Intermittent tepid blood cardioplegia improves clinical outcome.

Intermittent antegrade cold blood cardioplegia is the predominant method of myocardial protection, but recent studies suggest that warm or tepid blood cardioplegia may improve the return of myocardial metabolic and contractile function. Data were collected prospectively on 1,533 patients undergoing cardiopulmonary bypass in a single surgeon's practice. The use of intermittent antegrade cold (4 degrees C) blood cardioplegia in 951 consecutive patients from September 1994 to November 1997 was compared with intermittent antegrade tepid (28 degrees C) blood cardioplegia in 582 consecutive patients from July 1998 to July 2000. The two groups were similar, but the symptom class was more severe and there were more redo and combined procedures and more operations within 7 days of myocardial infarction in the tepid group. Significant clinical benefits identified in the tepid group included reduced usage of intraaortic balloon pumping postoperatively (4.4% versus 2.2%) and reduced incidence of postoperative atrial fibrillation (25.7% versus 20.6%). There was no significant difference in mortality, perioperative myocardial infarction, cerebrovascular events, or use of inotropics between the groups. Intermittent tepid blood cardioplegia is clinically appropriate and safe to use in patients undergoing cardiac surgery.