What anticoagulation strategy is essential after a mechanical heart valve replacement?

• A. Lifelong Anticoagulation with Warfarin and INR Monitoring
• B. Antiplatelet Therapy Alone
• C. Short-Term Heparin Therapy
• D. No Anticoagulation Needed

Answer: (A)

Mechanical valve surfaces are highly thrombogenic, so preventing clot formation on the valve requires ongoing systemic anticoagulation. Warfarin is used because it lowers the production of vitamin K–dependent clotting factors, and keeping the INR within a therapeutic range minimizes the risk of valve thrombosis and stroke. This is why lifelong anticoagulation with warfarin and regular INR monitoring is essential after a mechanical valve replacement. In the perioperative period, short-term heparin bridging may be used until warfarin reaches its therapeutic range. Antiplatelet therapy alone does not provide adequate protection for mechanical valves, and having no anticoagulation would leave a high risk of thromboembolism.