ACURATE IDE Trial Reveals Challenges for FDA Approval of Acurate neo2 Valve for TAVI

 The ACCURATE neo2™ Aortic Valve System is a transcatheter aortic valve replacement (TAVR) device developed by Boston Scientific. According to the manufacturer, its key features include:

• Active PVseal™ Technology: A 60% larger sealing skirt designed to conform to the native aortic annulus, minimizing paravalvular leak (PVL).

• Open-Frame Design: Provides unrestricted coronary access, facilitating future interventions.

• Supra-Annular Leaflets: Positioned to achieve large effective orifice areas and low transvalvular gradients, enhancing hemodynamic performance.

• Top-Down Deployment Mechanism: Allows precise positioning and stabilization during implantation.

The ACURATE IDE trial has yielded disappointing results for the Acurate neo2 valve, intended for transcatheter aortic valve implantation (TAVI). The trial aimed to evaluate the valve's effectiveness compared to established devices but did not meet its primary endpoint of noninferiority. Specifically, at one year, the combined rate of all-cause mortality, stroke, or rehospitalization was 16.16% in patients treated with the Acurate neo2 compared to 9.53% for those receiving Evolut or Sapien valves. This difference did not satisfy the criteria for noninferiority, as reported by lead investigator Michael Reardon, MD, from the Houston Methodist DeBakey Heart & Vascular Center.

Reardon proposed several potential reasons for these unsatisfactory results, including disruptions from the COVID-19 pandemic, operator experience, and supply chain issues. He noted that many operators had limited experience with the Acurate neo2, likely contributing to underexpansion of the valve frame in about 20% of cases. “Valve underexpansion is something that the whole field is starting to recognize now as a real problem for long-term valve outcomes,” he stated. He emphasized that when only well-expanded valves were analyzed, outcomes were comparable to those of control valves.

Despite these challenges, Reardon believes that the Acurate neo2 should not be dismissed outright. He highlighted its unique features, such as top-down deployment, allowing for precise positioning similar to balloon-expandable valves while retaining self-expanding benefits. He expressed optimism that with further testing focused on ensuring proper expansion, the valve could still demonstrate effectiveness and merit FDA approval.

Looking forward, future research directions include conducting additional studies to better understand and mitigate valve underexpansion issues. Reardon suggested creating educational resources and checklists for operators to help identify and correct underexpansion during procedures. This proactive approach aims to ensure that if operators achieve full expansion, clinical outcomes may align more closely with those seen in existing valve platforms.

Presented in TCT 2024