Head-to-head comparison of high-sensitivity troponin T and sensitive-contemporary troponin I regarding heart failure risk stratification

Background: High-sensitivity assays for cardiac troponins have recently become available, increasing the value of troponins in heart failure (HF) prognostication. We head-to-head compared the prognostic significance of high-sensitivity cardiac troponin T (hs-cTnT) and sensitive-contemporary cardiac troponin I (sc-cTnI) in an outpatient HF population. Methods: We studied 876 patients, mainly of ischemic etiology (52.1%). Median left ventricular ejection fraction was 34%. Median follow-up was 3.45 years. Comprehensive statistical measurements of performance (discrimination, calibration, and reclassification) were obtained. Results: hs-cTnT was ubiquitous in the patient cohort; sc-cTnI was detected in 276 patients (31.5%). During follow-up 311 patients died. According to multivariable Cox regression analysis, both hs-cTnT (HR 2.09, 95% CI 1.46-2.99, P < 0.001) and sc-cTnI (HR 1.61, 95% CI 1.24-2.08, P < 0.001) remained independent predictors of all cause and cardiovascular mortality. Using the best predictive cut-off point for both troponins calibration was better for hs-cTnT, which also reclassified a larger number of patients (NRI 9.0 [2.5;15.5] P = 0.007). The higher sensitivity of hs-cTnT permitted the identification of almost the double of deaths. Conclusion: Both hs-cTnT and sc-cTnI predict mortality in a real-life cohort of ambulatory HF patients. However, hs-cTnT showed globally better measures of performance and identified a higher proportion of decedents during follow-up. (C) 2013 Elsevier B.V. All rights reserved.