Bioprosthetic Aortic Valve Degeneration After TAVR and SAVR: Incidence, Diagnosis, Predictors, and Management

Abstract

Bioprosthetic aortic valve degeneration (BAVD) is a significant clinical concern following both transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR). The increasing use of bioprosthetic valves in aortic valve replacement in younger patients and the subsequent rise in cases of BAVD are acknowledged in this review which aims to provide a comprehensive overview of the incidence, diagnosis, predictors, and management of BAVD. Based on a thorough review of the existing literature, this article provides an updated overview of the biological mechanisms underlying valve degeneration, including calcification, structural deterioration, and inflammatory processes and addresses the various risk factors contributing to BAVD, such as patient demographics, comorbidities, and procedural variables. The difficulties in early detection and accurate diagnosis of BAVD are discussed with an emphasis on the need for improved imaging techniques. The incidence and progression of BAVD in patients undergoing TAVR versus SAVR are compared, providing insights into the differences and similarities between the two procedures and procedural impacts on valve longevity. The current strategies for managing BAVD, including re-intervention options of redo surgery and valve-in-valve TAVR, along with emerging treatments are discussed. The controversies in the existing literature are highlighted to offer directions for future investigations to enhance the understanding and management of BAVD.

Keywords: aortic stenosis; aortic valve replacement; bioprosthetic aortic valve; structural valve degeneration.

Figure 1

Summary of the potential pathophysiological mechanisms of bioprosthetic aortic valve degeneration.

Figure 2

A 38-year-old male with a history of a bicuspid aortic valve underwent SAVR at the age of 30. A CT scan (Panel A) demonstrated thickening of the aortic valve prosthesis leaflets, most notably the noncoronary-facing and right coronary-facing leaflets, both of which are hypomobile. Significant thickening extends to the base of the right and noncoronary cusps at the valve plane. A TTE examination showed that the aortic valve prosthesis leaflets were calcified with reduced opening from parasternal and apical views (Panels B,C). The systolic mean Doppler gradient was 28 mmHg (EOA 1.4 cm²) (Panels D,E). A TEE confirmed the severity of the stenosis (Panels F–H); all the leaflets had markedly reduced opening. They were calcified except for the leaflet towards the left coronary cusp, which was not well visualized. By planimetry, the aortic valve area was between 0.4 and 0.5 cm², indicative of severe aortic stenosis.

Figure 3

A 77-year-old male with a history of SAVR ten years ago. The patient developed severe SVD, and a valve-in-valve TAVR procedure was indicated. In the preoperative echocardiographic images (Panels A,B), moderate aortic valve stenosis and severe aortic valve regurgitation were observed. A 26 mm Edwards Sapien 3 Ultra transcatheter aortic valve bioprosthesis was implanted via a transfemoral approach (Panel C). Following the procedure (Panel D), a normal aortic prosthesis was observed with normal gradients (14 mmHg) and no prosthetic or periprosthetic aortic valve regurgitation.