Supra-Annular vs. Annular ValvEs for Small Annuli

Inclusion Criteria: * Symptomatic subjects with severe native aortic valve stenosis * aortic valve annulus mean diameter ≤23 mm * Patient meet commercial indication for transcatheter aortic valve replacement (TAVR) * Institutional heart team determines that TAVR is appropriate * Patient's anatomy is appropriate for either Medtronic Evolute or Edwards Sapien 3 Ultra Exclusion Criteria: * Subject unable or unwilling to provide informed consent * Intended concurrent structural heart procedure (e.g. transcatheter mitral valve repair or replacement, left atrial appendage closure) * Renal function precluding the administration of iodinated contrast (eGFR \< 30ml/min/1.73m2). An exception to this exclusion criterion is made if the subject is established on renal replacement therapy and is therefore able to receive intravenous iodinated contrast media * Pregnancy or intent on becoming pregnant prior to completion of all proctocol follow-up procedures * Patients at high risk for coronary obstruction * Patients with low-flow low gradient aortic valve stenosis * patients at high risk for annular rupture with implantation of a balloon expandable valve