Chronically anticoagulated patients who need surgery: can low-molecular-weight heparins really be used to "bridge" patients instead of intravenous unfractionated heparin?

Patients at high risk of arterial or venous thromboembolic events often receive chronic treatment with long-term oral anticoagulants such as warfarin. However, if these patients require an invasive procedure, they may require a temporary interruption of their warfarin therapy to minimize their bleeding risk during the procedure. As warfarin has a long half-life and an unpredictable pharmacokinetic profile, short-acting parenteral anticoagulants, such as unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH), may be of benefit in protecting the patient from thromboemboli while their warfarin dose is withheld. Such "bridging therapy" has traditionally been provided in-hospital with intravenous UFH; however, recent data have suggested that LMWH may be an effective alternative, with potential cost-savings due to the ability to provide bridging therapy in the outpatient setting. (c) 2009 Wiley-Liss, Inc.