Improving the hemocompatibility of heart valves

Heart valve replacement with a prosthetic heart valve (PHV) remains the most effective treatment for valvular diseases such as aortic stenosis (AS) and mitral regurgitation (MR); where degeneration is the most common aetiology followed by rheumatic disease. These relatively simple mechanical devices have considerably prolonged the lives of patients impacted with morbidity and poor prognosis. This has largely been possible to advancements in material science and valve design which have enhanced the durability of PHVs. However, issues with haemocompatibility such as haemolysis, thrombosis and calcification still often arise which can lead to mechanical obstruction or leaflet tearing, sometimes with fatal consequences. The journey to improving the haemocompatibility of heart valves has been complex, often driven by failure to join the loop between mechanical design and physiological requirements. This chapter explores two critical haemocompatibility themes; blood-valve surface interaction and the impact of valve design on blood flow, from early designs to refinement.