Myocardial injury and ck‐mb release during aortic valve surgery with selective coronary perfusion

The postoperative serum activity of creatine kinase MB isoenzyme (CK-MB) was studied in 25 patients undergoing isolated aortic valve replacement (Björk-Shiley prosthesis). Hypothermia at 30 degrees C and selective coronary perfusion (CP) were used for myocardial protection. Repeated electrocardiograms revealed no signs of perioperative myocardial infarction. In all patients, CK-MB was detected in the serum. The CK-MB as a percentage of total CK at peak CK-MB [12 +/- 1 (mean +/- SEM)] was of the same magnitude as that found in acute myocardial infarction (AMI). Peak CK-MB occurred 2 +/- 0 h after the end of surgery. Peak total CK occurred after 17 +/- 3 h, and the plasma half-life for total CK was three times that of CK-MB. Thus, the kinetics of serum CK differed from those in AMI, but were similar to those reported after coronary bypass operations. The release of CK-MB, as well as of asparatate aminotransferase and thermostable lactate dehydrogenase, was related to the duration of aortic cross-clamping (AC), with a marked increase after 90 min. In two subgroups with similar AC time, postoperative CK-MB activity was higher in the subgroup with longer CP, indicating that CP as a method of myocardial protection may be entirely beneficial.