Restarting Warfarin After Clexane Bridging in Metallic Mitral Valve

Introduction to Warfarin Resumption

• The American College of Cardiology recommends resuming warfarin at the patient's previous maintenance dose within 24 hours after adequate hemostasis is achieved, and continuing therapeutic-dose clexane until INR reaches 2.5-3.5 on two consecutive measurements 1, 2, 3

Timing of Warfarin Resumption

• Start warfarin within 24 hours after the procedure or once hemostasis is secured, as recommended by the American Heart Association 1, 4
• For patients with metallic mitral valves, early warfarin resumption is critical to minimize the period of subtherapeutic anticoagulation, according to the American College of Cardiology 2, 3

Warfarin Dosing Strategy

• The FDA label and ACC/AHA guidelines recommend restarting warfarin at the previous therapeutic dose rather than loading 1
• Resume warfarin at the exact maintenance dose that previously achieved therapeutic INR, with a target of 2.5-3.5 for metallic mitral valve, as recommended by the American College of Cardiology 6, 7

Bridging Anticoagulation Management

• Continue therapeutic-dose LMWH until adequate oral anticoagulation is re-established, as recommended by the American College of Cardiology 2, 3, 7
• Wait ≥24 hours after surgery before restarting therapeutic-dose LMWH to reduce bleeding risk, according to the American Heart Association 8

Monitoring Protocol

• Measure INR on day 4 after restarting warfarin, and repeat INR testing on days 7-10, as recommended by the American College of Cardiology 4
• Once INR reaches 2.5-3.5 on one measurement, recheck within 24 hours to confirm stability before discontinuing LMWH, according to the American Heart Association 7

Special Considerations for Metallic Mitral Valves

• Metallic mitral valves carry the highest thrombotic risk among prosthetic valves, with an annual thromboembolism risk without anticoagulation exceeding 10%, as reported by the American College of Cardiology 2
• The target INR of 2.5-3.5 is higher than for aortic mechanical valves due to increased thrombotic risk, according to the American College of Cardiology 6, 7, 9