Severe stenosis of bioprosthetic valve due to late valve thrombosis

The typical cause of bioprosthetic valve dysfunction over years is calcification of leaflets, pannus formation, or tears due to structural degeneration. Thrombosis is rare as the valves get endothelialized early on, and, hence, anticoagulation is not recommended beyond 6 months after valve replacement. While bioprosthetic valve thrombosis is unusual (0.03% to 0.34%/year), it can be associated with significant mortality and morbidity. Here, we present a case of a middle-aged man with history of bioprosthetic mitral valve who presented with syncopal episode and was referred to us for mitral valve replacement for tentative bioprosthetic valve degeneration and stenosis. However, preoperative work up revealed prosthetic valve thrombosis which was successfully treated with anticoagulation.