Annular versus supra-annular sizing for TAVI in bicuspid aortic valve stenosis.

We sought to compare annular versus supra-annular sizing for transcatheter aortic valve implantation (TAVI) in patients with a bicuspid aortic valve (BAV). In this retrospective single-centre analysis, we measured the aortic annulus (Ann) and intercommissural distance (ICD) on multidetector computed tomography scans in 217 BAV patients. With annular sizing being the default method for prosthesis size selection in all cases, we determined clinically relevant sizing errors and assessed the hypothetical impact of supra-annular sizing. Overall there was no significant difference between ICD and Ann (25.1 [23.5; 27.3] vs. 25.4 [23.6; 27.1] mm; p=0.24); intra-individually, ICD was similar to Ann in 26.7%, smaller in 40.1%, and larger in 33.2%. Annular sizing was appropriate in 96.3%, oversized in 0.5%, and undersized in 3.2% of cases. Supra-annular sizing would have resulted in a divergent size selection in 38.7% (smaller: 17.5%, larger: 19.8%, ICD out of range for TAVI prostheses: 1.4%) with potential improvement in a few cases with annular sizing errors, but potential worsening due to improper size selection in a much larger proportion of patients. Annular sizing for TAVI in BAV is feasible and safe. The added value of supra-annular sizing is questionable.