COR LOE Recommendation In patients with suspected or confirmed bioprosthetic valve thrombosis who are hemodynamically stable and have no contraindications to anticoagulation, initial treatment with a VKA is reasonable.1 6 Synopsis Patients with an obstructed bioprosthesis may have a thin layer of thrombus causing reduced leaflet motion. VKA treatment may result in resolution of the thrombus and improvement in valve function. Recommendation-Specific Supportive Text 1. Multiple small nonrandomized studies support the use of VKAs to treat patients with clinical and subclinical bioprosthetic valve thrombosis after both SAVR and TAVI.1,3,4,6,7 VKA anticoagulation can result in a significant reduction of transvalvu- lar gradient, improved leaflet motion, and clinical CLINICAL STATEMENTS AND GUIDELINES 11.8. Prosthetic Valve Stenosis 11.8.1. Diagnosis of Prosthetic Valve Stenosis Recommendations for Diagnosis of Prosthetic Valve Stenosis Referenced studies that support the recommendations are summarized in Online Data Supplement 40. COR LOE Recommendations In patients with suspected mechanical or bioprosthetic valve stenosis, TTE and TEE are recommended to diagnosis the cause and severity of valve obstruction, assess ventricular function, and estimate pulmonary artery In patients with mechanical valve stenosis, fluoroscopy or cine-CT is recommended to assess motion of the mechanical valve leaflets. In patients with bioprosthetic valve stenosis, 3D TEE or 4D CT imaging can be useful to rule out leaflet thrombosis.3 7 Synopsis Prosthetic valve stenosis can occur with both mechani- cal and bioprosthetic valves. 