Impact of Tissue Treatment and Leaflet Design on Fifth-Generation Balloon-Expandable Transcatheter Heart Valve...

Area of Science:

• Cardiovascular research
• Biomaterials science
• Medical device engineering

Background:

• The SAPIEN 3 Ultra RESILIA (S3UR) transcatheter heart valve features RESILIA-treated tissue and novel commissural attachments in smaller sizes (20 and 23 mm).
• Limited performance data exist for the S3UR valve, particularly in comparison to the SAPIEN 3 Ultra (S3U) valve.

Purpose of the Study:

• To conduct a benchtop comparison of the S3UR and S3U transcatheter heart valves.
• Evaluate performance in transcatheter aortic valve replacement (TAVR), valve-in-valve (VIV), and redo-TAVR scenarios.

Main Methods:

• Benchtop hydrodynamic testing of 23- and 26-mm S3UR and S3U valves under nominal and underexpanded conditions.
• VIV and redo-TAVR simulations using S3UR valves implanted in existing prosthetic valves.
• Material analysis including histology, light transmission, micrometering, micro-CT, and tensile testing of pericardium samples.
• Assessment of leaflet splay after modification.

Main Results:

• The 23-mm S3UR valve demonstrated a lower mean gradient and larger effective orifice area than the 23-mm S3U valve, with enhanced differences during underexpansion.
• Comparable performance was observed between 26-mm S3U and S3UR valves.
• S3UR leaflets were thinner but exhibited higher tensile strength; leaflet splay was reduced post-modification.
• VIV and redo-TAVR showed similar hydrodynamic performance between S3UR and S3U, with S3UR having a slightly lower mean gradient and larger effective orifice area in redo-TAVR.

Conclusions:

• Commissural modifications and thinner leaflets in smaller S3UR valves influence hydrodynamic performance, leaflet motion, and material properties.
• These design changes contribute to improved leaflet splay characteristics after modification.
• Further investigation is warranted to fully understand the clinical implications of these findings.