Antithrombotic therapy after surgical heart valve replacement
Patients with a mechanical heart valve require long-term anticoagulation with warfarin. The target international normalised ratio (INR) is generally either 2 to 3 or 2.5 to 3.5. Consider adding low-dose aspirin for patients with concurrent atherosclerotic disease or if thrombosis occurred despite therapeutic treatment with warfarinJoint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology, 2012.
Do not use a direct-acting oral anticoagulant (DOAC) for thrombotic prophylaxis in a patient with a mechanical heart valve; a randomised clinical trial demonstrated inferior thrombotic prophylaxis and a higher rate of bleeding complications with dabigatran compared to warfarin1Eikelboom, 2013.
Thromboprophylaxis following implantation of a tissue valve depends on patient factors (eg comorbidities, risk factors for bleeding) and the site of the valve. An aortic tissue valve carries a lower risk of thrombosis than a mitral tissue valve. Oral anticoagulation with warfarin is usually recommended for 3 months after insertion of a mitral tissue valve. Low-dose aspirin therapy is usually recommended for 3 months after insertion of an aortic tissue valve; however, 3 months of warfarin therapy is a reasonable alternativeJoint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology, 2012Nishimura, 2014.