Troponin T elevation after coronary bypass surgery: clinical relevance and correlation with perioperative variables

Abstract

Elevation in markers of myocardial necrosis is a common feature following coronary artery bypass surgery, but its relevance is unclear. The objective of this study was to evaluate the association between postoperative troponin T elevation, perioperative variables and clinical outcomes. We evaluated 100 low-risk patients undergoing first-time elective on-pump coronary artery bypass surgery. The mean age was 62 +/- 9.8 years and 83% were male; patients with diabetes mellitus, renal failure and impaired left ventricular function (ejection fraction < 40%) were excluded. Troponin levels were measured at baseline and 12 and 24 h following the onset of cardiopulmonary bypass. Predefined clinical endpoints included death, new Q waves on 12-lead electrocardiogram and inotropic requirement. Postoperative troponin elevation occurred in 95%. Troponin T elevation was related to the duration of cardiopulmonary bypass (P = 0.0001) and aortic cross-clamp time (P = 0.0003). There was also an inverse relationship with perioperative core temperature (P = 0.0001). There was no association between postoperative troponin elevation and clinical outcomes. Postoperative troponin T elevation occurs in the majority of patients undergoing elective on-pump coronary artery bypass surgery. In this low-risk cohort, troponin T elevation was associated with procedural duration but not with clinical outcome.