Robert H Christenson1, Ellis Jacobs2,3, Denise Uettwiller-Geiger4, Mathew P Estey5,6, Kent Lewandrowski7, Thomas I Koshy8, Kenneth Kupfer2, Yin Li2, James C Wesenberg9,10. 1. Department of Pathology, University of Maryland School of Medicine, Baltimore, MD. 2. Alere, Waltham, MA. 3. Department of Pathology, Mount Sinai School of Medicine, New York, NY. 4. John T Mather Memorial Hospital, Port Jefferson, NY. 5. DynaLIFEDx, Edmonton, Canada. 6. Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada. 7. Department of Pathology, Massachusetts General Hospital, Boston, MA. 8. The Binding Site Inc., San Diego, CA. 9. Alberta Health Service, Red Deer, Alberta, Canada. 10. Red Deer Regional Hospital Centre, Red Deer, Canada.
Abstract
BACKGROUND: We examined the concordance of 13 commercial cardiac troponin (cTn) assays [point-of-care, high-sensitivity (hs), and conventional] using samples distributed across a continuum of results. METHODS: cTnI (11 assays) and cTnT (2 assays) were measured in 191 samples from 128 volunteers. cTn assays included Abbott (iSTAT, STAT, and hs), Alere (Cardio 3), Beckman (AccuTnI+3), Pathfast (cTnI-II), Ortho (Vitros), Siemens (LOCI, cTnI-Ultra, Xpand, Stratus CS), and Roche [4th Generation (Gen), hs]. Manufacturer-derived 99th percentile cutoffs were used to classify results as positive or negative. Alternative 99th percentile cutoffs were tested for some assays. Correlation was assessed using Passing-Bablok linear regression, bias was examined using Bland-Altman difference plots, and concordance/discordance of each method comparison was determined using the McNemar method. RESULTS: Regression slopes ranged from 0.63 to 1.87, y-intercepts from 0.00 to 0.03 ng/mL, and r values from 0.93 to 0.99. The cTnT methods had a slope of 0.93, y-intercept of 0.02 ng/mL, and r value of 0.99. For the cTnI assays, positive, negative, and overall concordance was 76.2%-100%, 66.0%-100%, and 82.9%-98.4%, respectively. Overall concordance between the 4th Gen cTnT and hsTnT assays was 88.9%. A total of 30 of the 78 method comparisons showed significant differences in classification of samples (P <0.001); the iSTAT showed 10, hsTnT showed 9, AccuTnI+3 showed 5, Xpand showed 5, and Stratus CS showed 1. Using alternative 99th percentile cutoffs to those listed by manufacturers lowered the method discordance by 6-fold, from 30 to 5 (all involved iSTAT). CONCLUSIONS: These data provide insight into characteristics of cTn methods and will assist the healthcare community in setting expectations for relationships among commercial cTn assays.
BACKGROUND: We examined the concordance of 13 commercial cardiac troponin (cTn) assays [point-of-care, high-sensitivity (hs), and conventional] using samples distributed across a continuum of results. METHODS: cTnI (11 assays) and cTnT (2 assays) were measured in 191 samples from 128 volunteers. cTn assays included Abbott (iSTAT, STAT, and hs), Alere (Cardio 3), Beckman (AccuTnI+3), Pathfast (cTnI-II), Ortho (Vitros), Siemens (LOCI, cTnI-Ultra, Xpand, Stratus CS), and Roche [4th Generation (Gen), hs]. Manufacturer-derived 99th percentile cutoffs were used to classify results as positive or negative. Alternative 99th percentile cutoffs were tested for some assays. Correlation was assessed using Passing-Bablok linear regression, bias was examined using Bland-Altman difference plots, and concordance/discordance of each method comparison was determined using the McNemar method. RESULTS: Regression slopes ranged from 0.63 to 1.87, y-intercepts from 0.00 to 0.03 ng/mL, and r values from 0.93 to 0.99. The cTnT methods had a slope of 0.93, y-intercept of 0.02 ng/mL, and r value of 0.99. For the cTnI assays, positive, negative, and overall concordance was 76.2%-100%, 66.0%-100%, and 82.9%-98.4%, respectively. Overall concordance between the 4th Gen cTnT and hsTnT assays was 88.9%. A total of 30 of the 78 method comparisons showed significant differences in classification of samples (P <0.001); the iSTAT showed 10, hsTnT showed 9, AccuTnI+3 showed 5, Xpand showed 5, and Stratus CS showed 1. Using alternative 99th percentile cutoffs to those listed by manufacturers lowered the method discordance by 6-fold, from 30 to 5 (all involved iSTAT). CONCLUSIONS: These data provide insight into characteristics of cTn methods and will assist the healthcare community in setting expectations for relationships among commercial cTn assays.
Authors: John H Holmes; James Beinlich; Mary R Boland; Kathryn H Bowles; Yong Chen; Tessa S Cook; George Demiris; Michael Draugelis; Laura Fluharty; Peter E Gabriel; Robert Grundmeier; C William Hanson; Daniel S Herman; Blanca E Himes; Rebecca A Hubbard; Charles E Kahn; Dokyoon Kim; Ross Koppel; Qi Long; Nebojsa Mirkovic; Jeffrey S Morris; Danielle L Mowery; Marylyn D Ritchie; Ryan Urbanowicz; Jason H Moore Journal: Methods Inf Med Date: 2021-07-19 Impact factor: 1.800
Authors: Ziwei Lin; Swee Han Lim; Qai Ven Yap; Carol Hui Chen Tan; Yiong Huak Chan; Hung Chew Wong; E Shyong Tai; Arthur Mark Richards; Terrance Siang Jin Chua Journal: Int J Cardiol Heart Vasc Date: 2021-03-25