Boston Scientific’s ACURATE trial may have missed its primary endpoint, but the company’s Acurate neo2 valve isn’t just another player in the TAVR market.
As a self-expanding device with unique design features, the Acurate neo2 combines the strengths of the market-leading TAVR valves, promising ease of use, great coronary access, and low pacemaker rates. So, a setback for this valve is more than just a strikeout for Boston Scientific—it’s a missed opportunity for the patients and physicians who stand to benefit.
After speaking with Michael Reardon, MD, a co-investigator on the trial, I’m convinced that this miss deserves a closer look, and the Acurate neo2 valve deserves another chance at the plate.
The investigational device exemption (IDE) trial evaluated the Acurate neo2 valve in the treatment of patients with severe, symptomatic aortic stenosis at low, intermediate, high, and extreme risk of open-heart surgery. The valve is CE marked in Europe but is not approved in the United States. The randomized IDE trial pitted Acurate neo2 against a pre-defined control valve, either Edwards Lifesciences’ Sapien valve or Medtronic’s Evolut TAVR system, selected at the discretion of the implanting physician.
Image of the Acurate Neo2, courtesy of Boston Scientific
Right off the bat, the investigational device was at a disadvantage in this trial.
“Here you have this brand-new valve that nobody in the U.S. is using, it’s just as we start with the first wave of COVID, it takes us four years to finish this, the average time between implants is three months, and there are only three sites that did more than one a month,” said Reardon, a professor of cardiothoracic surgery at Houston Methodist DeBakey Heart & Vascular Center.
Not only did the pandemic present staffing challenges, making it tough for the investigators to get the research personnel they needed, and patient recruitment challenges, but the global supply chain crisis made it tough to get the balloons needed for the procedure. So, even though TAVR cases were still being performed commercially every week with Sapien or Evolut, the research cases with Acurate were fewer and farther between.
“So, to compare a valve that is brand new to you every couple of months to one you’re doing every week, multiple times, that built in a bias,” Reardon told me.
To add insult to injury, this is the first time in TAVR that an IDE trial has done an all-risk analysis right off the bat. When Edwards and Medtronic were going through their TAVR trials, they started with patients who were at extreme and high risk for open surgery before studying the valves in the lower risk populations.
“If you look at the original trials, we started with high and extreme risk, we learned about the valve, we iterated the valve, and then we applied it to intermediate risk, and then we learned about the valve, we iterated the valve, and we applied it to the low risk [patients],” Reardon said. “Well, here we’re asked to do all-risk analysis with no chance to learn or to iterate.”
Unlike previous times in medical device history when a high-profile IDE trial failed to meet its primary endpoint, the investigators already know what the problem was. A post-hoc analysis identified and evaluated expanded and under-expanded Acurate neo2 valve frames within the trial. The company reviewed key procedural factors, including pre- and post-dilation, which helps to prepare for, enable, and confirm proper valve expansion during the procedure. It turns out that about 20% of the Acurate neo2 valves were under-expanded.
“Under expansion means I didn’t expand the valve out as far as it was supposed to go. So, if it doesn’t expand out as far as it’s supposed to go, it’s not going to work normally,” Reardon told MD+DI. “And we know that in the world of endovascular stuff, under expansion is a bad thing.”
Fortunately, there is technology available to help implanting physicians know how to spot under expansion, and it’s easy to fix at the time of the procedure if they know to look for it.
With limited trial familiarity among U.S. physicians and an all-risk analysis setup, Boston Scientific’s Acurate neo2 was almost starting with two strikes in the ACURATE trial.
Reardon said if the trial had been done similarly to the original TAVR trials the investigating physicians would have learned how to look for and treat under expansion by the time the new valve was being implanted into lower-risk patients.
U.S. TAVR physicians and their patients deserve to have another choice on the market. Especially because, as Reardon told me, this wouldn’t be just another valve on the shelf.
“It is a self-expanding valve that is short – it’s very hard to have a short self-expanding valve, all the other ones are tall,” he said. “And the reason you can do that is to have these stabilizing arms that come out distally and lock the valve into place and then let the self-expanding valve go out. And that’s quick, easy, and reproducible; and you have huge coronary access, and you have low pacemaker rates.”
If you look at Edwards’ Sapien balloon-expanding valve, what physicians love about it, Reardon said, is that it’s quick and easy, offers coronary access, and has low pacemaker rates.
“If you look at self-expanding valves, what people love about it is they have superior hemodynamics and commissural alignment, which I can now do with Acurate too,” Reardon said. “So, I get kind of a little bit of both in this particular valve.”
Boston Scientific noted that there are conversations going on with FDA regarding next steps for the Acurate neo 2 valve, and Reardon says he is hoping for a reasonable path forward.
“I think not having this valve available for consideration for our patients would be very unfortunate,” he said.
With the right training and adjustments, the Acurate neo2 valve could step up to the plate and knock it out of the park for U.S. physicians and patients.
This post was originally published on here
