Direct comparison of clinical decision limits for cardiac troponin T and I

ObjectiveThe 99th percentile upper reference limit of high-sensitivity cardiac troponin (hs-cTn) from a healthy reference population is used for diagnosing acute myocardial infarction (AMI). Accepted current thresholds of hs-cTnT (Roche) and hs-cTnI (Abbott) are 14 and 26 ng/L, respectively. Since thresholds for hs-cTnT and hs-cTnI were derived from different reference cohorts it is unclear whether they are biologically equivalent. We directly assessed sex-specific and age-specific 99th percentile upper reference limits of hs-cTnT and hs-cTnI in a single reference cohort, to investigate whether current divergent thresholds of hs-cTnT and hs-cTnI stem from intrinsic assay differences or reflect cohort variation.MethodsA healthy reference population was derived from a population-based cohort (the Maastricht Study: n=3451; age: 40–75 years). Individuals with diabetes mellitus, a history of cardiovascular disease, cardiac ischaemia on ECG, N-terminal pro-brain natriuretic peptide >125 ng/L or estimated glomerular filtration rate