Real-World Experience With a Suprannular Self-Expanding Transcatheter Aortic Valve: The ALLOW Study

Transcatheter aortic valve replacement (TAVR) has evolved significantly, expanding its indication to lower surgical risk patients. However, challenges remain, including conduction disorders or paravalvular leak (PVL). The ALLEGRA TAVI system (Biosensors International) is a supra-annular self-expanding prosthesis designed to optimize implantation and hemodynamic performance.

The objective of this study was to analyze short-term outcomes following the implantation of the Allegra valve in real-world practice.

This multicenter retrospective study included 500 patients who underwent TAVR with the Allegra valve across 11 Spanish centers between 2017 and 2024. Success rates, complications, and 30-day clinical outcomes were analyzed.

The median age was 82.1 ± 5.5 years. The overall success rate was 96.8% (95% CI 94.8%-98.0%), with complications in 11.6% (95% CI 8.0%-13.0%) of cases. The need for permanent pacemaker implantation (PPI) was 19.2% (95% CI 16.0%-22.9%), while moderate-to-severe PVL occurred in 4.1% (95% CI 2.7%-6.3%). The in-hospital mortality rate was 1.0% (95% CI 0.5%-2.6%). Hemodynamic performance was favorable, with post-implant mean gradients of 4.0 mmHg (IQR 2.0-5.0 mmHg) in native aortic stenosis and 7.0 mmHg (IQR 5.0-10.0 mmHg) in valve-in-valve procedures. A reduction in complications was observed, but not significantly, with increased experience (15.2% vs. 10.4%, p 0.147), though without impact on success rates.

This study confirms that the Allegra valve is a safe and effective TAVR option, with outcomes comparable to other self-expanding prostheses. Further design optimization could reduce PVL and PPI rates. Long-term studies are needed to assess durability.