Transfermoral aortic valve implantation using self-expanding New Valve Technology (NVT) Allegra bioprosthesis: A pilot prospective study

Background: Transcatheter aortic valve implantation (TAVI) has become a standard therapeutic option for patients with severe aortic stenosis (AS) at high cardiac surgical risk. The aim of the NAUTILUS study was to investigate the safety and performance of the New Valve Technology (NVT) Allegra bioprosthesis in high-risk patients undergoing TAVI. Methods: Twenty seven patients with severe, symptomatic AS at high surgical risk were prospectively enrolled, who underwent treatment using the novel self-expanding NVT Allegra bioprosthesis via transfemoral approach (TF-TAVI). The primary end-point was all-cause mortality at 30 days. Results: Patients were elderly (83 years, range 75–89 years), and predominantly female (70.4%, n = 19). All patients were deemed to be at high surgical risk, with a mean logistic EuroSCORE of 12.4% (range, 2.8–31.8%). The bioprosthesis was successfully implanted in 96% of the cases (n = 25). The echocardiographic assessment confirmed good hemodynamic profile after implantation of the NVT Allegra bioprosthesis. Complications included cardiac tamponade (4%, n = 1) and the need for permanent pacemaker implantation (8%, n = 2). The analysis of procedural aspects showed a short learning effect related to the precise placement of the valve. A significant improvement in clinical symptoms were observed, and no patients died in-hospital or within 30 days of post-discharge observation. Conclusions: This prospective observation shows that the NVT Allegra bioprosthesis was associated with a satisfactory safety profile and a remarkable hemodynamic performance after implantation.