Cardiac Troponin T Measured by a High-Sensitivity Assay Predicts Recurrent Cardiovascular Events in Stable Coronary Heart Disease Patients with 8-Year Follow-up

BACKGROUND: The clinical relevance of slightly increased circulating troponin concentrations in patients with stable coronary heart disease (CHD) several weeks after an acute event or CABG has not been fully evaluated. METHODS: Baseline plasma concentrations of troponin T were measured with a high-sensitivity assay (hs-cTnT) (Roche Elecsys) in a cohort of 1050 CHD patients from 30 to 70 years of age. The prognostic value of hs-cTnT on a combined cardiovascular disease (CVD) end point after adjustment for covariates was determined with Cox proportional hazards modeling. RESULTS: The median hs-cTnT concentration was 10.9 ng/L (interquartile range, 5.1-18.9 ng/L). Increased hs-cTnT concentrations were associated with an older age, history of hypertension and diabetes, more advanced coronary artery disease, and other CHD risk factors. Furthermore, hs-cTnT concentration was strongly correlated with N-terminal pro B-type natriuretic peptide (NT-proBNP) and cystatin C (rho = 0.61, and rho = 0.32, respectively; both P values <0.0001). During a median follow-up of 8.1 years, 150 patients (14.3%) experienced a secondary CVD event. In a multivariate model, hs-cTnT was associated with a hazard ratio (HR) for secondary events of 2.83 (95% CI, 1.68-4.79) when the extreme quartiles were compared. Further adjustment for cystatin C, NT-proBNP, and C-reactive protein attenuated this association only slightly (HR, 2.27; 95% CI, 1.31-3.95); P for trend < 0.002). ROC curve analysis of a clinical model that added hs-cTnT to a baseline model showed nonsignificant improvement in the area under the curve (0.69 vs 0.67), whereas the net reclassification improvement was 17.2% (P = 0.029). CONCLUSIONS: Slightly increased hs-cTnT concentrations in stable CHD patients are associated with several cardiovascular disorders and predict long-term CVD events. (C) 2012 American Association for Clinical Chemistry