Self-Expanding Transcatheter Aortic Valve Replacement Versus Surgical Valve Replacement in Patients at High Risk for Surgery

Transcatheter aortic valve replacement (TAVR) has emerged as an alternative to surgical aortic valve replacement (SAVR) in patients with severe symptomatic aortic stenosis at extreme or high surgical risk. We have previously reported that TAVR with a self-expanding aortic valve bioprosthesis in patients at increased risk for surgery was associated with better 1-year and 2-year survival compared with surgery. Several studies have demonstrated sustained and even continuous reductions in aortic valve gradients and improvements in aortic valve area (AVA) after TAVR. One randomized study in high-risk patients showed that compared with SAVR, balloon-expandable TAVR resulted in larger indexed effective orifice area (EOA) and less patient-prosthesis mismatch (PPM), albeit with more paravalvular aortic regurgitation (AR); these opposing prognostic factors may have led to the similar 2-year survival rates in the 2 groups. Background—The CoreValve US High-Risk Clinical Study compared clinical outcomes and serial echocardiographic findings in patients with severe aortic valve stenosis after transcatheter aortic valve replacement (TAVR) with a selfexpanding bioprosthesis or surgical aortic valve replacement (SAVR). Methods and Results—Eligible patients were randomly assigned 1:1 to TAVR with a self-expanding bioprosthesis or SAVR (N=747). Echocardiograms were obtained at baseline, discharge, 30 days, 6 months, and 1 year after the procedure and were analyzed at a central core laboratory. Compared with SAVR patients (N=357), TAVR patients (N=390) had a lower mean aortic valve gradient, larger valve area, and less patient–prosthesis mismatch (all P<0.001), but more paravalvular regurgitation at discharge, which decreased at 1 year. SAVR patients experienced significant right ventricular systolic dysfunction at discharge and 1 month with normal right ventricular function at 1 year. One-year all-cause mortality was 14.2% for TAVR and 19.1% for SAVR patients. Preimplantation aortic regurgitation ≥mild was associated with reduced mortality hazard for both the TAVR (hazard ratio 0.48, 95% confidence interval 0.27–0.85; P=0.01) and the SAVR groups (hazard ratio 0.53, 95% confidence interval 0.32–0.87; P=0.01). Aortic regurgitation ≥mild after TAVR was associated with increased risk for all-cause mortality (hazard ratio 1.95, 95% confidence interval 1.08–3.53; P=0.03). Conclusions—In patients with severe aortic stenosis at increased surgical risk, TAVR was associated with better systolic valve performance, similar left ventricular remodeling, more paravalvular regurgitation, and less right ventricular systolic dysfunction compared with SAVR. Despite an overall mortality reduction for the TAVR group, ≥mild aortic valve regurgitation after TAVR was associated with an increased mortality hazard. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01240902. (Circ Cardiovasc Interv. 2016;9:e003426. DOI: 10.1161/CIRCINTERVENTIONS.115.003426.)