2023/09/06 | Research | Biomechanics
How do bioprosthetic heart valves fail? In the first detailed study of calcified heart valves, the ARTORG Cardiovascular Engineering group has joined forces with Empa and the Paul Scherrer Institute to analyze the nature and starting points of calcification, its chemical composition and the influence of blood flow and valve shape on the calcification process.
In the study, failed bioprosthetic heart valves provided for research by the Inselspital, underwent a subsequent detailed analysis process. At the Laboratory for Particles-Biology Interactions, Empa, they were analyzed via Micro-CT, two-photon microscopy, confocal microscopy and scanning electron microscopy to reveal calcification extent and propagation. The Paul Scherrer Institute investigated the microscopical calcification processes via small angle x-ray scattering. Through fluid-structure interaction simulation at the ARTORG Center it became possible to bridge these two insights by demonstrating the vital role of blood flow dynamics on the calcification. This simulation was able to show which fluid mechanical forces lead to calcification onset and how heart valve shapes influence the patterns observed on calcified bioprosthetic valves.
The study is the first of its kind observation of heart valve failure through calcification. It shows that flow does play an important role in calcification processes. The study results suggest that valve optimization for longer durability should not only focus on valve material but rather on valve shape as well – minimizing turbulence (a facilitating factor for calcification) and thus improving valve longevity.
Link to the study