Browse the corpus

©2013 UpToDate ® Print Email Ninth ed: ACCP evidence-based practice guidelines: Antithrombotic therapy in patients with mechanical heart valves • In patients with mechanical heart valves, vitamin K antagonist (VKA) therapy is recommended over no VKA therapy and over antiplatelet agents for long-term management. In patients with a mechanical aortic heart valve, VKA therapy with a target of 2.5 (range 2.0 to 3.0) is recommended over higher targets and is suggested over lower targets. In patients with a mechanical mitral heart valve, VKA therapy with a target of 3.0 (range 2.5 to 3.5) is suggested over lower targets. In patients with mechanical heart valves in both the aortic and mitral position, a target INR of 3.0 (range 2.5 to 3.5) is suggested over a target INR of 2.5. • In patients with a mechanical mitral or aortic valve at low risk of bleeding, an antiplatelet agent such as low-dose aspirin (50 to 100 mg/day) is suggested in addition to long-term VKA therapy (over not adding such an agent). • For post-operative bridging immediately after mechanical heart valve replacement, unfractionated heparin (subcutaneous prophylactic dose) or low molecular weight heparin (prophylactic or therapeutic dose) is suggested over intravenous therapeutic unfractionated heparin until the INR is stable on VKA therapy. The most commonly used vitamin K antagonist (VKA) is warfarin. Note that the above INR ranges relate mostly to bileaflet and newer generation tilting disk valves. For older valves, the 2012 guidelines refer to the 2001 guidelines. The 2001 guidelines recommended a target INR of  3.0 (2.5 to 3.5) for patients with (older) tilting disk valves. A combination of a target INR of 3.0 (range 2.5 to 3.5) plus aspirin 80 to 100 mg/d was recommended for patients with caged ball or caged disk valves. Data from Whitlock RP, Sun JC, Fremes SE, Rubens FD, Teoh KH. Antithrombotic and thrombolytic therapy for valvular disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141:e576S.