Background: This study evaluated the myocardial protective strategies in isolated coronary bypass surgeries.
Methods: One hundred and twenty-eight patients were prospectively randomized to 3 techniques of myocardial protection; group I (n = 47) antegrade/retrograde tepid blood cardioplegia, group II (n = 40) antegrade/retrograde cold blood cardioplegia with topical cooling, group III (n = 41) antegrade crystalloid cardioplegia with topical cooling.
Results: The incidence of spontaneous defibrillation was significantly higher in group I (p < 0.001) while the incidence of low cardiac output was not different between the 3 groups. The incidence of ventricular arrhythmia was higher in group III (p < 0.016 group III vs I). There was no significant statistical difference in hemodynamic recovery between the 3 groups. CK-MB levels were significantly lower in group I versus the other 2 groups, (p = 0.0013, 0.04). Acid release and oxygen extraction were higher in group II than in group I (p = 0.06) during cardioplegia and reperfusion. Lactate release was less in group I at the release of aortic cross-clamp, and reperfusion. There was no significant difference between the 3 groups in ICU stay, ventilation time, or hospital complications.
Conclusions: Tepid blood cardioplegia showed superiority in metabolic and functional recovery, whereas crystalloid cardioplegia had the highest incidence of postoperative arrhythmias. There was no significant statistical difference between the 3 groups in hospital mortality and morbidity.