Noninvasive hemodynamic assessment of aortic coarctation: multimodal imaging based-computational fluid dynamics

The gold standard assessment of coarctation of aorta (CoA) was achieved invasively by cardiac catheterization, which is associated with several risks including radiation exposure. The present study aimed to validate a multimodal imaging-based non-invasive computational framework for assessment of trans-coarctation pressure gradients (PG) in patients with severe coarctation of the aorta (CoA). Here we developed a non-invasive computational fluid dynamics (CFD) modeling framework based on multidetector computed tomography angiography (MDCTA) and ultrasound-derived input parameters, which incorporated into a lumped parameter model (LPM) and validated the results against measurements obtained via cardiac catheterization, both preoperatively and postoperatively. We used conventional Doppler estimates to make these correlations and to compare their diagnostic performance in identifying critical PG. The results indicated that for 18 patients with severe CoA the CFD simulation exhibited better concordance and correlation with catheter measurements compared to Doppler gradients (pre-intervention: 58.44 ± 17.77 vs. 55.72 ± 19.71 vs.57.78 ± 18.02 mmHg; post-intervention: 17.94 ± 10.54 vs. 15.65 ± 5.15 vs.20.61 ± 7.43 mmHg). Specifically, the CFD-derived PG showed a stronger correlation with catheter measurements (pre-intervention r = 0.89, post-intervention r = 0.90) than did Doppler-derived PG (pre-intervention r = 0.71, post-intervention r = 0.30). This CFD framework facilitated reliable quantification of PG and visualization of hemodynamic forces in patient-specific geometric models, and suggesting its potential as a non-invasive and effective approach for the assessment of CoA.