VPB1120 - Comparison between the DOAC Dipstick test in urine and chromogenic substrate methods in plasma on patients treated with direct oral anticoagulants.

Tuesday, July 12, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Co-Author(s)

Loula Papageorgiou, MD, MSc

Consultant Hematologist
Hematology and Thrombosis Center, Tenon University Hospital, Sorbonne University Recent affiliation : Interdisciplinary Cancer Course Department (DIOPP),Gustave Roussy
PARIS, Ile-de-France, France

Presenting Author(s)

JH

Job Harenberg

Professor
Faculty of Medicine Mannheim and Clinic Mannheim
Heidelberg, Baden-Wurttemberg, Germany

Co-Author(s)

SA

Sanny Auge

Specialist nurse
Hematology and Thrombosis Center, Tenon University Hospital
Paris, Ile-de-France, France
LT

Laetitia Tredler

Specialist nurse
Hematology and Thrombosis Center, Tenon University Hospital
PARIS, Ile-de-France, France
IE

Ismail Elalamy

Director of Hematology Department of Thrombosis Center, Tenon University Hospital
Medicine Sorbonne University
Paris, Ile-de-France, France
GG

Grigoris Gerotziafas

Associate Professor
Head of the research group ''Cancer Hemostasis and Angiogenesis'', INSERM UMRS-938 (Centre de Recherche Saint Antoine)
Paris, Ile-de-France, France

Background: The efficacy and safety of direct oral anticoagulants (DOACs) in patients with venous thromboembolism (VTE) is closely related to DOAC presence in plasma. The medical device DOAC Dipstick was developed based on the rationale that DOACs are excreted, hence easily detected, in urine.

Aims: The aim was to compare this tool to a standard chromogenic-substrate plasma assay.

Methods: A prospective observational cohort study was performed. Patients on DOACs were routinely assessed using STA®-Liquid Anti-Xa and STA®-Liquid Anti-IIa reagents (Diagnostica Stago, Asnieres, France). DOAC Dipstick test was performed on patients’ urine samples and visual evaluation of pads’ colors for oral direct factor -Xa (DXI) and thrombin inhibitors (DTI) by two trained staff members according to the instructions for use. Threshold plasma values for plasma concentrations inhibitors were set at >30 ng/ml and >20 ng/ml.

Results: The study assessed 124 patients (rivaroxaban n: 77, apixaban: 44, dabigatran n=2) recruited from the anticoagulation clinic of a tertiary hospital center. Due to a low number of patients in the DTI group, statistical analysis was performed on the DXI group. At >30 ng/ml threshold sensitivity and accuracy were at 98%, a positive predictive value (PPV) at 89%, specificity at 13% and a negative predictive value (NPV) at 50%. At a >20 ng/ml plasma threshold sensitivity and accuracy were at 97% and PPV was 100%. In absence of false positive and false negative values, specificity and NPV could not be determined. There were no differences between observers (kappa index 1.0).

Conclusion(s): Sensitivity and accuracy at >20 ng/ml may be higher compared to >30 ng/ml for rivaroxaban and apixaban. Higher numbers of negative DOAC Dipstick results are needed to specify plasma DOAC threshold values for DXI and DTI.