Effect of TAVR commissural alignment on coronary flow: A fluid-structure interaction analysis

Area of Science:

• Cardiovascular Engineering
• Biomedical Simulation
• Medical Device Technology

Background:

• Coronary obstruction is a severe complication following Transcatheter Aortic Valve Replacement (TAVR).
• Proper device positioning relative to coronary ostia is crucial for maintaining coronary perfusion.
• Current TAVR delivery systems often lack control over commissural alignment.

Purpose of the Study:

• To investigate the impact of TAVR commissural alignment on coronary perfusion.
• To evaluate the effect of commissural alignment on TAVR device performance using computational modeling.
• To assess hemodynamic and structural changes associated with varying degrees of commissural alignment.

Main Methods:

• A two-way computational fluid-structure interaction (FSI) model was employed.
• Simulations were performed across a range of commissural alignments.
• Hemodynamic biomarkers and device performance metrics were analyzed for each alignment scenario.

Main Results:

• Commissural misalignment decreased total coronary perfusion by 3.2% and single coronary branch flow by 6.8%.
• Impaired valvular function was observed, including a 2.5% reduction in systolic orifice area and a 5.3% increase in transvalvular pressure gradients.
• Diastolic leaflet stresses increased by 16.0% with misalignment.

Conclusions:

• Maximal misalignment of TAVR prosthesis commissures with native ones minimizes coronary perfusion and device performance.
• These findings underscore the importance of incorporating axial control into TAVR delivery systems.
• Establishing recommended commissural alignment values in clinical guidelines is crucial for optimizing TAVR outcomes.