Abstract 14286: Rapid Involution of a Bioprosthetic Transcatheter Aortic Valve Replacement Presenting as Late Bioprosthetic Stenosis

Abstract

A 65 year old male with a bioprosthetic 29 mm Edwards Sapien Ultra S3 TAVR implant for symptomatic severe aortic stenosis presented for evaluation after a 30-day transthoracic echocardiogram demonstrated bioprosthetic valve stenosis. Following TAVR deployment, TEE showed normal bioprosthetic valve function without evidence of significant paravalvular regurgitation. There were no procedural complications. Echocardiogram performed 1-day post-implantation demonstrated expected transvalvular gradients and valve area. The patient reported immediate symptomatic improvement following TAVR. At 30 days post-implant, TTE demonstrated a peak velocity of 3.37 m/s, mean gradient of 29 mmHg, dimensionless index of 0.29, and effective valve orifice area of 0.9 cm2. This was associated with a progressive decline in exercise capacity. At 57 days post-implant, TEE showed tissue growth of the aortic root anterior to the valve stent, causing deformation and under-expansion of the valve architecture from a circular to an ovoid shape. Notably, the bioprosthetic leaflets did not appear thickened or calcified, but exhibited restricted motion as a result of the abnormal valve architecture. Peak velocity had further increased to 4.6 m/s, with a mean gradient of 57 mmHg, dimensionless index of 0.21, and calculated effective orifice area of 0.52 cm2. Bioprosthetic aortic valve valve stenosis is an expected complication of valve replacement, though typically characterized by progressive leaflet calcification and pannus formation over several years or by valve thrombosis. Here, we present a rare case of rapidly progressive bioprosthetic TAVR stenosis identified at 30 days post-implantation after normal morphology and gradients on immediate and 1-day imaging. Stenosis was characterized by a process of tissue growth anterior to the stent with involution and underexpansion of the stent architecture and morphologically normal leaflet tissue.