Pressure-Resolved Predicted Local Pulse Wave Velocity in the Human Abdominal Aorta: Association with Model-Derived Arterial Wall Mechanics

Background: Pulse wave velocity (PWV) is commonly reported as a single value despite pressure-dependent arterial wall mechanics. We investigated whether associations between model-derived local PWV and constitutive parameters differed between diastolic and systolic loading. Methods: In this secondary analysis, previously collected abdominal aortic pressure and diameter measurements from 30 healthy participants were combined with a nonlinear constitutive model to identify c, k1, and k2. Local PWV was calculated from model-derived incremental stiffness using the Moens–Korteweg formulation. Multivariable regression and generalized estimating equations evaluated pressure-specific associations and interactions. Results: Model-derived local PWV was approximately 58% higher at systolic than at diastolic pressure. The pressure-by-log10(k2) interaction was statistically significant (B = −2.57; 95% CI, −3.88 to −1.25; false discovery rate [FDR]-adjusted p < 0.001). After FDR correction, k1 and log10(k2) remained associated with local PWV at diastolic pressure, whereas only log10(k2) remained associated at systolic pressure. Sensitivity and robustness analyses supported the principal finding. Conclusions: Model-derived local PWV varied with arterial loading, and its relationship with the constitutive parameters differed between diastolic and systolic conditions. Within this modeling framework, local PWV should be interpreted in relation to the pressure at which it is evaluated. Evaluation against independent PWV measurements in larger, more diverse populations is warranted.