Influence of ascending aorta diameter on short- and long-term clinical outcomes after transcatheter aortic valve implantation for bicuspid aortic valve stenosis

Background Bicuspid aortic valve (BAV) stenosis has been associated with challenging anatomical features for transcatheter aortic valve implantation (TAVI). Ascending aorta dilatation is frequently observed in patients with BAV stenosis and its implications for TAVI outcomes remain undetermined. Purpose To assess short and long-term clinical outcomes after TAVI for BAV stenosis according to ascending aorta diameter. Methods The study involved consecutive patients with computed tomography-diagnosed BAV who underwent TAVI due to symptomatic stenosis at 30 centres in Europe and North America with a long-time established interventional program and a systematic prospective collection of data. The primary outcome was a composite of death or stroke assessed from TAVI up to 3 years. Adjusted estimates were computed by binomial or linear multivariable mixed-effects models and semi-parametric shared frailty models accounting for multiple potential clinical, anatomical, and procedural confounders, transcatheter heart valve (THV) type, and centre. Results A total of 1815 patients with BAV treated by balloon- (1099, 60.6%) or self-expandable THV (716, 39.4%) were included. THVs were predominantly of newer generations (1439, 79.3%). The cohort was analysed according to the ascending aorta diameter, either <40 mm (1231, 67.8%) or ≥40 mm (584, 32.2%). The median ascending aorta diameters were 35.0 [32.2-37.2] mm and 43.0 [41.4-45.2] mm, respectively. Both unadjusted and adjusted in-hospital outcomes did not significantly differ between patients with normal or dilated ascending aorta. Moderate-to-severe postprocedural aortic regurgitation was not significantly different between groups (6.1% vs 5.7%). After multivariable adjustment, this conclusion remained unchanged (odds ratio [OR]MVA 0.84, 95% CI 0.47-1.50, P=0.557). At 3 years, death or stroke was not significantly different between patients with normal and dilated ascending aorta (24.5% vs 25.6%; hazard ratio [HR] 1.03, 95% CI 0.80-1.33, P=0.833). After multivariable adjustment, this result did not change (HRMVA 1.02, 95% CI 0.73-1.42, P=0.944). The individual outcomes of death (HRMVA 1.00, 95% CI 0.68-1.48), stroke (HRMVA 0.92, 95% CI 0.51-0.68, P=0.996), repeat valve replacement (HRMVA 1.44, 95% CI 0.52-4.03, P=0.695), valve thrombosis (HRMVA 1.00, 95% CI 0.68-1.48, P=0.663), and pacemaker implantation (HRMVA 1.01, 95% CI 0.74-1.38, P=0.974) were not significantly different between groups. Landmark analyses (30 days, 1 year, and 2 years), and subgroup and sensitivity analyses did not reveal inconsistencies. Conclusion In patients with BAV stenosis, cardiovascular outcomes after TAVI are not affected by baseline ascending aortic diameter.