Background: The simultaneous assessment of high-sensitivity cardiac troponin T (hscTnT) and NT-proBNP for predicting death in stable coronary artery disease (CAD) has yet not been examined. We investigated the additional contribution of hscTnT to the risk of mortality prediction of NT-proBNP in patients with stable CAD.
Methods: We studied 1469 patients with stable CAD enrolled in the Ludwigshafen Risk and Cardiovascular Health Study (LURIC). hscTnT and NT-proBNP were measured in baseline samples using immunoassays (Roche Diagnostics, Germany).
Results: Thirty-five percent (n=525) of the patients died during a median follow-up of 7 and a half years. In total 59.0% of the non-survivors and 25.2% of the survivors exhibited concentrations of hscTnT≥14 ng/L. Logistic regression analysis identified hscTnT and NT-proBNP as independent risk markers for short-term (1-year follow-up) and long-term (9-years follow-up) mortality. ROC curve analysis determined optimal univariate cut-offs at 14 ng/L and 443 µg/L for hscTnT (AUC 0.725, p<0.0001) and NT-proBNP (AUC 0.742, p<0.0001), respectively. Kaplan-Meier survival analysis based on optimized cut-offs for the simultaneous determination of both biomarkers confirmed the usefulness of additive hscTnT especially in prediction of short-term mortality. The prognostic benefit of the combined assessment of hscTnT and NT-proBNP could be confirmed by a significantly increased reclassification index (NRI) of 24.2%.
Conclusions: The majority of non-survivors exhibited increased hscTnT concentrations above 14 ng/L. The simultaneous determination of NT-proBNP and hscTnT was superior for risk stratification compared to determining either marker alone. Especially the prediction of the clinically important 1-year mortality was significantly improved by addition of hscTnT to NT-proBNP.