Review of anticoagulation options for mechanical valve prosthesis

Clinical guidelines recommend lifelong oral anticoagulation (OAC) with warfarin in all patients with mechanical valves with variance in the target INR for patient associated risk factors, type of mechanical valve or implant position of the valve. Recent randomized controlled trials have demonstrated that clinicians may consider a lower OAC strategy (INR: 1.5-2.5) in low (thrombogenic) risk patients undergoing bileaflet mechanical valve replacement thereby achieving similar thromboprophylaxis yet minimizing bleeding events. Likewise, physicians may also consider a lowered OAC option in high (thrombogenic) risk patients undergoing bileaflet mechanical valve replacement yielding similar efficacy (avoidance of thromboembolic events) and improving safety (bleeding events). Finally, while advancement of novel oral anticoagulants (NOACs) has been swift in the realm of atrial fibrillation anticoagulation management, NOACs for mechanical valves are currently contraindicated due to evidence of increased thromboembolic and bleeding risk. Future studies comparing NOACs and warfarin along with newer mechanical valve construction are eagerly being awaited.