Balloon-Expandable Versus Self-Expanding Prostheses for Transcatheter Treatment of Patients With Low-Flow, Low-Gradient Aortic Stenosis

Background: The use of balloon-expandable valves (BEVs) or self-expanding valves (SEVs) for transcatheter aortic valve replacement (TAVR) in patients with low-flow, low-gradient aortic stenosis (LFLG-AS) has been poorly investigated. Aim of this study is to evaluate the procedural and clinical outcomes of patients with severe low-flow, low-gradient aortic stenosis undergoing TAVR with current-generation prostheses. Methods: This registry-based, multicenter, cohort study included consecutive patients with low-flow, low-gradient aortic stenosis undergoing TAVR from January 2019 to December 2024 at 17 high-volume Italian centers. The study population was divided into 2 groups according to the use of BEVs or SEVs. The primary outcome was all-cause mortality up to 1 year. Results: The study involved 1380 patients; 592 (42.9%) underwent TAVR with BEVs, and 788 (57.1%) with SEVs. At discharge, BEVs were linked to higher mean transvalvular gradients (P<0.001) and a higher percentage of moderate predicted patient-prosthesis mismatch (P<0.001) compared with SEVs. After propensity score weighting, the Cox analysis showed no difference for the risk of the primary outcome (adjusted hazard ratio [HR]:1.23; 95% CI: 0.88-1.72), cardiovascular mortality (adjusted HR:1.37; 95% CI: 0.94-1.97), stroke (adjusted HR:1.83; 95% CI: 0.85-3.95), and myocardial infarction (adjusted HR:1.03; 95% CI: 0.40-2.69) between groups; however, the use of BEVs was associated with a significantly higher risk for HF hospitalization up to 1 year (adjusted HR: 1.54; 95% CI:1.05-2.25). Conclusions: In this real-world study on TAVR treatment for patients with low-flow, low-gradient aortic stenosis, there was no difference in mortality rates between BEVs and SEVs up to 1 year. However, the use of BEVs was linked to less favorable hemodynamic performance and a higher risk of HF hospitalization. Registration: URL: https://clinicaltrials.gov/; Unique identifier: NCT06589063.