Transcatheter aortic valve implantation in low-risk tricuspid or bicuspid aortic stenosis: The NOTION-2 trial

Published in Congress: EuroPCR 2024

Link: https://academic.oup.com/eurheartj/advance-article-abstract/doi/10.1093/eurheartj/ehae331/7673297?redirectedFrom=fulltext&login=false

Dr. Yasin Özen

Introduction:
When treating elderly individuals with severe symptomatic aortic stenosis (AS), transcatheter aortic valve implantation (TAVI) has emerged as the preferred option. The purpose of this study was to compare TAVI with surgery for both bicuspid and tricuspid AS in low-risk patients 75 years of age or younger.

Methods:
The NOTION-2 trial enrolled and 1:1 randomized low-risk patients aged ? 75 years with severe symptomatic AS to TAVI or surgery. The primary endpoint was a composite of all-cause mortality, stroke or rehospitalization (related to the procedure, valve or heart failure) at 12 months.

Results:
A mean age of 71.1 years and a median risk score of 1.1% from the Society of Thoracic Surgeons were observed in the 370 individuals that were included. There were one hundred patients with bicuspid AS. 10.2% of the TAVI group and 7.1% of the surgical group experienced the primary endpoint at one year (absolute risk difference 3.1%; 95% confidence interval [CI], -2.7% to 8.8%; hazard ratio (HR) 1.4, 95% CI: 0.7 to 2.9; p=0.3). Patients who underwent TAVI were more likely to experience non-disabling stroke, permanent pacemaker implantation, moderate-to-greater paravalvular regurgitation, and reduced risk of significant hemorrhage and new-onset atrial fibrillation than those who underwent surgery. In patients treated with TAVI or surgery, the risk of the primary composite endpoint was 8.7% and 8.3% for tricuspid AS patients (HR 1.0, 95% CI: 0.5 to 2.3), and 14.3% and 3.9% for bicuspid AS patients (HR 3.8, 95% CI: 0.8 to 18.5) (P for interaction=0.1).

Conclusions:
When comparing TAVI versus surgery for severe symptomatic AS in low-risk patients under 75 years old, the composite rate of death, stroke, or rehospitalization at one year was comparable. Young bicuspid AS patients' TAVI results are cause for concern and demand more research.

Comment:
TAVI has now established itself as the procedure of choice for patients with symptomatic severe AS who are not suitable for surgery. With the introduction of TAVI, the success of TAVI brought to mind the idea that it could also be used in patients with medium and low risk for surgery. The superiority over surgical valve replacement in the results of successive TAVI studies such as SURTAVI, PARTNER 2A and PARTNER 3 increased the popularity of TAVI. NOTION 2 results similarly showed that TAVI may be an alternative in patients with severe AS. However, young patients with bicuspid aorta may be at a disadvantage that may increase the risk of the procedure, as in older patients. The NOTION 2 study will pave the way for examining patients with severe AS with bicuspid aorta in future studies.