RecruitingDevice studyPROGRESS: Management of Moderate Aortic Stenosis by Clinical Surveillance or TAVRThis study objective is to establish the safety and effectiveness of the Edwards SAPIEN 3 / SAPIEN 3 Ultra / SAPIEN 3 Ultra RESILIA Transcatheter Heart Valve systems in subjects with moderate, calcific aortic stenosis. Following completion of enrollment, subjects will be eligible for enrollment in the continued access phase of the trial.