Aims cardiac biomarkers are routinely elevated after uncomplicated cardiac surgery to levels considered diagnostic of myocardial infarction in ambulatory populations. We investigated the diagnostic power of electrocardiogram (ECG) and cardiac biomarker criteria to predict clinically relevant myocardial injury using benchmarks of mortality and increased hospital length of stay (HLOS) in patients undergoing coronary artery bypass graft (CABG) surgery.Methods and resultsPerioperative ECGs, creatinine kinase MB fraction, and cardiac troponin I (cTnI) were assessed in 545 primary CABG patients. None of the ECG criteria for myocardial injury predicted mortality or HLOS. However, post-operative day (POD) 1 cTnI levels independently predicted 5-year mortality (hazard ratio = 1.42; 95 CI 1.14-1.76 for each 10 g/L increase; P = 0.009), while adjusting for baseline demographic characteristics and perioperative risk factors. Moreover, cTnI was the only biomarker that significantly improved the prediction of 5-year mortality estimated by the logistic Euroscore (P = 0.02). Furthermore, the predictive value of cTnI for 5-year mortality was replicated in a separately collected cohort of 1031 CABG patients using cardiac troponin T.ConclusionElectrocardiogram diagnosis of post-operative myocardial injury after CABG does not independently predict an increased risk of 5-year mortality or HLOS. Conversely, cTnI is independently associated with an increased risk of mortality and prolonged HLOS.
Bibliographical noteFunding Information:
Conflict of interest: J.D.M. received a Bayerw Fellowship in Blood Conservation; S.K.S. received funding from Siemens Medical Solutions Diagnostics, Tarrytown, NY, USA; J.D.M and A.A.F. received a Society of Cardiovascular Anaesthesiologists Research Starter Grant; A.A.F. received a Foundation in Anaesthesia Education and Research Starter Grant; C.D.C. and A.A.F. received a grant from NIH (NCRR M01 02558); and S.C.B. received a grant from NIH (NHLBI HL-068774).
This work was supported by the Bayerw Fellowship in Blood Conservation, Biosite Inc., San Diego, CA, USA (J.D.M.); NIH (HL-068774 to S.C.B., NCRR M01 02558 to C.D.C. and A.A.F.); Society of Cardiovascular Anaesthesiologists Research Starter Grant; and Siemens Medical Solutions Diagnostics, Tarrytown, NY (J.D.M.).
- Cardiopulmonary bypass