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 patients undergoing aortic valve replacement because of the potential for prosthesis-patient mismatch (PPM). This study aimed to compare the clinical and hemodynamic outcomes of self-expandable valve (SEV) versus balloon-expandable valve (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 the baseline characteristics. Bioprosthesis valve dysfunction was based on modified Valve Academic Research Consortium 3 criteria. A total of 1,170 TAVI procedures were performed between 2018 and 2022. After applying the exclusion criteria, 332 patients reported a SAA at computed tomography scan, and the 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 BEVs than SEVs. At follow-up, significant differences favoring the SEV group regarding bioprosthesis valve dysfunction 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) than a SEV. Short- and midterm all-cause and cardiac-related mortality did not differ between the 2 groups. Future randomized studies with extended follow-ups are warranted to validate these outcomes.