Comparison of Cardiac Troponin T and I: Impact on Definitions of Perioperative Myocardial Infarction After Coronary Artery Bypass Grafting

Background We aimed to directly compare the postoperative release dynamics of cTn (cardiac troponin) T and I after uneventful coronary artery bypass graft surgery and analyze differences between cTnT and cTnI regarding biomarker thresholds across various definitions of perioperative myocardial infarction. Methods Patients >18 years of age undergoing isolated coronary artery bypass graft surgery were included. Measurements of cTnT/I were performed in the same patients from the same blood samples. Patients with patent bypass grafts on postoperative computed tomography and without a ≥10% decrease in left ventricular ejection fraction, indicating an uneventful postoperative course, were included. Criteria for perioperative myocardial infarction were applied according to current guidelines and recommendations (Universal Definition of Myocardial Infarction, the Academic Research Consortium‐2, VISION [Vascular Events in Surgery Patients Cohort Evaluation]). Results The study included 258 patients (median 69 [interquartile range, 62–75] years). Median postoperative peak values were 349 ng/L (interquartile range, 206–547) for cTnT and 1517 ng/L (interquartile range, 752–2897) for cTnI and were seen on the first postoperative day most frequently. The required biomarker cutoffs according to Universal Definition of Myocardial Infarction, Academic Research Consortium‐2, and VISION trial were exceeded more often for cTnI compared with cTnT (eg, Universal Definition of Myocardial Infarction: n=181 [72.4%; 95% CI, 67%–78%] for cTnI versus n=150 [60.0%; 95% CI, 54%–66%] for cTnT; P