scholarly journals Multicenter Evaluation of an Automated Assay for Troponin I

2002 ◽  
Vol 48 (6) ◽  
pp. 869-876 ◽  
Author(s):  
Denise Uettwiller-Geiger ◽  
Alan HB Wu ◽  
Fred S Apple ◽  
Anthony W Jevans ◽  
Per Venge ◽  
...  
Keyword(s):  
Detection Limit ◽  
Troponin I ◽  
Reference Population ◽  
Reference Limit ◽  
Automated Assay ◽  
Heparin Plasma ◽  
Edta Plasma ◽  
Upper Reference Limit ◽  
Matched Samples ◽  
Assay Interference

Abstract Background: Cardiac troponin I (cTnI) is a powerful tool to aid in the diagnosis of myocardial infarction and cardiac muscle damage. We describe an assay that overcomes problems of early assays that were often affected by cTnI degradation, assay interference, poor sensitivity, and imprecision. Methods: The analytical performance of the Access® AccuTnITM assay (Beckman Coulter) was evaluated at five institutions. Controls, zero calibrator, and diluted patient samples were used to determine precision, detection limit, functional sensitivity, and linearity. The 97.5 and 99 percentiles of a reference population were determined. Common interferents and heterophilic patient samples were tested. Equimolarity was determined by assaying samples with various ratios of free and complexed cTnI. Matched samples drawn into serum, EDTA, lithium heparin, and sodium heparin sample tubes were compared. Results: Total imprecision (CVs) was 4.0–8.8% between 0.40 and 31 μg/L cTnI. The detection limit was <0.01 μg/L. The 97.5 percentile upper reference limit (URL) was 0.03 μg/L (CV = 20%), and the 99 percentile URL was 0.04 μg/L (CV = 14%). Total CVs of 10% and 20% were seen at and above 0.06 and 0.03 μg/L, respectively. The assay was linear to >60 μg/L and not affected by common assay interferents. An equimolar response was observed with free, complexed, phosphorylated, and dephosphorylated forms of cTnI. Results were 4% lower in serum and 14% lower in EDTA plasma than in lithium heparin plasma (P <0.01), independent of cTnI concentration. Conclusion: AccuTnI is a sensitive and precise assay for the measurement of cTnI.

Clinical and analytical evaluation of kits for measurement of creatine kinase isoenzyme MB.

1986 ◽  
Vol 32 (1) ◽  
pp. 186-191 ◽  
Author(s):  
T R Koch ◽  
U J Mehta ◽  
H C Nipper
Keyword(s):  
Creatine Kinase ◽  
Clinical Performance ◽  
Reference Population ◽  
Reference Ranges ◽  
Diagnostic Specificity ◽  
Electrophoretic Method ◽  
Reference Limit ◽  
Coronary Care ◽  
Upper Reference Limit ◽  
Creatine Kinase Isoenzyme Mb

Abstract We studied the analytical and clinical performance of six methods for creatine kinase (EC 2.7.3.2) isoenzyme MB (CK-MB): three immunoassays (Behring, Hybritech, and International Immunoassay Labs); one immunoinhibition assay (Roche); one immunoinhibition/column method (Du Pont); and one electrophoretic method (Beckman). Between-day precision for all kits was poor at the upper reference limit. All methods gave results linearly related to CK-MB concentration and all were free from CK-MM, CK-BB, and adenylate kinase interference. Only the Du Pont method was adversely affected by atypical isoenzymes. For diagnosis of acute myocardial infarction in a coronary care population (n = 40; prevalence = 45%), all methods were approximately 95% efficient, when appropriate reference criteria were used. Some manufacturers fail to provide data for an appropriate (acutely ill, non-infarct) reference population; decreased diagnostic specificity may result from use of reference ranges based on results for healthy subjects. Expression of CK-MB as a percent of total CK degrades efficiency unless total CK is markedly increased.

Abstract 14870: Clinical Significance of Troponin Elevation in a Contemporary Hospitalized Population: Endotypes, Morbidity and In-hospital Mortality

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Michael Briscoe ◽  
Robert A Sykes ◽  
Thomas Krysztofiak ◽  
Kenneth Mangion ◽  
Oliver H Peck ◽  
...  
Keyword(s):  
Clinical Significance ◽  
Myocardial Injury ◽  
Troponin I ◽  
Coronary Revascularization ◽  
High Sensitivity ◽  
Hospitalized Patients ◽  
Troponin Elevation ◽  
Reference Limit ◽  
Upper Reference Limit

Introduction: Unplanned hospitalizations are commonly associated with a circulating troponin concentration >99 th percentile upper reference limit (URL). In order to better understand the clinical significance of troponin elevation, we evaluated outcomes in hospitalized patients according to cardiac endotype. Methods: We prospectively screened consecutive hospitalized patients with elevated high-sensitivity troponin-I (hs-TnI) concentrations (Abbott ARCHITECT troponin-I assay; sex-specific URL, 99 th centile: male: >34ng/L; female: >16ng/L) within a regional cardiac care network (population 650,000). A cardiology clinical team adjudicated individual patient records and assigned endotypes by consensus agreement according to the Fourth Universal Definition of Myocardial Infarction (MI). Endotypes were sub-classified into etiological category by inciting event(s). Characteristics and comorbidity were compared and outcomes recorded on virtual follow-up until June 2 nd 2020. Results: A total of 390 consecutive patients with ≥1 hs-TnI value >URL between March 1-April 15, 2020, were evaluated; 44 patients were excluded ( Duplicates: 2; Missing data: 41; Research patient: 1 ). Of 346 who qualified for inclusion, an index diagnosis of Type 1 MI (T1MI), T2MI and myocardial injury were assigned in 115 (33.2%), 79 (22.8%) and 152 (43.9%) patients, respectively. Compared with T1MI, patients with T2MI and myocardial injury had lower peak hs-TnI values (median [IQR]: 86 [250-697] vs 5020 [853-7774]ng/L; p< 0.01), lower estimated 10-year survival (40.2% vs 53.4%; p=0.002), less frequently underwent coronary revascularization (1.4% vs 45.2%; p<0.0005) and had longer inpatient stay (13.0 vs 6.1 days). Inpatient and overall mortality rates from admission to follow-up (median [range]: 71 [0-151] days) were higher among patients with T2MI and myocardial injury (19.9% vs 7.8%; p=0.004; and 26.0% vs 11.3%; Log rank (Mantel-Cox) X 2 = 1.927; p=0.003) independent of similar cardiovascular risk profiles. Conclusions: Despite lower peak circulating troponin concentrations, patients with T2MI and myocardial injury had higher inpatient mortality, lower estimated 10-year survival and longer in-hospital stay compared to those with T1MI.

Assessing matrix, interferences and comparability between the Abbott Diagnostics and the Beckman Coulter high-sensitivity cardiac troponin I assays

2018 ◽  
Vol 56 (7) ◽  
pp. 1176-1181 ◽  
Author(s):  
Peter A. Kavsak ◽  
Paul Malinowski ◽  
Chantele Roy ◽  
Lorna Clark ◽  
Shana Lamers
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Matrix Effects ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Mean Difference ◽  
Plasma Samples ◽  
Matrix Interferences ◽  
Heparin Plasma ◽  
Edta Plasma

Abstract Background: Analytical evaluation of high-sensitivity cardiac troponin (hs-cTn) assays, with particular attention to imprecision, interferences and matrix effects, at normal cTn concentrations, is of utmost importance as many different clinical algorithms use concentration cutoffs <10 ng/L for decision-making. The objective for the present analytical study was to compare the new Beckman Coulter hs-cTnI assay (Access hsTnI) to Abbott’s hs-cTnI assay in different matrices and for different interferences, with a focus on concentrations <10 ng/L. Methods: The limit of blank (LoB) and the limit of detection (LoD) were determined in different matrices for the Beckman hs-cTnI assay. Passing-Bablok regression and difference plots were determined for 200 matched lithium heparin and EDTA plasma samples for the Beckman assay and 200 lithium heparin samples for the Abbott assay. Both EDTA and heparin plasma samples were also evaluated for stability under refrigerated conditions, for endogenous alkaline phosphatase interference and for hemolysis and icterus. Results: The Beckman hs-cTnI assay LoB was 0.5 ng/L with the following range of LoDs=0.8–1.2 ng/L, with EDTA plasma yielding lower concentrations as compared to lithium heparin plasma (mean difference=−14.9%; 95% CI=−16.9 to 12.9). Below 10 ng/L, lithium heparin cTnI results from the Beckman assay were on average 1.1 ng/L (95% CI=0.7 to 1.5) higher than the Abbott results, with no difference between the methods when using EDTA plasma (mean difference =−0.1 ng/L; 95% CI=−0.3 to 0.2). Low cTnI concentrations were less effected by interferences in EDTA plasma. Conclusions: The Access hsTnI method can reliably detect normal cTnI concentrations with both lithium heparin and EDTA plasma being suitable matrices.

Emergency department triage of patients with acute chest pain: definition of cardiac troponin I decisional value to manage patients without electrocardiographic evidence of ischemia

2004 ◽  
Vol 42 (5) ◽  
Author(s):  
Pascale Beyne ◽  
Erik Bouvier ◽  
Patrick Werner ◽  
Pierre Bourgoin ◽  
Damien Logeart ◽  
...  
Keyword(s):  
Chest Pain ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Acute Chest Pain ◽  
Final Diagnosis ◽  
Cardiac Troponin I ◽  
Reference Limit ◽  
Coronary Syndrome ◽  
Definition Of ◽  
Upper Reference Limit

AbstractThe aim of this study was to define the use of a new cardiac troponin I (cTnI) assay for emergency patients with chest pain and no specific electrocardiographic changes consistent with the presence of ischemia. Patients (n=106) admitted in Emergency/Cardiology Departments for chest pain and suspicion of acute coronary syndrome (ACS) were randomized into two diagnosis groups (ACS or non-ACS) by two independent cardiologists. cTnI measurements were performed at admission, and 6 hours and 12 hours later with a new generation assay (Access AccuTnI, Beckman Coulter). Using an upper reference limit of 0.04 μg/l, 27 patients had a cTnI elevation not related to the final diagnosis of ischemia; the positive predictive value (PPV) was 67% with specificity 48%. The decisional value was re-defined and set at 0.16 μg/l, a concentration corresponding to the 99th percentile of the non-ACS patient group. Precision (coefficient of variation) was 8% at this level, PPV 97% and specificity 98%. This new decisional value is now used in our institution and could be included in standard care guidelines to improve the management of patients presenting chest pain in emergency departments.

scholarly journals Improved detection of minor ischemic myocardial injury with measurement of serum cardiac troponin I

1997 ◽  
Vol 43 (11) ◽  
pp. 2047-2051 ◽  
Author(s):  
Fred S Apple ◽  
Alireza Falahati ◽  
Pamela R Paulsen ◽  
Elizabeth A Miller ◽  
Scott W Sharkey
Keyword(s):  
Cardiac Troponin ◽  
Myocardial Injury ◽  
Troponin I ◽  
Cardiac Troponin I ◽  
Clinical Sensitivity ◽  
Reference Limit ◽  
Normal Limits ◽  
Serial Serum ◽  
Upper Reference Limit ◽  
Serum Cardiac Troponin

Abstract This study compared the diagnostic accuracy of the measurement of serum cardiac troponin I (cTnI) with creatine kinase (CK) MB mass in patients with minor myocardial injury whose measured total CK activity did not exceed twice the upper reference limit (300 U/L for men; 200 U/L for women). Forty-eight consecutive patients presenting with chest pain and with in-hospital documentation of myocardial injury were enrolled. Electrocardiogram, echocardiogram, and serial serum CK-MB mass, cTnI, and total CK were measured over 36 h after admission. Peak total CK activity was within normal limits in 28 patients (58%). The mean (±SD) peak CK-MB mass and cTnI concentrations were: 16.4 (11.8) μg/L and 132 (13.0) μg/L; respectively. The peak biochemical marker index (defined as CK-MB or cTnI divided by its respective upper reference limit) was significantly (P &lt;0.05) higher for cTnI than for CK-MB from 7 to 36 h. The clinical sensitivity for detection of myocardial injury for cTnI was 100% [95% confidence interval (CI): 87.2% to 100%], compared with 81.8% (CI: 67.3% to 91.8%) for CK-MB. Thus, cTnI was more sensitive than CK-MB mass for detection of myocardial injury in patients with small increases of total CK.

Analytical evaluation of the new Beckman Coulter Access high sensitivity cardiac troponin I immunoassay

2017 ◽  
Vol 56 (1) ◽  
Author(s):  
Giuseppe Lippi ◽  
Anna Ferrari ◽  
Giorgio Gandini ◽  
Matteo Gelati ◽  
Claudia Lo Cascio ◽  
...  
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Cardiac Troponin I ◽  
Analytical Performance ◽  
The Novel ◽  
Reference Limit ◽  
Automated Immunoassay ◽  
Upper Reference Limit

AbstractBackground:This study was aimed to evaluate the analytical performance of the novel chemiluminescent and fully-automated Beckman Coulter Access hsTnI high-sensitivity immunoassay for measurement of cardiac troponin I (cTnI).Methods:The study, using lithium heparin samples, included assessment of limit of blank (LOB), limit of detection (LOD), functional sensitivity, linearity, imprecision (within run, between-run and total), calculation of 99th percentile upper reference limit (URL) in 175 healthy blood donors (mean age, 36±12 years; 47% women) and comparison with two other commercial cTnI immunoassays.Results:The LOB, LOD and functional sensitivity of Access hsTnI were 0.14, 0.34 and 1.35 ng/L, respectively. The within-run, between-run and total imprecision was 2.2%–2.9%, 4.6%–5.4%, and 5.4%–6.1%, respectively. The linearity was excellent in the range of cTnI values between 0.95 and 4195 ng/L (r=1.00). The 99th percentile URL was 15.8 ng/L. Measurable cTnI values were found in 173/175 healthy subjects (98.9%). Good agreement of cTnI values was found with AccuTnI+3 (r=0.97; mean bias, −9.3%), whereas less satisfactory agreement was found with Siemens Dimension Vista cTnI (r=0.95; mean bias, −55%).Conclusions:The results of our evaluation of the Beckman Coulter Access hsTnI indicate that the analytical performance of this fully-automated immunoassay is excellent.

scholarly journals Temporal Evolution of Serum Concentrations of High‐Sensitivity Cardiac Troponin During 1 Year After Acute Coronary Syndrome Admission

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Victor J. van den Berg ◽  
Rohit M. Oemrawsingh ◽  
Victor A. W. M. Umans ◽  
Isabella Kardys ◽  
Folkert W. Asselbergs ◽  
...  
Keyword(s):  
Acute Coronary Syndrome ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Temporal Evolution ◽  
High Sensitivity ◽  
Interindividual Variation ◽  
Mixed Effect ◽  
Reference Limit ◽  
Coronary Syndrome ◽  
Upper Reference Limit

Background Detailed insights in temporal evolution of high‐sensitivity cardiac troponin following acute coronary syndrome (ACS) are currently missing. We aimed to describe and compare the post‐ACS kinetics of high‐sensitivity cardiac troponin I (hs‐cTnI) and high‐sensitivity cardiac troponin T (hs‐cTnT), and to determine their intra‐ and interindividual variation in clinically stable patients. Methods and Results We determined hs‐cTnI (Abbott) and hs‐cTnT (Roche) in 1507 repeated blood samples, derived from 191 patients with ACS (median, 8/patient) who remained free from adverse cardiac events during 1‐year follow‐up. Post‐ACS kinetics were studied by linear mixed‐effect models. Using the samples collected in the 6‐ to 12‐month post‐ACS time frame, patients were then considered to have chronic coronary syndrome. We determined (differences between) the average hs‐cTnI and average hs‐cTnT concentration, and the intra‐ and interindividual variation for both biomarkers. Compared with hs‐cTnT, hs‐cTnI peaked higher (median 3506 ng/L versus 494 ng/L; P <0.001) and was quicker below the biomarker‐specific upper reference limit (16 versus 19 days; P <0.001). In the post–6‐month samples, hs‐cTnI and hs‐cTnT showed modest correlation ( r spearman =0.60), whereas the average hs‐cTnT concentration was 5 times more likely to be above the upper reference limit than hs‐cTnI. The intraindividual variations of hs‐cTnI and hs‐cTnT were 14.0% and 18.1%, while the interindividual variations were 94.1% and 75.9%. Conclusions Hs‐cTnI peaked higher after ACS and was quicker below the upper reference limit. In the post–6‐month samples, hs‐cTnI and hs‐cTnT were clearly not interchangeable, and average hs‐cTnT concentrations were much more often above the upper reference limit than hs‐cTnI. For both markers, the within‐patient variation fell largely below beween‐patient variation. Registration URL: https://www.trialregister.nl ; unique identifiers: NTR1698 and NTR1106.

Sample matrix and high-sensitivity cardiac troponin I assays

2019 ◽  
Vol 57 (5) ◽  
pp. 745-751 ◽  
Author(s):  
Peter A. Kavsak ◽  
Chantele Roy ◽  
Paul Malinowski ◽  
Lorna Clark ◽  
Shana Lamers ◽  
...  
Keyword(s):  
Excellent Agreement ◽  
Cardiac Troponin ◽  
Troponin I ◽  
High Sensitivity ◽  
Reference Interval ◽  
Storage Conditions ◽  
Reference Intervals ◽  
Limit Of Quantification ◽  
Heparin Plasma ◽  
Edta Plasma

Abstract Background Manufacturers of high-sensitivity cardiac troponin (hs-cTn) assays have restricted use of what sample types or matrices are acceptable to use for measurement. Our goal was to evaluate the comparability of the Siemens ADVIA Centaur hs-cTnI assay across different matrices and under different storage conditions. Methods Three different QC-plasma matrices were evaluated for imprecision <10 ng/L. Passing-Bablok regression and difference plots were determined for cTnI concentrations spanning the reference interval (limit of quantification to male 99th-percentile: 2.5 ng/L to <60 ng/L) between serum and lithium heparin plasma, lithium heparin and EDTA plasma and between the Siemens and Abbott hs-cTnI assays. Stability at room temperature (RT) and 2–8 °C was also assessed across the three matrices. Results Over 16-weeks the SDs were ≤1.0 ng/L for QCs ranging from 5.0 to 8.3 ng/L. Across the reference interval there was excellent agreement between lithium heparin plasma and serum for the Siemens hs-cTnI assay (slope=0.98/intercept=–0.1), however, cTnI concentrations were proportionally lower in EDTA as compared to lithium heparin plasma (slope=0.90, 95% CI: 0.88–0.92). In lithium heparin plasma the Siemens hs-cTnI concentrations were higher than the Abbott hs-cTnI concentrations (slope=1.26/intercept=–0.2). Stability of cTnI in lithium heparin plasma as compared in serum and EDTA plasma appeared more labile, with decreases ≥20% in concentrations evident as early as 1-day in storage at RT. Conclusions There is excellent agreement in concentrations between lithium heparin plasma and serum with the Siemens ADVIA Centaur hs-cTnI assay; however, cTnI concentrations in EDTA plasma are lower. Reference intervals and clinical studies in EDTA plasma for the Centaur hs-cTnI assay are required before clinical use.

Discordance between results for serum troponin T and troponin I in renal disease

1995 ◽  
Vol 41 (2) ◽  
pp. 312-317 ◽  
Author(s):  
V Bhayana ◽  
T Gougoulias ◽  
S Cohoe ◽  
A R Henderson
Keyword(s):  
Renal Failure ◽  
Troponin I ◽  
Troponin T ◽  
Myocardial Damage ◽  
Light Chains ◽  
Reference Limit ◽  
Clinical Investigations ◽  
Total Creatine ◽  
Upper Reference Limit ◽  
Peak Value

Abstract Two patients were investigated for unexplained increases in troponin T. In the first patient, who had rhabdomyolysis and acute renal failure, troponin T reached a peak value of 13.50 micrograms/L (67.5-fold the upper reference limit). The second patient had chronic renal failure and the troponin T peak value was 2.85 micrograms/L (14.3-fold the upper reference limit). Clinical investigations indicated no evidence of myocardial damage. Serum or plasma specimens were analyzed for total creatine kinase (CK), CK-2 mass, CK-2 isoform ratio, myoglobin, troponin T, troponin I, and myosin light chains; all except troponin I were at above-normal concentrations. We also investigated six additional renal patients with above-normal troponin T; troponin I was slightly increased in only one of these six patients. Our findings demonstrate discordance between results for troponin T and troponin I in renal patients.

Evaluating of prognostic value of biomarker and upper reference limit calculating

2020 ◽  
Vol 20 (2) ◽  
pp. 79-86
Author(s):  
Nikolay S. Bunenkov ◽  
Gulnara F. Bunenkova ◽  
Vladimir V. Komok ◽  
Oleg A. Grinenko ◽  
Alexander S. Nemkov
Keyword(s):  
Logistic Regression ◽  
Data Analysis ◽  
Prognostic Value ◽  
Troponin I ◽  
Clinical Laboratory ◽  
Artery Bypass ◽  
Youden Index ◽  
Reference Limit ◽  
Saint Petersburg ◽  
Upper Reference Limit

Objective: to develop algorithm of assessment of prognostic value of biomarker (troponin I) for predicting death after coronary artery bypass grafting. Materials and methods. Data collection was performed according to prospective non-randomized clinical trial AMIRI CABG in Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russia between 20162019 years with 336 patients. There is database with clinical, laboratory and instrumental data. Statistics were calculated with SAS Enterprise Guide 6.1 software. Prognostic capability of biomarker for death were evaluated with logistic regression. Spline of relation between death and biomarker level were plotted using coefficient of logistic regression and intercept. Upper reference limit was calculated with Youden index. Results. There was developed algorithm to assess prognostic value of biomarker and its usefulness for clinical application and to define upper reference limit of biomarker. This algorithm could be useful for physicians and researchers for data analysis. Conclusion. Presented algorithm of data analysis allows to assess prognostic value of novel biomarker and its clinical usefulness.

Sign in / Sign up

Export Citation Format

Share Document