BackgroundTranscatheter aortic valve implantation (TAVI) in bicuspid aortic valve (BAV) stenosis has become more frequent in the last years. This may pose challenges for long-time valve durability. Therefore, we aimed to evaluate the prevalence of bioprosthetic valve dysfunction (BVD) with the newest-generation devices in BAV stenosis up to one-year follow-up (FU).MethodsThe primary endpoint was defined as the prevalence of BVD during the first procedural year according to Valve Academic Research Consortium (VARC)-3 criteria. Secondary endpoints were defined as failure in device success and clinical endpoints according to VARC-3.ResultsA total of 107 patients were included. Of these, 34 subjects (31.8%) met the criteria for BVD during a mean FU of 263 ± 180 days, of which 20.2% were already documented after thirty days. Device success after one year was lower in the + BVD cohort (57.6% vs. 98.7%, p < 0.0001*). The rates of structural valve deterioration were 6.5%, non-structural valve deterioration (NSVD) 17.8%, subclinical leaflet thickening 10.3%, and endocarditis 0.9%. NSVD was foremost triggered by patient prosthesis mismatch in balloon-expandable valves. Hemodynamic valve deterioration stage 1 and 2 was confirmed in 16.8% of + BVD patients, while stage 1 and 3 bioprosthetic valve failure occurred in 1.9%. There was no impact of BVD on mortality.ConclusionThere is critical evidence of early BVD after TAVI in BAV during one-year FU in one-third of patients, also lowering device success. The most frequently observed bioprosthetic valve dysfunction was NSVD due to patient prosthesis mismatch following TAVI with a balloon-expandable valve.