Cardiac troponin I measurement with the ACCESS® immunoassay system: analytical and clinical performance characteristics

Abstract We evaluated the ACCESS® cardiac troponin I (cTnI) immunoassay as a marker for myocardial infarction (MI). Total imprecision was 6.0% to 13.5%, the minimum detectable concentration was 0.007 μg/L, and the limit of quantitation was 0.046 μg/L. Comparison of cTnI measurement between the ACCESS and Stratus systems (n = 114) showed a proportional difference: ACCESS cTnI = 0.0996 Stratus cTnI + 0.049 μg/L (r = 0.811). Fifty-nine of 61 ambulatory patients without cardiac symptoms had no detectable cTnI (95% range, 0.00 to 0.025 μg/L). The optimum cutoff for discriminating MI (n = 289, 45 with MI) was 0.15 μg/L by receiver operator characteristic curve analysis; at this cutoff, the ACCESS cTnI assay showed a sensitivity of 88.9% (95% CI, 79.7–98.1%) and specificity of 91.8% (95% CI, 88.4–95.2%). The ACCESS cTnI assay results showed 89.4% and 93.0% concordance with the MB isoenzyme of creatine kinase (CK-MB) mass and Stratus cTnI results, respectively, for classification of patients with suspected MI. The ACCESS cTnI assay appears to show sensitivity and specificity comparable with those of both CK-MB mass and Stratus cTnI assays for the diagnosis of MI in patients presenting within 12 h of onset of symptoms.

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Analytical assessment of ortho clinical diagnostics high-sensitivity cardiac troponin I assay

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2020-1115 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Peter A. Kavsak ◽

Tara Edge ◽

Chantele Roy ◽

Paul Malinowski ◽

Karen Bamford ◽

...

Keyword(s):

Cardiac Troponin ◽

Troponin I ◽

Limit Of Detection ◽

Clinical Performance ◽

Characteristic Curve ◽

Area Under The Curve ◽

High Sensitivity ◽

Cardiac Troponin I ◽

Clinical Diagnostics ◽

Ortho Clinical Diagnostics

AbstractObjectivesTo analytically evaluate Ortho Clinical Diagnostics VITROS high-sensitivity cardiac troponin I (hs-cTnI) assay in specific matrices with comparison to other hs-cTn assays.MethodsThe limit of detection (LoD), imprecision, interference and stability testing for both serum and lithium heparin (Li-Hep) plasma for the VITROS hs-cTnI assay was determined. We performed Passing-Bablok regression analyses between sample types for the VITROS hs-cTnI assay and compared them to the Abbott ARCHITECT, Beckman Access and the Siemens ADVIA Centaur hs-cTnI assays. We also performed Receiver-operating characteristic curve analyses with the area under the curve (AUC) determined in an emergency department (ED)-study population (n=131) for myocardial infarction (MI).ResultsThe VITROS hs-cTnI LoD was 0.73 ng/L (serum) and 1.4 ng/L (Li-Hep). Stability up to five freeze-thaws was observed for the Ortho hs-cTnI assay, with the analyte stability at room temperature in serum superior to Li-Hep with gross hemolysis also affecting Li-Hep plasma hs-cTnI results. Comparison of Li-Hep to serum concentrations (n=202), yielded proportionally lower concentrations in plasma with the VITROS hs-cTnI assay (slope=0.85; 95% confidence interval [CI]:0.83–0.88). In serum, the VITROS hs-cTnI concentrations were proportionally lower compared to other hs-cTnI assays, with similar slopes observed between assays in samples frozen <−70 °C for 17 years (ED-study) or in 2020. In the ED-study, the VITROS hs-cTnI assay had an AUC of 0.974 (95%CI:0.929–0.994) for MI, similar to the AUCs of other hs-cTn assays.ConclusionsLack of standardization of hs-cTnI assays across manufacturers is evident. The VITROS hs-cTnI assay yields lower concentrations compared to other hs-cTnI assays. Important differences exist between Li-Hep plasma and serum, with evidence of stability and excellent clinical performance comparable to other hs-cTn assays.

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Clinical Use of a New High-Sensitivity Cardiac Troponin I Assay in Patients with Suspected Myocardial Infarction

Clinical Chemistry ◽

10.1373/clinchem.2019.304725 ◽

2019 ◽

Vol 65 (11) ◽

pp. 1426-1436 ◽

Cited By ~ 12

Author(s):

Jasper Boeddinghaus ◽

Raphael Twerenbold ◽

Thomas Nestelberger ◽

Luca Koechlin ◽

Desiree Wussler ◽

...

Keyword(s):

Myocardial Infarction ◽

Diagnostic Accuracy ◽

Cardiac Troponin ◽

Troponin I ◽

Clinical Performance ◽

High Sensitivity ◽

Primary Objective ◽

Cardiac Troponin I ◽

Primary Analysis ◽

Derivation Cohort

Abstract 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 hs-cTnI-VITROS-0/1-h algorithm. RESULTS AMI was the adjudicated final diagnosis in 158 of 1231 (13%) patients. At presentation, the AUC for hs-cTnI-VITROS was 0.95 (95% CI, 0.93–0.96); for hs-cTnT-Elecsys, 0.94 (95% CI, 0.92–0.95); and for hs-cTnI-Architect, 0.92 (95% CI, 0.90–0.94). AUCs for hs-cTnI-Centaur and hs-cTnI-Access were 0.95 (95% CI, 0.94–0.97). Applying the derived hs-cTnI-VITROS-0/1-h algorithm (derivation cohort n = 519) to the validation cohort (n = 520), 53% of patients were ruled out [sensitivity, 100% (95% CI, 94.1–100)] and 14% of patients were ruled in [specificity, 95.6% (95% CI, 93.4–97.2)]. Patients ruled out by the 0/1-h algorithm had a survival rate of 99.8% at 30 days. Findings were confirmed in the secondary analyses using the adjudication including serial measurements of hs-cTnI-Architect. CONCLUSIONS The hs-cTnI-VITROS assay has at least comparable diagnostic accuracy with the currently best validated hs-cTnT and hs-cTnI assays. ClinicalTrials.gov Identifier NCT00470587.

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Comparable detection of acute myocardial infarction by creatine kinase MB isoenzyme and cardiac troponin I

Clinical Chemistry ◽

10.1093/clinchem/40.7.1291 ◽

1994 ◽

Vol 40 (7) ◽

pp. 1291-1295 ◽

Cited By ~ 197

Author(s):

J E Adams ◽

K B Schechtman ◽

Y Landt ◽

J H Ladenson ◽

A S Jaffe

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Creatine Kinase ◽

Cardiac Troponin ◽

Troponin I ◽

Characteristic Curve ◽

Cardiac Injury ◽

Cardiac Troponin I ◽

Creatine Kinase Mb ◽

Coronary Care

Abstract Although measurement of cardiac troponin I (cTnI) is, in some situations, more specific for detection of cardiac injury than is measurement of the MB isoenzyme of creatine kinase (MBCK), its sensitivity and specificity relative to MBCK for detection of myocardial infarction has not been established. Accordingly, we studied prospectively 199 consecutive patients admitted to the coronary care unit. Values of MBCK and cTnI mass were determined in all samples. Of the 188 patients admitted with a suspicion of acute myocardial ischemia, 89 were diagnosed as having an acute myocardial infarction on the basis of the patterns of MBCK values. Eighty-six of these patients also had increased cTnI (concordance, 96.6%); three did not. Of the patients diagnosed as without infarction, five with unstable angina and symptoms in the day(s) prior to admission had increased cTnI, for a cTnI specificity of 94.9%. Receiver operating characteristic curve analysis indicated that cTnI and MBCK had statistically indistinguishable diagnostic accuracies for the detection of acute myocardial infarction.

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Prognostic Value of Elevated Cardiac Troponin I Levels in Pre-dialysis Chronic Kidney Disease Patients without Cardiac Symptoms

Asian Journal of Medicine and Health ◽

10.9734/ajmah/2017/38087 ◽

2017 ◽

Vol 8 (4) ◽

pp. 1-8

Author(s):

Ehimen Odum ◽

Victor Wakwe ◽

Hope Bell-Gam ◽

Richard Oko-Jaja

Keyword(s):

Chronic Kidney Disease ◽

Kidney Disease ◽

Cardiac Troponin ◽

Prognostic Value ◽

Troponin I ◽

Cardiac Troponin I ◽

Cardiac Symptoms

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Clinical performance of cardiac Troponin I: A comparison between the POCT AQT90 FLEX and the Dimension Vista analyzer in an emergency setting

Clinical Biochemistry ◽

10.1016/j.clinbiochem.2017.03.027 ◽

2017 ◽

Vol 50 (13-14) ◽

pp. 763-767 ◽

Cited By ~ 9

Author(s):

Monica Maria Mion ◽

Giada Bragato ◽

Alessandra Casarotti ◽

Chiara Cosma ◽

Stefania Vigolo ◽

...

Keyword(s):

Cardiac Troponin ◽

Troponin I ◽

Clinical Performance ◽

Cardiac Troponin I ◽

Emergency Setting

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Analytical validation of a highly sensitive point-of-care system for cardiac troponin I determination

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2019-0801 ◽

2019 ◽

Vol 58 (1) ◽

pp. 138-145 ◽

Cited By ~ 4

Author(s):

Federica Braga ◽

Elena Aloisio ◽

Andrea Panzeri ◽

Takahito Nakagawa ◽

Mauro Panteghini

Keyword(s):

Cardiac Troponin ◽

Troponin I ◽

Limit Of Detection ◽

Clinical Performance ◽

Point Of Care ◽

Total Error ◽

Method Comparison ◽

Reference Limit ◽

Highly Sensitive ◽

Limit Of Quantitation

Abstract Background Highly sensitive cardiac troponin assays (hs-cTn) are not available as point-of-care (POC) measurements. As rapid testing cannot be achieved at the expense of clinical performance, there is an urgent need to develop and rigorously validate POC hs-cTn. Konica Minolta (KM) has recently developed a surface plasmon-field enhanced fluorescence spectroscopy-based POC hs-cTn I system. Methods We validated the analytical characteristics of the KM POC system according to the international guidelines. Results Limit of blank (LoB) and limit of detection (LoD) were 0.35 and 0.62 ng/L, respectively, hs-cTn I concentrations corresponding to a total CV of 20%, 10% and 5% were 1.5, 3.9 and 11.0 ng/L, respectively. Method comparison studies showed that KM calibration was successfully traced to higher-order references. Limit of quantitation (LoQ), i.e. the hs-cTn I concentration having a total error of measurement of ≤34%, was 10.0 ng/L. The upper reference limit (URL) for 600 healthy blood donors was calculated at 12.2 ng/L (90% confidence interval [CI]: 9.2–39.2), while sex-partitioned URLs were 20.6 (males) and 10.7 ng/L (females), respectively (p < 0.0001). KM assay measured hs-cTn I concentrations >LoD in 65.7% of all reference individuals, in 76.7% of males and in 54.7% of females, respectively. Conclusions The KM system joins the characteristics of POC systems to the analytical performance of hs-cTn.

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The Antibody Configurations of Cardiac Troponin I Assays May Determine Their Clinical Performance

Clinical Chemistry ◽

10.1373/clinchem.2005.064857 ◽

2006 ◽

Vol 52 (5) ◽

pp. 832-837 ◽

Cited By ~ 52

Author(s):

Stefan James ◽

Mats Flodin ◽

Nina Johnston ◽

Bertil Lindahl ◽

Per Venge

Keyword(s):

Monoclonal Antibodies ◽

Cardiac Troponin ◽

Troponin I ◽

Clinical Performance ◽

Cardiac Troponin I ◽

Unstable Coronary Artery Disease ◽

Reference Limits ◽

Risk Patients ◽

Artery Disease ◽

Roche Diagnostics

Abstract Background: Previous studies have shown superior clinical performance of the cardiac troponin I (cTnI) assay from Beckman-Coulter Diagnostics. This assay had a unique combination of monoclonal antibodies with 2 monoclonal antibodies directed against epitopes near the NH2 terminus of the heart-specific region of troponin I. The approach has been adopted by the new cTnI assay from Abbott Diagnostics. The aim of our study was to investigate whether this approach affects the clinical performance of cTnI assays. Methods: Cardiac troponin concentrations were measured in a random sample of patients with unstable coronary artery disease included in the GUSTO IV trial (n = 696) by the AccuTnI (Beckman-Coulter Diagnostics), Architect cTnI (Abbott Diagnostics), Immulite 2500 cTnI (Diagnostics Products Corporation), and Elecsys 2010 cTnT (Roche Diagnostics) assays and related to the 1-year mortality. The primary cutoff concentrations were based on the 99th percentile upper reference limits and an imprecision (CV) ≤10%. Results: The sensitivities of the AccuTnI and Architect cTnI assays in identifying patients who died within 1 year were equal and were significantly higher (P <0.05) than those of the Immulite 2500 cTnI and the Elecsys cTnT assays. The concordance between the AccuTnI and Architect cTnI assays was 97%, but concordances between the Architect cTnI and the Elecsys cTnT assays were 89%–92% with more at-risk patients (P <0.01 to P <0.001) identified by the Architect cTnI assay. Conclusions: The Architect cTnI assay has clinical performance similar to that of the AccuTnI, probably as a result of the inclusion of a monoclonal antibody against troponin I epitope 41–49 in the assay.

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