Impact of Aortic Annulus Angulation on the Outcomes of Transcatheter Aortic Valve Replacement in Bicuspid Anatomy

Objective: This study aimed to explore the impact of aortic annulus angulation on outcomes in patients with bicuspid aortic valves (BAVs) undergoing transcatheter aortic valve replacement (TAVR) with new-generation valves. Methods: A retrospective study was conducted among patients who underwent TAVR with new-generation self-expandable (SE) or balloon-expandable (BE) transcatheter heart valves (THV) at West China Hospital between January 2018 and November 2022. Their CT scans, from which the annulus angulation was derived, and other clinical information were retrieved through the electronic patient record system. The mean annulus angulation of the whole cohort served as the cut-off value for further group assignment. The primary endpoint was device success at 30 d. Secondary endpoints included the need for >1 THV, vascular complications, permanent pacemaker implantation, paravalvular leak of at least mild severity, 30-day and 6-month mortality, etc. Multivariable logistic regression analysis was performed to identify independent predictors of the clinical outcomes. Results: A total of 180 patients were included in the study, 137 with SE THVs and 43 with BE THVs. The annulus angulation of all patients was 55.6° ± 10.0°, therefore, the patients were further stratified by 56°. Among the 43 BE THV recipients, the annulus angulation ≥ 56° group was older, shorter, had less valve calcification, and larger sinotubular junction and maximal ascending aorta diameters (all P < 0.05); however, the primary and secondary endpoints did not differ significantly between the annulus angulation <56° and ≥ 56° groups. Among the 137 SE THV recipients, despite larger maximal ascending aorta diameters in annulus angulation ≥56° group ((43.4 ± 4.3) mm vs. (41.3 ± 4.0) mm; P = 0.003), it did not influence device success at 30 d, the need for >1 transcatheter heart valve, vascular complications, paravalvular leak of at least mild severity, and 6-month mortality (all P > 0.05). However, the SE THV group with annulus angulation ≥ 56° had a higher incidence of permanent pacemaker implantation (27.6% vs. 8.9%, P = 0.004). Annulus angulation ≥57° was an independent predictor of permanent pacemaker implantation in patients with BAV receiving SE TAVR (odds ratio: 3.28, 95% confidence interval: 1.28–8.40; P = 0.01). Conclusion: Increased annulus angulation did not influence device success for both new-generation BE and SE THVs in patients with BAV. However, increased annulus angulation was associated with a higher risk of permanent pacemaker implantation in patients undergoing SE TAVR, while no such association was observed in those who underwent BE TAVR.