Boston Scientific (NYSE:BSX) announced that its Acurate neo2 aortic valve system failed to meet the primary endpoint in the ACURATE IDE study. The trial evaluated the Acurate neo2 transcatheter aortic valve replacement (TAVR) system for patients with severe, symptomatic aortic stenosis across various risk levels. Data presented at Transcatheter Cardiovascular Therapeutics (TCT) 2024 revealed a statistically significant difference in the composite rate of all-cause mortality, stroke, or rehospitalization at one year compared to a control valve.
The ACURATE IDE study compared Acurate neo2, Boston Scientific’s second-generation TAVR technology, against a control arm consisting of either the Edwards Sapien or Medtronic Evolut valves, selected at the physician's discretion. The trial enrolled patients with severe, symptomatic aortic stenosis deemed to be at low, intermediate, high, and extreme risk for open-heart surgery.
Primary Endpoint Missed
The study results showed a 16.16% composite rate of all-cause mortality, stroke, or rehospitalization at one year in the Acurate neo2 arm, compared to 9.53% in the control arm. This difference did not meet the pre-specified criterion for non-inferiority, with a non-inferiority posterior probability of 77.9%, falling short of the 97.5% threshold.
Post-hoc Analysis Reveals Impact of Valve Expansion
Boston Scientific conducted a post-hoc analysis to assess the impact of Acurate neo2 valve expansion. The analysis identified that approximately 20% of implanted valves were under-expanded. Patients with fully expanded Acurate neo2 valves showed similar rates of death, stroke, or rehospitalization at one year compared to the control group. However, patients with under-expanded valves experienced worse outcomes.
Dr. Michael Reardon, professor of cardiothoracic surgery at Houston Methodist DeBakey Heart & Vascular Center and co-principal investigator of the ACURATE IDE trial, noted the challenges of conducting the trial over 47 months, including during the COVID-19 pandemic. He stated, “These data add to the breadth of clinical knowledge of the ACURATE valve platform and provide compelling insights on the importance of procedural optimization that will be beneficial for TAVR moving forward.”
Future Plans for Acurate neo2
Despite the trial's outcome, Boston Scientific intends to continue working with the FDA to pursue regulatory approval for the Acurate platform in the U.S. The company believes that further investigation into procedural techniques to mitigate valve under-expansion may improve outcomes.
Dr. Janar Sathananthan, chief medical officer, Interventional Cardiology Therapies, Boston Scientific, commented on the broader implications of the findings: “We believe the findings from the ACURATE IDE post-hoc analysis and implementation of steps to mitigate valve under-expansion may improve outcomes for the ACURATE valve and have important implications on other commercially available TAVR valves, and we look forward to studying these improved techniques in future trials of the device.”
Analyst Perspective
Needham analyst Mike Matson suggested that the trial's extended duration and the impact of the COVID-19 pandemic may have affected the results, potentially due to disruptions in enrollment and reduced opportunities for centers to gain experience with the Acurate neo2 system. Matson also noted that the results might impact the valve's pathway to FDA approval, potentially requiring additional clinical data.
