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Age and Sex Dependent Upper Reference Limits for the High Sensitivity Cardiac Troponin T Assay.
J Am Coll Cardiol. 2014 Jan 30;
Authors: Gore MO, Seliger SL, Defilippi CR, Nambi V, Christenson RH, Hashim IA, Hoogeveen RC, Ayers CR, Sun W, McGuire DK, Ballantyne CM, de Lemos JA
Abstract
OBJECTIVES: To determine the 99(th) percentile upper reference limit for the highly sensitive cardiac troponin T assay (hs-cTnT) in three large independent cohorts.
BACKGROUND: The presently recommended 14 ng/L cutpoint for the diagnosis of myocardial infarction using the hs-cTnT assay was derived from small studies of presumably healthy individuals, with relatively little phenotypic characterization.
METHODS: Data were included from three well characterized population-based studies: the Dallas Heart Study (DHS), the Atherosclerosis Risk in Communities (ARIC) Study, and the Cardiovascular Health Study (CHS). Within each cohort, reference subcohorts were defined excluding individuals with recent hospitalization, overt cardiovascular disease and kidney disease (subcohort 1) and further excluding those with subclinical structural heart disease (subcohort 2). Data were analyzed stratified by age, sex and race.
RESULTS: The 99(th) percentile values for the hs-cTnT assay in DHS, ARIC and CHS were 18, 22 and 36 ng/L respectively (subcohort 1) and 14, 21 and 28 ng/L respectively (subcohort 2). These differences in 99(th) percentile values paralleled age differences across cohorts. Analyses within sex/age strata yielded similar results between cohorts. Within each cohort, 99(th) percentile values increased with age and were higher in men. More than 10% of men aged 65-74 with no cardiovascular disease in our study had cTnT values above the current myocardial infarction threshold.
CONCLUSIONS: Use of a uniform 14 ng/L cutoff for the hs-cTnT assay may lead to over-diagnosis of myocardial infarction, particularly in men and the elderly. Clinical validation is needed of new age- and sex-specific cutoff values for this assay.
PMID: 24530665 [PubMed - as supplied by publisher]