Whether to intensify VKA therapy or add low-dose aspirin is a patient-specific, shared deci- sion-making proposition that must weigh several factors, including bleeding risk. 3. In those patients with a bioprosthetic valve who have a stroke or embolic event, further imaging with TEE or 3D CT scanning may show leaflet thrombosis, which should respond to anticoagu- lation with either a VKA or a NOAC.1,2 The effec- tiveness of anticoagulation in aortic and mitral bioprosthetic valve recipients in whom leaflet thrombosis cannot be established as the cause of thromboembolism is uncertain, and patients should undergo a full neurological evaluation to rule out other causes of the neurological event. Shared decision-making that accounts for bleed- ing risk is a central feature of management. 11.6. Acute Mechanical Valve Thrombosis 11.6.1. Diagnosis of Acute Mechanical Valve Thrombosis Recommendation for Diagnosis of Acute Mechanical Valve Thrombosis Referenced studies that support the recommendation are summarized in Online Data Supplement 38. COR LOE Recommendation In patients with suspected mechanical prosthetic valve thrombosis, urgent evaluation with TTE, TEE, fluoroscopy, and/ or multidetector CT imaging is indicated to assess valve function, leaflet motion, and the presence and extent of thrombus.1 7 Synopsis Mechanical valve thrombosis is typically a subacute to acute event resulting in rapid valve dysfunction because of abnormal or absent motion of the valve leaflets, which often is associated with inadequate VKA anticoagulation. However, recurrent valve thrombosis can be associated with pannus ingrowth in the chronic setting. Mechanical valve thrombosis can present with rapid onset of symp- toms or acute pulmonary edema. Physical examination may demonstrate a stenotic murmur and muffled closing clicks, and further urgent diagnostic evaluation is required. The annual rate of prosthetic valve thrombosis with me- chanical valves ranges from 0.1% to 5.7%. 