CLINICAL STATEMENTS AND GUIDELINES For patients with bioprosthetic heart valves or annuloplasty rings who are receiving anticoagulation for AF, it is reasonable to consider the need for bridging anticoagulant therapy around the time of invasive procedures on the basis of the CHA2 -VASc score weighed against the risk of bleeding. For patients who are undergoing invasive procedures and have 1) a mechanical AVR and any thromboembolic risk factor, 2) an older-generation mechanical AVR, or 3) a mechanical mitral valve replacement, bridging anticoagulation therapy during the preoperative time interval when the INR is subtherapeutic is reasonable on an individualized basis, with the risks of bleeding weighed against the benefits of thromboembolism prevention. Synopsis The management of patients with prosthetic heart valves or repaired native valves in whom interrup- tion of anticoagulant therapy is needed for diagnostic or surgical procedures should take into account the type and location of the valve, the type of proce- dure, thromboembolic risk factors, the length of time over which oral anticoagulation will be withheld, and bleeding risk. Bridging therapy with either intra- venous unfractionated heparin (UFH) or low-molec- ular-weight heparin (LMWH) has evolved empirically to reduce thromboembolic events during temporary interruption of oral anticoagulation in higher-risk pa- tients, such as those with a mechanical mitral valve replacement or AVR and additional risk factors for Recommendation-Specific Supportive Text 1. Antithrombotic therapy should not be stopped for procedures in which bleeding is unlikely or would be inconsequential if it occurred (eg, surgery on the skin, dental cleaning, or simple treatment for dental caries). Eye surgery, particularly for cata- racts or glaucoma, is usually associated with very little bleeding and thus is frequently performed without alteration of anticoagulation with a VKA. 2. 