Improved Hemodynamics with Self-Expanding Compared to Balloon Expandable Transcatheter Aortic Valve Implantation in Small Annulus Patients: A Propensity-Matched Analysis

Patients with small aortic annuli (SAA) pose a challenge in aortic valve replacement patients due to potential for prosthesis-patient mismatch (PPM). The objective of this study was to compare clinical and hemodynamic outcomes of self-expandable valves (SEV) versus balloon-expandable valves (BEV) transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis and SAA. All patients who underwent TAVI for severe native aortic stenosis with a SAA between January 2018 and December 2022 were retrospectively included in the study from a single center. Propensity score matching was performed to balance baseline characteristics. Bioprosthesis valve dysfunction (BVD) was based on modified Valve Academic Research Consortium 3 (VARC-3) criteria. A total of 1170 TAVI procedures were performed between 2018 and 2022. After applying the exclusion criteria, 332 patients reported a SAA at CT scan and matching created 109 balanced pairs. Echocardiographic data at discharge showed higher mean transvalvular gradients (p<0.001), higher grades of mitral regurgitation (p=0.029), and lower ejection fraction (p<0.043) in BEV when compared to SEV. At follow-up, significant differences favoring the SEV group regarding BVD were observed (p=0.002), especially in terms of severe PPM (p=0.046), and at least moderate structural valve deterioration (p=0.040). In conclusion, TAVI in patients with SAA using a BEV was associated with lower valve areas, higher mean pressure gradients and PPM (including severe) compared to SEV. Short- and midterm all-cause and cardiac-related mortality did not differ between the two groups. Future randomized studies with extended follow-ups are warranted to validate these outcomes.