A patient with a prosthetic heart valve needs to receive antithrombotic therapy. The primary risk for thromboemboli is during the first 3 months after surgery, but some patients benefit from prolonged therapy.


Antithrombotic regimens:

(1) aspirin 75 to 100 mg per day (an alternative agent is needed if there is aspirin intolerance)

(2) warfarin therapy


Therapy for First 3 Months After Valve Replacement Surgery

Prosthetic Valve



mitral valve

warfarin with INR 2.5 to 3.5


aortic valve


warfarin with INR 2.0 to 3.0


After the first 3 months many patients are kept on aspirin for the rest of their lives.


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