Why is this study important? 

• Lack of randomized comparison between transcatheter aortic valve replacement (TAVR or TAVI) and surgical aortic valve replacement (SAVR) in younger, low-risk patients, including those with both tricuspid and bicuspid aortic stenosis (AS). 
• A large population of young, low-risk patients are currently treated with TAVI despite insufficient evidence supporting this approach.

What question was this study supposed to answer? 

• What are the clinical outcomes in low-risk and young (≤ 75yrs) AS patients treated with TAVR and SAVR, including those with both tricuspid and bicuspid AS?
• Prior studies comparing low-risk patients such as PARTNER 3, Evolut Low risk, and NOTION trials demonstrated similar or lower mortality and stroke with TAVR when compared to SAVR. However, a significant portion of the patients in the trial were >75yrs old, and bicuspid AS patients were excluded. 

What did the study show? 

• 370 patients were randomized to TAVR (n=187) and SAVR (n=183), 
• Primary endpoint: composite of death, stroke, or rehospitalization at one year was similar between TAVR and SAVR groups (10.2 % Vs. 7.1%; Hazard ratio, 1.4 [95% CI, 0.7-2.9]).
• Death and disabling stroke were similar between the TAVR and SAVR groups at one year (3.2% vs 1.6%, Hazard ratio, 2.0 [95% CI, 0.5-7.8]).
• TAVR was associated with higher non-disabling stroke and moderate or greater paravalvular regurgitation. However, the difference was contributed by the higher rate of events in bicuspid TAVR cohort.
• TAVR had higher new permanent pacemaker implantation, but lower new onset atrial fibrillation and major bleeding compared to SAVR.
• TAVR cohort had more rapid improvement in dyspnea and quality of life compared to surgery. 

Key Takeaways:

• There is clinical equipoise for TAVR Vs. SAVR in the overall study cohort of low-risk, young patients (≤75yrs old) concerning death, stroke, or rehospitalization at one year. 
• A larger trial specifically focusing on outcomes in young patients with bicuspid AS may be beneficial to better assess issues specific to this population.