BACKGROUND: The CoreValve U.S. Pivotal High Risk Trial was the first randomized trial to show superior 1-year mortality of transcatheter aortic valve replacement (TAVR) compared with surgical aortic valve replacement (SAVR) among high operative mortality-risk patients. OBJECTIVES: The authors sought to compare TAVR to SAVR for mid-term 5-year outcomes of safety, performance, and durability. METHODS: Surgical high-risk patients were randomized (1:1) to TAVR with the self-expanding bioprosthesis or SAVR. VARC-1 (Valve Academic Research Consortium I) definitions were applied. Severe hemodynamic structural valve deterioration was defined as a mean gradient ≥40 mm Hg or a change in gradient ≥20 mm Hg or new severe aortic regurgitation. Five-year follow-up was planned. RESULTS: A total of 797 patients were randomized at 45 U.S. centers, of whom 750 underwent an attempted implant (TAVR = 391, SAVR = 359). The overall mean age was 83 years, and the STS score was 7.4%. All-cause mortality rates at 5 years were 55.3% for TAVR and 55.4% for SAVR. Subgroup analysis showed no differences in mortality. Major stroke rates were 12.3% for TAVR and 13.2% for SAVR. Mean aortic valve gradients were 7.1 ± 3.6 mm Hg for TAVR and 10.9 ± 5.7 mm Hg for SAVR. No clinically significant valve thrombosis was observed. Freedom from severe SVD was 99.2% for TAVR and 98.3% for SAVR (p = 0.32), and freedom from valve reintervention was 97.0% for TAVR and 98.9% for SAVR (p = 0.04). A permanent pacemaker was implanted in 33.0% of TAVR and 19.8% of SAVR patients at 5 years. CONCLUSIONS: This study shows similar mid-term survival and stroke rates in high-risk patients following TAVR or SAVR. Severe structural valve deterioration and valve reinterventions were uncommon. (Safety and Efficacy Study of the Medtronic CoreValve® System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement; NCT01240902).