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

2019 ◽  
Vol 58 (1) ◽  
pp. 138-145 ◽  
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.

Determination of sex-specific 99th percentile upper reference limits for a point of care high sensitivity cardiac troponin I assay

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fred S. Apple ◽  
Karen Schulz ◽  
Christian W. Schmidt ◽  
Trees S. Y. van Domburg ◽  
Judith M. Fonville ◽  
...  
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Limit Of Detection ◽  
Point Of Care ◽  
High Sensitivity ◽  
The Novel ◽  
Limit Of Quantitation ◽  
Reference Limits ◽  
Males And Females

Abstract Objectives High sensitivity (hs) cardiac troponin (cTn) assays are defined per the IFCC Committee on Clinical Application of Cardiac Biomarker (C-CB) by the ability to measure ≥ 50% of concentrations greater than the limit of detection (LoD) with an impression of ≤10% at sex-specific 99th percentiles. Our study determined the sex-specific 99th percentile upper reference limits for males and females utilizing heparinized plasma from AACC universal sample bank for the Siemens point of care (POC) Atellica® VTLi hs-cTnI immunoassay. Methods Apparently healthy subjects, included overall 693, males 363, and females 330, following exclusionary surrogate biomarker use of hemoglobin A1c, NT-proBNP, and eGFR, along with statin medication. hs-cTnI was measured in a central laboratory, on multiple POC Atellica® VTLi immunoassay analyzers. The LoD was 1.24 ng/L and limit of quantitation (CV 20%) was 6.7 ng/L. 99th percentile URLs were determined by the nonparametric (NP) method. Results Histograms of the hs-cTnI concentrations (ng/L) for males and females were used to visualize the distributions and concentrations in men and women and differed significantly (pre- and post-exclusion, both p <0.001). 99th percentile URLs were: overall 23 ng/L (90% CI 20–32 ng/L); male 27 ng/L (CI 21–37 ng/L); female 18 ng/L (CI 9–78 ng/L). The percentages of subjects having a measurable concentration ≥ the LoD were: overall 83.7%, male 87.3%, female 79.7%. Conclusions Our findings show the novel POC Atellica® VTLi hs-cTnI assay meets the designation of a ‘high-sensitivity’ assay using heparinized plasma.

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

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.

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.

Potential impact of a novel pathway for suspected myocardial infarction utilising a new high-sensitivity cardiac troponin I assay

2021 ◽  
pp. emermed-2020-210812
Author(s):  
Rob Meek ◽  
Louise Cullen ◽  
Zhong Xian Lu ◽  
Arthur Nasis ◽  
Lisa Kuhn ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Routine Care ◽  
Primary Objective ◽  
Cardiac Troponin I ◽  
Post Discharge ◽  
Reference Limit

BackgroundHigh-sensitivity cardiac troponin I (hs-cTnI) assays promise high diagnostic accuracy for myocardial infarction (MI). In an ED where conventional cTnI was in use, we evaluated an assessment pathway using the new Access hsTnI assay.MethodsThis retrospective analysis recruited ED patients with suspected MI between June and September 2019. All patients received routine care with a conventional cTnI assay (AccuTnI +3: limit of detection (LoD) 10 ng/L, 99th centile upper reference limit (URL) 40 ng/L, abnormal elevation cut-point 80 ng/L). Arrival, then 90-minute or 360-minute cTnI levels for low and non-low risk patients, respectively (ED Assessment of Chest pain score) guided diagnosis and disposition which was at treating physician discretion. The same patients had arrival and 90-minute or 180-minute samples drawn for hs-cTnI levels (Access hsTnI: LoD 2 ng/L, 99th centile URL 10 ng/L (females) and 20 ng/L (males); abnormal elevation above the URL and delta >30%). Treating physicians were blinded to the hs-cTnI results. Using the hs-cTnI values, investigators retrospectively assigned likely diagnosis, disposition and likelihood of a 30-day major adverse cardiac event (MACE). Admission was recommended for significantly rising hs-cTnI elevations. The primary objective was to demonstrate an acceptable unexpected 30-day post-discharge MACE rate of <1%. cTnI elevation rates, diagnostic outcomes and ED disposition were also compared between pathways.ResultsFor the 935 patients, unexpected 30-day post-discharge MACE rates were 0/935 (0%, 95% CI 0% to 0.4%) with the conventional or novel pathway. For the high-sensitivity and conventional assays, respectively, abnormal elevation rates were 29% (95% CI 26% to 32%) and 19% (95% CI 17% to 22%), for MI were 9% (95% CI 8% to 11%) and 8% (95% CI 6% to 10%), and for hospital admission were 42% (95% CI 39% to 45%) and 43% (95% CI 40% to 47%).ConclusionThe novel pathway using the Access hsTnI assay has an acceptably low 30-day MACE rate.

scholarly journals Detectable High-Sensitivity Cardiac Troponin within the Population Reference Interval Conveys High 5-Year Cardiovascular Risk: An Observational Study

2018 ◽  
Vol 64 (7) ◽  
pp. 1044-1053 ◽  
Author(s):  
Martin P Than ◽  
Sally J Aldous ◽  
Richard W Troughton ◽  
Christopher J Pemberton ◽  
A Mark Richards ◽  
...  
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Cox Regression ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Major Adverse Cardiovascular Events ◽  
Reference Limit ◽  
Coronary Syndrome ◽  
Increased Risk

Abstract BACKGROUND Increased cardiac troponin I or T detected by high-sensitivity assays (hs-cTnI or hs-cTnT) confers an increased risk of adverse prognosis. We determined whether patients presenting with putatively normal, detectable cTn concentrations [&gt; limit of detection and &lt; upper reference limit (URL)] have increased risk of major adverse cardiovascular events (MACE) or all-cause mortality. METHODS A prospective 5-year follow-up of patients recruited in the emergency department with possible acute coronary syndrome (ACS) and cTn concentrations measured with hs-cTnI (Abbott) and hs-cTnT (Roche) assays. Cox regression models were generated with adjustment for covariates in those without MACE on presentation. Hazard ratios (HRs) for hs-cTn were calculated relative to the HRs at the median concentration. RESULTS Of 1113 patients, 836 were without presentation MACE. Of these, 138 incurred a MACE and 169 died during a median 5.8-year follow-up. HRs for MACE at the URLs were 2.3 (95% CI, 1.7–3.2) for hs-cTnI and 1.8 (95% CI, 1.3–2.4) for hs-cTnT. Corresponding HRs for mortality were 1.7 (95% CI, 1.2–2.2) for hs-cTnI and 2.3 (95 % CI, 1.7–3.1) for hs-cTnT. The HR for MACE increased with increasing hs-cTn concentration similarly for both assays, but the HR for mortality increased at approximately twice the rate for hs-cTnT than hs-cTnI. Patients with hs-cTnI ≥10 ng/L or hs-cTnT ≥16 ng/L had the same percentage of MACE at 5-year follow-up (33%) as patients with presentation MACE. CONCLUSIONS Many patients with ACS ruled out and putatively normal but detectable hs-cTnI concentrations are at similar long-term risk as those with MACE. hs-cTnT concentrations are more strongly associated with 5-year mortality than hs-cTnI.

scholarly journals 101 Clinical Performance of a Novel Point-of-Care Technology for Bedside Measurement of Cardiac Troponin-I

2016 ◽  
Vol 68 (4) ◽  
pp. S41
Author(s):  
P. Hausfater ◽  
S. Blaschke ◽  
E. Giannitsis ◽  
M. Khellaf ◽  
J. Mair ◽  
...  
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Clinical Performance ◽  
Point Of Care ◽  
Cardiac Troponin I ◽  
Point Of Care Technology ◽  
Care Technology

Evaluation of a New Skeletal Troponin I Assay in Patients with Idiopathic Inflammatory Myopathies

2020 ◽  
Vol 5 (2) ◽  
pp. 320-331
Author(s):  
Katriina Bamberg ◽  
Laura Mehtälä ◽  
Olli Arola ◽  
Seppo Laitinen ◽  
Pauliina Nordling ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Troponin I ◽  
Limit Of Detection ◽  
Clinical Performance ◽  
Low Grade ◽  
Idiopathic Inflammatory Myopathies ◽  
Strong Positive Correlation ◽  
Inflammatory Myopathies ◽  
Reference Limit ◽  
Upper Reference Limit

Abstract Background The current biomarkers for diagnosis and monitoring of injured and diseased skeletal muscles, such as creatine kinase (CK), have limited tissue specificity and incapability to differentiate between pathological and physiological changes. Thus, new biomarkers with improved diagnostic accuracy are needed. Our aim was to develop and validate a novel assay for skeletal troponin I (skTnI), and to assess its clinical performance in patients with idiopathic inflammatory myopathies (IIM). Methods A two-step fluoroimmunoassay was used to analyze samples from healthy reference individuals (n = 140), patients with trauma (n = 151), and patients with IIM (n = 61). Results The limit of detection was 1.2 ng/mL, and the upper reference limit (90th percentile) was 5.2 ng/mL. The median skTnI concentrations were &lt;limit of detection (LoD), 2.7 ng/mL, and 8.6 ng/mL in reference, trauma, and IIM cohorts, respectively. Differences in measured skTnI levels were statistically significant between all three study cohorts (Kruskal–Wallis P &lt; 0.001; Mann–Whitney P &lt; 0.001 for all). skTnI and CK had a strong positive correlation (Spearman’s r = 0.771, P &lt; 0.001), and the longitudinal changes in skTnI mirrored those observed with CK. Conclusions With the skTnI assay, patients with IIM were identified from healthy individuals and from patients with traumatic muscular injuries. When compared to CK, skTnI appeared to be more accurate in managing patients with low-grade IIM disease activities. The developed assay serves as a reliable analytical tool for the assessment of diagnostic accuracy of skTnI in the diagnosis and monitoring of myopathies.

scholarly journals Clinical Performance of Two Highly Sensitive Cardiac Troponin I Assays

2009 ◽  
Vol 55 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Per Venge ◽  
Stefan James ◽  
Leif Jansson ◽  
Bertil Lindahl
Keyword(s):  
At Risk ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Clinical Performance ◽  
Composite Endpoint ◽  
Outcome Data ◽  
Cardiac Troponin I ◽  
Healthy Population ◽  
Reference Limit ◽  
Patients At Risk

Abstract Background: The aim of this study was to compare the clinical performance of 2 sensitive cTnI assays with 10% CV imprecision below the 99th percentile upper reference limit. Methods: We measured cardiac troponin and N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations in a random sample of the Global Use of Strategies To Open Occluded Coronary Arteries (GUSTO) IV cohort (n = 1251). Outcome data of 1-year mortality and the composite endpoint DMI [death and/or myocardial infarction (MI) within 30 days] were available in all patients. The 99th percentile of a healthy population was estimated from the Sweden Women and Men and Ischemic Heart Disease (SWISCH) cohort (n = 442). We measured cardiac troponin I (cTnI) using the Access AccuTnI (Beckman Coulter) and Centaur TnI Ultra (Siemens Healthcare Diagnostics) and NT-proBNP using the Elecsys 2010 (Roche Diagnostics). Results: Applying the 10% CV cutoff, the sensitivity of the Access AccuTnI assay in identifying DMI and death was higher than that of the Centaur TnI Ultra (P = 0.02 and P &lt; 0.001), and the AccuTnI assay also identified more patients at risk (P &lt; 0.001) and with poor outcome. Applying the 99th percentile cutoffs, AccuTnI identified more patients at risk than the Centaur TnI (P &lt; 0.001) and with significant differences in outcome. Significantly more patients with cardiac troponins below the cutoffs as measured by Centaur TnI had increased NT-proBNP concentrations (P &lt; 0.001) compared with AccuTnI. Conclusions: The AccuTnI assay identified more patients at risk than the Centaur cTnI Ultra assay. Our results demonstrate the clinical potential of high-sensitivity cardiac troponin assays for the identification of patients at risk of dying from cardiovascular disease.

Diagnostic accuracy of the Troponin-only Manchester Acute Coronary Syndromes (T-MACS) decision aid with a point-of-care cardiac troponin assay

2020 ◽  
Vol 37 (4) ◽  
pp. 223-228 ◽  
Author(s):  
Abdulrhman Alghamdi ◽  
Charles Reynard ◽  
Niall Morris ◽  
Phil Moss ◽  
Heather Jarman ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Predictive Value ◽  
Cardiac Troponin ◽  
Acute Coronary Syndromes ◽  
Decision Aid ◽  
Troponin I ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Serial Sampling ◽  
Coronary Syndromes

ObjectivePoint-of-care (POC) cardiac troponin (cTn) assays have a rapid turnaround time but are generally less sensitive than laboratory-based assays. Previous research found that the Abbott i-Stat cardiac troponin I (cTnI) assay has good diagnostic accuracy when used with the Troponin-only Manchester Acute Coronary Syndromes (T-MACS) decision aid and serial sampling over 3 hours. Accuracy of other assays may differ. We therefore evaluated the diagnostic accuracy of a different POC cTnI assay with serial sampling over 3 hours, both with T-MACS and when used alone.MethodsIn a prospective diagnostic accuracy study at eight EDs in England (July 2015–October 2017), we collected clinical data from consenting adults with suspected ACS at the time of assessment in the ED. Blood samples were drawn on arrival and 3 hours later for POC cTnI (Cardio 3 Triage, Alere). The target condition was an adjudicated diagnosis of acute myocardial infarction (AMI), based on reference standard serial laboratory-based cTn testing. We calculated test characteristics for POC cTnI using the limit of detection (LoD, 0.01 µg/L) and the T-MACS decision aid.ResultsOf 347 participants, 59 (14.9%) had AMI. With serial POC cTnI testing over 3 hours, POC cTnI at the LoD cut-off ruled out AMI in 193 (55.6%) patients with 98.1% sensitivity (95% CI 89.9% to 100.0%) and 99.5% negative predictive value (NPV, 95% CI 96.5% to 99.9%). T-MACS ruled out AMI in 117 (33.7%) patients with 98.1% sensitivity (95% CI 89.9% to 100%) and 99.2% NPV (95% CI 94.3% to 99.9%). T-MACS ruled in AMI with 97.9% specificity (95% CI 95.8% to 99.5%) and 83.7% positive predictive value (95% CI 70.6% to 91.7%).ConclusionsWith serial sampling over 3 hours, the Alere Cardio 3 Triage cTnI assay has relatively high NPV for AMI using either the LoD cut-off alone or the T-MACS decision aid. However, wide CIs around the measures of diagnostic accuracy mean that further prospective testing of this strategy is required before clinical implementation.Trial registration numberUKCRN 18000.

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