Clinical Relevance of Troponin T Profile Following Cardiac Surgery

Background: Peak postoperative cardiac troponin T (cTnT) independently predicts mid- and long-term outcome of cardiac surgery patients. A few studies however reported 2 peaks of cTnT over the first 48-72 hours following myocardial reperfusion. The aim of the current study was to better understand underlying reasons of this cTnT profile and possible consequences on clinical outcome. Methods: All consecutive adult cardiac surgical procedures performed with an extra-corporeal circulation during a >6 years period were retrospectively evaluated. Patients with a myocardial infarction (MI) 6 to ≤12 hours (n=366), >12 to ≤18 hours (n=176), >18 to ≤24 hours (171), >24 hours (218). Age (OR: 1.023; CI:1.016-1.030) and isolated CABG (OR: 1.779; CI: 1.114-2.839) were independent predictors of a late increase of cTnT over a limit of 1 ng/ml (p<0.05), whereas isolated valve procedures (OR:0.685; CI: 0.471-0.998) and cross-clamp duration (OR: 0.993; CI: 0.990-0.997) independently predicted an early elevation (p<0.05). Delayed elevation over 1 ng/ml correlated with a higher rate of post-operative complications including MI (19.8% vs. 7.2%), new renal insufficiency (16.3% vs. 6.7%), MACCE (32.0% vs. 15.5%) or death (7.4% vs. 4.4%). Conclusion: Profile of cTnT elevation following cardiac surgery depends on patients’ intrinsic factors, type of surgery and duration of cross-clamp time. Delayed increase is of higher clinically relevance than prompt post-operative elevation.