ISTH 2015 - Thomas Ortel, Chief, Division of Hematology, Professor of Medicine and Hematology and Medical Director, Clinical Coagulation Laboratory, Duke University Medical Center - The management of patients with atrial fibrillation on warfarin who need treatment interruption for surgery/procedure is a common clinical problem. Bridging with low-molecular-weight heparin has been used to minimize the time that patients are not anticoagulated to mitigate the risk for arterial thromboembolism. This study seeks to determine the efficacy and safety of bridging anticoagulation.