Impact of age on cardiac troponin concentration among healthy individuals

BACKGROUND: The 99th percentile of cardiac troponin (cTn) among healthy individuals is the diagnostic cutoff for myocardial infarction. This study investigates the effect of age on the 99th percentile of cTn among healthy individuals. METHODS: We sampled healthy Danish blood donors, screened using hemoglobin A1c, N-terminal pro-brain natriuretic peptide, and creatinine. The cTn assays investigated were Siemens Atellica and Dimension Vista hs-cTnI, Abbott hs-cTnI, Vitros hs-cTnI, and Roche hs-cTnT. The 99th percentiles were calculated using the non-parametric method and modeled using quantile regressions adjusted for sex and creatinine concentration. RESULTS: We included 2287 participants, excluding 118 due to a history of heart disease, insufficient plasma, or biomarker screening, leaving 2169 participants with a median age of 58 years (IQR 49-69 years), and 1152 (53 %) were female. Concentrations increased with age for all assays (p < 0.001). Only the 99th percentile of hs-cTnT was significantly associated with age (0.42 ng/L increase/year, p < 0.001); for participants >70 years, the 99th percentile was 36.8 ng/L (90 % CI 33.8-40.7 ng/L), with 22.2 % above the manufacturer's 99th percentile. The difference in the 99th percentile between age groups was less clear for cTnI, except for the Vitros assay: <50 years 6.5 ng/L (90 % CI 5.0-26.9 ng/L) vs >70 years 17.3 ng/L (90 % CI 9.7-33.2 ng/L). CONCLUSIONS: Age was associated with increased cTn concentrations for all assays. The correlation was strongest for hs-cTnT, where the 99th percentile for participants >70 years was more than double compared to those <50 years, with over 20 % exceeding the manufacturer's 99th percentile. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT05336435.