@article {6238, title = {Age- and sex-dependent upper reference limits for the high-sensitivity cardiac troponin T assay.}, journal = {J Am Coll Cardiol}, volume = {63}, year = {2014}, month = {2014 Apr 15}, pages = {1441-8}, abstract = {

OBJECTIVES: The study sought to determine the 99th percentile upper reference limit for the high-sensitivity cardiac troponin T assay (hs-cTnT) in 3 large independent cohorts.

BACKGROUND: The presently recommended 14 ng/l cut point 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 3 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 99th percentile values for the hs-cTnT assay in DHS, ARIC, and CHS were 18, 22, and 36 ng/l (subcohort 1) and 14, 21, and 28 ng/l (subcohort 2), respectively. These differences in 99th percentile values paralleled age differences across cohorts. Analyses within sex/age strata yielded similar results between cohorts. Within each cohort, 99th percentile values increased with age and were higher in men. More than 10\% of men 65 to 74 years of age with no cardiovascular disease in our study had cardiac troponin T 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.

}, keywords = {Adult, Age Factors, Aged, Biological Assay, Biomarkers, Blood Chemical Analysis, Cohort Studies, Cross-Sectional Studies, Female, Humans, Male, Middle Aged, Myocardial Infarction, Reference Values, Risk Assessment, Sensitivity and Specificity, Severity of Illness Index, Sex Factors, Troponin T}, issn = {1558-3597}, doi = {10.1016/j.jacc.2013.12.032}, author = {Gore, M Odette and Seliger, Stephen L and deFilippi, Christopher R and Nambi, Vijay and Christenson, Robert H and Hashim, Ibrahim A and Hoogeveen, Ron C and Ayers, Colby R and Sun, Wensheng and McGuire, Darren K and Ballantyne, Christie M and de Lemos, James A} } @article {6878, title = {Prognostic Significance of High-Sensitivity Cardiac Troponin T Concentrations between the Limit of Blank and Limit of Detection in Community-Dwelling Adults: A Metaanalysis.}, journal = {Clin Chem}, volume = {61}, year = {2015}, month = {2015 Dec}, pages = {1524-31}, abstract = {

BACKGROUND: There is controversy regarding whether to report concentrations of high-sensitivity cardiac troponin T (hs-cTnT) to the limit of blank (LOB) (3 ng/L) or the limit of detection (LOD) (5 ng/L) of the assay in community-based cohorts. We hypothesized that hs-cTnT concentrations between the LOB and LOD would be associated with poorer cardiovascular outcomes compared to concentrations below the LOB.

METHODS: hs-cTnT was analyzed in a total of 10 723 participants from the Cardiovascular Health Study (CHS), Atherosclerosis Risk in Communities (ARIC) study, and Dallas Heart Study (DHS). Participants were divided into 2 groups, those with hs-cTnT concentrations below the limit of blank (LOB) (<3 ng/L) and those with hs-cTnT between the LOB and limit of detection (LOD) (3-4.99 ng/L). Cross-sectional associations with traditional cardiovascular risk factors and cardiac structural measurements, and longitudinal associations with long-term cardiovascular outcomes of incident heart failure and cardiovascular death, were determined.

RESULTS: Participants with hs-cTnT between the LOB and LOD for all 3 cohorts were older, more likely to be male, and have a higher burden of cardiovascular risk factors and structural pathology. A metaanalysis of the 3 cohorts showed participants with hs-cTnT between the LOB and LOD were at increased risk of new-onset heart failure (hazard ratio, 1.18; 95\% CI, 1.02-1.38) and cardiovascular mortality (hazard ratio, 1.29; 95\% CI, 1.06-1.57).

CONCLUSIONS: hs-cTnT concentrations between the LOB and LOD (3-4.99 ng/L) are associated with a higher prevalence of traditional risk factors, more cardiac pathology, and worse outcomes than concentrations below the LOB (<3 ng/L).

}, keywords = {Aged, Atherosclerosis, Biomarkers, Cross-Sectional Studies, Female, Heart Failure, Humans, Independent Living, Limit of Detection, Longitudinal Studies, Male, Middle Aged, Myocardial Infarction, Prognosis, Risk Assessment, Risk Factors, Sex Factors, Troponin T}, issn = {1530-8561}, doi = {10.1373/clinchem.2015.244160}, author = {Parikh, Ravi H and Seliger, Stephen L and de Lemos, James and Nambi, Vijay and Christenson, Robert and Ayers, Colby and Sun, Wensheng and Gottdiener, John S and Kuller, Lewis H and Ballantyne, Christie and deFilippi, Christopher R} }