Methods: Between April 2005 and June 2008, a total of 60 patients (36 males, 24 females; mean age 60.6 years; range 57 to 65) who were scheduled for coronary artery bypass grafting were prospectively randomized to receive one of three different strategies of myocardial preservation. Group A (n=20) received antegrade crystalloid cardioplegia, Group B (n=20) received antegrade blood cardioplegia, and Group C (n=20) received antegrade blood cardioplegia with carnitine. Samples for lactate dehydrogenase (LDH), creatinine phosphokinase (CPK), creatinine phosphokinasemyocardial band (CK-MB), and Troponin-I were taken from coronary sinus during the operation and from peripheral venous line postoperatively. Blood samples were obtained before CPB, just after CPB and postoperative 1, 6, 12, 24 and 48 hours. Levels of CPK, CK-MB and Troponin-T levels were studied by immunoassay method.

Results: The patients who received carnitine had significantly improved cardiac output, cardiac index, and right and left ventricular stroke work immediately after cardiopulmonary bypass and at the first postoperative hour (p=0.01). Troponin-T levels decreased in all patients after 12 hours postoperatively, and this change was most prominent in Group C (p=0.001).

Conclusion: Intravenous supplementation of carnitine during cardioplegia provides better results on the recovery of cardiac function and metabolic parameters after coronary artery bypass grafting.