Coarctation of the aorta (CoA) is associated with reduced life expectancy despite successful surgical treatment.
Interestingly, much of the related long-term morbidity can be explained by abnormal hemodynamics, vascular
biomechanics and cardiac function. MRI has played an important role in assessing coarctation severity, but the
heterogeneity and small number of patients at each center presents an obstacle for determining causality. This work
describes optimized imaging parameters to create computational fluid dynamics (CFD) models revealing changes in
hemodynamics and vascular biomechanics from a rabbit model. CoA was induced surgically at 10 weeks using silk or
dissolvable ligatures to replicate native and end-to-end treatment cases, respectively. Cardiac function was evaluated at
32 weeks using a fastcard SPGR sequence in 6-8 two-chamber short-axis views. Left ventricular (LV) volume, ejection
fraction, and mass were quantified and compared to control rabbits. Phase contrast (PC) and angiographic MRI were
used to create CFD models. Ascending aortic PCMRI data were mapped to the model inflow and outflow boundary
conditions replicated measured pressure (BP) and flow. CFD simulations were performed using a stabilized finite
element method to calculate indices including velocity, BP and wall shear stress (WSS). CoA models displayed higher
velocity through the coarctation region and decreased velocity elsewhere, leading to decreased WSS above and below
the stenosis. Pronounced wall displacement was associated with CoA-induced changes in BP. CoA caused reversible LV
hypertrophy. Cardiac function was maintained, but caused a persistent hyperdynamic state. This model may now be used
to investigate potential mechanisms of long-term morbidity.