Patients on warfarin with a low-risk for thrombotic events do not require bridging anticoagulation. If interruption is necessary, warfarin can be stopped 5 days prior to a planned procedure and resumed when it is felt to be safe to do so afterwards. Bridging with LMWH or UFH has been shown to cause excess bleeding when compared with no bridging and may ultimately delay resumption of warfarin. High-risk patients (e.g. mechanical mitral valve, venous thromboembolism within the last 3 months or atrial fibrillation with recent stroke/TIA) should be considered for bridging if the risk of thrombosis is higher than the risk of peri-procedural bleeding.
Sources:
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Health Quality Ontario. Heparin bridging therapy during warfarin interruption for surgical and invasive interventional procedures: a rapid review of primary studies [Internet]. 2014 [cited 2014 Aug 21].
Siegal D, et al. Periprocedural heparin bridging in patients receiving vitamin K antagonists: systematic review and meta-analysis of bleeding and thromboembolic rates. Circulation. Sep 25 2012;126(13):1630-1639. PMID: 22912386.
Spyropoulos AC, et al. How I treat anticoagulated patients undergoing an elective procedure or surgery. Blood. Oct 11 2012; 120(15):2954-2962. PMID: 22932800.