Transcatheter Aortic Valve Implantation in Low-Risk Tricuspid or Bicuspid Aortic Stenosis: The NOTION-2 Trial

The NOTION-2 trial aimed to compare transcatheter aortic valve implantation (TAVI) with surgical aortic valve replacement (SAVR) in low-risk patients less than 75 years old, including with both tricuspid and bicuspid aortic stenosis (AS). Low-risk patients aged less than 75 years with severe symptomatic AS were enrolled and randomized to TAVI or SAVR. The primary endpoint was a composite of all-cause mortality, stroke, or rehospitalization related to the procedure, valve, or heart failure at 12 months. A total of 370 patients were enrolled with a mean age of 71.1 years and a median Society of Thoracic Surgeons risk score of 1.1 percent. A total of 100 patients had bicuspid AS. While major bleeding and new-onset atrial fibrillation were more common among SAVR patients, non-disabling stroke, permanent pacemaker implantation, and moderate or greater paravalvular regurgitation were more frequent in the TAVI group. Overall, the rate of the composite of death, stroke, or rehospitalization at one year was similar between TAVI (10.2 percent) and SAVR (7.1 percent). The absolute risk difference was 3.1 percent with a 95 percent confidence interval (CI), −2.7 percent to 8.8 percent; hazard ratio (HR) 1.4, 95 percent CI: 0.7 to 2.9; p = 0.3. The risk of the primary composite endpoint was 8.7 percent and 8.3 percent in patients with tricuspid AS (HR 1.0, 95 percent CI: 0.5 to 2.3) and 14.3 percent and 3.9 percent in patients with bicuspid AS (HR 3.8, 95 percent CI: 0.8 to 18.5) treated with TAVI or SAVR, respectively (P for interaction = 0.1). Based on the results, the authors call for caution in young bicuspid AS TAVI patients.