Chromogenic anti-Xa test: the ratio between heparin activity units and concentration of apixaban and rivaroxaban

Author:

Titaeva E. V.1ORCID,Dobrovolsky A. B.1ORCID

Affiliation:

1. National Medical Research Center of Cardiology

Abstract

Introduction. The direct oral anticoagulants (DOC) therapy does not require alaboratory control; however, it may be required to determine the anticoagulationlevel to choose a treatment strategy if alarge bleeding is developing or emergency surgery is needed.The objective of this experimental study was to investigate the relationship between the residual factor Xa (FXa) activity, anti-Xa activity units oflow molecular weight heparins (LMWH), and the apixaban and rivaroxaban plasma concentrations in a chromogenic anti-Xa assay.Material and methods. Concentrated DOC solutions were prepared by extracting apixaban and rivaroxaban from crushed tablets using methanol and dimethyl sulfoxide, respectively. The resulting solutions were added to the donor plasma pool until final inhibitor concentrations are achieved in the range from 10 to 100 ng/ml plasma. Anti-Xa activity was determined using an STA-compact analyser and the Liquid anti-Xa reagent kit, an analysis protocol, and calibrators designed to control the LMWH therapy. The effect on the thrombin formation dynamics was investigated using the thrombin generation test (TGT) and the PPR reagent as a trigger (final concentrations of tissue factor are 5 pM, and those of phospholipids are 4 μM). TGT curves were analysed using the Thrombinoscope program.Results. It was shown that in the anti-Xa activity test version designed to control the LMWH therapy, there is a high correlation (R2 > 0.98) between thelogarithm of the residual factor Xa activity and the content of apixaban and rivaroxaban in the range from 10 to 80 ng/ml. Rivaroxaban shows about 1.5 times more anti-Xa activity than apixaban at equal concentrations. It was also shown that apixaban and rivaroxaban at doses equal both in concentration and in anti-Xa activity differ in their effect on the thrombin formation dynamics and thrombin inactivation in the TGT.Conclusion. In the LMWH anti-Xa activity test version, the measured range of apixaban and rivaroxaban includes 30 ng/ml and 50 ng/ ml concentrations taken as “cut-off points” to determine the treatment tactics in emergency cases. However, thelack of certified DOC calibratorslimits the use of this test in clinical practice.

Publisher

Remedium, Ltd.

Reference25 articles.

Cited by 1 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3