Affiliation: Network of Excellence for Functional Biomaterials (NFB), National University of Ireland, Galway, IDA Business Park, Dangan, Galway, Ireland.
Despite the significant advances in cardiac surgery, heart valve replacement still faces a dilemma. While mechanical valves offer lifelong durability they also commit patients to anticoagulation treatment for the rest of their life. On the other hand, bioprosthetic valves have superior hemodynamic performance but durability of the bioprosthesis limits their use to the elderly, with early onset calcification being the primary cause of biomaterial breakdown. Considering that bioprosthetic valves are not reliant upon anticoagulation, there has been much focus on measures to overcome their issues with durability. Firstly, the calcification process has been studied and factors such as young patient age, use of glutaraldehyde fixative, the presence of phospholipids along with cell debris in the valve tissue and mechanical stress have been identified to influence tissue mineralization. Therefore different calcification reduction strategies are being sought: new fixatives have been developed and tested and post-treatments have been added to tissue processing. This review presents the pathophysiology of tissue valve calcification and focuses on the multiple approaches developed to prevent bioprosthetic heart valve calcification, as well as on their general outcomes and translation to clinical applications.