Thromboembolism in bioprosthetic heart valve recipients should similarly raise suspicion of IE or new-onset AF in the right clini- cal setting. Leaflet thrombosis occurs more frequently with bioprosthetic transcatheter aortic valves than with bioprosthetic surgical aortic valves.1 4 Intensification of antithrombotic therapy should always account for indi- vidual patient bleeding risk (Figure 13). Recommendation-Specific Supportive Text 1. There are no comparative-effectiveness trials from which to assess the relative utility of higher-inten- sity VKA therapy versus standard VKA therapy plus low-dose aspirin in mechanical valve recipi- ents who have experienced stroke or systemic embolism while in target INR range. Excluding the common clinical occurrence of extended time in a subtherapeutic INR range is the first priority. Assessment of medication adherence, intercur- rent illness, new or recently adjusted medications, dietary changes, and alcohol intake is critical. Whether to intensify VKA therapy or add low- dose aspirin is a patient-specific, shared decision- making proposition that must weigh several factors, including bleeding risk. 2. The approach to management of the patient with a systemic embolic event and a mechani- cal mitral prosthesis includes review of INR levels to ensure the patient is in the target INR range most of the time. INR levels may have been sub- therapeutic because of suboptimal medication adherence, intercurrent illness, new or recently adjusted medications, dietary changes, or alcohol intake. 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. 