Although the large phase III trials comparing NOACs with warfarin excluded patients with moderate to severe rheumatic MS or mechani- cal heart valves, some did include patients with other VHD and bioprosthetic valve replacement Many patients who develop an indica- tion for anticoagulation late after bioprosthetic heart valve replacement or native valve repair are treated safely with direct oral anticoagulants, as predicated on their CHA2 -VASc score and the predicted risks of bleeding. Considerations about the need for bridging therapy in these individu- als can follow the same strategy applied to other subsets of patients who have AF without mod- erate to severe rheumatic MS or a mechanical prosthesis. 5. When interruption of oral VKA therapy is deemed necessary, the agent is usually stopped 3 to 4 days before the procedure and is restarted postopera- tively as soon as bleeding risk allows. Bridging anticoagulation with intravenous UFH or subcuta- neous LMWH is started when the INR falls below the therapeutic threshold (ie, 2.0 or 2.5, depend- ing on the clinical context), usually 36 to 48 hours before surgery, and is stopped 4 to 6 hours (for intravenous UFH) or 12 hours (for subcutaneous LMWH) before the procedure. There are no ran- domized comparative-effectiveness trials evaluat- ing a strategy of bridging versus no bridging in adequate numbers of patients with prosthetic heart valves who need temporary interruption of oral anticoagulant therapy, although such studies are ongoing. 