Evaluation of "new" cardiac markers for ruling out myocardial infarction after coronary artery bypass grafting.
OBJECTIVE
This study was conducted to evaluate the value of serum troponin T, myoglobin, and creatine kinase (CK)-MB mass concentrations for ruling out perioperative myocardial infarction (poMI) early after cardiac surgery.


METHODS
Retrospective study.


METHODS
Cardiothoracic surgery department in a university hospital.


METHODS
One hundred eighty-one patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass were included.


METHODS
Serum concentrations of troponin T, myoglobin, and CK-MB mass were measured preoperatively (baseline), on arrival at the cardiosurgical ICU (CICU), and at 2, 4, 8, 12, 16, and 20 h after arrival at the CICU. The strength of markers studied for ruling out poMI was studied using receiver operating characteristics curves. Based on these curves, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each marker at every time point were calculated.


RESULTS
poMI developed in 14 patients. On arrival at the CICU, all markers were significantly increased from baseline concentrations in both patient groups. In patients with poMI, serum concentrations of troponin T, myoglobin, and CK-MB mass were significantly higher than in control patients from 8, 2, and 0 h after arrival on the CICU, respectively. CK-MB mass was the earliest marker, and its NPV reached 98.6% 12 h after arrival at the CICU. On arrival at the CICU, the NPV for CK-MB mass already reached 96.7%. The NPV for myoglobin reached 98.4% 12 h after arrival at the CICU. Troponin T was not an early marker for ruling out poMI, with an NPV reaching 98.6% 12 h after arrival on the CICU. During the first 8 h after arrival at the CICU, sensitivity, specificity, PPV, and NPV of CK-MB mass exceeded those of myoglobin and troponin T. In later measurements (until 20 h after arrival at the CICU), troponin T gave the most sensitive definition of poMI.


CONCLUSIONS
For ruling out poMI on the CICU after CABG, CK-MB mass is a better marker than myoglobin and troponin T during the first 12 h after arrival on the CICU. Using these markers, postoperative treatment of cardiac surgical patients might be further improved.
Fransen
Erik J
EJ
Department of Cardiothoracic Surgery, University Hospital Maastricht, P. Debyelaan 25, 6202 AZ Maastricht, the Netherlands. efr@scpc.azm.nl
Diris
Jart H C
JH
Maessen
Jos G
JG
Hermens
Wim Th
WT
van Dieijen-Visser
Marja P
MP
D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000379:methods; D003402:Creatine Kinase / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000209:etiology; D009211:Myoglobin / Q000032:analysis*; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011336:Probability; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D020107:Troponin T / Q000032:analysis*
D015415:Biomarkers; D009211:Myoglobin; D020107:Troponin T; D003402:Creatine Kinase