Acurate Neo Still Falls Short of Sapien 3 in SCOPE 1-Year Follow-up

Longer-term follow-up from the head-to-head SCOPE I trial suggests that patients with aortic stenosis treated with the self-expanding Acurate neo (Boston Scientific) had similar clinical outcomes and functional improvements compared with those treated with the balloon-expandable Sapien 3 valve (Edwards Lifesciences). But as seen in the 30-day results presented at TCT 2019, the rate of paravalvular regurgitation remained significantly higher with Acurate neo.

The overall “hemodynamic profile,” as documented by the aortic valve mean pressure gradient and effective orifice area, however, was better with the neo than with Sapien 3.

Presenting the results during a late-breaking clinical science session at TCT Connect 2020, Thomas Walther, MD, PhD (University Hospital Frankfurt, Germany), said extended follow-up of these patients is necessary to determine the impact of the differential valve performance on long-term outcomes.

“I’m talking 3, 5, and hopefully 10 years,” said Walther. “Only then will we see if this supra-annular device has better or worse durability. This is early data.”

Howard Herrmann, MD (Hospital of the University of Pennsylvania/Penn Medicine, Philadelphia), who moderated the session, said comparative trials with different TAVR devices have been lacking but are invaluable for clinicians. “TAVR has really gotten to the point where it’s such a mature procedure we can treat the great majority of patients with any of several devices and get excellent outcomes,” he said. “The future is really going to be about understanding the nuances of each individual device so that we can get excellent outcomes in every patient, and that’s going to require these head-to-head trials to understand the small differences between devices.”

So far, however, current data suggest Acurate neo in its current design isn’t quite up to par with other devices, Herrmann said.

Although SCOPE I was underpowered for clinical events, such as mortality and stroke, the trends all went in the wrong direction with Acurate neo at 1 year. In addition, the device recently failed to demonstrate noninferiority at 30 days when compared with the self-expanding CoreValve Evolut (Medtronic) in SCOPE II, Herrmann pointed out.

Longer-Term Follow-up

In SCOPE I, clinical follow-up at 1 year was available in more than 96% of the 739 patients randomized in the trial. There was an absolute 3.0% higher risk of all-cause mortality with Acurate neo compared with Sapien 3, but the difference was not statistically significant (11.1% vs 8.1%; HR 1.32; 95% CI 0.82-2.12). Similarly, there was a numerically higher rate of all-cause mortality or disabling stroke with Acurate neo—12.5% versus 9.2% with Sapien 3—but again the difference was not significant.

Overall, there were improvements in NYHA functional class and quality of life from baseline to 1 year, with no significant differences between those treated with Acurate neo and those treated with Sapien 3.

At 1 year, just like at 30 days, significantly more patients treated with Acurate neo had moderate-to-severe aortic regurgitation (AR). Overall, 7.1% and 1.8% of patients had moderate and severe AR, respectively, compared with just 3.6% of patients treated with Sapien 3 who had moderate AR (there was no severe AR with Sapien 3 at 1 year). Walther pointed out that the majority of patients in both arms had only mild or no aortic incompetence.

In contrast, the effective orifice area was larger and aortic valve mean gradient lower with Acurate neo. In an analysis that focused on the clinical impact of AR, there was no difference in the risk of all-cause or cardiovascular death among patients with moderate/severe AR and those without AR. Similarly, there was no difference in the risk of all-cause or cardiovascular death among patients with mild AR compared with those without AR.  

“In the end, in this relatively short 1-year follow-up, aortic regurgitation didn’t play a role regarding patient deaths,” said Walther.

Following the presentation, Walther acknowledged the high rate of AR at 30 days and 1 year with Acurate neo, which he called “disappointing.” The next-generation Acurate neo2 is being slowly rolled out to some centers, he said, and the design has been tweaked to reduce the rate of paravalvular leak. As such, he is optimistic that better clinical outcomes will result from these design improvements. Nonetheless, he defended the 1-year findings, noting there was no statistical difference in any of the clinical events, and better hemodynamics with Acurate neo.

David Cohen, MD (Kansas City, MO), however, wasn’t completely sold, although he was intrigued by the findings. “Today, we would not tolerate a valve that has 10% moderate or severe paravalvular regurgitation. That’s not something we’re happy to see,” he said. “Nonetheless, this valve did have that and yet the quality of life was very similar. You wonder if there is some offsetting benefit or balance between the lower gradient and aortic regurgitation.”

In terms of use, Cohen doesn’t anticipate the first-generation Acurate neo will have a clinical role in the United States, even if approved, given the high rate of paravalvular regurgitation.

“I’m hopeful the next-generation device will seal better and get rid of the aortic regurgitation and then I could see this playing a particular role in places where we like to use self-expanding valves, where there is worry about annular rupture from annular calcification or outflow tract calcification, and where we need coronary access,” said Cohen. “That’s really the difference between this device and other self-expanding devices, like CoreValve. This has very, very nice coronary access through the very open frame in the supra-annular position.”  

Acurate neo gained European CE Mark approval in 2014.