High-Sensitivity Cardiac Troponin T and N-terminal pro-B-type Natriuretic Peptide in Acute Heart Failure: Data from the ACE 2 Study.

BACKGROUND To assess if cardiac troponins can improve diagnostics of acute heart failure (AHF) and provide prognostic information in patients with acute dyspnea. METHODS We measured cardiac troponin T with a high-sensitivity assay (hs-cTnT) in 314 patients hospitalized with acute dyspnea. The index diagnosis was adjudicated and AHF patients were stratified into AHF with reduced or preserved ejection fraction (HFrEF/HFpEF). The prognostic and diagnostic merit of hs-cTnT was compared to the merit of N-terminal pro-B-type natriuretic peptide (NT-proBNP). RESULTS In the total population, median age was 73 (quartile [Q] 1-3 63-81) years and 48% were women. One-hundred-forty-three patients were categorized as AHF (46%) and these patients had higher hs-cTnT concentrations than patients with non-AHF-related dyspnea: median 38 (Q1-3 22-75) vs. 13 (4-25) ng/L; p<0.001. hs-cTnT concentrations were similar between patients with HFrEF and HFpEF (p=0.80), in contrast to NT-proBNP, which was higher in HFrEF (p<0.001). C-statistics for discriminating HFpEF from non-AHF-related dyspnea was 0.80 (95% CI 0.73-0.86) for hs-cTnT, 0.79 (0.73-0.86) for NT-proBNP, and 0.83 (0.76-0.89) for hs-cTnT and NT-proBNP in combination. Elevated hs-cTnT remained associated with HFpEF in logistic regression analysis after adjusting for demographics, comorbidities and renal function. During median 27 months of follow-up, 114 (36%) patients died in the total population. Higher hs-cTnT concentrations were associated with increased risk of all-cause mortality after adjustment for clinical variables and NT-proBNP: hazard ratio 1.30 (95% CI 1.07-1.58), p=0.009. CONCLUSION hs-cTnT measurements improve diagnostic accuracy for HFpEF and provide independent prognostic information in unselected patients with acute dyspnea.