Impact of Aortic Annulus Size on Clinical and Hemodynamic Outcomes of Transcatheter Aortic Valve Implantation With the Navitor Valve

Background: Patients with small aortic annuli undergoing transcatheter aortic valve implantation (TAVI) are at risk of higher residual transvalvular gradients. Evidence on the performance of new-generation intra-annular self-expanding valves in this anatomical setting remains limited. Aims: To evaluate the impact of annular size on procedural, hemodynamic, and mid-term clinical outcomes after TAVI with the Navitor valve. Methods: Patients were stratified by annular area measured by multi-slice computed tomography, defining a small annulus as ≤ 430 mm2. Primary endpoints at 12 months were: (i) a clinical composite of all-cause death, disabling stroke, or heart failure rehospitalization, and (ii) a composite endpoint of bioprosthetic valve dysfunction. Secondary endpoints included VARC-3–defined procedural and early outcomes and valve hemodynamic performance. Results: The study population comprised 218 patients, of whom 91 (41.7%) had a small annulus. VARC-3 technical success was high and comparable between small and non-small annuli (96.7% vs. 96.1%). Patients with small annuli had higher early post-procedural mean transvalvular gradients (7.7 ± 3.8 vs. 6.6 ± 3.0 mmHg; p = 0.029) and smaller effective orifice areas index (1.1 ± 0.3 vs. 1.3 ± 0.2 cm2/m2; p = 0.037), while the incidence of mean gradients ≥ 20 mmHg remained low (1.1% vs. 0.0%; p = 0.432). At 12 months, the clinical composite endpoint occurred in 8.8% of patients with small annuli and 10.2% with non-small annuli (p = 0.759). Bioprosthetic valve dysfunction was infrequent and similar between groups (6.6% vs. 6.3%; p = 0.875). Conclusions: TAVI with the Navitor intra-annular self-expanding valve was associated with high procedural success, favorable valve hemodynamics, and comparable mid-term clinical outcomes irrespective of annular size.