Coronary Perfusion Versus Cold Ischemic Arrest During Aortic Valve Surgery

Abstract

Sixty-four randomized patients undergoing primary, isolated, scheduled, prosthetic aortic valve replacement were studied to determine the safety of coronary perfusion and mild hypothermia (31 patients) and of cold ischemic arrest (33 patients). Cardiac performance, metabolism, and isoenzyme release and the electrocardiogram were studied early postoperatively. No differences greater than expected by chance were found between the two groups; however, the difference between group means of several hemodynamic variables was significantly larger than experimental error. Combined abnormalities of creatine phosphokinase (CPK) and lactic dehydrogenase (LDH) heart-specific isoenzymes, indicative of myocardial necrosis, were found in 33 of 48 patients (68.7%) so studied. The incidence was similar in both study groups. In 14 of 52 (27%) patients with electrocardiographic studies, changes indicative of new infarction or ischemia were demonstrated, but no differences in incidence between the two groups of patients were found. In both groups the transmyocardial excess lactate immediately postoperatively was elevated, falling to near normal over the next 24 hours. Aortic crossclamp and cardiopulmonary bypass times were less by 27% and 21% respectively when cold ischemic arrest was used.