In North America, approximately 2 million patients with chronic atrial fibrillation or atrial flutter are receiving long-term therapy with an anticoagulant medication called warfarin. Warfarin is given to decrease the risk arterial thrombotic events (ATEs) or blood clots.
Each year, approximately 400,000 (20%) of these patients require temporary interruption of warfarin because of an elective surgery, placing them at increased risk of these events.
In about 3/5 of these patients, clinicians use bridging anticoagulation before and after surgery, usually with subcutaneous (under the skin) injections of a low-molecular-weight heparin. Other clinicians do not use bridging anticoagulation because the time of being off warfarin is short (~8 days), bridging may be costly and increase the risk of bleeding, and the evidence that is prevents ATEs is lacking.
Overall, there is uncertainty about the benefit or harm of bridging anticoagulation. This research study will determine the possible benefits and harms of bridging anticoagulation and will inform doctors of the best way to care for patients in the future.