Cardiac Myosin-Binding Protein C Release Profile After Cardiac Surgery in Intensive Care Unit

Background. Cardiac surgical procedures produce iatrogenic myocardial cell injury with necrosis that result in an obligatory release of biomarkers. Cardiac myosin binding protein C (cMyBP-C) has recently emerged as a specific and sensitive biomarker in patients with acute myocardial injury. We therefore aimed to investigate the release profiles of cMyBP-C after cardiac surgical procedures. Methods. Enzyme-linked immunosorbent assay to detect blood cMyBP-C was established by using two monoclonal antibodies against N-terminus of human cMyBP-C. Consecutive patients undergoing cardiac operations (N = 151) were recruited in this study. Blood cMyBP-C was assayed preoperatively, at intensive care unit arrival (0 hour after the operation), at 2 to 48 hours, and before discharge. The characteristics and detailed surgical procedure were recorded. Results. The established immunoassay was capable of detecting human cMyBP-C (0 to 1000 ng/L). The released cMyBP-C peaked immediately after cardiac surgery (0 h), attaining 3.8-fold higher than before the operation, dropped abruptly within 24 hours, and stayed at a higher level until discharge. Postoperative cMyBP-C levels correlated positively with high-sensitivity cardiac troponin T (hs-cTnT), creatine kinase, myoglobin, and creatine kinase MB isoenzyme. Different cardiac surgical procedures were characterized by different levels of release of cardiac biomarkers. Isolated off-pump coronary artery bypass grafting was associated with the smaller amount of cMyBP-C release, whereas valve replacement/plasty surgery produced higher release, in particular the multiple-valve surgery. Both cMyBP-C and hs-cTnT correlated with surgical techniques, postoperative intensive care unit stay, and hospital stay. Conclusions. Circulating cMyBP-C is a promising novel biomarker for evaluating cardiac surgical trauma in patients undergoing a cardiac operation. (C) 2019 by The Society of Thoracic Surgeons