{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,26]],"date-time":"2025-09-26T13:10:02Z","timestamp":1758892202586,"version":"3.44.0"},"reference-count":19,"publisher":"Danish Medical Association","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Dan Med J"],"abstract":"<jats:p>INTRODUCTION. Patients on warfarin are normally required to interrupt treatment for a fixed number of days prior to an invasive procedure. This study aimed to investigate the potential influence of the warfarin maintenance dose and the initial international normalised ratio (INR) level on the duration of the break required to achieve the planned target INR.\n\nMETHODS. A total of 120 patients on self-managed warfarin treatment measured INR once daily for five days before the intervention and were guided by the anticoagulation clinic on when to discontinue warfarin. Depending on the bleeding risk of the planned intervention, the target INR on the day of the intervention was \u2264 1.4, \u2264 2.5 or \u2264 3.0.\n\nRESULTS. From day 1 to day 5 after interruption of warfarin, the INR ratio (INRdayX\/INRday0) decreased exponentially, with wide interpatient variation in the rate of decrease. Patients with a maintenance warfarin dose &lt; 25 mg\/week decreased significantly less in INR during the first day after stopping warfarin than patients who received a higher maintenance dose (9% vs 15%; p &lt; 0.04). The INR half-life after day 1 was 113 hours for patients receiving &lt; 25 mg\/week and 101 hours for patients receiving \u2265 25 mg\/week.\n\nCONCLUSIONS. The duration of pre-interventional discontinuation of warfarin can be individualised by knowing the maintenance dose, baseline INR and target INR for the planned procedure.\n\nFUNDING. None.\n\nTRIAL REGISTRATION. Quality assessment study approved by the legal department of the Capital Region of Denmark. Approval number: p-2024-15914.<\/jats:p>","DOI":"10.61409\/a01250048","type":"journal-article","created":{"date-parts":[[2025,7,2]],"date-time":"2025-07-02T02:35:07Z","timestamp":1751423707000},"page":"1-9","source":"Crossref","is-referenced-by-count":0,"title":["Discontinuation of warfarin prior to elective invasive procedures"],"prefix":"10.61409","author":[{"given":"J\u00f8rn Dalsgaard","family":"Nielsen","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thomas Steffen","family":"Hermann","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"40208","published-online":{"date-parts":[[2025,6]]},"reference":[{"key":"ref0","doi-asserted-by":"publisher","unstructured":"Shah S, Nayfeh T, Hasan B, et al. Perioperative management of vitamin K antagonists and direct oral anticoagulants. Chest. 2023;163(5):1245-1257. https:\/\/doi.org\/10.1016\/j.chest.2022.11.032","DOI":"10.1016\/j.chest.2022.11.032"},{"key":"ref1","doi-asserted-by":"publisher","unstructured":"Schulman S, Elbazi R, Zondag M, O'Donnell M. Clinical factors influencing normalization of prothrombin time after stopping warfarin: a retrospective cohort study. Thromb J. 2008;6:15. https:\/\/doi.org\/10.1186\/1477-9560-6-15","DOI":"10.1186\/1477-9560-6-15"},{"key":"ref2","doi-asserted-by":"publisher","unstructured":"Kamali F, Khan TI, King BP, et al. Contribution of age, body size, and CYP2C9 genotype to anticoagulant response to warfarin. Clin Pharmacol Ther. 2004;75(3):204-212. https:\/\/doi.org\/10.1016\/j.clpt.2003.10.001","DOI":"10.1016\/j.clpt.2003.10.001"},{"key":"ref3","doi-asserted-by":"publisher","unstructured":"Hylek EM, Regan S, Go AS, et al. Clinical predictors of prolonged delay in return of the international normalized ratio to within the therapeutic range after excessive anticoagulation with warfarin. Ann Intern Med. 2001;135(6):393-400. https:\/\/doi.org\/10.7326\/0003-4819-135-6-200109180-00008","DOI":"10.7326\/0003-4819-135-6-200109180-00008"},{"key":"ref4","doi-asserted-by":"publisher","unstructured":"Yang L, Ge W, Yu F, Zhu H. Impact of VKORC1 gene polymorphism on interindividual and interethnic warfarin dosage requirement: a systematic review and meta-analysis. Thromb Res. 2010;125(4):e159-e166. https:\/\/doi.org\/10.1016\/j.thromres.2009.10.017","DOI":"10.1016\/j.thromres.2009.10.017"},{"key":"ref5","doi-asserted-by":"publisher","unstructured":"Botton MR, Viola PP, Meireles MR, et al. Identification of environmental and genetic factors that influence warfarin time in therapeutic range. Genet Mol Biol. 2020;43(1 suppl 2):e20190025. https:\/\/doi.org\/10.1590\/1678-4685-gmb-2019-0025","DOI":"10.1590\/1678-4685-gmb-2019-0025"},{"key":"ref6","doi-asserted-by":"publisher","unstructured":"Garcia DA, Regan S, Henault LE, et al. Risk of thromboembolism with short-term interruption of warfarin therapy. Arch Intern Med. 2008;168(1):63-69. https:\/\/doi.org\/10.1001\/archinternmed.2007.23","DOI":"10.1001\/archinternmed.2007.23"},{"key":"ref7","doi-asserted-by":"publisher","unstructured":"Kuo HC, Liu FL, Chen JT, et al. Thromboembolic and bleeding risk of periprocedural bridging anticoagulation: a systematic review and meta\u2010analysis. Clin Cardiol. 2020;43(5):441-449. https:\/\/doi.org\/10.1002\/clc.23336","DOI":"10.1002\/clc.23336"},{"key":"ref8","doi-asserted-by":"publisher","unstructured":"Kovacs MJ, Wells PS, Anderson DR, et al. Postoperative low molecular weight heparin bridging treatment for patients at high risk of arterial thromboembolism (PERIOP2): double blind randomised controlled trial. BMJ. 2021;373:n1205. https:\/\/doi.org\/10.1136\/bmj.n1205","DOI":"10.1136\/bmj.n1205"},{"key":"ref9","doi-asserted-by":"publisher","unstructured":"Baron TH, Kamath PS, McBane RD. Management of antithrombotic therapy in patients undergoing invasive procedures. N Engl J Med. 2013;368(22):2113-2124. https:\/\/doi.org\/10.1056\/NEJMra1206531","DOI":"10.1056\/NEJMra1206531"},{"key":"ref10","doi-asserted-by":"publisher","unstructured":"Dunn AS, Turpie AGG. Perioperative management of patients receiving oral anticoagulants: a systematic review. Arch Intern Med. 2003;163(8):901-908. https:\/\/doi.org\/10.1001\/archinte.163.8.901","DOI":"10.1001\/archinte.163.8.901"},{"key":"ref11","doi-asserted-by":"publisher","unstructured":"Larson BJG, Zumberg MS, Kitchens CS. A feasibility study of continuing dose-reduced warfarin for invasive procedures in patients with high thromboembolic risk. Chest. 2005;127(3):922-927. https:\/\/doi.org\/10.1378\/chest.127.3.922","DOI":"10.1378\/chest.127.3.922"},{"key":"ref12","doi-asserted-by":"publisher","unstructured":"Rhodes DA, Severson EP, Hodrick JT, et al. Discontinuation of warfarin is unnecessary in total knee arthroplasty. Clin Orthop Relat Res. 2010;468(1):120-126. https:\/\/doi.org\/10.1007\/s11999-009-1128-8","DOI":"10.1007\/s11999-009-1128-8"},{"key":"ref13","doi-asserted-by":"publisher","unstructured":"Spyropoulos AC, Brohi K, Caprini J, et al. Scientific and Standardization Committee communication: guidance document on the periprocedural management of patients on chronic oral anticoagulant therapy: recommendations for standardized reporting of procedural\/surgical bleed risk and patient\u2010specific thromboembolic risk. J Thromb Haemost. 2019;17(11):1966-1972. https:\/\/doi.org\/10.1111\/jth.14598","DOI":"10.1111\/jth.14598"},{"key":"ref14","doi-asserted-by":"publisher","unstructured":"White RH, McKittrick T, Hutchinson R, Twitchell J. Temporary discontinuation of warfarin therapy: changes in the international normalized ratio. Ann Intern Med. 1995;122(1):40-42. https:\/\/doi.org\/10.7326\/0003-4819-122-1-199501010-00006","DOI":"10.7326\/0003-4819-122-1-199501010-00006"},{"key":"ref15","doi-asserted-by":"publisher","unstructured":"Liang Y, Yang G, Li H, et al. Anticoagulation decision-making before non-cardiac surgery in patients with mechanical heart valve: a retrospective study. Heliyon. 2023;9(6):e16858. https:\/\/doi.org\/10.1016\/j.heliyon.2023.e16858","DOI":"10.1016\/j.heliyon.2023.e16858"},{"key":"ref16","doi-asserted-by":"publisher","unstructured":"Schulman S, Anger\u00e5s U, Bergqvist D, et al. Definition of major bleeding in clinical investigations of antihemostatic medicinal products in surgical patients. J Thromb Haemost. 2010;8(1):202-204. https:\/\/doi.org\/10.1111\/j.1538-7836.2009.03678.x","DOI":"10.1111\/j.1538-7836.2009.03678.x"},{"key":"ref17","doi-asserted-by":"publisher","unstructured":"Kampouraki E, Wynne H, Avery P, Kamali F. Validation of an algorithm to predict decline in INR following warfarin cessation in patients undergoing invasive procedures. J Thromb Thrombolysis. 2020;49(4):630-635. https:\/\/doi.org\/10.1007\/s11239-019-02017-2","DOI":"10.1007\/s11239-019-02017-2"},{"key":"ref18","doi-asserted-by":"publisher","unstructured":"Tomita H, Kadokami T, Momii H, et al. Patient factors against stable control of warfarin therapy for Japanese non-valvular atrial fibrillation patients. Thromb Res. 2013;132(5):537-542. https:\/\/doi.org\/10.1016\/j.thromres.2013.09.003","DOI":"10.1016\/j.thromres.2013.09.003"}],"container-title":["Danish Medical Journal"],"original-title":[],"deposited":{"date-parts":[[2025,9,26]],"date-time":"2025-09-26T12:55:51Z","timestamp":1758891351000},"score":1,"resource":{"primary":{"URL":"https:\/\/ugeskriftet.dk\/dmj\/A01250048"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6]]},"references-count":19,"URL":"https:\/\/doi.org\/10.61409\/a01250048","relation":{},"ISSN":["2245-1919"],"issn-type":[{"type":"electronic","value":"2245-1919"}],"subject":[],"published":{"date-parts":[[2025,6]]}}}