ApixaShield for Reducing Valve Leaflet Thrombogenicity

Valvular heart disease is a common and frequently underdiagnosed condition that is increasing with population ageing. Population-based studies show that up to 50% of adults aged >65 years have valve abnormality, with >10% reaching clinical significance. In Australia, >12,000 valve procedures are performed annually, with volumes rising. Replacement with a bioprosthetic valve, typically derived from bovine or porcine tissue, is the dominant treatment.

While these devices restore function, they undergo progressive degeneration leading to failure, typically within 10–15 years. As a result, most patients will require repeat intervention during their lifetime. Despite advances in delivery, durability has not improved, and valve failure remains the defining unresolved limitation.

Bioprosthetic valves deteriorate over a long-term cascade of events that begins with the formation of tiny blood clots on the new valve leaflets within days to months after implantation. These clots double the risk of long-term valve failure by silently triggering inflammation and calcification. Because these clots are small and highly localised, increasing the dosage of blood thinners are not effective and raise the risk of serious bleeding.

Our approach

This project is developing ApixaShield, a nano-engineered surface coating for pericardium leaflets. ApixaShield is designed to be applied in the operating room without requiring changes to current valve designs or implantation procedures.

By locally presenting anti-coagulant drugs that enhance pericardium resistance to subclinical thrombosis, the coating offers a unique strategy to extend leaflet durability with potential impact for all bioprosthetic valves.