Diagnostic validation of a novel high-sensitivity cardiac troponin T assay

AIMS: High-sensitivity cardiac troponin (hs-cTn) assays are integral to evaluating suspected myocardial infarction (MI). A recently developed hs-cTnT assay requires diagnostic and prognostic evaluation. METHODS AND RESULTS: Patients presenting to the emergency department with suspected non-ST-elevation MI were prospectively evaluated. Discrimination was tested using the area under the curve (AUC). Diagnostic performance was assessed with previously derived cut-off concentrations and ESC 0/1 h algorithm. Head-to-head comparisons between the new and established assays were performed. Prognostic performance of hs-cTnT for 1-year mortality and major adverse cardiac events (MACE) was analysed using adjusted Cox regression. In 1415 patients, mean age 64 years and 64.2% male, MI was diagnosed in 12.1%. The novel TnT hs Gen 6 assay demonstrated excellent discrimination with an AUC on admission of 0.87 (95% CI: 0.84, 0.90) and 0.91 (95% CI: 0.89, 0.93) after 1 h. Using a 0 h cut-off <8 ng/L or <18 ng/L and Δ 0/1 h of <2 ng/L enabled rule-out in 54.3% (95% CI: 51.7%, 57.0%), with a NPV of 99.5% (95% CI: 98.7%, 99.9%); sensitivity was 97.7% (95% CI: 94.1%, 99.4%). For rule-in, a 0 h cut-off ≥112 ng/L or a Δ 0/1 h ≥ 10 ng/L yielded a PPV of 58.5% (95% CI: 51.9%, 64.9%) and specificity of 92.2% (95% CI: 90.6%, 93.6%) with rule-in of 16.5% (95% CI: 14.6%, 18.6%). Hs-cTnT was associated with 1-year mortality [hazard ratio (HR) 1.39 (95% CI: 1.28, 1.51)] and MACE [HR 1.22 (95% CI: 1.15, 1.29)]. CONCLUSION: The novel hs-cTnT assay demonstrates high diagnostic accuracy to rule-out or diagnose MI and offers valuable prognostic information regarding 1-year mortality and MACE.Trial Registration: clinicaltrials.gov (NCT02355457).