Quantification of regional differences in aortic stiffness in the aging human

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Computational Mechanics

Background:

• Aortic stiffening is linked to cardiovascular, neurovascular, and renovascular diseases.
• Understanding the interplay between aortic stiffness and hemodynamics is crucial for disease management.
• Existing clinical metrics for arterial stiffness have limitations.

Purpose of the Study:

• To quantify and compare regional nonlinear biaxial mechanical properties of the human aorta.
• To provide data for large-scale computational fluid-solid interaction (FSI) and fluid-solid growth (FSG) simulations.
• To identify needs for future research in arterial mechanics.

Main Methods:

• Compilation and analysis of 19 existing literature datasets on human aorta mechanical properties.
• Calculation of linearized stiffness values over the cardiac cycle.
• Focus on nonlinear biaxial mechanical properties.

Main Results:

• Consistent quantification of regional nonlinear biaxial mechanical properties of the human aorta.
• Calculation of linearized stiffness values suitable for FSI and FSG simulations.
• Significant variability observed in existing data.

Conclusions:

• There is a pressing need for more standardized biaxial testing of the human aorta.
• Data collection should vary by location, age, and include young healthy controls.
• Improved data will advance understanding and modeling of aortic diseases.