Self-expanding or balloon-expandable TAVR in patients with a small aortic annulus: A review

Abstract

Transcatheter Aortic Valve Replacement (TAVR) has revolutionized the treatment of severe aortic stenosis, particularly in patients at intermediate or high surgical risk. However, valve selection in individuals with a small aortic annulus remains a clinical challenge. Comparative data on self-expanding (SE) and balloon-expandable (BE) valves are limited, and recent evidence has focused on identifying the optimal prosthesis for this subgroup. This review critically evaluates the comparative outcomes of SE and BE valves in patients with small aortic annuli, emphasizing findings from the Small Annuli Randomized to Evolut or SAPIEN Trial (SMART) and contextualizing them with evidence from major trials including CHOICE, SOLVE-TAVI, SCOPE I, and FRANCE-TAVI. The SMART trial demonstrated that SE valves were non-inferior to BE valves for the composite endpoint of death, disabling stroke, or heart failure rehospitalization at 12 months, while achieving superior valve hemodynamics. SE valves were associated with lower mean gradients, larger effective orifice areas, and reduced rates of prosthesis–patient mismatch and bioprosthetic valve dysfunction. Other clinical studies have shown that BE valves may offer greater procedural precision, better positioning, and lower rates of paravalvular regurgitation. Both SE and BE valves represent effective options for TAVR in patients with small aortic annuli. SE valves provide improved hemodynamic performance, whereas BE valves may offer procedural advantages. Valve selection should be individualized based on anatomical characteristics and operator experience. Long-term studies are required to assess valve durability and late clinical outcomes.

Keywords: Transcatheter aortic valve replacement, Balloon-expandable valve, Self-expanding valve, Small aortic annulus, Aortic stenosis, SMART trial