Intermittent Antegrade Tepid Versus Cold Blood Cardioplegia in Elective Myocardial Revascularization

Background. The ideal temperature for blood cardioplegia administration remains controversial. Methods. Fifty-two patients who required elective myocardial revascularization were prospectively randomized to receive intermittent antegrade tepid (29°C; group T, 25 patients) or cold (4°C; group C, 27 patients) blood cardioplegia. Results. The two cohorts were similar with respect to all preoperative and intraoperative variables. The mean septal temperature was higher in group T (T, 29.6° ± 1.1°C versus 17.5° ± 3.0°C; p < 0.0001). After reperfusion, group T exhibited significantly greater lactate and acid release despite similar levels of oxygen extraction (p < 0.05). The creatine kinase-MB isoenzyme release was significantly lower in group T (764 ± 89 versus 1,120 ± 141 U · h/L; p < 0.04). Hearts protected with tepid cardioplegia demonstrated significantly increased ejection fraction with volume loading, improvement in left ventricular function at 12 hours, and decreased need for postoperative inotropic support (p < 0.05). The frequency of ventricular defibrillation after cross-clamp removal was lower in this cohort (p < 0.05). There were no hospital deaths, and both groups had similar postoperative courses. Conclusions. Intermittent antegrade tepid blood cardioplegia is a safe and efficacious method of myocardial protection and demonstrates advantages when compared with cold blood cardioplegia in elective myocardial revascularization.