Definition: bridging anticoagulation therapy is designed to minimize the risk of thromboembolism in high-risk patients when anticoagulation therapy is suspended and to minimize the risk of bleeding after high-risk procedures (1).

Treatment (1):

• Mechanical heart valve:
• Bridging therapy required: mitral-valve replacement, >=2 mechanical valves, non-bileaflet aortic-valve replacement, or aortic valve replacement with prior stroke, TIA, intracardiac thrombus, or cardioembolic event.
• No bridging therapy: aortic-valve replacement, bileaflet prosthesis, and no prior stroke, TIA, intracardiac thrombus, or cardioembolic event.
• Nonvalvular atrial fibrillation:
• Bridging therapy required: prior stroke or embolic event, cardiac thrombus, or CHADS2 score of >=4.
• No bridging therapy: no prior stroke or embolic event, absence of cardiac thrombus, or CHADS2 score of <4.
• Venous thromboembolism:
• Bridging therapy required:
• Venous thromboembolism within previous 3 months or severe thrombophilia.
• Consider inferior vena cava filter if venous thromboembolism occurred <1 month previously, if urgent or emergency surgery is required, or if there is a contraindication to anticoagulation therapy.
• No bridging therapy: venous thromboembolism >3 months previously or no additional risk factors (e.g., active cancer and nonsevere thrombophilia).

• Stop warfarin 5 days before a high-risk procedure, and when the INR falls below the therapeutic range, begin low-molecular-weight heparin at a therapeutic dose:
• For patients with a mechanical heart valve or atrial fibrillation, use enoxaparin at a dose of 1 mg per kilogram of body weight, administered every 12 hours, or dalteparin at a dose of 100 IU per kilogram, administrered every 12 hours.
• For patients with venous thromboembolism, use enoxaparin at a dose of 1.5 mg per kilogram or dalteparine at a dose of 200 IU per kilogram once daily.
• The final dose (either enoxaparin at a dose of 1 mg per kilogram or dalteparin at a dose of 100 IU per kilogram) should be administered 24 hours before the procedure.
• Chech the INR on the morning of the procedure. Restart warfarin therapy immediately after the procedure is hemostasis is secured, and reinstitute treatment with subcutaneous low-molecular-weight heparin or intravenous unfractionated heparin at therapeutic dose (without bolus) 48 hours after the procedure if no bleeding has occured, with the exception that for patients undergoing endoscopic sphincterotomy, heparin therapy should be initiated after 72 hours (2).
• Discontinue heparin therapy when the INR is in the therapeutic range (approximately 5 days later).