Annular Ellipticity and Sizing Strategy in Transcatheter Aortic Valve Implantation: Independent or Combined Risk Patterns?

BACKGROUND: Elliptical annular anatomy has been considered a risk factor for adverse outcomes after TAVI, particularly paravalvular leakage (PVL). Prosthesis oversizing is thought to improve sealing, but the interaction between annular shape and sizing strategy remains unclear. AIM: To evaluate the combined impact of annular shape and sizing strategy on procedural success and short-term outcomes. METHODS: In this retrospective single-center study, 509 patients undergoing TAVI between January 2021 and December 2024 were analyzed. Ellipticity index (EI) was defined as the ratio of maximum to minimum annular diameter on preprocedural CT. The sizing index (SI) was calculated as prosthesis diameter relative to mean annular diameter. Primary and secondary endpoints were device success and PVL ≥ mild, PPI, new-onset LBBB, and early safety. RESULTS: Mean EI and SI were 1.27 ± 0.10; 15.3% ± 12.4%. Device success was achieved in 89% and was not significantly associated with EI (aOR 0.197, 95% CI 0.013-3.309, p = 0.25). Increasing SI was associated with higher device success, although this association did not reach statistical significance (aOR 1.017, p = 0.088). Success rates peaked with moderate oversizing (6%-15%; 93%). PVL ≥ mild occurred in 30% with undersizing and 14% with optimal oversizing but showed no association with EI or SI. Heatmaps showed lower device success when high EI (> 1.32) coincided with suboptimal SI (≤ 5% or ≥ 25%). CONCLUSION: Annular ellipticity alone did not predict adverse outcomes. While exploratory analysis suggested reduced device success in patients with both high ellipticity and suboptimal sizing, no significant interaction was identified. Moderate oversizing was associated with the most favorable results.