Dr. Ömer Furkan Demir

Name of the study: One-year Outcomes of ACURATE neo2 vs Approved TAVR Devices in All-risk patients with Severe AS: the ACURATE IDE trial

Published in congress: TCT 2024

Link:     https://www.acc.org/Latest-in-Cardiology/Clinical-Trials/2024/10/29/03/43/acurate-ide

Introduction:
Transcatheter aortic valve implantation (TAVI) has been shown to be no better or inferior to surgical aortic valve replacement in a series of randomized clinical trials. These studies have primarily demonstrated the efficacy of the balloon-expandable SAPIEN (Edwards Lifesciences) and self-expanding CoreValve/Evolut (Medtronic) devices.

Objective:
The aim of this study was to compare the Acurate neo2 self-expanding valves with the previously proven Sapien or Evolut valves in patients with advanced aortic stenosis who were followed up and scheduled for TAVI.
The Acurate neo valve is a self-expanding valve and has an open-cell structure to avoid obstructing the coronary circulation. It also has an outer skirt to prevent paravalvular leakage and axial stabilization belts to better stabilize the valve position.

Methods:
In the study, patients with advanced aortic stenosis were randomly divided into 2 groups as Acurate neo2 self-expandable valve (n=752) and other valves on available (n=748; 504 Sapien and 244 Evolut). Inclusion criteria for the patients were having a diagnosis of severe aortic stenosis and aortic annulus dimensions between 21-27 mm. Exclusion criteria were; bicuspid aortic valve, pre-existing prosthetic aortic or mitral valve, severe aortic or mitral insufficiency, severe calcification in the aortic annulus, presence of hypertrophic cardiomyopathy, severe vascular disease, having had an acute myocardial infarction within the last month, having had a stroke or TIA within the last 6 months, renal failure, having a history of endocarditis within the last 6 months, having hemodynamic instability, and untreated coronary artery disease. The primary endpoint of the study was all-cause mortality, stroke and rehospitalization.

Results:
A total of 1500 patients were included in the study. Patients were followed for 12 months after TAVI procedure. The mean age of the patients included in the study was 78 years and 53% of the patients were female. The primary outcome of all-cause death, stroke or rehospitalization was 16.16% in the Acurate neo2 group and 9.53% in the conventional TAVI group.
When the results were examined separately, 1-year mortality (5.0% vs. 3.9%), stroke (5.7% vs. 3.4%) and rehospitalization (5.3% vs. 3.5%) were all individually more observed in the Acurate neo2 group. The mean aortic valve gradient evaluated by echocardiography after the procedure was calculated as 8 mmHg in the Acurate neo2 group, 11.6 mmHg in the Sapien group and 7 mmHg in the Evolut group. Mild paravalvular insufficiency at discharge was found to be 23% in the Acurate neo2 group, 6.7% in the Sapien group and 28% in the Evolut group. Moderate paravalvular insufficiency at discharge was found to be 1% in the Acurate neo2 group, 0% in the Sapien group and 0.8% in the Evolut group. Severe paravalvular insufficiency at discharge was; It was determined as 0.1% in the Acurate neo2 group, 0% in the Sapien group and 0% in the Evolut group.
Approximately 20% of the Acurate neo2 group had inadequate valve expansion. When the primary outcomes were examined in this group; 18.8% of those with inadequate valve expansion and 12.4% of those with good valve expansion occurred (p=0.05).

Conclusions:
Based on these results, the Acurate IDE study demonstrated that the Acurate neo2 valve is no better than other valves used on the market.

Comment:
In patients with severe aortic stenosis, the Acurate neo2 valve has not been shown to be non-inferior to other valves on the market (Sapien and Evolut). All-cause mortality, stroke and rehospitalization tended to be higher in the Acurate neo2 group compared to the conventional TAVI group. Echocardiographically assessed transvalvular gradients were relatively low in this group (8.0%); however, there was a relatively high incidence of paravalvular insufficiency (23% mild, 1.0% moderate, 0.1% severe).
Michael Reardon, who led the study, offered a number of theories as to why the trial did not yield the hoped-for results, including the impact of the COVID pandemic on recruitment, staffing, supply chain issues, and operator experience. He noted that only 10% of operators had the chance to perform more than 10 cases with the new valve. In a retrospective review of cases, it was found that approximately 20% of the Acurate neo2 valve group had inadequate valve rim expansion, something that could have been easily corrected if detected during the procedure. He noted that in analyses with well-expanded valves alone, the results were much more similar between the trial arms.
With these results, Acurate neo2 appears to be an alternative to other valves for now, but is not a true competitor to transcatheter heart valves such as Evolut and Sapien.