Troponin I was determined using a contemporary sensitive assay (TnI Ultra, Siemens) with 10 % coefficient of variation (0.03 ng/mL) below the published 99th percentile (0.04 ng/mL) in 5000 participants (49.2 % female) of the Gutenberg Health Study, a community-based, prospective, observational single-center cohort study. The calculated 99th percentile cut-offs were tested in 1818 patients with suspected AMI.
Troponin I concentration representing the 99th percentile of the overall study population was 0.04 ng/mL. Excluding individuals with prevalent cardiovascular disease lowers the 99th percentile to 0.034 ng/mL. Exclusion of individuals with traditional risk factors or elevated natriuretic peptide leads to further reduction with 0.029/0.028 ng/mL. These lower cut-offs detect more patients at risk in individuals with suspected AMI. Correlations of troponin I with age, gender and traditional risk factors were observed.
Troponin I concentrations in apparently healthy individuals are dependent on prevalent cardiovascular diseases, traditional risk factors, gender and age. Application of corresponding cut-offs in diagnosis of AMI alters the group of patients potentially at risk.