Coronary Flow Impacts Aortic Leaflet Mechanics and Aortic Sinus Hemodynamics

Area of Science:

• Cardiovascular Science
• Biomedical Engineering
• Hemodynamics

Background:

• Mechanical stresses on aortic valve leaflets initiate calcific aortic valve disease.
• Non-coronary leaflets calcify first, suggesting coronary flow influences leaflet mechanics and sinus hemodynamics.

Purpose of the Study:

• To investigate the impact of physiological coronary flow on aortic valve leaflet mechanics and sinus hemodynamics.
• To compare blood flow patterns and leaflet motion with and without coronary flow in an in vitro model.

Main Methods:

• High-resolution, time-resolved particle image velocimetry (PIV) was used.
• A porcine aortic valve was mounted in a physiological aorta sinus chamber with controlled coronary resistance.
• Analysis included streak plots, velocity vectors, and shear stress contours.

Main Results:

• Coronary flow deepened sinus vorticity and increased flow velocity near the leaflet base.
• The presence of coronary flow increased shear stress and washout near the leaflet.
• Leaflet opening area increased by approximately 10% with coronary flow.

Conclusions:

• Physiological coronary flow significantly improves aortic valve leaflet mechanics and sinus hemodynamics.
• Coronary flow reduces low wall shear stress conditions and enhances washout at the leaflet base.
• These findings suggest a protective role for coronary flow against calcific aortic valve disease initiation.