Larger or smaller, which size of balloon expandable transcatheter aortic valve is better for border zone aortic annulus?

Author(s): Tomohiro Kawaguchi, Masayuki Doi, Shinichi Shirai

Transcatheter Aortic Valve Implantation (TAVI) is an established treatment for Aortic Stenosis (AS). In the balloon expandable aortic valve, SAPIEN 3, valve size is selected based on the size chart published by the manufacturer. However, in patients with border zone annulus, the valve sizing is chosen at the discretion of the clinicians, which is controversial. Larger Transcatheter Heart Valves (THV) with underfilling have been found to contribute to larger effective orifice area, and both larger THV sizing and smaller THV sizing with overfilling have been found to reduce the transvalvular mean pressure gradient. Larger THV sizing with underfilling might reduce aortic regurgitation compared with small THV sizing with overfilling. With larger THV sizing, coronary impairment can occur considering redo TAVI if the THV commissure level is located above the sino-tubular junction level. Smaller THVs should be considered for patients with the possibility of a redo TAVI procedure if coronary obstruction can be avoided. When a larger THV is selected for border zone cases, implantation with underfilling is safe and feasible for avoiding annular rupture. In TAVI with SAPIEN 3 for border zone cases, valve size selection should be made according to each patient’s background and anatomical features. Considering lifetime management of patients with AS, careful and ‘tailor-made’ TAVI strategies could be essential to ensuring the best treatment option in border zone cases.