NEOPRO: Two Next-Gen TAVR Valves Show Promise at 30 Days

SAN DIEGO, CA—An observational comparison of two next-generation, self-expanding transcatheter heart valves shows similar success rates and clinical outcomes at 30 days, with researchers attributing differences in bleeding, vascular complications, and pacemaker rates to delivery and design features.

“It’s important to have [these] type of comparisons,” remarked Mayra Guerrero, MD (Mayo Clinic, Rochester, MN), who was not involved in the study, during a media briefing at TCT 2018. “Opposite to what we have said for stents, [where] the bar is so high already and it's hard to make it perfect, . . . we’re not there yet with transcatheter valves in any position. I think the fact we’re seeing another choice of a self-expandable valve that may not compromise access to the left coronary to me is very valuable.”

For the NEOPRO study, Azeem Latib, MB, BCh (EMO-GVM Centro Cuore Columbus, Milan, Italy), who presented the results today in a late-breaking clinical science session, and colleagues retrospectively looked at 1,551 patients who underwent TAVR with either the Acurate neo (Boston Scientific) or Evolut PRO (Medtronic) valves at 24 centers between January 2012 and March 2018. Both devices are self-expanding, are supra-annular in design, and have pericardial sealing skirts. However, the Acurate neo requires delivery through a larger sheath and has lower radial strength compared with Evolut PRO.

Overall, the primary endpoint of VARC-2 device success was reached in 92.0% and 90.7% of the patients treated with Acurate neo and Evolut PRO, respectively (P = 0.539). Results were similar in the propensity score matched population (90.6% vs 91.6%; P = 0.751). There were also no differences in moderate-to-severe paravalvular regurgitation between the devices in the overall study (5.2% vs 5.7%; P = 0.659) or in the propensity cohort (7.3% vs 5.7%; P = 0.584).

However, the rate of any bleeding was higher in the Acurate neo arm (14.9% vs 8.5%; P = 0.004), and this was driven by a higher rate of minor bleeding. Vascular complications were also more frequent with Acurate neo (17.1% vs 11.6%; P = 0.025), but the rate of new permanent pacemakers was higher with Evolut PRO (8.8% vs 13.2%; P = 0.045).

At baseline, patients who received the Acurate neo (n = 1,263) had less peripheral vascular disease, were more likely to be classified as NYHA class III-IV, and tended to have less calcified aortic valves compared to those who were implanted with Evolut PRO (n = 288). Also, TAVR with Evolut PRO was associated with more conscious sedation, less pre- and postdilatation, less pericardial tamponade, and a lower mean aortic valve gradient.

An “important bias” in this study, Latib highlighted, is that because Evolut PRO costs more than Evolut R in Europe, “in most centers, physicians will prepare to pay the extra money for the more complex patients. Physicians selected Evolut PRO when they saw more severe calcification because there was a significant price difference, and that's I think to be taken into account.”

Correcting for Confounders

A challenge with observational analyses “is the selection that physicians have,” noted Ajay Kirtane, MD (NewYork-Presbyterian/Columbia University Irving Medical Center, New York, NY), during the media briefing. “Did you find . . . that sites used more of one than the other? Were sites using both? Were there specific clinical characteristics that were difficult to adjust for that might have led a site or a doctor to use one versus the other?” he asked.

“The one thing we were worried about, because the study is over a long period, was is there a learning curve, in particular with the neo valve,” Latib replied, adding that they noticed that device success was lower with Acurate for the first 2 years it was available with the caveat that fewer procedures were being performed at that stage. “In individual centers that had both valves, there was no difference in the subanalysis, but when you look at the baseline characteristics, there clearly were differences. The difference was that physicians in more calcified anatomies were choosing the Evolut PRO because it had more radial strength and in less calcified anatomies choosing the Acurate.”

Panelist Lars Søndergaard, MD, DMSc (Rigshospitalet, Copenhagen, Denmark), said that it is important to pay attention to the fact that different centers have different thresholds for what constitutes moderate regurgitation and also varying preferences for valve choice, especially in a propensity analysis like this one.

Latib acknowledged that “we can never correct for all the confounders, but what we tried to do in a retrospective way is find and identify outliers,” especially with regard to paravalvular leak and pacemaker rates. He also noted that they excluded patients with prior pacemakers, because “that has been a huge limitation of previous studies. . . . I think everybody should be reporting pacemaker rates, excluding patients already on pacemakers,” in order to identify the true rate of new pacemaker use.  

Both of these devices are clinically used in Europe and “have become standard of practice in many centers,” Latib said. While the Evolut PRO was approved by the US Food and Drug Administration for use last year, the Acurate neo is not commercially available in the US. However, Latib said, the pivotal trial for the latter device is planned for next year. “I think this [research] maybe gives some idea of what possible event rates will be in that study, but I think it also I hope helps physicians in making decisions about tailoring the choice of valve for your patient,” he concluded.