Nicorandil pretreatment and improved myocardial protection during cold blood cardioplegia.

OBJECTIVE

The present study was designed to assess whether pretreatment with nicorandil enhanced myocardial protection provided by cold (15 degrees C) high-potassium (25 mmol/l) blood cardioplegia during open heart surgery.

METHODS

Subjects were 40 patients with a variety of acquired heart diseases undergoing cardiac surgery involved cardiopulmonary bypass. They were randomly divided into two groups, 25 pretreated nicorandil (0.3 mg/kg) 30 minutes before aortic cross clamping, 15 not pretreated. After aortic cross clamping, the initial dose of cardioplegic solution (10 ml/kg) was administered through the ascending aorta and supplemental doses of cardioplegia (5 ml/kg) given each 30 minutes thereafter. Preoperative and postoperative cardiac troponin-T, myosin light chain 1 and cardiac enzymes were measured and hemodynamic data recorded.

RESULTS

Postoperative serum creatine kinase and myosin light chain 1 were significantly lower in the nicorandil pretreatment group than in controls. Serum glutamic oxalacetic transaminase and troponin-T were lower and cardiac output was higher after surgery in the nicorandil group, although not statistically significant.

CONCLUSION

This data suggests that pretreatment with nicorandil enhances the myocardial protection achieved by cold blood cardioplegia.