New Insights Into the Pathophysiology of Structural Bioprosthetic Valve Degeneration

Biological heart valves (BHVs) are currently the main prosthetic substitute used to treat patients with severe valvular heart diseases. Unlike mechanical valves, BHVs provide better hemodynamic profile and lower thrombogenicity. However, their durability remains one of the main concerns in the field. Structural bioprosthetic valve degeneration (SVD) is a progressive phenomenon occurring early postimplantation and characterized by the fibro-calcification of the BHV leaflets, which leads to BHV failure over ∼10 years. SVD is currently an unpreventable and untreatable condition occurring in all BHV. The pathophysiological mechanisms leading to the development and progression of SVD remain largely unknown. However, a better understanding of these mechanisms will provide valuable data to improve BHV durability via the development of preventive treatments and/or newly engineered biological tissues. In this review, we provide a contemporary overview of the complex and interrelated pathophysiological mechanisms leading to SVD. We discussed the relevant studies in the fields, addressing the role of (i) the biomaterial structure and manufacturing processes, (ii) the active cell-mediated fibro-calcific processes, (iii) the residual immunogenicity of the currently animal-derived biomaterial, and (iv) the subclinical thrombosis, in the development and progression of SVD.