Warm blood cardioplegia versus cold crystalloid cardioplegia for myocardial protection during coronary artery bypass grafting surgery

We retrospectively analyzed early results of coronary artery bypass grafting (CABG) surgery using two different types of cardioplegia for myocardial protection: antegrade intermittent warm blood or cold crystalloid cardioplegia. From January 2015 to October 2016, 330 consecutive patients underwent isolated on-pump CABG. Cardiac arrest was obtained with use of warm blood cardioplegia (WBC group, n = 297) or cold crystalloid cardioplegia (CCC group, n = 33), according to the choice of the surgeon. Euroscore II and preoperative characteristics were similar in both groups, except for the creatinine clearance, slightly lower in WBC group (77.33 ± 27.86 mL/min versus 88.77 ± 51.02 mL/min) (P < 0.05). Complete revascularization was achieved in both groups. In-hospital mortality was 2.0% (n = 6) in WBC group, absent in CCC group. The required mean number of cardioplegia’s doses per patient was higher in WBC group (2.3 ± 0.8) versus CCC group (2.0 ± 0.7) (P = 0.045), despite a lower number of distal coronary artery anastomoses (2.7 ± 0.8 versus 3.2 ± 0.9) (P = 0.0001). Cardiopulmonary and aortic cross-clamp times were similar in both groups. The incidence of perioperative myocardial infarction (WBC group 3.4% versus CCC group 3.0%) and low cardiac output syndrome (4.4% versus 3.0%) were similar in both groups. As compared with WBC group, in CCC group CK-MB/CK ratio >10% was lower during each time points of evaluation, with a statistical significant difference at time 0 (4% ± 1.6% versus 5% ± 2.5%) (P = 0.021). In presence of complete revascularization, despite the value of CK-MB/CK ratio >10% was less in the CCC group, clinical results were not affected by both types of cardioplegia adopted to myocardial protection. As compared with cold crystalloid, warm blood cardioplegia requires a shorter interval of administration to achieve better myocardial protection.