Final answer:
The discontinuation and restart of warfarin in aortic valve prosthesis depends on the type of prosthesis and the risk of thrombosis or bleeding. For mechanical valve prostheses, long-term anticoagulation therapy is usually required. For bioprosthetic valve prostheses, the duration of anticoagulation therapy may vary.
Step-by-step explanation:
The discontinuation and restart of warfarin in patients with an aortic valve prosthesis depend on several factors, including the type of valve prosthesis and the risk of thrombosis or bleeding. It is important to balance the need for anticoagulation therapy to prevent clotting with the risk of bleeding complications. In general, warfarin should be discontinued before and restarted after any surgical procedure involving the valve prosthesis to minimize the risk of bleeding during the procedure.
For mechanical valve prostheses, long-term anticoagulation therapy is usually required due to the increased risk of clotting. In these cases, warfarin is typically not discontinued and maintained at an appropriate dose to achieve the target INR (International Normalized Ratio) levels.
On the other hand, for bioprosthetic valve prostheses, the duration of anticoagulation therapy may vary depending on individual patient factors, such as the risk of thrombosis and bleeding. Warfarin may be discontinued after a certain period (e.g., 3 months) and replaced with an antiplatelet agent, such as aspirin.