MUNICH, GERMANY — In the hands of experienced operators, the self-expanding Acurate Neo (Boston Scientific/Symetis) and balloon-expandable Sapien 3 (Edwards Lifesciences) valves resulted in very high success rates for both devices but with some distinguishing valve characteristics, new research shows[1].
Among 933 patients undergoing transcatheter aortic-valve replacement (TAVR), the Acurate Neo was associated with more paravalvular leakage than the Sapien 3 (4.8% vs 1.8; P=0.008), but this was offset by lower rates of elevated (>20 mm Hg) valve gradients (3.2% vs 6.9%; P=0.021).
Use of the Acurate Neo valve was also associated with a lower need for permanent pacemaker implantations (9.9% vs 15.5%; P=0.024), according to the study, published in the October 23, 2017 issue of JACC: Cardiovascular Interventions.
“There are certain characteristics of the valves that are really visible up to a certain degree that are astonishing to us, such as the gradients in the balloon-expandable valves. We didn’t expect that at all,” senior author Dr Christian Hengstenberg (German Heart Center, Munich) told theheart.org | Medscape Cardiology.
Mean transvalvular gradients were significantly lower with the Acurate Neo than the Sapien 3 before discharge (9 mm Hg vs 13 mm Hg; P<0.001) and at 30 days (8 mm Hg vs 12 mm Hg; P<0.001), a benefit observed in all three valve sizes used.
Hengstenberg and his colleagues credit the lower gradients and permanent pacemaker implantation rate to the design of the Acurate Neo, which allows top-down deployment and anchoring of the nitinol valve in a supra-annular position, whereas with the Sapien 3, both the struts of the stent and the valve are anchored in the annulus.
“With the top-down implantation process you usually don’t touch the conduction system at all. So the radial force on the conduction system is probably less with the Symetis as compared with the Edwards valve, and this has been quite consistently shown in many publications,” he said.
No head-to-head comparative data are available for the Sapien 3 valve, approved in the US in June 2015, and the Acurate Neo, which received CE mark in Europe in 2014 but remains investigational in the US.
In an effort to fill this gap, the investigators used nearest-neighbor matching to identify 622 patients treated with Sapien 3 (23-, 26, or 29-mm) and 311 treated with Acurate Neo (small, medium, large) among 1121 consecutive patients with symptomatic severe aortic stenosis at three high-volume centers in Germany between January 2014 and January 2016.
Patients treated with the Acurate Neo were more symptomatic (82% vs 75% NYHA class 3 or 4), while those treated with the Sapien 3 had a larger aortic annular area (4.8 cm2 vs. 4.4 cm2), a difference that remained after matching.
Device failure rates were similar between the Acurate Neo and Sapien 3 groups (10.9% vs 9.6%; P=0.708) and in the subgroup with heavily calcified or eccentric annuli.
The Acurate Neo and Sapien 3 also had comparable in-hospital complications, including stroke, major vascular complications, and life-threatening bleeding; 30-day mortality (2.3% vs 1.9%); and the VARC 2–defined early safety composite end point at 30 days (15.8% vs 15.6%).
Despite the potential advantage of more predictable and accurate deployment with the Acurate Neo, however, “there was no specific evidence of improved device accuracy,” Dr Kreton Mavromatis (Emory University, Atlanta, GA) writes in an accompanying editorial[2].
Both valves were placed in the correct position in 99% of cases, and there was no difference in the need for multiple valves or conversion to surgical valve replacement.
He also points out that the Sapien 3 permanent pacemaker implantation rate, although consistent with early studies, is higher than what is now expected given the shift toward a shallower implantation depth. “Whether procedural changes (such as less aggressive predilation) may also result in lower permanent pacemaker implantation requirements with Acurate Neo remains to be seen,” he added.
Predilation was used in 95.8% of Accurate Neo and 74.3% of Sapien 3 patients, and postdilation in 42.1% vs 23.8%, respectively.
“Because this is a self-expanding valve, you can have a sort of borderline radial force, so if you haven’t prepared your valve properly it might be a problem not only crossing but with obtaining good clinical results, which is why predilation is mandatory for us; and this also explains the rate of postdilation,” Hengstenberg said. “For the Sapien, however, we don’t think you usually need predilation, but this is a three-center study, so there are different opinions.”
Mavromatis observed that two ongoing randomized trials, SCOPE I and SCOPE II, comparing Acurate Neo with Sapien and Medtronic’s Evolut valve, may help identify differences that could distinguish the Acurate Neo in an increasingly crowded market.
But, “perhaps most important” to the Acurate Neo’s future, he added, is the commitment of Boston Scientific, which acquired Symetis in May 2017 and appears to have its repositionable Lotus valve ahead of the Acurate Neo in the US approval process. “How long and how intensely Boston Scientific will develop both valves remains to be seen.”
In Germany, Hengstenberg said the Acurate Neo is running behind the Sapien and Evolut R valves with roughly a 7% or 8% market share, the same as the Lotus before concerns about premature pin release prompted a worldwide recall of all Lotus valves from commercial and clinical sites in February 2017.
“In my view, the Symetis valve is more or less an all-comer valve like the Sapien valve, but in patients with left ventricular outflow track calcification, that’s a no-go for me with balloon-expandable valves,” he said.
Hengstenberg has reported proctor fees and speaker honoraria from Edwards Lifesciences and Symetis. Disclosures for the coauthors are listed inthe paper. Mavromatis reported no relevant financial relationships.
Follow Patrice Wendling on Twitter: @pwendl. For more from theheart.org | Medscape Cardiology, follow us on Twitter and Facebook.
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