Association between high-sensitivity troponin T levels and postoperative outcomes after cardiac surgery

BACKGROUND High-sensitivity troponin T (hsTnT) is a sensitive marker of myocardial injury. After cardiac surgery, however, postoperative concentrations are elevated in almost all patients because of procedure-related myocardial injury, making clinical interpretation difficult. OBJECTIVE To determine whether postoperative hsTnT provides incremental prognostic value beyond EuroSCORE II for predicting adverse outcomes after cardiac surgery. DESIGN Retrospective cohort study. SETTING Single tertiary care centre, June 2019 to June 2024. PATIENTS Adult patients undergoing cardiac surgery. MAIN OUTCOME MEASURES The primary outcome was all-cause in-hospital mortality; secondary outcomes included intensive care unit and hospital length of stay and need for percutaneous coronary intervention. RESULTS Among 4102 procedures with available EuroSCORE II, the baseline model using only EuroSCORE II, showed excellent discrimination for in-hospital mortality (area under the receiver operating characteristic curve 0.84). Adding postoperative day 1 hsTnT resulted in a small but significant improvement in discrimination with an increase in the area under the curve of 0.03 (95% confidence interval (CI) 0.01 to 0.05), P = 0.01 and an integrated discrimination improvement of 0.03 (95% CI 0.01 to 0.05). HsTnT measured immediately after surgery and the relative postoperative change in hsTnT did not improve discrimination. Higher hsTnT concentrations at both time points were associated with a longer intensive care unit stay, D0: hazard ratio 0.936 (95% CI 0.920 to 0.952), P < 0.001; D1: 0.889 (95% CI 0.870 to 0.907], P < 0.001); a longer hospital stay, D0: 0.902 (95% CI 0.886 to 0.917), P < 0.001; D1: 0.855 (95% CI 0.837 to 0.874), P < 0.001); and a higher risk of percutaneous coronary intervention, D0: 1.232 (95% CI 1.150 to 1.319), P < 0.001; D1: 1.329 (95% CI 1.228 to 1.439), P < 0.001). Relative postoperative changes in hsTnT were not associated with these outcomes. CONCLUSION Postoperative high-sensitivity troponin T adds little incremental prognostic value beyond EuroSCORE II for in-hospital mortality after cardiac surgery. Higher postoperative hsTnT concentrations were associated with longer intensive care unit and hospital stay and an increased risk of percutaneous coronary intervention, suggesting that they primarily reflect perioperative myocardial injury rather than short-term mortality risk.