Reviewer: Dr. Ekrem Şahan

Study: Comparison of Balloon-Expanding Valve Systems for the Treatment of Failed narrow Surgical Aortic Bioprostheses: The LYTEN Study

Published in Congress: EUROPCR 2022

Introduction: Valve in valve-transcatheter aortic valve replacement (viv-TAVR) is one of the treatment options for failed valves in surgically applied aortic valve bioprostheses. In the LYTEN study, viv-TAVR procedures with balloon-expanding valve (BEV) and self-expanding valve (SEV) were compared.

Objective: The aim of the LYTEN study was to compare the hemodynamic results between balloon-expanding SAPIEN (3/ULTRA) and self-expanding Evolut (R/PRO/PRO+) valve systems in patients who underwent VİV-TAVR.

Methods: Patients with unsuccessful small (≤23 mm) surgical bioprosthesis valves were randomized to undergo VİV-TAVR procedures BEV and SEV systems. The primary endpoint was valve hemodynamics (maximal/mean residual gradients; severe patient valve incompatibility or moderate-to-severe aortic regurgitation [AR]) at day 30 as assessed by Doppler-echocardiography.

Results: A total of 102 patients were randomized for the study, and 98 of these patients underwent the kik-TAVR procedure (BVA: 46, UPS: 52). Valve implantations were successful in all of the applied procedures. There was no difference in clinical outcomes at 30 days, including death and stroke, when both groups were compared. Lower mean and maximal transvalvular gradient values (15±8 vs. 23±8 mmHg, p?0.001; 28±16 vs. 40±13 mmHg, p?0.001) were obtained in patients in the UPS group, and patient valve incompatibility findings were also observed. was less (44% vs. 64%, p=0.07). Moderate to severe aortic regurgitation was not observed after the procedure in either group. Fifty-five patients (SEV: 27, BEV: 28) underwent invasive valve hemodynamic evaluation during the procedure, and there was no difference between the mean and maximum transvalvular gradients between the two groups (p=0.41 and p=0.70, respectively).

Conclusion: In patients with failed surgical aortic bioprosthesis with small diameter, vlave in valve-TAVR procedure with self-expanding valve was associated with better valve hemodynamics when evaluated by echocardiography. There was no difference between the groups in terms of invasive valve hemodynamic evaluation and 30-day clinical results during the procedure.

Comment: Although surgically performed bioprosthetic aortic valve replacement provides an advantage in terms of use of anticoagulants, its degenerative process is faster when compared to metallic prostheses. In such cases, the risk of reoperation increases and TAVR may be an option in these patients. In this study, in which self-expanding valve and balloon-expanding valve systems were compared in failed aortic bioprostheses with small valve area, the success of all procedures and the absence of death and stroke in the 30-day follow-up indicate that TAVR is an option for failed surgical aortic bioprostheses. In addition, self-expanding valve systems can be preferred in order to obtain better valve hemodynamics in the intravalve TAVR procedure