Postoperative cardiac troponin I (cTnI) level and its prognostic value for patients undergoing mitral valve surgery

Abstract

It has previously been reported that cardiac troponin I (cTnI) is useful in predicting the postoperative course after cardiac surgery, and that elevated serum cTnI levels are associated with increased in-hospital mortality. However, these findings have been reported in heterogeneous groups of cardiac surgical procedures. In the current study, the usefulness of postoperative cTnI measurements for the prediction of patient outcomes in a specific group of cardiac surgical procedures was determined, with the analysis limited to patients undergoing mitral valve surgery. The results of cTnI measurements were compared with postoperative creatine kinase-myocardial band fraction (CK-MB) levels.A total of 24 patients who underwent mitral valve surgery from July 2004 to April 2009 were retrospectively studied. Serum cTnI and CK-MB levels were measured on postoperative day (POD) 0 (immediately after surgery), and on POD 1, 2, and 3. The relationship between serum cTnI and CK-MB levels, cardiopulmonary bypass (CPB) time, aorta cross-clamping (AoC) time, and the length of ICU stay and postoperative hospital stay (POHS) were evaluated.CPB and AoC time influenced postoperative cTnI and CK-MB levels. Values of cTnI on POD 1 and POD 2 were significantly correlated with the length of ICU stay, whereas only the CK-MB level on POD 2 was significantly correlated with the length of ICU stay. In addition, the cTnI levels on POD 1 and POD 2 were significantly correlated with POHS, however, there was no relationship between postoperative CK-MB levels and POHS. Postoperative cTnI measurements are more useful than CK-MB measurements in predicting the postoperative course of a patient following mitral valve surgery.