Absence of surgi- cal expertise should be considered in the clinical decision-making process as a factor that favors thrombolytics, whereas recurrent valve thrombo- sis favors a surgical approach (Table 23). 11.7. Bioprosthetic Valve Thrombosis 11.7.1. Diagnosis of Bioprosthetic Valve Thrombosis Recommendation for Diagnosis of Bioprosthetic Valve Thrombosis COR LOE Recommendation In patients with suspected bioprosthetic valve thrombosis, 3D TEE or 4D CT imaging can be useful to rule out leaflet thrombosis.1 5 Synopsis Bioprosthetic valve thrombosis is most common in the first 3 months after implantation but also has been de- scribed in patients years (typically 1 or 2) after valve im- plantation, with the longest interval being 6.5 years.6 Bioprosthetic valves are less thrombogenic than their mechanical counterparts. However, the diagnosis of subclinical bioprosthetic valve thrombosis has increased with use of CT imaging and as a function of the in- creased numbers of implanted bioprosthetic valves, in- Recommendation-Specific Supportive Text 1. Bioprosthetic valve thrombosis appears to be more common with transcatheter than with surgical bioprosthetic valves. Leaflet thrombosis often is suspected on the basis of an increased transvalvular velocity on routine echocardio- graphic monitoring and can be confirmed by the finding of hypoattenuation of the valve leaflets on CMR imaging. When there is clinical evidence of stenosis, 3D TEE or 4D CT imaging may be useful to detect a layer of valve throm- bus, which may respond to treatment with oral anticoagulation. 11.7.2. Medical Therapy Recommendation for Medical Therapy Referenced studies that support the recommendation are summarized in Online Data Supplement 39. 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. 