Valve dysfunction in patients with bicuspid aortic stenosis undergoing surgical aortic valve replacement versus transcatheter aortic valve replacement

Patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) has shown to be non-inferior compared to surgical aortic valve replacement (SAVR). However, patients with bicuspid aortic valve (BAV) were not included in most of the leading large randomized trials, resulting in limited mid-term data in this cohort of patients. Since patients with bicuspid AS need valve replacement at an earlier age, valve durability and valve dysfunction should be taken into account. This multicenter retrospective observational study is conducted across 13 centers in Europe and South America in patients with severe AS and BAV who underwent SAVR or TAVR with newer generation valves. Primary outcome was one-year composite outcome (death, stroke, hospitalization, and valve dysfunction). In this sub analysis we focus on valve dysfunction at one year. Valve dysfunction was defined as clinical valve thrombosis, endocarditis, or need for valve replacement of any cause (including need for a second valve during initial TAVR procedure). The hazard ratio is corrected with Fine-Gray analysis was performed treating death as competing risk. A total of 997 patients with BAV and AS who underwent either SAVR or TAVR were included in this study. SAVR was performed in 537 (53.9%) patients and TAVR in 460 (46.1%) patients. Patients undergoing SAVR were younger (72.0 vs 78.0 years, p<0.001), were more often males (67.6% vs 48.5%, p<0.001), and a lower EuroScore II (1.54% vs 2.23%, p<0.001) than patients undergoing TAVR. In the SAVR group 84.5% of the procedures was executed with a full median sternotomy, and 446 (97.2%) of patients with TAVR was executed transfemoral. Patients with SAVR were more often treated with small valves of 18-23 mm (65.5% vs 10.5%, p=0.01), and patients undergoing TAVR more often with larger valves of 29-34mm (1.5% vs 56.0%, p<0.001). At one-year follow-up there were 4 patients (0.9%) with valve dysfunction in the SAVR group, and 16 patients (4.6%) in the TAVR group (subdistribution hazard ratio 5.03, 95% CI 1.69-15.0,p=0.004). For patients undergoing SAVR, reason of valve dysfunction was severe paravalvular leakage requiring valve replacement (25%) and endocarditis (75%). Reason for valve dysfunction in the TAVR group was in 3 patients (18.8%) severe paravalvular leakage, 6 patients (37.5%) valve thrombosis, 3 patients (18.8%) endocarditis, and in 4 patients (25.0%) valve migration during the index-procedure. Time-to-event figure is presented in figure 1. In this real-world cohort of patients with BAV, TAVR was associated with higher rates of valve dysfunction at the one-year follow-up compared to SAVR. While the incidence of endocarditis appeared similar between the two procedures, the unique anatomical features of the bicuspid aortic valve may have a greater impact on valve thrombosis and migration in TAVR compared to surgical approaches for severe AS and BAV.