Patient-Specific Computer Simulation to Optimize Transcatheter Heart Valve Sizing and Positioning in Bicuspid Aortic Valve

Abstract

ABSTRACT Background Outcomes of transcatheter aortic valve replacement (TAVR) in bicuspid aortic valve (BAV) might be improved through better transcatheter heart valve (THV) sizing and positioning. Patient-specific computer simulation may be used to identify an optimal THV size and implant depth that minimizes paravalvular regurgitation. We sought to examine whether the usage of optimal THV sizing and positioning would be associated with improved clinical outcomes. Methods A multi-center retrospective study was performed on patients who had undergone TAVR in BAV. Finite element models of the aortic root were created and then finite element analysis was performed using different THV sizes and implant depths. Computational fluid dynamics was undertaken. Patients were classified as having optimal THV sizing and positioning if the predicted paravalvular regurgitation of the computer simulation corresponding to the implanted THV size and implant depth was within 5 mL/sec of the best possible computer simulation, and non-optimal if not. Clinical outcomes were compared between the two patient groups. Results A total of 50 patients were included in the study. Paravalvular regurgitation severity was higher in patients where non-optimal THV sizing and positioning was used (P < 0.001). At 2 years, the Kaplan-Meier estimate of the rate of death from any cause was higher in the group where non-optimal THV sizing and positioning was used (34.5% vs. 9.1%; hazard ratio, 6.23; 95% confidence interval, 1.04 to 37.44; P = 0.02 by log-rank test). Conclusion Computer simulation suggests that the usage of optimal THV sizing and positioning might improve clinical outcomes of TAVR in BAV. Abbreviations: AUC: area under the receiver operating characteristic curve; BAV: bicuspid aortic valve; BAVi: bicuspid aortic valve imaging; CI: confidence interval; CPI: contact pressure index; CT: computed tomography; TAVR: transcatheter aortic valve replacement; THV: transcatheter heart valve