Subclinical leaflet thrombosis in surgical and transcatheter bioprosthetic aortic valves: an observational study

Use of transcatheter aortic valve replacement (TAVR) for severe aortic stenosis (AS) has grown rapidly over the last decade and the technology has correspondingly matured. Nevertheless, recent data suggest that subclinical thrombosis may form on some leaflets of the TAVR prostheses following implant. The frequency, implications, and required treatment of this process are largely unknown, as is the relevance to surgical aortic valve replacement (SAVR). Two single centre registries, The Assessment of Transcatheter and Surgical Aortic Bioprosthetic Valve Thrombosis and its Treatment with Anticoagulation (RESOLVE) and the Subclinical Aortic Valve Bioprosthesis Thrombosis Assessed with Four-Dimensional Computed Tomography (SAVORY), collectively enrolled 890 non-consecutive patients who underwent 4D volume-rendered CT at various intervals following TAVR (752 patients) or SAVR (138 patients) between 2014 and 2017 with the intent to explore the prevalence of subclinical leaflet thrombosis. Relative to SAVR prostheses, a higher percentage of TAVR patients had thrombus detected (12% vs …