Abstract 13177: The Association Between Insufficient Valve Expansion and Aortic Valve Calcification for Transcatheter Valve Implantation With Self-Expandable Valve

Background: Transcatheter aortic valve implantation (TAVI) has emerged as the preferred treatment for severe aortic stenosis. Nevertheless, severe calcification remains a factor leading to insufficient valve expansion and paravalvular leakage (PVL) after TAVI, mainly when using the self-expandable valve. We aimed to investigate the relationship between calcification and valve expansion using pre- and post-operative computed tomography (CT) scans, by comparing with valve phantoms as a reference standard. Methods: We enrolled 62 consecutive patients (mean age: 84.2 ± 4.4 years, 23 male) who underwent TAVI with the Evolut PRO+. We measured the aortic valve's calcium volume (Ca-Vol) by contrast-enhanced CT. The shorter diameter (mm) and the area (cm 2 ) of the base of the implanted valve were measured. We performed CT scans of valve phantoms for each size and defined the measured shorter diameter and the base area as the reference standard. We calculated the insufficiency of valve expansion as the ratio of the patient valve's shorter diameter and base area to that of the phantom valve. PVL was defined as more than mild regurgitation by transthoracic echocardiography. Results: The base area of valve phantoms was 3.6, 4.1, 6.4, and 8.4 cm 2 for 23, 26, 29, and 34 mm, respectively. The shorter diameter and base area of the implanted valve were 15.7 ± 2.6, 15.2 ± 2.8, 17.3 ± 4.0, 23.9 ± 1.8 mm, and 2.7 ± 0.7, 2.5 ± 0.6, 3.4 ± 1.0, and 6.2 ± 1.6 cm 2 for 23, 26, 29, and 34 mm (n=4, 31, 24, and 3, respectively). Significant inverse correlations were observed between Ca-Vol and shorter diameter ratio (r 2 = 0.1, P = 0.009), area ratio (r 2 = 0.1, P = 0.006), and PVL (r 2 = 0.4, P < 0.001), respectively. On the other hand, there was no significant correlation between area ratio and PVL (r 2 = 0.004, P = 0.6). Conclusion: Severe calcification in the aortic valve was associated with insufficient valve expansion and PVL for the Evolut PRO+.