Supra-Annular Sizing for Prediction of THV Expansion in Bicuspid Aortic Valves: A MSCT Study

Abstract

ABSTRACT Background Multislice computed tomography (MSCT) is the most common sizing method for transcatheter aortic valve implantation (TAVI) in the bicuspid aortic valve (BAV). It is unclear whether annular and supra-annular dimensions could predict final prosthesis diameter and expansion. This study aimed to identify baseline MSCT measurement that could predict the geometry of the transcatheter heart valve (THV) in BAV patients undergoing TAVI for symptomatic aortic stenosis (AS). Methods One hundred and two BAV patients undergoing TAVI for AS were included in this observational, retrospective, single-center study. Pre- and post-TAVI MSCT were compared. On pre and post MSCT, means of perimeter-derived diameter (PdD) and ellipticity indexes were measured at the annular plane and 4 mm and 8 mm above, and intercommissural distance (ICD) at 4 and 8 mm. Results Comparison of pre- and post-TAVI PdDs at 3 levels showed that pre-TAVI PdD at +4 mm was comparable to post-TAVI PdD at annulus (24.2 ± 2.6 mm vs. 24.0 ± 2.7 mm; p = 0.87; mean difference: 0.04; SD: 2.54; 95% CI: −0.46; 0.54) and at +4 mm (24.2 ± 2.6 mm vs. 23.7 ± 2.5 mm; p = 0.16; mean difference: 0.36; SD: 2.60; 95% CI: −0.15; 0.87). All other comparisons showed significant difference between pre and post dimensions, with reduction in post-TAVI THV dimensions, as compared to baseline measurements, suggesting underexpansion. Pre- and post-TAVI ellipticity indexes comparison showed significant reduction in post-TAVI ellipticity indexes at 3 levels, suggesting a more circular THV geometry. Conclusion In BAV, supra-annular PdD at 4 mm was comparable to post-TAVI THV PdDs. THV underexpansion and anatomical reshaping occurred after TAVI in BAV. Abbreviations AS, aortic stenosis; BAV, bicuspid aortic valve; ICD, intercommissural distance; MSCT, multislice computed tomography; PdD, perimeter-derived diameter; STS, Society of Thoracic Surgeons score; TAVI, transcatheter aortic valve implantation; THV, transcatheter heart valve.