Combined use of high-sensitivity cardiac troponin T and N-terminal pro-B type natriuretic peptide improves measurements of performance over established mortality risk factors in chronic heart failure

Abstract

Background: Heart failure still maintains a high mortality. Biomarkers reflecting different pathophysiological pathways are under evaluation to better stratify the mortality risk. The objective was to assess high-sensitivity cardiac troponin T (hs-cTnT) in combination with N-terminal pro-B type natriuretic peptide (NT-proBNP) for risk stratification in a real-life cohort of ambulatory heart failure patients.

Methods: We analyzed 876 consecutive patients (median age 70.3 years, median left ventricular ejection fraction 34%) treated at a heart failure unit. A combination of biomarkers reflecting myocyte injury (hs-cTnT) and myocardial stretch (NT-proBNP) was used in addition to an assessment based on established mortality risk factors (age, sex, left ventricular ejection fraction, New York Heart Association functional class, diabetes, estimated glomerular filtration rate, ischemic etiology, sodium, hemoglobin, β-blocker treatment, and angiotensin converting enzyme inhibitor or angiotensin II receptor blocker treatment).

Results: During a median follow-up of 41.4 months, 311 patients died. In the multivariable Cox proportional hazards model, hs-cTnT and NT-proBNP were independent prognosticators (P = .003 each). The combined elevation of both biomarkers above cut-off values significantly increased the risk of death (HR 7.42 [95% CI, 5.23-10.54], P < .001). When hs-cTnT and NT-proBNP were individually included in a model with established mortality risk factors, measurements of performance significantly improved. Results obtained for hs-cTnT compared with NT-proBNP were superior according to comprehensive discrimination, calibration, and reclassification analysis (net reclassification indices of 7.7% and 1.5%, respectively).

Conclusions: hs-cTnT provides significant prognostic information in a real-life cohort of patients with chronic heart failure. Simultaneous addition of hs-cTnT and NT-proBNP into a model that includes established risk factors improves mortality risk stratification.