Do we still need CK-MB in coronary artery bypass grafting surgery?

Aim. The aim of this study was to evaluate the role of cardiac Troponin I (cTnI) and CK-MB for early prediction of outcome of patients undergoing coronary artery bypass grafting (CABG) surgery. Methods. In 134 consecutivepatients undergoing CABG-surgery blood samples were analyzed for cTnI concentration and CK-MB activity. ECG, hemodynamic parameters and the need for inotropic support, were continuously registered. Patients were divided into group A (uneventful course), group B (ischemia by ECG, hemodynamic stability) and group C (ischemia by ECG and IABP). Results. After removal of X-clamp an increase cTnI and CK-MB was observed in all patients. Five hrs after stop of CPB group A (8.3′4.2 μg/L) had lower cTnI values compared to group B (14.8′5.3 μg/L) (p-0.035) and C (54′22.8 μg/L) (p=0.023). The cut off value was 14.8 μg/L. Sensitivity and specificity (99%/97%) was higher for cTnI than for CK-MB (90%/30%). The positive predictive value of outcome was better for cTnI (86%) than for CK-MB (33%). Conclusion. CTnI is a specific and sensitive marker for evaluation of perioperative myocardial ischemia (PMI). Additional determination of CK-MB activity does not provide further clinical information. CTnI should be the marker of first choice in CABG surgery.