Retrograde continuous warm blood cardioplegia reduces oxidative stress during coronary artery bypass grafting

Myocardial oxidative stress during retrograde continuous blood cardioplegia (RCBC) was evaluated in 22 patients undergoing elective aortocoronary bypass surgery. The patients were divided into two groups: Group C (n=11) received cold RCBC, and Group W (n=11) received warm RCBC. Myocardial oxidative stress was assessed by measuring the release of oxidized glutathione (GSSG), malondialdehyde (MDA), and myeloperoxidase (MPO) in the coronary sinus plasma before aortic clamping, at 1, 5, and 10 minutes after unclamping. Both the hemodynamic recovery and the creatine kinase MB (CKMB) activity were measured perioperatively until 24 hours after unclamping. In Group C, a significant coronary sinus release of GSSG was found in the early reperfusion period in comparison to Group W. No significant difference in the release of MDA nor MPO was noted in the two groups. The recoveries in the left and right ventricular functions, and the peak CK-MB activity were similar in both groups. In conclusion, warm blood cardioplegia is thus considered to protect the myocardium from ischemia-reperfusion injury better than cold blood cardioplegia under retrograde continuous perfusion.