Prediction of Underexpansion Following Transcatheter Aortic Valve Implantation and Efficacy of Balloon Postdilatation.

BACKGROUND: Transcatheter heart valve (THV) underexpansion following transcatheter aortic valve implantation (TAVI) is associated with elevated gradients, paravalvular leak, and/or risk of hypoattenuating leaflet thickening. We aimed to simulate TAVI using pre-TAVI computed tomography (CT) images to predict the extent of THV underexpansion and the effect of staged balloon postdilatation on THV expansion. METHODS: Patients who underwent balloon postdilatation as a staged procedure for symptomatic THV dysfunction following native or valve-in-valve TAVI with available pre-TAVI, post-TAVI, and post-balloon aortic valvuloplasty CT between 2016 and 2023 were analyzed. TAVI and postdilatation were simulated computationally in patient-specific models using finite element analysis. Simulations were performed in blinded fashion without information of index procedure. THV expansion was defined as the percentage of THV area achieved by THV in CT or modeling when compared to nominal area defined by THV manufacturer. RESULTS: Among patients with balloon-expandable THVs following TAVI, the differences in expansion between CT and simulation measurements were -0.88% ± 3.27% (p = 0.75), -3.11% ± 4.65% (p = 0.26), and -3.27% ± 4.67% (p = 0.03) at the inflow, mid, and outflow regions, respectively. Following postdilatation, the differences in expansion between CT and simulation measurements were -0.60% ± 4.7% (p = 0.71), -1.64% ± 6.0% (p = 0.99), and -1.13% ± 4.2% (p = 0.55), respectively. Among patients with self-expandable THVs following TAVI, the percentage difference between CT and simulation measurements were 6.2% ± 4.2% (p = 0.99) and 9.3% ± 2.7% (p = 0.99) at the inflow and mid regions, respectively. Following postdilatation, the differences in expansion between CT and simulation measurements were 9.0% ± 3.2% and 8.9% ± 3.4%, respectively. CONCLUSIONS: Patient-specific computational modeling can predict THV underexpansion during the index procedure and the effect of postdilatation on THV expansion.