Novel Real-Time Fluoroscopic Assessment Method of THV Expansion Following Balloon-Expandable TAVR

BACKGROUND: Transcatheter heart valve (THV) underexpansion after transcatheter aortic valve replacement may be associated with worse outcomes. THV expansion can be assessed fluoroscopically using a pigtail for calibration; however, the accuracy of this technique specific to transcatheter aortic valve replacement is unknown. We assessed the accuracy and reproducibility of a novel fluoroscopic method to assess THV expansion using the THV commissural post for calibration. METHODS: Patients who underwent transcatheter aortic valve replacement with a SAPIEN 3 (S3) THV had documented 3 cusp and cusp overlap views, and post-implant computed tomography was identified. THV expansion was fluoroscopically assessed in the 3 cusp and cusp overlap views using the S3 commissural post height and the pigtail as a reference for calibration. The correlation between the 2 methods and computed tomography was evaluated. RESULTS: Forty patients were included. On the bench, the commissural post height measured 3.3, 3.5, 4.0, and 4.5 mm for the 20 mm S3, 23 mm S3, 26 mm S3, and 29 mm S3, respectively. The Pearson correlation coefficient (r) with computed tomography for measuring the inflow, mid-portion, and outflow THV diameter was 0.98, 0.97, and 0.98 for the commissural post height method and 0.82, 0.81, and 0.78 for the pigtail method, respectively. Unlike the pigtail method, the correlation between the commissural post height method and computed tomography remained strong across all THV sizes and in both the 3 cusp and cusp overlap views. CONCLUSIONS: The commissural post height method is a novel real-time fluoroscopic tool that has the potential to assess THV expansion and guide further optimization after balloon-expandable transcatheter aortic valve replacement.