OBJECTIVES: The purpose of this study was to prospectively evaluate the safety and clinical performance of the CoreValve Evolut R transcatheter aortic valve replacement (TAVR) system (Medtronic, Inc., Minneapolis, Minnesota) in a single-arm, multicenter pivotal study in high- or extreme-risk patients with symptomatic aortic valve stenosis. BACKGROUND: Although outcomes following TAVR are improving, challenges still exist. The repositionable 14-F equivalent CoreValve Evolut R TAVR system was developed to mitigate some of these challenges. METHODS: Suitable patients (n = 60) underwent TAVR with a 26- or 29-mm Evolut R valve. Primary safety endpoints were mortality and stroke at 30 days. Primary clinical performance endpoints were device success per the VARC-2 (Valve Academic Research Consortium-2) and the percent of patients with mild or less aortic regurgitation 24 h to 7 days post-procedure. RESULTS: Patients (66.7 female; mean age 82.8 +/- 6.1 years; Society of Thoracic Surgeons Score 7.0 +/- 3.7 ) underwent TAVR via the transfemoral route in 98.3 , using a 29-mm valve in 68.3 of patients. All attempts at repositioning were successful. No death or stroke was observed up to 30 days. The VARC-2 overall device success rate was 78.6 . Paravalvular regurgitation post TAVR was mild or less in 96.6 , moderate in 3.4 , and severe in 0 at 30 days. Major vascular complications occurred in 8.3 , and permanent pacemaker implantation was required in 11.7 of patients. CONCLUSIONS: The repositionable 14-F equivalent Evolut R TAVR system is safe and effective at treating high-risk symptomatic aortic stenosis patients. Repositioning was successful when required in all patients, with low rates of moderate or severe paravalvular aortic regurgitation and low permanent pacemaker implantation. (The Medtronic CoreValve Evolut R CE Mark Clinical Study; NCT01876420).