scholarly journals Concordance, Variance, and Outliers in 4 Contemporary Cardiac Troponin Assays: Implications for Harmonization

2012 ◽  
Vol 58 (1) ◽  
pp. 274-283 ◽  
Author(s):  
Jacobus P J Ungerer ◽  
Louise Marquart ◽  
Peter K O'Rourke ◽  
Urs Wilgen ◽  
Carel J Pretorius
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Troponin T ◽  
Analytical Imprecision ◽  
Universal Definition ◽  
Definition Of ◽  
Abbott Architect ◽  
Roche Cobas

Abstract BACKGROUND Data to standardize and harmonize the differences between cardiac troponin assays are needed to support their universal status in diagnosis of myocardial infarction. We characterized the variation between methods, the comparability of the 99th-percentile cutoff thresholds, and the occurrence of outliers in 4 cardiac troponin assays. METHODS Cardiac troponin was measured in duplicate in 2358 patient samples on 4 platforms: Abbott Architect i2000SR, Beckman Coulter Access2, Roche Cobas e601, and Siemens ADVIA Centaur XP. RESULTS The observed total variances between the 3 cardiac troponin I (cTnI) methods and between the cTnI and cardiac troponin T (cTnT) methods were larger than expected from the analytical imprecision (3.0%–3.7%). The between-method variations of 26% between cTnI assays and 127% between cTnI and cTnT assays were the dominant contributors to total variances. The misclassification of results according to the 99th percentile was 3%–4% between cTnI assays and 15%–17% between cTnI and cTnT. The Roche cTnT assay identified 49% more samples as positive than the Abbott cTnI. Outliers between methods were detected in 1 patient (0.06%) with Abbott, 8 (0.45%) with Beckman Coulter, 10 (0.56%) with Roche, and 3 (0.17%) with Siemens. CONCLUSIONS The universal definition of myocardial infarction should not depend on the choice of analyte or analyzer, and the between- and within-method differences described here need to be considered in the application of cardiac troponin in this respect. The variation between methods that cannot be explained by analytical imprecision and the discordant classification of results according to the respective 99th percentiles should be addressed.

Evaluation of First-Draw Whole Blood, Point-of-Care Cardiac Markers in the Context of the Universal Definition of Myocardial Infarction: A Comparison of a Multimarker Panel to Troponin Alone and to Testing in the Central Laboratory

2011 ◽  
Vol 135 (4) ◽  
pp. 459-463
Author(s):  
Elizabeth Lee-Lewandrowski ◽  
James L Januzzi ◽  
Ricky Grisson ◽  
Asim A Mohammed ◽  
Grant Lewandrowski ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Troponin T ◽  
Point Of Care ◽  
Cardiac Troponin T ◽  
Central Laboratory ◽  
Universal Definition ◽  
Definition Of

Abstract Context.—Previous studies evaluating point-of-care testing (POCT) for cardiac biomarkers did not use current recommendations for troponin cutoff values or recognize the recent universal definition of acute myocardial infarction. Traditionally, achieving optimal sensitivity for the detection of myocardial injury on initial presentation required combining cardiac troponin and/or creatine kinase isoenzyme MB with an early marker, usually myoglobin. In recent years, the performance of central laboratory combining cardiac troponin assays has improved significantly, potentially obviating the need for a multimarker panel to achieve optimum sensitivity. Objective.—To compare 2 commonly used POCT strategies to a fourth generation, central laboratory cardiac troponin T assay on first-draw specimens from patients being evaluated for acute myocardial infarction in the emergency department. The 2 strategies included a traditional POCT multimarker panel and a newer POCT method using cardiac troponin I alone. Design.—Blood specimens from 204 patients presenting to the emergency department with signs and/or symptoms of myocardial ischemia were measured on the 2 POCT systems and by a central laboratory method. The diagnosis for each patient was determined by retrospective chart review. Results.—The cardiac troponin T assasy alone was more sensitive for acute myocardial infarction than the multimarker POCT panel with equal or better specificity. When compared with a POCT troponin I, the cardiac troponin T was also more sensitive, but this difference was not significant. The POCT troponin I alone also had the same sensitivity as the multimarker panel. Conclusions.—Testing for combining cardiac troponin alone using newer, commercially available, central laboratory or POCT assays performed with equal or greater sensitivity to acute myocardial infarction as the older, traditional, multimarker panel. In the near future, high-sensitivity, central laboratory troponins will be available for routine clinical use. As a result, the quality gap between central laboratories and older POCT methods will continue to widen, unless the performance of the POCT methods is improved.

scholarly journals Diagnosis of Type 1 and Type 2 Myocardial Infarction Using a High-Sensitivity Cardiac Troponin I Assay with Sex-Specific 99th Percentiles Based on the Third Universal Definition of Myocardial Infarction Classification System

2015 ◽  
Vol 61 (4) ◽  
pp. 657-663 ◽  
Author(s):  
Yader Sandoval ◽  
Stephen W Smith ◽  
Karen M Schulz ◽  
MaryAnn M Murakami ◽  
Sara A Love ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Classification System ◽  
Cardiac Troponin ◽  
Troponin I ◽  
High Sensitivity ◽  
The Third ◽  
Universal Definition ◽  
Definition Of

Abstract BACKGROUND The frequency and characteristics of myocardial infarction (MI) subtypes per the Third Universal Definition of MI (TUDMI) classification system using high-sensitivity (hs) cardiac troponin assays with sex-specific cutoffs is not well known. We sought to describe the diagnostic characteristics of type 1 (T1MI) and type 2 (T2MI) MI using an hs–cardiac troponin I (hs-cTnI) assay with sex-specific cutoffs. METHODS A total of 310 consecutive patients with serial cTnI measurements obtained on clinical indication were studied with contemporary and hs-cTnI assays. Ninety-ninth percentile sex-specific upper reference limits (URLs) for the hs-cTnI assay were 16 ng/L for females and 34 ng/L for males. The TUDMI consensus recommendations were used to define and adjudicate MI based on each URL. RESULTS A total of 127 (41%) patients had at least 1 hs-cTnI exceeding the sex-specific 99th percentiles, whereas 183 (59%) had hs-cTnI within the reference interval. Females had more myocardial injury related to supply/demand ischemia than males (39% vs 18%, P = 0.01), whereas males had more multifactorial or indeterminate injury (52% vs 33%, P = 0.05). By hs-cTnI, there were 32 (10%) acute MIs, among which 10 (3%) were T1MI and 22 (7%) were T2MI. T2MI represented 69% (22 out of 32) of all acute MIs, whereas T1MI represented 31% (10 out of 32). Ninety-five patients (31%) had an increased hs-cTnI above the 99th percentile but did not meet criteria for acute MI. The most common triggers for T2MI were tachyarrhythmias, hypotension/shock, and hypertension. By contemporary cTnI, more MIs (14 T1MI and 29 T2MI) were diagnosed. By contemporary cTnI, there were 43 MIs, 14 T1MI, and 29 T2MI. CONCLUSIONS Fewer MI diagnoses were found with the hs-cTnI assay, contrary to the commonly accepted idea that hs-cTnI will lead to excessive false-positive diagnoses.

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

2016 ◽  
Vol 62 (8) ◽  
pp. 1106-1114 ◽  
Author(s):  
Jacobus Petrus Johannes Ungerer ◽  
Jillian Russyll Tate ◽  
Carel Jacobus Pretorius
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Troponin T ◽  
Reference Intervals ◽  
Cardiac Troponin I ◽  
Poor Correlation ◽  
Highly Sensitive ◽  
Analytical Imprecision ◽  
Abbott Architect ◽  
High Sensitive Troponin

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. METHODS Blood was collected from 2005 apparently healthy blood donors. Cardiac troponin was measured with Abbott Architect STAT high sensitive troponin I, Beckman Coulter Access AccuTnI+3, and Roche Elecsys troponin T highly sensitive assays. RESULTS The 99th percentile cutoff limits were as follows: Abbott cardiac troponin I (cTnI) 28.9 ng/L; Beckman Coulter cTnI 31.3 ng/L; and Roche cardiac troponin T (cTnT) 15.9 ng/L. Correlation among the assays was poor: Abbott cTnI vs Beckman Coulter cTnI, R2 = 0.18; Abbott cTnI vs Roche cTnT, R2 = 0.04; and Beckman Coulter cTnI vs Roche cTnT R2 = 0.01. Of the results above the cutoff 50% to 70% were unique to individual assays, with only 4 out of 20 individuals above the cutoff for all 3 assays. The observed differences among assays were larger than predicted from analytical imprecision. CONCLUSIONS The 99th percentile cutoff values were in agreement with those reported elsewhere. The poor correlation and concordance amongst the assays were notable. The differences found could not be explained by analytical imprecision and indicate the presence of inaccuracy (bias) that is unique to sample and assay combinations. Based on these findings we recommend less emphasis on the cutoff value and greater emphasis on δ values in the diagnosis of myocardial infarction.

Independent and combined effects of biotin and hemolysis on high-sensitivity cardiac troponin assays

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kellisha Harley ◽  
Sarah Bissonnette ◽  
Rosanna Inzitari ◽  
Karen Schulz ◽  
Fred S. Apple ◽  
...  
Keyword(s):  
Cardiac Troponin ◽  
Clinical Laboratory ◽  
Troponin T ◽  
High Sensitivity ◽  
Combined Effects ◽  
Over The Counter ◽  
Heparin Plasma ◽  
Abbott Architect ◽  
Roche Cobas

Abstract Objectives This study compared the independent and combined effects of hemolysis and biotin on cardiac troponin measurements across nine high-sensitivity cardiac troponin (hs-cTn) assays. Methods Parallel cTn measurements were made in pooled lithium heparin plasma spiked with hemolysate and/or biotin using nine hs-cTn assays: Abbott Alinity, Abbott ARCHITECT i2000, Beckman Access 2, Ortho VITROS XT 7600, Siemens Atellica, Siemens Centaur, Siemens Dimension EXL cTnI, and two Roche Cobas e 411 Elecsys Troponin T-hs cTnT assays (outside US versions, with and without increased biotin tolerance). Absolute and percent cTn recovery relative to two baseline concentrations were determined in spiked samples and compared to manufacturer’s claims. Results All assays except the Ortho VITROS XT 7600 showed hemolysis and biotin interference thresholds equivalent to or greater than manufacturer’s claims. While imprecision confounded analysis of Ortho VITROS XT 7600 data, evidence of biotin interference was lacking. Increasing biotin concentration led to decreasing cTn recovery in three assays, specifically both Roche Cobas e 411 Elecsys Troponin T-hs assays and the Siemens Dimension EXL. While one of the Roche assays was the most susceptible to biotin among the nine studied, a new version showed reduced biotin interference by approximately 100-fold compared to its predecessor. Increasing hemolysis also generally led to decreasing cTn recovery for susceptible assays, specifically the Beckman Access 2, Ortho VITROS XT 7600, and both Roche Cobas e 411 Elecsys assays. Equivalent biotin and hemolysis interference thresholds were observed at the two cTn concentrations considered for all but two assays (Beckman Access 2 and Ortho VITROS XT 7600). When biotin and hemolysis were present in combination, biotin interference thresholds decreased with increasing hemolysis for two susceptible assays (Roche Cobas e 411 Elecsys and Siemens Dimension EXL). Conclusions Both Roche Cobas e 411 Elecsys as well as Ortho VITROS XT assays were susceptible to interference from in vitro hemolysis at levels routinely encountered in clinical laboratory samples (0–3 g/L free hemoglobin), leading to falsely low cTn recovery up to 3 ng/L or 13%. While most assays are not susceptible to biotin at levels expected with over-the-counter supplementation, severely reduced cTn recovery is possible at biotin levels of 10–2000 ng/mL (41–8,180 nmol/L) for some assays. Due to potential additive effects, analytical interferences should not be considered in isolation.

scholarly journals Clinical Evaluation of the ACS:180 Cardiac Troponin I Assay

2001 ◽  
Vol 38 (5) ◽  
pp. 509-519 ◽  
Author(s):  
Paul O Collinson ◽  
Nigel Wiggins ◽  
David C Gaze
Keyword(s):  
Endurance Training ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Troponin T ◽  
Training Group ◽  
Storage Conditions ◽  
Cardiac Troponin I ◽  
Admission Diagnosis ◽  
Coronary Syndromes ◽  
Analytical Imprecision

All patients admitted to the coronary care unit with suspected acute coronary syndromes were evaluated by serial electrocardiography and blood draws on admission and at 4 and 12h from admission. Diagnosis was based on conventional WHO criteria. Samples were measured for creatine kinase (CK), cardiac troponin T (cTnT), myoglobin, CK isoenzyme MB (CK-MB) and cardiac troponin I (cTnI). A set of samples from individuals undergoing extreme endurance training was also examined. Analytical imprecision was consistent with published quality goals. Samples were stable for cTnI under a range of storage conditions, including multiple freeze-thaw cycles. CK-MB, cTnI and cTnT were equally efficient for the diagnosis of acute myocardial infarction, irrespective of the final diagnostic criteria used. Both cTnI and cTnT were of equal efficiency in the identification of a high-risk subgroup of patients with unstable angina. Significant elevations of cTnI were not seen in an endurance-training group.

Cardiac troponins and mortality in type 1 and 2 myocardial infarction

2017 ◽  
Vol 55 (2) ◽  
Author(s):  
Giuseppe Lippi ◽  
Fabian Sanchis-Gomar ◽  
Gianfranco Cervellin
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Troponin T ◽  
Post Discharge ◽  
Assay Sensitivity ◽  
Percentage Difference ◽  
Cardiac Troponins

AbstractBackground:The pathogenesis of different types of myocardial infarction (MI) differs widely, so that accurate and timely differential diagnosis is essential for tailoring treatments according to the underlying causal mechanisms. As the measurement of cardiac troponins is a mainstay for diagnosis and management of MI, we performed a systematic literature analysis of published works which concomitantly measured cardiac troponins in type 1 and 2 MI.Methods:The electronic search was conducted in Medline, Scopus and Web of Science using the keywords “myocardial infarction” AND “type(-)2” OR “type II” AND “troponin” in “Title/Abstract/Keywords”, with no language restriction and date limited from 2007 to the present.Results:Overall, 103 documents were identified, but 95 were excluded as precise comparison of troponin values in patients with type 1 and 2 MI was unavailable. Therefore, eight studies were finally selected for our analysis. Two studies used high-sensitivity (HS) immunoassays for measuring cardiac troponin T (HS-TnT), one used a HS immunoassay for measuring cardiac troponin I (HS-TnI), whereas the remaining used conventional methods for measuring TnI. In all studies, regardless of type and assay sensitivity, troponin values were higher in type 1 than in type 2 MI. The weighted percentage difference between type 1 and 2 MI was 32% for TnT and 91% for TnI, respectively. Post-discharge mortality obtained from pooling individual data was instead three times higher in type 2 than in type 1 MI.Conclusions:The results of our analysis suggest that the value of cardiac troponins is consistently higher in type 1 than in type 2 MI.

Abstract 19710: Causes for Increased Cardiac Troponin I Using Gender-Specific 99th Percentiles From a High Sensitivity Assay in a US Population

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Yader Sandoval ◽  
Stephen W Smith ◽  
Karen M Schulz ◽  
MaryAnn M Murakami ◽  
Fred S Apple
Keyword(s):  
Myocardial Ischemia ◽  
Cardiac Troponin ◽  
Myocardial Injury ◽  
Troponin I ◽  
Plaque Rupture ◽  
High Sensitivity ◽  
The United States ◽  
Universal Definition ◽  
Definition Of ◽  
Gender Specific

Introduction: High-sensitivity cardiac troponin (hs-cTn) assays have not yet been FDA cleared for clinical use in the United States (US). Pending expected approval of hs-cTn assays, which will use gender-specific cutoffs (GSC), it is relevant to recognize the causes of cTn increases using hs-cTnI assays in a US population. Our purpose was to describe the frequency of distinct etiologies of hs-cTnI assay increases using GSC. Methods: Retrospective study of 310 patients with serial hs-cTnI (Abbott ARCHITECT, 99th percentiles: F:16 ng/L; M:34 ng/L) measurements. Patients with an increased hs-cTnI were adjudicated into categories according to the 3rd Universal Definition of MI. Categories included, A: primary myocardial ischemia (i.e. plaque rupture); B: injury secondary to supply/demand imbalance; C: injury not related to myocardial ischemia (i.e. cardiac contusion, ablation, shock, surgery); D: multifactorial or indeterminate myocardial injury (i.e. heart failure, critically ill, pulmonary HTN, sepsis, stroke, renal failure, pulmonary embolism); E: Unknown. Results: 127 (41%) had an increased hs-cTnI above the GSC 99th percentile, whereas 183 (59%) had a normal hs-cTnI. The most common causes of hs-cTnI increases were: a) multifactorial or indeterminate injury - 43% among all patients and 52% in males, and b) supply/demand imbalance - 39% in women (Table). Injury related to primary myocardial ischemia was present in 10% (n=13). Females had more injury related to supply/demand ischemia than males (39% vs. 18%, p=0.01), whereas males had more multifactorial or indeterminate injury (52% vs. 33%, p=0.05). Conclusions: Most increased hs-cTnI values were explained by non-plaque rupture conditions. Males tended to have hs-cTnI increases due to multifactorial/indeterminate causes, whereas in women supply/demand imbalance was the most common etiology. Investigations are needed to better understand if etiologies of myocardial injury have gender differences.

Abstract 350: Assessment of Clinicians’ Attitudes and Knowledge About Cardiac Troponin Testing

2020 ◽  
Vol 13 (Suppl_1) ◽  
Author(s):  
Sandeep Jain ◽  
Andrew Hammes ◽  
Eric Rudofker ◽  
Karen Ream ◽  
Andrew E Levy
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Troponin ◽  
Myocardial Injury ◽  
The United States ◽  
Advanced Practice ◽  
Attitudes And Knowledge ◽  
Universal Definition ◽  
Definition Of ◽  
Attending Physicians

In the United States, the positive predictive value (PPV) of cardiac troponin for type 1 myocardial infarction is substantially lower than in Europe (15% vs. 50%). Further, even with publication of the 4 th Universal Definition of Myocardial Infarction, recent studies have shown that inaccurate classification of myocardial injury is common among clinicians in the United States. These findings are at least partly attributable to clinicians’ knowledge and attitudes about cardiac troponin testing; a survey of these parameters has never been conducted. Clinicians at the University of Colorado completed a brief 8-question multiple-choice survey related to troponin use, definitions of myocardial infarction and clinical assessment of elevated troponin levels. The survey was distributed via secure email and administered electronically using the Qualtrics™ platform. Responses were anonymous, completion was estimated to take 3 minutes and a lottery award system was used as an incentive for participation. Respondents included trainees, advanced practice providers and attending physicians from internal medicine, emergency medicine and medical subspecialties. We plan to obtain a total of 300 responses with descriptive findings of preliminary results included below. The survey was completed by 114 clinicians: 37 interns (32%), 45 residents (39%), 9 advanced practice providers (8%), 11 fellows (10%), and 12 attending physicians (11%). Regarding indications for troponin testing, 93% (106/114) indicated that they “usually” or “always” check troponin levels in patients with chest pain. More interestingly, 46% (52/112) reported checking troponin on “undifferentiated patients” at least half the time. For troponin interpretation, 97% (110/114) of participants identified that troponin levels alone cannot rule in or rule out coronary artery disease. In contrast, only 36% (41/114) and 55% (63/114), respectively, identified the NPV and PPV of a contemporary troponin assay for type 1 MI. Further, only 50% (57/114) of respondents identified that the likelihood of type 1 MI increases as troponin levels increase. Three brief clinical vignettes revealed that, while 78% (89/114) and 74% (45/61) of participants, respectively, identified type 1 MI and type 2 MI presentations, only 40% (21/53) of respondents correctly identified a vignette for non-ischemic myocardial injury. Concordant with this finding, 54% (61/114) of clinicians correctly identified the 4 th Universal Definition of Myocardial Infarction. These preliminary findings highlight important facets of clinician attitudes and knowledge about troponin testing that help explain the poor PPV for troponin and diagnostic misclassification observed among U.S. clinicians. These results could help guide curricular and clinical decision support interventions designed to improve the use and interpretation of cardiac troponin testing.

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