarh, India. nevinkc2001@yahoo.com
Puri
G D
GD
Thingnam
S K S
SK
D000328:Adult; D002315:Cardiopulmonary Bypass; D052283:Creatine Kinase, MM Form / Q000097:blood; D005260:Female; D006321:Heart / Q000187:drug effects*; D006331:Heart Diseases / Q000097:blood / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020108:Nicorandil / Q000494:pharmacology*
D020108:Nicorandil; D052283:Creatine Kinase, MM Form