Abstract
The treatment of aortic and mitral valve disease requiring replacement has shifted to an increasing use of bioprosthetic heart valves. Due to their limited durability, there is a growing need for reintervention in the setting of failing bioprosthesis. Even though the gold standard for the treatment of failed bioprosthesis remains surgical repair or replacement, valve-in-valve (ViV) transcatheter aortic and mitral valve replacement have emerged as safe and effective alternatives for patients who are at high or prohibitive risk for surgery. Both procedures are associated with a substantial risk of postprocedural thromboembolic events and valvular thrombosis that is often higher than transcatheter replacement of native valves. With guidelines lacking specific protocols and a limited number of available studies, the optimal postprocedural antithrombotic therapy remains to be clarified. Multiple factors including valvular hemodynamics, the characteristics of the failing surgical valve, and the choice of the new transcatheter heart valve (THV) must be considered. Additionally, patients are often at an advanced age with multiple comorbidities and may require oral anticoagulation (OAC) due to other indications such as atrial fibrillation. Although the recommended antithrombotic strategy for native transcatheter aortic valve replacement (TAVR) is antiplatelet monotherapy with aspirin or a P2Y12 inhibitor in the absence of another anticoagulation indication, the use of oral anticoagulants including vitamin K antagonists (VKAs) and direct thrombin inhibitors has been shown to be effective in reducing valvular thrombosis and are commonly used after ViV procedures. Prospective studies investigating these results specifically for ViV transcatheter aortic and mitral valve replacement are needed to identify the optimal antithrombotic therapy.