Cardiac troponin I versus creatine kinase-MB in the detection of postoperative cardiac events after coronary artery bypass grafting surgery.
OBJECTIVE
Several studies suggest that postoperarive concentrations of cardiac troponin-I (cTnI) may increase in patients undergoing aorto-coronary bypass grafting (CABG). The degree and pattern of release appears to be associated with perioperative myocardial damage.


METHODS
This was a prospective observational study with serial sampling conducted at the Departments of Cardiothoracic Surgery and Anesthesiology, University Hospital of Ioannina, Ioannina, Greece. The levels of cTnI and creatine kinase-MB (CK-MB) preoperatively, upon admission to the intensive care unit and at 12, 24, 36 and 48 hours after surgery, as well as daily from postoperative days 3-7 were determined in 41 consecutive patients (33 males and 8 females, aged 64.8+/-6.1 years) who underwent CABG with cardiopulmonary bypass. The Authors compared the patterns and variation of cTnI and creatine kinase (CK)-MB after CABG in patients with or without postoperative cardiac events (PCEs).


RESULTS
Eleven patients experienced a PCE (postoperative ventricular and supraventricular arrhythmia, need for intra-aortic balloon pump (IABP) for >12 hours, or postoperative myocardial infarction, [MI]). In patients without PCE the elevation of cTnI peaked at 24 hours after surgery, while in patients with PCE maximal values of cTnI occurred after 36 hours. CTnI levels correlated with CK-MB after the procedure. Receiver-operating characteristic (ROC) curve analysis indicated that cTnI is superior to CK-MB with regard to PCE diagnosis following CABG (area under the ROC curve, 0.73, 95% CI (0.53-0.93) versus 0.54, 95% CI, (0.25-0.83).


CONCLUSIONS
CTnI seems to be more valuable compared to CK-MB in the detection of PCEs in patients undergoing coronary surgery.
Tzimas
P G
PG
Department of Anesthesiology and Postoperative Intensive Care, School of Medicine, University of Ioannina, Ioannina, Greece.
Milionis
H J
HJ
Arnaoutoglou
H M
HM
Kalantzi
K J
KJ
Pappas
K
K
Karfis
E
E
Korantzopoulos
P
P
Drossos
G
G
Papadopoulos
G S
GS
D000368:Aged; D015415:Biomarkers / Q000097:blood; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D052279:Creatine Kinase, MB Form / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006331:Heart Diseases / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012107:Research Design; D013997:Time Factors; D016896:Treatment Outcome; D019210:Troponin I / Q000097:blood*; D015854:Up-Regulation
D015415:Biomarkers; D019210:Troponin I; D052279:Creatine Kinase, MB Form