Multicentric Prospective Validation of a Universal Test to Quantify Apixaban, Rivaroxaban, Danaparoid and Fondaparinux Levels

Study Overview
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Brief Summary
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Despite their usefulness in perioperative and acute care settings, factor-Xa inhibitors-specific assays are scarcely available, contrary to heparin anti-Xa assay. The investigators aimed at assessing whether the widely used heparin anti-Xa assay can quantify the apixaban, rivaroxaban, fondaparinux and danaparoid levels.

Official Title
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Multicentric Prospective Validation of a Universal Test to Quantify Apixaban, Rivaroxaban, Danaparoid and Fondaparinux Levels

Conditions
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Anticoagulation, Venous Thromboembolism, Atrial Fibrillation

Intervention / Treatment
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* Diagnostic Test: Estimated anticoagulant level (conversion factor x anti-Xa activity)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria : Blood sample from adult patients treated with apixaban or rivaroxaban or danaparoid or fondaparinux Exclusion Criteria : Patients treated with unfractionated heparin or low molecular weight heparin

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Derivation cohort<br>In the derivation cohort, we will determined the conversion factor linking apixaban, rivaroxaban, fondaparinux, or danaparoid measured level, on the one hand, and heparin anti-Xa activity, on the other hand. | Diagnostic Test: Estimated anticoagulant level (conversion factor x anti-Xa activity)<br>* Estimated anticoagulant level (conversion factor x anti-Xa activity)<br>|
| Validation cohort<br>In the validation cohort, for each tested anticoagulant, we will used the conversion factor determined in the derivation cohort to infer the estimated level of anticoagulant from heparin anti-Xa activity: estimated anticoagulant level = conversion factor for this anticoagulant × heparin anti-Xa activity The agreement between measured and estimated levels of each factor-Xa inhibitor will be assessed. | Diagnostic Test: Estimated anticoagulant level (conversion factor x anti-Xa activity)<br>* Estimated anticoagulant level (conversion factor x anti-Xa activity)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Agreement between measured and estimated levels of each factor-Xa inhibitor | An estimated anticoagulant level between 80 and 120% of the value obtained by the reference method (specific assay) will be deemed clinically acceptable, i.e. the patient's management would have been the same. | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of the performance of the estimated anticoagulant level method by an inter-laboratory comparison program |  | 2 years | 
| Cost comparison (estimated anticoagulant level method versus specific dosage) |  | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Anticoagulants (MeSH), Blood Coagulation Tests (MeSH), Drug monitoring (MeSH), Factor Xa Inhibitors (MeSH), Heparin (MeSH)