Discordance with 3 Cardiac Troponin I and T Assays: Implications for the 99th Percentile Cutoff

Abstract

BACKGROUND:We compared the 99th percentile reference intervals with 3 modern cardiac troponin assays in a single cohort and tested the hypothesis that the same individuals will be identified as above the cutoff and that differences will be explained by analytical imprecision.

The 99th percentile of reference population for cTnI and cTnT assay: methodology, pathophysiology and clinical implications

“…Regarding the highly sensitive cTnT ECLIA method, variability among the 99th URL values reported in different studies and by manufacturers is very similar (Table 5) [9,12,26,41,124,[126][127][128]. Considering as a whole the clinical studies including a total of 10,078 individuals [9,12,26,47,124,[126][127][128], median (25th-75th percentiles) values of 99th URL results of highly sensitive cTnT ECLIA method are for the overall population 14.6 (13.2-18.0) ng/L, for men 16.0 (15.0-19.5) ng/L, and for women 12.0 (9.6-12.5) ng/L, respectively.…”

“…Regarding the highly sensitive cTnI assay, results of studies investigating 99th URL values in apparently healthy individuals using the ARCHITECT method are reported in Table 4 [9,14,29,[120][121][122][123][124][125][126]. These data are from a total of 12,768 (11,237 on excluding those reported by manufacturer) apparently healthy subjects of different ethnicities, including Asian [121,123,125], Australian [120], European [14,29,122,126] and North American [9] populations.…”

“…These data are from a total of 12,768 (11,237 on excluding those reported by manufacturer) apparently healthy subjects of different ethnicities, including Asian [121,123,125], Australian [120], European [14,29,122,126] and North American [9] populations. On considering these studies overall [9,14,29,[120][121][122][123][124][125][126], median (25th-75th percentiles), the 99th URL values are 19.3 (13.5-23.7) ng/L (M 26.0 [19.6-29.5] ng/L), and (F 11.9 [10.8-18.3] ng/L). However, these studies vary greatly for population size (range, 366-2608), age of participants (age range 18-98 years), inclusion/exclusion criteria (especially in evaluating presence of asymptomatic cardiac disease and co-morbidities -e.g.…”

“…However, these studies vary greatly for population size (range, 366-2608), age of participants (age range 18-98 years), inclusion/exclusion criteria (especially in evaluating presence of asymptomatic cardiac disease and co-morbidities -e.g. hypertension, obesity, diabetes mellitus, renal disease), and statistical analysis (parametric or non-parametric) approach for calculating 99th percentile and exclusion of outliers [9,14,29,[120][121][122][123][124][125][126]. Studies following more rigorous criteria, using both laboratory and clinical data to include/exclude healthy volunteers, tended to report lower 99th URL results for both genders [29,120].…”

“…Considering as a whole the clinical studies including a total of 10,078 individuals [9,12,26,47,124,[126][127][128], median (25th-75th percentiles) values of 99th URL results of highly sensitive cTnT ECLIA method are for the overall population 14.6 (13.2-18.0) ng/L, for men 16.0 (15.0-19.5) ng/L, and for women 12.0 (9.6-12.5) ng/L, respectively. The results reported by Gaggin et al [128], including data related to two different populations (i.e.…”