BackgroundTranscatheter aortic valve replacement (TAVR) in patients with bicuspid aortic valve (BAV) stenosis is technically challenging and is burdened by an increased risk of paravalvular regurgitation (PVR). ObjectivesThe aim of this study was to identify the incidence, predictors, and clinical outcomes of PVR after TAVR in Sievers type 1 BAV stenosis. MethodsConsecutive patients with Sievers type 1 BAV stenosis undergoing TAVR with current-generation transcatheter heart valves (THVs) in 24 international centers were enrolled. PVR was graded as none/trace, mild, moderate, and severe according to echocardiographic criteria. The endpoint of major adverse events (MAEs), defined as a composite of all-cause death, stroke, or hospitalization for heart failure, was assessed at the last available follow-up. ResultsA total of 946 patients were enrolled. PVR occurred in 423 patients (44.7%)—mild, moderate, and severe in 387 (40.9%), 32 (3.4%), and 4 (0.4%) patients, respectively. Independent predictors of moderate or severe PVR were a larger virtual raphe ring perimeter (adjusted OR: 1.07; 95% CI: 1.02-1.13), severe annular or left ventricular outflow tract calcification (adjusted OR: 5.21; 95% CI: 1.45-18.77), a self-expanding valve (adjusted OR: 9.01; 95% CI: 2.09-38.86), and intentional supra-annular THV positioning (adjusted OR: 3.31; 95% CI: 1.04-10.54). At a median follow-up of 1.3 years (Q1-Q3: 0.5-2.4 years), moderate or severe PVR was associated with an increased risk of MAEs (adjusted HR: 2.52; 95% CI: 1.24-5.09). ConclusionsAfter TAVR with current-generation THVs in Sievers type 1 BAV stenosis, moderate or severe PVR occurred in about 4% of cases and was associated with an increased risk of MAEs during follow-up.