Evaluation of the DOAC-Stop Procedure by LC-MS/MS Assays for Determining the Residual Activity of Dabigatran, Rivaroxaban, and Apixaban

Abstract

The effect of direct oral anticoagulants (DOACs) on laboratory tests dependent on the production of their targets, factor IIa and factor Xa (FXa), is a well-known problem and can cause both false positive and negative results. Therefore, the correct interpretation of tests performed in patients receiving DOACs is necessary to avoid misclassification and subsequent clinical consequences. However, even with significant experience, there are situations where it is not possible to assess the influence of some methods. Particularly important is the situation in the diagnosis of lupus anticoagulants using the dilute Russell viper venom timetest, which is based on direct FXa activation. A very promising solution to this situation is offered by the DOAC laboratory balancing procedure DOAC-Stop. For evaluating the effectiveness of this procedure, 60 (20 apixaban, 20 dabigatran, and 20 rivaroxaban) patients treated with DOACs were enrolled. All patient samples were analyzed for the presence of individual DOAC types and subsequently subjected to the DOAC-Stop procedure.We evaluated its effectiveness by our own high-performance liquid chromatography-coupled tandem mass spectrometrymethod, which simultaneously sets all high-sensitivity DOACs. Unlike coagulation tests based on the determination of the residual effects of DOACs on target enzymes, which is complicated by extensive interindividual variation, this methodology is highly specific and sensitive.The DOAC-Stop procedure eliminated dabigatran from 99.5%, rivaroxaban from 97.9%, and apixaban from 97.1% of participants in our group. Residual amounts did not exceed 2.7 ng/mL for dabigatran, 10.9 ng/mL for rivaroxaban, or 13.03 ng/mL for apixaban, which are safe values that do not affect either screening or special coagulation tests.

The effect of DOACs on laboratory tests and their removal by activated carbon to limit interference in functional assays

“…A particular version in mini‐tablet form was developed for more convenient application to 1ml volumes of test plasmas (DOAC Stop™, Haematex). Several studies have now been published which confirm that it and similar products (DOAC Remove) may be useful in blood coagulation testing labs to eliminate the in vitro effect of DOACs 6‐16 ; especially in testing for lupus anticoagulant.…”

“…Slavik et al 15 investigated the degree of removal of DOACs in 60 patient plasmas by DOAC Stop™ using a highly sensitive HPLC/MS method. Residual amounts did not exceed 2.7 ng/mL for dabigatran, 10.9 ng/mL for rivaroxaban and 13.0 ng/mL for apixaban.…”

Escaping the catch 22 of lupus anticoagulant testing

“…DOAC-STOP can be added to samples before testing and it does not affect dRVVT in patients who do not receive DOACs 21. When using DOAC-STOP, the results from patients in DOACs can be interpreted 15 19 22–24. A simple charcoal product (DOAC-Remove, 5-Diagnostics, Basel, Switzerland) may offer an alternative solution to eliminate anticoagulation effects before LAC testing 16 25.…”

The Relationship between the Initial Anti‐factor Xa Measurement and the Duration of Direct Oral Anticoagulant Influence in Patients Transitioning to Heparin

“…There are available materials, such as DOAC Stop, which are marketed as removing DOACs. However, there are studies suggesting that not all of the DOAC is removed 22 and that there can be residual inhibition from the DOAC in the anti-Xa assay. 23 The method presented herein allows for using the aPTT to ensure that the heparin has been removed.…”