Prognostic significance of cardiopulmonary bypass time and postoperative serum enzyme levels in coronary surgery.

The serum activity concentrations of creatine kinase MB isoenzyme (CK-MB) after coronary bypass operations are correlated with the duration of extracorporeal circulation (ECC) and aortic cross-clamping (AC), and the kinetics of serum enzyme appearance in this situation differ from the findings in acute myocardial infarction, as shown in previous papers. In the present investigation, the functional significance of different levels of postoperative serum CK-MB activity was studied in 21 patients by clinical re-examination, including exercise test, after 18 months. The possible long-term effect of extended periods of ECC and AC was further evaluated in another series of 21 patients, with coronary angiography and heart catheterization performed before and one year after coronary surgery. It is concluded that if successful revascularization is achieved by operation, the duration of ECC and AC, and the magnitude of postoperative CK-MB release, appear to have no significance for future myocardial function.