Abstract 14677: Oxidative Damage in Failed Clinical Bioprosthetic Heart Valve Explants

Introduction: Bioprosthetic heart valves (BHVs), fabricated from glutaraldehyde-fixed bovine pericardium or porcine aortic valves, have been widely used in valve replacement surgery. However, BHVs fail over time due to structural degeneration. Despite frequent observations of calcification-associated BHV failure, more than 25% of BHV structural failures occur without calcification. Previously, we reported that oxidative stress may have a pivotal role in noncalcific BHV failure. Moreover, oxidation-induced formation of dityrosine (DT) crosslinks via hydroxyl- and tyrosyl-radical mediated pathways was only detected in clinical BHV explants. Yet the mechanism of DT formation and its role in structural degeneration of clinical BHV is incompletely understood. Hypothesis: Oxidative damage to BHV is due to a specific spatial localization of DT crosslink formation mediated by myeloperoxidase (MPO) and/or iron (Fe) deposition in clinical BHV explants Method u0026 Results: BHVs from 7 human subjects were collected and ...