Geometric Determinants of Post-stenotic Energetics in Coarctation of Aorta: Linking Centerline Morphology to Downstream Energy Loss.

While pressure gradient remains the clinical gold standard for diagnosing coarctation of the aorta (CoA), it does not fully capture the complexity of post-stenotic flow behavior, particularly the elevated energy dissipation downstream of the coarctation arising from complex anatomy and flow dynamics. This study investigates the relationship between coarctation and descending aorta anatomy, post-stenotic flow energy loss, and its association with left ventricular (LV) workload. A cohort of 20 CoA patients was analyzed. Anatomical features, including centerline topology and cross-sectional area variation along the descending aorta, were extracted from CT and MRI images. Patient-specific multiscale computational simulations were employed to quantify three-dimensional aortic hemodynamics, cardiac function, and systemic hemodynamics. Results demonstrate that energy dissipation per unit volume in the descending aorta correlates with the combined effect of the kinetic energy available at the coarctation site and the centerline tangent angle difference between the coarctation site and the downstream descending aorta. These parameters were also found to significantly influence LV workload expended for post-stenotic energy loss. This study underscores the critical role of descending aorta anatomy in shaping post-coarctation flow energetics and highlights the importance of incorporating anatomical and energetic metrics alongside pressure gradients to better assess disease severity and cardiac burden in CoA patients.