Point-of-care monitoring of vitamin K-antagonists: validation of CoaguChek XS test strips with International Standard thromboplastin

2012 ◽  
Vol 65 (11) ◽  
pp. 1031-1035 ◽  
Author(s):  
Anton M H P van den Besselaar ◽  
Nathalie C V Péquériaux ◽  
Marij Ebben ◽  
Joke van der Feest ◽  
Kerst de Jong ◽  
...  
Keyword(s):  
The Netherlands ◽  
Vitamin K ◽  
Point Of Care ◽  
Vitamin K Antagonists ◽  
Capillary Blood ◽  
Blood Samples ◽  
Test Strips ◽  
International Standard ◽  
The Mean ◽  
Coaguchek Xs

AimsMany patients treated with vitamin K-antagonists (VKA) use point-of-care (POC) whole blood coagulometers for self-testing. The majority of patients in the Netherlands use one type of POC coagulometer, that is, the CoaguChek XS. Each new lot of test strips for the CoaguChek XS is validated by a group of collaborating thrombosis centres. We assessed the International Normalised Ratio (INR) differences between each of 51 new lots of test strips and the International Standard for thromboplastin rTF/95 or its successor rTF/09.MethodsEach year, a particular lot of CoaguChek XS test strips was used as reference lot. The reference lot was validated by comparison to the International Standard, yielding a relationship between the reference lot INR and International Standard INR. Successive lots of test strips were compared to the reference lot by three centres using 19–29 capillary blood samples obtained from VKA-treated patients. Each patient provided two blood drops from the same finger prick, one for the reference lot strip and one for the new lot.ResultsThe mean INR differences between each lot and the International Standard varied between −8% and +4%. The mean absolute values of the relative differences varied between 2.4% and 8.1%. There were small but clinically unimportant differences in INR between the first and second drop of blood.ConclusionsAccuracy of CoaguChek XS INR determinations can be assessed by a group of collaborating centres using a limited number of capillary blood samples. As the mean INR differences with the International Standard were smaller than 10%, the lots were approved for use by the Netherlands Thrombosis Services.

Point-of-care testing and INR within-subject variation in patients receiving a constant dose of vitamin K antagonist

2015 ◽  
Vol 114 (12) ◽  
pp. 1260-1267
Author(s):  
Joseph S. Biedermann ◽  
Marieke J. H. A. Kruip ◽  
A. M. H. P. van den Besselaar
Keyword(s):  
Blood Coagulation ◽  
Vitamin K ◽  
Whole Blood ◽  
Point Of Care ◽  
Vitamin K Antagonists ◽  
Professional Staff ◽  
Self Testing ◽  
Target Intensity ◽  
Constant Dose ◽  
Coaguchek Xs

SummaryMany patients treated with vitamin K antagonists (VKA) determine their INR using point-of-care (POC) whole blood coagulation monitors. The primary aim of the present study was to assess the INR within-subject variation in self-testing patients receiving a constant dose of VKA. The second aim of the study was to derive INR imprecision goals for whole blood coagulation monitors. Analytical performance goals for INR measurement can be derived from the average biological within-subject variation. Fifty-six Thrombosis Centres in the Netherlands were invited to select self-testing patients who were receiving a constant dose of either acenocoumarol or phenprocoumon for at least six consecutive INR measurements. In each patient, the coefficient of variation (CV) of INRs was calculated. One Thrombosis Centre selected regular patients being monitored with a POC device by professional staff. Sixteen Dutch Thrombosis Centres provided results for 322 selected patients, all using the CoaguChek XS. The median within-subject CV in patients receiving acenocoumarol (10.2 %) was significantly higher than the median CV in patients receiving phenprocoumon (8.6 %) (p = 0.001). The median CV in low-target intensity acenocoumarol self-testing patients (10.4 %) was similar to the median CV in regular patients monitored by professional staff (10.2 %). Desirable INR analytical imprecision goals for POC monitoring with CoaguChek XS in patients receiving either low-target intensity acenocoumarol or phenprocoumon were 5.1 % and 4.3 %, respectively. The approximate average value for the imprecision of the CoaguChek XS, i. e. 4 %, is in agreement with these goals.

Unreliability of Point of Care Devices for INR Monitoring of Oral Anticoagulant Therapy. A Re-Evaluation.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2206-2206
Author(s):  
Caryn O. Sands ◽  
Vilma Padilla ◽  
Khrishan Naraine ◽  
Jacob Rand ◽  
Amy S. Fox
Keyword(s):  
Oral Anticoagulant ◽  
Dose Adjustment ◽  
Point Of Care ◽  
Oral Anticoagulant Therapy ◽  
Vitamin K Antagonists ◽  
Rapid Analysis ◽  
Capillary Blood ◽  
Ease Of Use ◽  
Oral Anticoagulant Treatment ◽  
Blood Samples

Abstract Oral anticoagulant treatment with vitamin K antagonists has been encumbered by the need for interval monitoring of INRs to adjust dosage. Point of Care (POC) testing of capillary blood has come into widespread use because of the advantages of rapid analysis and dose adjustment. To assess the reliability of this procedure, we compared INR results from 2 POC devices from different manufacturers - POC1 and POC2 - and compared these results to standard assays on venous samples with a BCS automated analyzer. 78 patients on warfarin for at least 3 months were studied. Results of 56 patients with POC2 and 76 patients with POC1 were compared to the BCS. Capillary blood samples were taken within 30 minutes of the venous draw. The therapeutic INR range was considered to be 2.0–3.5. The bias plots for the 2 POC methods compared to the reference INR are shown in the 2 Figs, below. Within the therapeutic range, 71% and 85% of the results correlated with BCS for POC1 and the POC2, respectively. Both instruments showed the greatest variation from the reference measurement at INR values greater than 2.5 Both POC methods demonstrated clinically relevant overestimates of INR(see table). Figure Figure Figure Figure Agreement % of Reference INR Values to POC INR Reference INR* POC1-subtherapeutic POC1-therapeutic POC1-supratherapeutic POC2-subtherapeutic POC2-therapeutic * INR = 2.0–3.5 BCS-subtherapeutic 77% 23% - 63% 37% BCS-therapeutic 4% 71% 25% 5% 85% BCS-supratherapeutic - - 100% - 33% Conclusion: This study raises a significant question rearding the accuracy of POC methods for INR determinations. Despite ease of use and immediacy of results, the lack of correlation, even under study conditions, and the potentials for under-and overdosing makes relying on these devices problematic.

Abstract 164: Specific Point-of-Care Testing of Coagulation in Patients Treated With Non-Vitamin K Antagonist Oral Anticoagulants Part I (SPOCT-NOAC I)

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Florian Härtig ◽  
Andreas Peter ◽  
Charlotte Spencer ◽  
Matthias Ebner ◽  
Christine S Zürn ◽  
...  
Keyword(s):  
Vitamin K ◽  
Point Of Care ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Rapid Assessment ◽  
Plasma Concentrations ◽  
Vitamin K Antagonist ◽  
Point Of Care Testing ◽  
Blood Samples ◽  
First Time

Introduction: Non-vitamin K antagonist oral anticoagulants (NOAC) are increasingly replacing vitamin K antagonists for prevention of thromboembolism in atrial fibrillation (AF) and venous thrombosis. Ischemic stroke rate in NOAC-treated AF-patients is 1-2% per year. Subsequently, stroke physicians face a growing number of NOAC-treated patients with acute stroke. Rapid assessment of coagulation in NOAC-treated patients is vital prior to thrombolysis, but existing point-of-care testing (POCT) is suboptimal. For the first time we evaluate NOAC-specific POCT. Hypothesis: Ecarin clotting time (ECT)- and anti-Xa activity-POCT accurately predict plasma concentrations of dabigatran and apixaban/edoxaban/rivaroxaban. Methods: 80 patients receiving first NOAC-dose and 80 already on NOAC-treatment will be enrolled (N=40 for each NOAC). Subjects receiving other anticoagulants will be excluded. 6 blood samples will be collected from each patient: before drug intake, 30min, 1, 2, and 8h after intake, and before next dose. NOAC-concentrations will be measured by mass spectrometry. Results (preliminary): Until now 138 blood samples of 23 dabigatran-treated patients were analyzed. Dabigatran-concentrations ranged from 0-371ng/mL. ECT-POCT ranged from 20-219s. Pearson’s correlation coefficient showed strong correlation for ECT-POCT and dabigatran-concentrations (r=0.94, p<0.001). Dabigatran-concentrations >50ng/mL (threshold for thrombolysis according to expert recommendation) were detected by ECT-POCT (>50s) with 100% sensitivity and 82% specificity. Baseline-samples not containing any dabigatran yielded normal ECT-POCT. Conclusions: This is the first study evaluating NOAC-specific POCT. Preliminary results show excellent correlation for ECT-POCT and dabigatran; relevant dabigatran-concentrations were detected in 100%. More pioneering results on NOAC-specific POCT will be presented.

Accuracy assessment of consecutive test strip lots for whole blood INR point-of-care instruments: clarifying the role of frozen plasma pools

2019 ◽  
Vol 57 (9) ◽  
pp. 1349-1357 ◽  
Author(s):  
Antonius M.H.P. van den Besselaar ◽  
Charmane F. Abdoel ◽  
Claudia J.J. van Rijn ◽  
Felix J.M. van der Meer ◽  
Christa M. Cobbaert
Keyword(s):  
Whole Blood ◽  
Accuracy Assessment ◽  
Test Strip ◽  
Positive Trend ◽  
Accuracy Evaluation ◽  
Blood Samples ◽  
Test Strips ◽  
International Standard ◽  
Coaguchek Xs ◽  
Frozen Plasma

Abstract Background In the Netherlands, each new lot of test strips for the CoaguChek XS is validated by a group of collaborating centers. The purpose of this study was to assess the accuracy of the international normalized ratio (INR) measured with consecutive test strip lots and the suitability of frozen plasma pools for accuracy evaluation. Methods Each year, a particular lot of CoaguChek XS test strips is used as reference lot. The reference lots have been validated with the International Standard for thromboplastin rTF/09, yielding a mathematical relationship (R1) between reference lot INR and International Standard INR. New lots are compared to the reference lot using patients’ capillary blood samples, yielding a relationship (R2) between the new lot INR and the reference lot INR. INRs of the blood samples were within the 1.5–4.5 interval. In parallel, three frozen plasmas pools are analyzed with the test strips. The distance of each plasma point to the line of relationship R2 was assessed. Results Fifty-four test strip lots have been evaluated during 3 years (2014–2016). Mean INR differences between test strip lot and International Standard rTF/09 varied between −0.14 and +0.20 (−4% and +8%, respectively). A positive trend with strip lot sequence number was observed (p<0.001). In several cases, the distance of the frozen plasmas to the whole blood relationship (R2) was greater than the critical value for commutability. Conclusions Using whole blood, all evaluated test strip lots met the analytical bias criterion of ±10%. Frozen plasma pools behave differently compared to whole blood and are not suitable for assessing absolute accuracy of new CoaguChek XS test strips.

Abstract 20: Specific Point-of-care Testing of Coagulation in Patients Treated with Non-vitamin K Antagonist Oral Anticoagulants Part I (SPOCT-NOAC I)

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Florian J Härtig ◽  
Andreas Peter ◽  
Charlotte Spencer ◽  
Matthias Ebner ◽  
Christine Meyer-Zuern ◽  
...  
Keyword(s):  
Vitamin K ◽  
Whole Blood ◽  
Point Of Care ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Rapid Assessment ◽  
Plasma Concentrations ◽  
Vitamin K Antagonist ◽  
Point Of Care Testing ◽  
Blood Samples

Introduction: Non-vitamin K antagonist oral anticoagulants (NOAC) are increasingly replacing vitamin K antagonists for prevention of thromboembolism in atrial fibrillation (AF). Despite treatment, stroke rate in NOAC-treated AF-patients remains 1-2% per year. Subsequently, stroke physicians face a growing number of NOAC-treated patients with acute stroke. Rapid assessment of coagulation in NOAC-treated patients is vital prior to thrombolysis or reversal therapy, but existing point-of-care testing (POCT) is suboptimal. For the first time we evaluate NOAC-specific POCT. Hypothesis: Ecarin clotting time (ECT)- and anti-Xa activity (ENOX)-POCT predict plasma concentrations of dabigatran and apixaban/edoxaban/rivaroxaban. Methods: 80 patients receiving first NOAC-dose and 80 already on NOAC-treatment are enrolled in the SPOCT-NOAC I trial (N=40 for each NOAC). Subjects receiving other anticoagulants are excluded. Six blood samples are collected from each patient: before drug intake, 30min, 1, 2, and 8h after intake, and before next dose. NOAC-concentrations are measured by mass spectrometry. Results: 240 blood samples of 40 dabigatran-treated patients were analyzed. Dabigatran-concentrations ranged from 0-274ng/mL. ECT-POCT ranged from 20-196s. Pearson’s correlation coefficient showed strong correlation between ECT-POCT and dabigatran-concentrations (r=0.87). Performance was improved through the use of citrated in place of non-citrated whole blood (r=0.93). Dabigatran-concentrations >50ng/mL (threshold for thrombolysis according to expert recommendation) were detected by ECT-POCT >50s with 98% sensitivity and 79% specificity. Baseline-samples not containing any dabigatran yielded normal ECT values. Conclusions: This is the first study evaluating NOAC-specific POCT. Final results in the dabigatran group of SPOCT-NOAC show excellent correlation between ECT-POCT and dabigatran plasma concentrations; performance of ECT-POCT is even increased through the use of citrated whole blood. Relevant dabigatran-concentrations are detected with excellent sensitivity and specificity. In addition to ECT-POCT, we will present data on ENOX-POCT from apixaban-, edoxaban- and rivaroxaban-treated patients.

scholarly journals Comparison of Left Atrial Appendage Occlusion versus Non-Vitamin-K Antagonist Oral Anticoagulation in High-Risk Atrial Fibrillation: An Update

2021 ◽  
Vol 8 (6) ◽  
pp. 69
Author(s):  
Shaojie Chen ◽  
K. R. Julian Chun ◽  
Zhiyu Ling ◽  
Shaowen Liu ◽  
Lin Zhu ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Ischemic Stroke ◽  
High Risk ◽  
Vitamin K ◽  
Major Bleeding ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Vitamin K Antagonists ◽  
Left Atrial Appendage Occlusion ◽  
The Mean

Transcatheter left atrial appendage occlusion (LAAO) is non-inferior to vitamin K antagonists (VKAs) in preventing thromboembolic events in atrial fibrillation (AF). Non-vitamin K antagonists (NOACs) have an improved safety profile over VKAs; however, evidence regarding their effect on cardiovascular and neurological outcomes relative to LAAO is limited. Up-to-date randomized trials or propensity-score-matched data comparing LAAO vs. NOACs in high-risk patients with AF were pooled in our study. A total of 2849 AF patients (LAAO: 1368, NOACs: 1481, mean age: 75 ± 7.5 yrs, 63.5% male) were enrolled. The mean CHA2DS2-VASc score was 4.3 ± 1.7, and the mean HAS-BLED score was 3.4 ± 1.2. The baseline characteristics were comparable between the two groups. In the LAAO group, the success rate of device implantation was 98.8%. During a mean follow-up of 2 years, as compared with NOACs, LAAO was associated with a significant reduction of ISTH major bleeding (p = 0.0002). There were no significant differences in terms of ischemic stroke (p = 0.61), ischemic stroke/thromboembolism (p = 0.63), ISTH major and clinically relevant minor bleeding (p = 0.73), cardiovascular death (p = 0.63), and all-cause mortality (p = 0.71). There was a trend toward reduction of combined major cardiovascular and neurological endpoints in the LAAO group (OR: 0.84, 95% CI: 0.64–1.11, p = 0.12). In conclusion, for high-risk AF patients, LAAO is associated with a significant reduction of ISTH major bleeding without increased ischemic events, as compared to “contemporary NOACs”. The present data show the superior role of LAAO over NOACs among high-risk AF patients in terms of reduction of major bleeding; however, more randomized controlled trials are warranted.

Comparative study of i-SENS glucometers in neonates using capillary blood samples

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ha Nui Kim ◽  
Soo-Young Yoon
Keyword(s):  
Reference Values ◽  
Point Of Care ◽  
Evaluation Process ◽  
Capillary Blood ◽  
Performance Criteria ◽  
Accuracy Evaluation ◽  
Blood Samples ◽  
Average Reference ◽  
Error Grid ◽  
Accuracy Performance

Abstract Objectives The accuracy of point-of-care blood glucometers in the detection and evaluation of neonatal hypoglycemia is a concern. This study compared the performance of three i-SENS glucometers with that of the YSI 2300 STAT Plus Analyzer, which was used as a reference. Methods The leftover neonatal capillary blood samples of 319 patients were used in this study. The evaluation process and accuracy performance criteria were based on the International Organization for Standardization 15197:2013 guidelines. The evaluation involved three i-SENS glucometers (BAROzen H Expert plus, CareSens PRO, and CareSens H Beat) and the ACCU-CHEK® Inform II glucometer. Results The accuracy evaluation yielded acceptable results as follows: a) 100 and 100% for BAROzen H Expert plus; 99.8 and 100% for CareSens PRO; 98.7%, and 97.2% for CareSens H Beat glucometers were within the range of ±0.8 mmol/L (15 mg/dL) and ±15% of the average reference values at glucose concentrations <5.55 mmol/L (100 mg/dL) and ≥5.55 mmol/L (100 mg/dL), respectively, and b) all estimated glucose values (100%) were within the zones A and B of Consensus Error Grid for all three i-SENS glucometers. There was good correlation between the glucose values estimated by the glucometers and the reference values (R>0.990). Conclusions This study demonstrated that i-SENS glucometers exhibit acceptable performance and can be used as effective point-of-care devices in neonates.

Changes Of Coagulation Activation Parameters After Discontinuation Of VTE Treatment With Vitamin-K Antagonists, Apixaban, Rivaroxaban Or Dabigatran and Impact On Clinical Outcome After 12 Months

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3647-3647
Author(s):  
Sebastian Werth ◽  
Christina Köhler ◽  
Siegmund Gehrisch ◽  
Thoralf Stange ◽  
Jan Beyer-Westendorf
Keyword(s):  
Vitamin K ◽  
Research Funding ◽  
Vitamin K Antagonists ◽  
Activation Parameters ◽  
Coagulation Activation ◽  
Predictive Values ◽  
Blood Samples ◽  
End Of Treatment ◽  
Recurrent Vte ◽  
D Dimer

Abstract Background At the end of VTE treatment, increasing D-Dimer levels after discontinuation of Vitamin-K antagonists (VKA) have been shown to indicate coagulation activation and increased risk of VTE recurrence. However, it is unknown if changes of coagulation activation parameters will be similar after discontinuation of direct oral anticoagulants (DOAC) such as apixaban, rivaroxaban and dabigatran. Furthermore, the clinical impact of these changes is still unclear. Objectives To quantify changes of coagulation activation parameters at the end of VTE treatment with VKA or DOAC and to evaluate their positive predictive value for VTE recurrence at 12 months. Patients and Methods Blood samples for coagulation tests were collected from consenting patients with proximal VTE who discontinued anticoagulation treatment at the end of apixaban, dabigatran or rivaroxaban phase-III VTE treatment trials. Furthermore, similar samples were obtained from VKA patients at the end of treatment. From all patients, samples for D-dimer (DD), prothrombin fragments (F1+2) and thrombin-antithrombin complexes (TAT) measurements were collected at the end of treatment and 4 weeks later. Samples were analysed by blinded lab personnel and statistically evaluated for differences between VKA and DOAC regarding changes between both samples as well as absolute values at 4 weeks. Finally, all patients underwent 12 months follow-up by phone calls to establish rates of recurrent VTE or death from any cause. Results Blood samples were obtained from patients discontinuing apixaban (A; n=37), dabigatran (D; n=17), rivaroxaban (R; n=9) and VKA (n=184), respectively. Absolute values and relative changes of DD, F1+2 and TAT at baseline and 4 weeks were not significantly different between VKA or the DOAC cohorts. Irrespective of the anticoagulant treatment, DD and F1+2 but not TAT demonstrated a significant increase between baseline and week 4 (figure 1). At 12 months, 18 patients (7.3%) had recurrent VTE and 2 patients (0.8%) were dead. Regarding clinical outcomes at 12 months, the negative predictive values (NPV) of DD, F1+2 and TAT were highest for patients after VKA treatment (at least 0.93) and systematically lower for DOAC patients (ranging between 0.86 and 0.91). In contrast, positive predictive values (PPV) of DD, F1+2 and TAT were systematically higher in DOAC patients (0.19 to 0.43) compared to VKA patients (0.03-0.16) with highest values for TAT-complexes > 200% baseline (PPV VKA 0.14; PPV DOAC 0.43), which was also seen in logistic regression analysis with a significant risk increase for VTE/death (Odds ratio for TAT > 200% baseline 5.0; p=0.006). None of the other parameters showed a correlation to the risk of recurrent VTE or death. Conclusion Changes of DD, F1+2 and TAT values post treatment are not different between patients discontinuing VTE treatment with VKA, apixaban, dabigatran or rivaroxaban. NPV of DD, F1+2 and TAT for recurrent VTE/death are higher in VKA than DOAC patients, while PPV are higher in DOAC patients. At 4 weeks, a TAT increase over 200% of baseline value was found to be associated with a 5-fold increase of recurrent VTE or death with a PPV of 0.14 for VKA patients and of 0.43 for DOAC patients. Disclosures: Werth: Bayer Healthcare: Honoraria. Beyer-Westendorf:Bayer Healthcare: Research Funding, Speakers Bureau; Boehringer Ingelheim: Research Funding, Speakers Bureau; Pfizer: Research Funding, Speakers Bureau.

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