Early Prognostic Value of High-Sensitivity Troponin T after Coronary Artery Bypass Grafting

Background Periprocedural myocardial injury after coronary artery bypass grafting (CABG) may affect the patient's prognosis and may be due to a different set of factors beyond the atherosclerotic plaque instability. Considering the challenges in the diagnosis of myocardial injury after CABG, the aim of this study was to determine the association between postoperative early elevation of high-sensitivity troponin T (hsTnT) and all-cause 30-day mortality after CABG. Methods We enrolled 600 consecutive patients who underwent CABG. The hsTnT value was measured immediately before surgery and in the morning of the first postoperative day. Results The baseline hsTnT was 13 ng/L (7–26 ng/L) and 273 patients (45.7%) had baseline hsTnT above the 99th percentile/upper reference limit (URL) (14 ng/L). The median for hsTnT at first postoperative day was 235 ng/L (152–425 ng/L). We calculated the postoperative hsTnT ratio to URL for each patient, representing the number of times exceeding the URL (hsTnT value divided by 14 ng/L). The multivariate analysis by Cox proportional hazard model revealed that age (years) (hazard ratio [HR] = 1.13, 95% confidence interval [CI]: 1.07–1.20; p < 0.001) and postoperative hsTnT ratio to URL (per 10-fold increase) (HR = 1.06, 95% CI: 1.04–1.08; p < 0.001) were independent predictors of all-cause 30-day mortality after CABG. Conclusion In our series, age and higher postoperative hsTnT levels were independent and reliable predictors of all-cause 30-day mortality after CABG.