Balloon-Expandable TAVR Bioprostheses: Area or Perimeter Sizing? A Prospective Pilot Study

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology
• Medical Device Technology

Background:

• Current transcatheter aortic valve replacement (TAVR) practices utilize area sizing for balloon-expandable (BE) valves, despite their circular frame potentially mismatching elliptical annuli.
• This discrepancy may lead to relative undersizing and suboptimal clinical outcomes for BE valves.
• Self-expanding valves are sized using annulus perimeter, suggesting a potential benefit for perimeter-based sizing in BE valves.

Purpose of the Study:

• To develop and evaluate a perimeter-based sizing algorithm for the Myval BE valve.
• To assess the safety and feasibility of perimeter sizing in patients undergoing TAVR with the Myval BE valve.

Main Methods:

• A prospective, single-center study included 60 patients with severe aortic stenosis treated with the Myval BE valve.
• Perimeter sizing was employed with a limited oversizing margin of 3.7% ± 1.3% relative to the annulus perimeter.
• Clinical outcomes were assessed at 30 days and 1 year post-TAVR, with echocardiographic follow-up at 30 days.

Main Results:

• At 30 days, pacemaker implantation (PPI) and stroke rates were 2% and 3%, respectively. No moderate-severe paravalvular leak (PVL) or cardiac death occurred.
• At 1 year, cardiac death and stroke rates were 3% and 8%, respectively.
• A larger valve size was implanted in 33.3% of patients compared to area sizing calculations.

Conclusions:

• Perimeter sizing with the Myval BE valve facilitated the use of larger valve sizes and demonstrated favorable clinical outcomes, including low PPI and no significant PVL.
• This alternative sizing method shows promise for improving TAVR procedures with BE valves.
• A randomized controlled trial is planned to confirm the superiority of perimeter sizing.