A study on correlation between preprocedural CT indexes and procedural success rate of transfemoral transcatheter aortic valve replacement with different self-expanding valves (VitaFlow or VenusA-Valve) in patients with pure native aortic regurgitation

Background: The rate of procedural success of transfemoral transcatheter aortic valve replacement (TAVR) with self-expanding valves in patients with pure native aortic regurgitation (PNAR) is quite low. Which anatomy evaluated by computed tomography (CT) as well as which kind of self-expanding valve is associated with higher success rate remain unknown. The aims of this study were to evaluate the relationship between preprocedural CT indexes and procedural success rate and to compare the procedural success rates between 2 kinds of self-expanding valves with different shaped frameworks. Methods: This was a retrospective comparative study. The study enrolled the symptomatic patients with severe PNAR, who were treated by transfemoral TAVR using a VenusA-Valve (Venus Medtech, Hangzhou, China) or a VitaFlow valve (Microport, Shanghai, China) at Zhongshan Hospital, Fudan University from October 2018 to December 2020. The procedural success rate (VARC-2 standard) was recorded. Preprocedural CT data were collected, including the perimeters of the aortic annulus (AA), left ventricular outflow tract (LVOT), sinotubular junction (STJ), and ascending aorta (AAO) and the angle of the aortic root. Leaflet thickening was evaluated qualitatively. Results: A total of 77 patients with a mean Society of Thoracic Surgeons (STS) score of 7.7±5.9 underwent TAVR. The total rate of procedural success was 80.5%. In the successful procedure group, the circumferences of the AA, LVOT, and STJ measured by CT were significant smaller than those in the failed procedure group (P=0.02, P=0.002 and P=0.045, respectively). Meanwhile, there were more patients with leaflet thickening in the successful procedure group (58.1% vs. 20.0%; P=0.02). The VenusA-Valve and the Vita-Flow valve were used in 47 patients and 30 patients, respectively. The procedural success rate was significantly higher in the VitaFlow group than in the VenusA-Valve group (93.3% vs. 72.3%; P=0.048), which was mainly due to the lower incidence of second transcatheter heart valves implantations in the VitaFlow group (6.7% vs. 27.7%; P=0.048). Conclusions: Severe PNAR patients with a smaller AA, LVOT, and STJ and leaflet thickening might have a higher success rate in transfemoral TAVR using a self-expanding valve. The self-expanding valve with a non-A-shaped framework might be a better choice for improved procedural outcomes.