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Point-of-care testing (POCT) for D-dimer is an alternative to -laboratory testing for the exclusion of venous thromboembolism (VTE). This critical review by the "CEC et biologie délocalisée" working group of the "Société Française de Thrombose et d'Hémostase" (French Society of -Thrombosis and Haemostasis) aims to present the characteristics of six POCT D-dimer assays available in France in 2023. The article highlights the need to define VTE -exclusion thresholds specific to each technique and validated by clinical studies. There is insufficient data to validate the use of cut off suggested by manufacturers, and age-adjusted thresholds. The article discusses the role of laboratories in justifying and prescribing POCT D-dimer, according to objective criteria, such as the availability and turnaround time of classical laboratory tests. They should also encourage rational prescribing, limited to patients with low risk of venous thromboembolism, following an assessment of clinical probability according to national and international guidelines.
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INTRODUCTION: In Bordeaux University Hospital, neurologists are required to prescribe thrombolysis using telemedicine (telethrombolysis) for anticoagulated stroke patients admitted in peripheral centers in the Nouvelle-Aquitaine region. However, due to the bleeding risk, the maximum concentration of DOAC authorizing thrombolysis is 30, 50 or 100 ng/mL (depending on the sources and the patient-specific benefit-risk ratio). Most of the time, specific assays of Direct Oral Anticoagulants (DOACs) are not available in these peripheral centers. We therefore studied an alternative test: the Unfractionated Heparin (UFH) anti-Xa activity which is available in most laboratories and could be used to estimate the DOAC concentration. METHODS: Five centers were included in our study: three centers using the Liquid Anti-Xa HemosIL® Werfen reagent and two centers using the STA-Liquid Anti-Xa® Stago reagent. For each reagent, we established correlation curves between DOAC and UFH anti-Xa activities and determinated UFH cut-offs for the thresholds of 30, 50 and 100 ng/mL respectively. RESULTS: A total of 1455 plasmas were tested. There is an excellent correlation between DOAC and UFH anti-Xa activities using a third-degree modeling curve, independently the reagent used. However, a significant inter-reagent variability is observed concerning the obtained cut-offs. CONCLUSION: Our study makes unsuitable the use of a universal cut-off. In opposition to recommendations made by other publications, the UFH cut-offs must be adapted to the reagent used locally by the laboratory, and to the considered DOAC.
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Heparina , Rivaroxabán , Humanos , Rivaroxabán/uso terapéutico , Anticoagulantes/farmacología , Anticoagulantes/uso terapéutico , Inhibidores del Factor Xa/uso terapéutico , Pruebas de Coagulación Sanguínea , Piridonas/uso terapéutico , Heparina de Bajo-Peso-MolecularRESUMEN
BACKGROUND: The presence of dextran sulfate (DS) in reagents and the type of blood collection tube (citrate/citrated-theophylline-adenosine-dipyridamole [CTAD]) can lead to discrepancies between unfractionated heparin (UFH) anti-Xa levels. OBJECTIVES: To evaluate the extent of the effect (1) of different reagents containing or not containing DS and (2) of the blood collection tubes, on UFH anti-Xa levels, in various clinical situations (NCT04700670). METHODS: We prospectively included patients from eight centers: group (G)1, cardiopulmonary bypass (CPB) after heparin neutralization (n = 39); G2, cardiothoracic intensive care unit (ICU) after CPB (n = 35); G3, medical ICU (n = 53); G4, other medical inpatients (n = 38). Blood was collected into citrated and CTAD tubes. Chromogenic anti-Xa assays were centrally performed, using seven reagent/analyzer combinations including two without DS. The association between anti-Xa levels and covariates was tested using a linear mixed-effects model. RESULTS: We analyzed 4,546 anti-Xa values from 165 patients. Median anti-Xa levels were systematically higher with reagents containing DS, whatever the patient group, with the greatest effect observed in G1 (0.32 vs. 0.05 IU/mL). Anti-Xa levels were slightly higher in CTAD than in citrate samples, irrespective of the assay. The model showed: (1) a significant dextran-patient group interaction (p < 0.0001), the effect of DS on anti-Xa levels varying from 30.9% in G4 to 296% in G1, and (2) a significant effect of CTAD, varying between patient groups (p = 0.0302). CONCLUSION: The variability of anti-Xa levels with a great overestimation of the values, using a reagent containing DS, can lead to different treatment decisions, especially after heparin neutralization by protamine. Clinical consequences of these differences remain to be demonstrated.
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Anticoagulantes , Heparina , Humanos , Heparina/efectos adversos , Anticoagulantes/uso terapéutico , Estudios Prospectivos , Enfermedad Crítica , Heparina de Bajo-Peso-Molecular , Ácido Cítrico , Citratos/uso terapéutico , Inhibidores del Factor Xa , Tiempo de Tromboplastina ParcialRESUMEN
ACT (Activated Clotting Time) is a point of care test (POCT) on whole blood, used to monitor the heparinization of patients in the operating room in cardiac surgery (ExtraCorporeal Circulation ECC) and in interventional cardiology (TAVI, AF ablation). The ACT is concerned both by the ISO 22 870 standard and French regulations regarding POCT. We performed an important work at the Bordeaux CHU on its accreditation, by rationalizing and making the park uniform (11 HemochronTM Signature Elite), standardizing the training and the habilitation of operators in medical units, introducing periodic quality controls, centralizing in the laboratory the management of the devices and reagents and by connecting it to the laboratory's computer system (Middleware, SIL et expert softwares). One year after, we have some positive feedbacks with only a few technical problems and with only few remarks raised during internal audits.
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Procedimientos Quirúrgicos Cardíacos , Heparina , Humanos , Heparina/uso terapéutico , Pruebas en el Punto de Atención , Acreditación , Hospitales , Tiempo de Coagulación de la Sangre TotalRESUMEN
INTRODUCTION: The use of direct oral anticoagulants (DOAC) is increasing. Specific concentrations are available and have been proven to be reliable and reproducible in optimising patient care. This retrospective, monocentric study aimed to describe the indications and consequences of monitoring DOAC plasma levels on patient care. MATERIALS AND METHODS: We collected data of patients hospitalised at the Bordeaux University Hospital between January 2017 and December 2018. These included demographics, indications, type, dose of DOAC, standard coagulation tests, creatinine clearance and DOAC plasma concentration using specifically calibrated rivaroxaban and apixaban anti-Xa and dabigatran anti-IIa assays. The date of last DOAC intake, the time between intake and plasma level measurement were also collected and analysed. RESULTS: A total of 2197 DOAC assays in 1488 patients were obtained in various clinical situations: urgent or elective procedures, context of acute renal failure, suspicion or occurrence of ischemic strokes, intra-cranial and other bleeding sites. Interpretation of these assays led physicians to maintain, postpone or cancel invasive and high haemorrhagic risk procedures in 757, 261 and 56 cases respectively. The remaining 1123 assays were associated with no significant modification of patient care. DOAC plasma concentration was ≤30 ng ml-1 (sensitivity 85.4%, specificity 73.6%, positive predictive value 71.1%, negative predictive value 86.7%, AUC 0.81) after a last intake of at least 2 days. CONCLUSIONS: Our study is, to date, the largest report of real-life measurement of specific DOAC plasma level at a single institution. Patient care was not modified in more than half of the assays.