Intra-annular self-expanding or balloon-expandable TAVI in small annuli: the NAVULTRA registry

Background: Comparative data between self-expanding Navitor (NAV) and balloon-expandable SAPIEN 3 Ultra (ULTRA) transcatheter heart valves (THVs) in patients with small aortic annuli are lacking. Aims: This study sought to evaluate outcomes of transcatheter aortic valve implantation (TAVI) using the intra-annular NAV and the ULTRA THVs in severe aortic stenosis patients with small annuli. Methods: Patients with an aortic annulus area ≤430 mm2 undergoing TAVI with either NAV or ULTRA from the NAVULTRA registry were included. Propensity-matched analysis was performed for adjustment. Primary endpoints included 1-year mortality, a composite endpoint (all-cause mortality, disabling stroke, or heart failure hospitalisation), and 30-day device-oriented outcomes (severe prosthesis-patient mismatch, moderate or greater paravalvular leak [PVL], mean gradient ≥20 mmHg). Results: Among 1,617 patients, 524 propensity score-matched pairs were analysed. At 1 year, all-cause mortality was 8.8% with NAV versus 9.0% with ULTRA (adjusted p=0.585), and the composite endpoint occurred in 11.3% versus 11.8%, respectively (adjusted p=0.149). The device-oriented endpoint favoured NAV compared to ULTRA (6.0% vs 29.3%; adjusted p<0.01), with a lower residual transvalvular gradient (7.3 mmHg vs 12.7 mmHg; adjusted p<0.01), and reduced incidence of any prosthesis-patient mismatch (odds ratio 0.27, 95% confidence interval: 0.18-0.43; adjusted p<0.01). However, NAV was associated with higher rates of mild paravalvular leak (NAV 33.5% vs ULTRA 23.2%; adjusted p<0.05) and permanent pacemaker implantation (PPI; NAV 20.1% vs 11.9% ULTRA; adjusted p<0.01). Conclusions: In patients with small aortic annuli, TAVI with both NAV and ULTRA provided comparable 1-year clinical outcomes, but NAV showed better haemodynamic performance at the cost of higher rates of mild PVL and PPI.