Self-Expanding Evolut Valves Edge Out Sapien in Majority-Female TAVR Trial

ATLANTA — For transcatheter aortic valve replacement (TAVR) candidates with a small aortic annulus, the two leading platforms offered differing hemodynamic valve performances despite being similarly effective at 1 year, according to the SMART trial.

The composite endpoint of mortality, disabling stroke, or heart failure rehospitalization through 12 months reached 9.4% among such patients randomized to the supra-annular self-expanding (SE) Evolut platform, which met prespecified criteria for non-inferiority against the competing intra-annular balloon-expandable (BE) Sapien (10.6%, HR 0.90, 95% CI 0.56-1.43), reported Howard Herrmann, MD, of the University of Pennsylvania in Philadelphia.

Importantly, bioprosthetic valve dysfunction (BVD) rates through 12 months strongly favored the Evolut group (9.4% vs 41.6%, P<0.001), the difference driven by hemodynamic structural valve dysfunction (i.e., mean gradients 20 mmHg and higher) and non-structural valve dysfunction (severe patient-prosthetic mismatch [PPM] or moderate-or-worse total aortic regurgitation [AR]), Herrmann said in a presentation at the American College of Cardiology (ACC) annual meeting.

Mean gradients at 12 months also favored the Evolut group (7.7 vs 15.7 mmHg, P<0.001), as did effective orifice area (1.98 vs 1.50 cm², P<0.001) and incident moderate or severe PPM at 30 days (10.3% vs 35.1%, P<0.001).

“Based on the large differences observed in valve performance, we expect that the [self-expanding valve] will demonstrate improved valve durability and outcomes during longer follow-up,” Herrmann concluded. Findings from the SMART trial were simultaneously published in The New England Journal of Medicine.

ACC session discussant Suzanne Baron, MD, MSc, of Massachusetts General Hospital in Boston, called it an “incredible feat” that the investigators have conducted the largest randomized TAVR trial enrolling mostly women (over 85%) for the comparison of two common transcatheter devices for severe aortic stenosis.

A small aortic annulus is a common finding in women, a major group that had been underrepresented in the landmark TAVR trials.

“Women are underdiagnosed, undertreated, and underrepresented in clinical trials,” Herrmann said, noting that this may be in part due to their different presentation, typically later in the course of aortic stenosis. Sex differences also suggest women tend to have more diffuse fibrosis and less calcification, which appear to contribute to complications after TAVR. “For these reasons, it’s critically important to study women,” he stressed.

Baron said that for now, SMART’s results are “reassuring” as they suggest Evolut and Sapien TAVR can both be safe and effective treatments for severe aortic stenosis. Whether the curves separate over time was her concern.

Herrmann predicted that differences in outcomes will appear between 2 and 4 years for TAVR patients with small aortic annuli, as any small difference in device hemodynamics is magnified in this group. It might be no surprise that the Evolut confers better hemodynamics, given it is a relatively large implant fitting just above the annulus and features outlying struts that do not block leaflet movement, he explained during a press conference.

“There is no question that these data show that SE Evolut TAVR device results significantly less BVD, PPM, improved quality of life, which should lead to improved outcomes with later follow-up, which we are planning for all these patients,” SMART co-investigator Roxana Mehran, MD, of Mount Sinai School of Medicine in New York City, told MedPage Today.

Conducted in 13 countries, SMART included TAVR patients with severe symptomatic aortic stenosis and a small aortic valve annulus (≤430 mm²). The trial included all-comers across surgical risk categories.

Investigators had 737 patients randomized 1:1 to Evolut or Sapien TAVR. Mean age was just over 80, with over 85% women. The STS-PROM score was approximately 3.3%, and about 40% were classed as New York Heart Association functional class III or IV. About 4% of the cohort had bicuspid anatomy. Average aortic annulus size was just over 380 mm² in both groups.

The Evolut group received a Evolut PRO, Evolut PRO+, or Evolut FX device. The majority got a 26-mm device.

Sapien patients received a Sapien 3 or Sapien 3 Ultra device, nearly all at the 23-mm size.

The lack of between-group difference in clinical outcomes was supported by similar findings across the individual endpoints of mortality, disabling stroke, and heart failure rehospitalization.

Rate of pacemaker implants at 30 days (12.1 vs 7.8%) and 12 months (14.0% vs 9.3%) were statistically similar between the SE and BE TAVR groups. Mehran noted the systematic application of the cusp overlap technique by operators in this trial.

The SMART investigators acknowledged that their results may not be generalizable to other TAVR platforms.

During the press conference, Herrmann and Baron agreed that hemodynamics are among many factors that go into a heart team’s choice for a specific TAVR platform. These include concerns about vascular access, coronary access, conduction disease resulting in a need for a pacemaker, valve durability, and potential subsequent interventions during the patient’s lifetime.

“It’s a much more complex discussion than when we were starting to do TAVR 13 years ago,” Baron said.

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