{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,13]],"date-time":"2025-11-13T23:52:10Z","timestamp":1763077930854,"version":"3.45.0"},"reference-count":33,"publisher":"Georg Thieme Verlag KG","license":[{"start":{"date-parts":[[2025,11,13]],"date-time":"2025-11-13T00:00:00Z","timestamp":1762992000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Semin Thromb Hemost"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Direct oral anticoagulants (DOACs), including direct thrombin inhibitors (dabigatran) and direct factor Xa inhibitors (apixaban, rivaroxaban, edoxaban), have transformed anticoagulant management in recent years due to their predictable pharmacodynamics, rapid onset of action, and fixed dosing without the need for routine laboratory monitoring. Unfractionated heparin (UFH) remains the anticoagulant of choice for patients who are acutely unwell and treated in intensive care units due to its short half-life, reversibility, ease of dose titration, and nonrenal dependent excretion. It is therefore not uncommon for an individual's anticoagulation management to require rapid changing from DOAC to UFH. Due to UFH's complex pharmacokinetics, including nonspecific binding to acute phase proteins and dose-dependent clearance, careful laboratory monitoring, generally with activated partial thromboplastin time (APTT) or anti-factor Xa (anti-Xa) activity, is necessary. When transitioning from a DOAC to UFH, overlapping pharmacologic effects can significantly interfere with coagulation assays, particularly if residual DOAC levels persist at the time UFH is initiated. DOACs can prolong the APTT and elevate anti-Xa activity, leading to overestimation of UFH activity, inappropriate dose adjustments, and increased risk of bleeding or thromboembolic events. Here, we examine the laboratory implications of transitioning from DOAC therapy to UFH, with a focus on the performance and interpretation of APTT and anti-Xa assays in the presence of residual DOAC levels and how to overcome the interference of DOAC in UFH monitoring. We suggest an algorithm to follow during this transition.<\/jats:p>","DOI":"10.1055\/a-2734-2293","type":"journal-article","created":{"date-parts":[[2025,11,13]],"date-time":"2025-11-13T23:48:15Z","timestamp":1763077695000},"source":"Crossref","is-referenced-by-count":0,"title":["Transitioning of Patients from Direct-Acting Oral Anticoagulant to Heparin: Impact on Laboratory Testing"],"prefix":"10.1055","author":[{"given":"Deepa J.","family":"Arachchillage","sequence":"additional","affiliation":[{"name":"Department of Immunology and Inflammation, Centre for Haematology, Imperial College London, United Kingdom"},{"name":"Department of Haematology, Imperial College Healthcare NHS Trust, London, United Kingdom"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Saravanan","family":"Vinayagam","sequence":"additional","affiliation":[{"name":"North West London Pathology, Imperial College Healthcare NHS Trust, London, United Kingdom"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Annie","family":"Parsons","sequence":"additional","affiliation":[{"name":"North West London Pathology, Imperial College Healthcare NHS Trust, London, United Kingdom"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nilanthi","family":"Karawitage","sequence":"additional","affiliation":[{"name":"North West London Pathology, Imperial College Healthcare NHS Trust, London, United Kingdom"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mike","family":"Laffan","sequence":"additional","affiliation":[{"name":"Department of Immunology and Inflammation, Centre for Haematology, Imperial College London, United Kingdom"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"194","published-online":{"date-parts":[[2025,11,13]]},"reference":[{"issue":"9921","key":"ref1","doi-asserted-by":"crossref","first-page":"955","DOI":"10.1016\/S0140-6736(13)62343-0","article-title":"Comparison of 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Macedo","year":"2018","journal-title":"Ann Pharmacother"},{"issue":"09","key":"ref26","doi-asserted-by":"crossref","first-page":"880","DOI":"10.1002\/phar.2444","article-title":"The relationship between the initial anti-factor Xa measurement and the duration of direct oral anticoagulant influence in patients transitioning to heparin","volume":"40","author":"M D Plum","year":"2020","journal-title":"Pharmacotherapy"},{"issue":"06","key":"ref27","doi-asserted-by":"crossref","first-page":"2060","DOI":"10.1016\/j.jtha.2025.02.026","article-title":"How to deal with interference on heparin anti-Xa activity caused by oral factor FXa inhibitors: communication from the ISTH SSC Subcommittee on Control of Anticoagulation","volume":"23","author":"N Gendron","year":"2025","journal-title":"J Thromb Haemost"},{"issue":"05","key":"ref28","doi-asserted-by":"crossref","first-page":"953","DOI":"10.1111\/ijlh.14321","article-title":"DOAC-remove to counteract the interference of anti-Xa oral anticoagulants on the monitoring of heparin","volume":"46","author":"S Melicine","year":"2024","journal-title":"Int J Lab Hematol"},{"issue":"07","key":"ref29","doi-asserted-by":"crossref","first-page":"777","DOI":"10.1177\/1060028015578451","article-title":"Heparin-calibrated chromogenic anti-Xa activity measurements in patients receiving rivaroxaban: can this test be used to quantify drug level?","volume":"49","author":"R C Gosselin","year":"2015","journal-title":"Ann Pharmacother"},{"key":"ref30","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.thromres.2022.05.005","article-title":"Low molecular weight heparin anti-Xa assays can identify patients with clinically important apixaban and rivaroxaban drug levels","volume":"215","author":"S Mithoowani","year":"2022","journal-title":"Thromb Res"},{"issue":"07","key":"ref31","doi-asserted-by":"crossref","first-page":"1653","DOI":"10.1111\/jth.14806","article-title":"Anti-factor IIa (FIIa) heparin assay for patients on direct factor Xa (FXa) inhibitors","volume":"18","author":"M Stuart","year":"2020","journal-title":"J Thromb Haemost"},{"issue":"03","key":"ref32","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1111\/bjh.16091","article-title":"A diagnostic solution for haemostasis laboratories for patients taking direct oral anticoagulants using DOAC-Remove","volume":"187","author":"S Cox-Morton","year":"2019","journal-title":"Br J Haematol"},{"issue":"18","key":"ref33","doi-asserted-by":"crossref","first-page":"5955","DOI":"10.3390\/jcm12185955","article-title":"Management of patients treated with direct oral anticoagulants in clinical practice and challenging scenarios","volume":"12","author":"F Luc\u00e0","year":"2023","journal-title":"J Clin Med"}],"container-title":["Seminars in Thrombosis and 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