Introduction
Elevation of blood serum troponin I (cTnI) and other cardiac enzymes is a key feature of cardiac ischemia and myocardial infarction1,2. In the event of myocardial infarction, detectable troponin elevation is present within a few hours of the event, and peak levels are reached by 24-48 hours3. Presence of acute coronary syndrome with troponin elevation has been demonstrated to signify higher risk of mortality than patients without troponin elevation4,5. Furthermore, mortality risk increases following coronary revascularization, both via percutaneous coronary intervention or coronary artery bypass grafting (CABG), when preprocedural troponin levels are elevated6–12. It is well-documented that pre-revascularization troponin elevation is associated with decreased survival, however, the significance of peak troponin level on outcomes of revascularization has been more controversial5,6,13. The purpose of this study was to evaluate the impact of preoperative peak troponin level on short- and long-term outcomes of isolated CABG for non-ST-elevation myocardial infarction (NSTEMI).