Standardisation of cardiac troponin I measurement: past and present (original) (raw)
Related papers
Clinical Chemistry, 2016
BACKGROUND Cardiac troponin I (cTnI) and cardiac troponin T (cTnT) determinations are fixtures in clinical practice and research. Cardiac troponin testing has been the standard of practice for the diagnosis of acute myocardial infarction (AMI), early rule-out, risk stratification, and outcomes assessment in patients presenting with acute coronary syndrome (ACS) and non-ACS myocardial injury. We recognize from reading the literature over the past several years how poorly understood the analytical characteristics are for cTnI and cTnT assays by laboratorians, clinicians, and scientists who use these assays. CONTENT The purposes of this mini-review are (a) to define limit of blank, limit of detection, limit of quantification, and imprecision, (b) overview the analytical characteristics of the existing cardiac troponin assays, (c) recommend approaches to define a healthy (normal) reference population for determining the 99th percentile and the appropriate statistic to use for this calcu...
Clinical chemistry and laboratory medicine : CCLM / FESCC, 2015
As a part of an International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) project to prepare a commutable reference material for cardiac troponin I (cTnI), a pilot study evaluated current cTnI assays for measurement equivalence and their standardization capability. cTnI-positive samples collected from 90 patients with suspected acute myocardial infarction were assessed for method comparison by 16 cTnI commercial assays according to predefined testing protocols. Seven serum pools prepared from these samples were also assessed. Each assay was assessed against median cTnI concentrations measured by 16 cTnI assays using Passing-Bablok regression analysis of 79 patient samples with values above each assay's declared detection limit. We observed a 10-fold difference in cTnI concentrations for lowest to highest measurement results. After mathematical recalibration of assays, the between-assay variation for patient samples reduced on average from 40% to 22% at low cT...
Cardiac troponin I: the gold standard in acute myocardial infarction diagnosis
Bosnian journal of basic medical sciences / Udruženje basičnih mediciniskih znanosti = Association of Basic Medical Sciences, 2003
Cardiovascular diseases are leading cause of morbidity in the world. Measurement of the level of biochemical markers in the serum is one of World Health Organisation (WHO) criteria in diagnosing acute myocardial infarction (AMI). Non-specific clinical state of patients and insufficiently sensitive electrocardiographic (ECG) diagnostics, at patient's hospital admission time, point out the importance of biochemical markers in acute myocardial infarction diagnosis. Technology development and new diagnostic methods lead to the invention of highly sensitive and specific marker as myocardial damage evidence. Cardiac Troponin I (cTnI) is specific marker for myocardial damage1. Its elevation in the serum within myocardial ischemia symptomatology is important in diagnosis of myocardial infarction.
Sequential assessment of troponin in the diagnosis of myocardial infarction
Clinical laboratory science : journal of the American Society for Medical Technology, 2013
According to the American Heart Association, cardiovascular disease accounts for more than one third of all deaths in the United States. 1 The purpose of this retrospective case-control study was to determine which sample taken in a sequential draw was most important in diagnosing an acute myocardial infarction (AMI). One-hundred subjects were selected from a convenience sample. The "risk" of AMI diagnosis was modeled using binary multiple logistic regression. Overall, 78% (39 out of 50 cases) were diagnosed with an AMI at Tinitiai. Clearly, the initial cTnI assay is the most critical of the four sequential time points for the accurate assessment of the presence or absence of an AMI. Most importantly, sequential troponin testing increased the ability to diagnose AMI by 10-fold.
Clinical Chemistry, 2019
BACKGROUND We aimed to validate the clinical performance of the high-sensitivity cardiac troponin I [VITROS® Immunodiagnostic Products hs Troponin I (hs-cTnI-VITROS)] assay. METHODS We enrolled patients presenting to the emergency department with symptoms suggestive of acute myocardial infarction (AMI). Final diagnoses were centrally adjudicated by 2 independent cardiologists considering all clinical information, including cardiac imaging: first, using serial hs-cTnT-Elecsys (primary analysis) and, second, using hs-cTnI-Architect (secondary analysis) measurements in addition to the clinically used (hs)-cTn. hs-cTnI-VITROS was measured at presentation and at 1 h in a blinded fashion. The primary objective was direct comparison of diagnostic accuracy as quantified by the area under the ROC curve (AUC) of hs-cTnI-VITROS vs hs-cTnT-Elecsys and hs-cTnI-Architect, and in a subgroup also hs-cTnI-Centaur and hs-cTnI-Access. Secondary objectives included the derivation and validation of an h...
Critical reviews in clinical laboratory sciences, 2017
Implementation of cardiac troponin (cTn) assays has revolutionized the diagnosis, risk stratification, triage and management of patients with suspected myocardial infarction (MI). The Universal Definition of MI brought about a shift in the diagnostics of MI, from an approach primarily based on electrocardiography (ECG) to one primarily based on biomarkers. Currently, detection of a rise and/or fall in concentration or activity of myocardial necrosis biomarkers, preferentially cTns, with at least one value above the 99th percentile upper reference limit (URL), is the essential component for the diagnosis of MI. High-sensitivity cardiac troponin (hs-cTn) assays with their superior analytical performance were designed to further facilitate clinical decision making. The ability of hs-cTn assays to detect measurable cTn concentrations in at least 50% of healthy individuals, along with their improved precision (expressed as coefficient of variation ≤10% at the 99th percentile URL) associa...
CMAJ Open, 2014
H igh-sensitivity troponin assays have greatly improved the analytical performance of conventional cardiac troponin T and I testing. 1-3 These assays permit the measurement of cardiac troponin concentrations that are about one-tenth of those measurable with conventional assays. 4 The detection level is close to the physiologic concentrations of these biomarkers; 5 therefore, there is interest in using high-sensitivity assays to diagnose acute myocardial infarction (MI) accurately, possibly within 3 hours of admission. The ability to use the rate of change in troponin level to diagnose acute MI is also being investigated. Many institutions throughout Europe and North America have transitioned from using the conventional troponin T assay to the high-sensitivity troponin T assay with no technical issues; both assays are run using the same analyzer. 6 However, the US Food and Drug Administration has yet to approve the use of the high-sensitivity assays. This is partly because of the need for more information about their diagnostic accuracy and risk stratification. 7 One of the main challenges is the potential for overdiagnosis of acute coronary syndromes because of the increased sensitivity of the high-sensitivity troponin test. Our aim was to assess the use of this test as a diagnostic tool. The early and accurate detection of myocardial injury leads to potentially earlier diagnosis
International Journal of Cardiology
Objectives The aim of this study is to compare a new improved point of care cardiac troponin assay (new POC-cTnI) with 1. its predecessor (old POC-cTnI) and 2. a high sensitivity assay (hs-cTnI) for the diagnosis of acute myocardial infarction (AMI) and for major adverse cardiac events (MACE) by 30 days. Methods This is a single centre observational study, set in Christchurch Hospital, New Zealand. Patients presenting to the emergency department with non-traumatic chest pain underwent blood sampling at 0 h and 2 h post presentation for analysis with the 3 cTnI assays for the outcome of AMI and for analysis using an accelerated diagnostic protocol (ADP-normal 2 h troponins, normal electrocardiograms and Thrombolysis In Myocardial Infarction (TIMI) score of 0 or ≤ 1) for 30 day MACE. Results Of 962 patients, 220 (22.9%) had AMI. Old POC-cTnI was least sensitive at 70.0% (65.4–73.9%) by 2 h (p < 0.001). New POC-cTnI, sensitivity 93.6% (89.9–96.2%) had similar sensitivity to hs-cTnI,...
Interpretation of positive troponin results among patients with and without myocardial infarction
Proceedings (Baylor University. Medical Center), 2017
Measuring cardiac troponins is integral to diagnosing acute myocardial infarction (AMI); however, troponins may be elevated without AMI, and the use of multiple different assays confounds comparisons. We considered characteristics and serial troponin values in emergency department chest pain patients with and without AMI to interpret troponin excursions. We compared serial troponin in 124 AMI and non-AMI patients from the observational Performance of Triage Cardiac Markers in the Clinical Setting (PEARL) study who presented with chest pain and had at least one troponin value exceeding the 99th percentile of normal. Because 8 assays were used during data collection, we employed a method of scaling the troponin value to the corresponding assay's 99th percentile upper reference limit to standardize the results. In 81 AMI patients, 96% had elevated troponin at the first test following initial elevation, compared to 73% of the 43 non-AMI patients (P < 0.001). Scaling troponin to t...