Small Annuli Randomized to Evolut or SAPIEN Trial - SMART

Apr 07, 2024
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Author/Summarized by Author:
Anthony A. Bavry, MD, MPH, FACC
Summary Reviewer:
Kim A. Eagle, MD, MACC
Trial Sponsor:
Medtronic
Date Presented:
04/07/2024
Date Published:
04/07/2024
Original Posted Date:
04/07/2024
References

Contribution To Literature:

The SMART trial showed that a self-expanding valve is noninferior to a balloon-expandable TAVR valve despite having a lower mean Doppler-derived gradient.

Description:

The goal of the trial was to evaluate a self-expanding valve compared with a balloon-expandable valve among patients with aortic stenosis and a small aortic annulus undergoing treatment with transcatheter aortic valve replacement (TAVR).

Study Design

  • Randomized
  • Parallel
  • Stratified

Patients with aortic stenosis and a small aortic annulus undergoing TAVR were randomized to a self-expanding valve (n = 355) vs. a balloon-expandable valve (n = 361). Patients in the self-expanding valve group were treated with the Evolut Pro/Pro+/Fx valves. Patients in the balloon-expandable valve group were treated with the Sapien 3 Ultra valve.

  • Total number of enrollees: 716
  • Duration of follow-up: 12 months
  • Mean patient age: 80 years
  • Percentage female: 88%
  • Percentage with diabetes: 29%

Inclusion criteria:

  • Symptomatic severe aortic stenosis
  • Small aortic annulus defined as CT area ≤4.3 cm2

Other salient features/characteristics:

  • Bicuspid aortic valve, 4%
  • Mean aortic annulus, 3.8 cm2

Principal Findings:

The first co-primary outcome (death, stroke, or heart failure hospitalization) at 12 months was 9.4% in the self-expanding valve group vs. 10.6% in the balloon-expandable valve group (p for noninferiority < 0.001).

The second co-primary outcome (bioprosthetic valve dysfunction, defined as mean gradient ≥20 mm Hg, severe prosthesis-patient mismatch, or ≥ moderate aortic regurgitation, thrombosis, endocarditis, or re-intervention) at 12 months was 9.4% in the self-expanding valve group vs. 41.6% in the balloon-expandable valve group (p for superiority < 0.001).

Secondary outcomes:

  • Mean gradient ≥20 mm Hg: 3.2% in the self-expanding valve group vs. 32.2% in the balloon-expandable group
  • Severe prosthesis-patient mismatch or ≥ moderate aortic regurgitation: 5.9% in the self-expanding valve group vs. 18.2% in the balloon-expandable group
  • Clinical valve thrombosis: 0.3% in the self-expanding valve group vs. 0.3% in the balloon-expandable group
  • Endocarditis: 0.6% in the self-expanding valve group vs. 2.3% in the balloon-expandable group
  • Reintervention: 0.9% in the self-expanding valve group vs. 0.6% in the balloon-expandable group
  • Permanent pacemaker at 30 days: 12.1% in the self-expanding valve group vs. 7.8% in the balloon-expandable valve group (p = 0.055)
  • Valve embolization at 30 days: 1.1% in the self-expanding valve group vs. 0% in the balloon-expandable valve group (p = 0.043)
  • Mean gradient at 12 months: 7.7 mm Hg in the self-expanding valve group vs. 15.7% in the balloon-expandable valve group (p < 0.001)
  • Mean effective orifice area at 12 months: 1.98 cm2 in the self-expanding valve group vs. 1.5 cm2 in the balloon-expandable valve group (p < 0.001)

Interpretation:

Among patients with severe aortic stenosis and a small aortic annulus, a self-expanding valve was noninferior to a balloon-expandable TAVR valve despite having lower mean Doppler-derived gradients. Other lines of evidence have shown that among patients with a similarly sized aortic annulus, self-expanding valves have lower Doppler-derived aortic valve gradients compared with balloon-expandable valves. However, this difference is no longer observed when considering invasive-derived aortic valve gradients for self-expanding valves compared with balloon-expandable valves. Accordingly, it is unknown if the second co-primary outcome in this trial would have been different if invasive gradients, rather than Doppler gradients, were examined 12 months after the valve procedure. The relatively short follow-up in this trial may not have been long enough to detect a difference in clinical outcomes between valve types.

References:

Herrmann HC, Mehran R, Blackman DJ, et al., on behalf of the SMART Trial Investigators. Self-Expanding or Balloon-Expandable TAVR in Patients With a Small Aortic Annulus. N Engl J Med 2024;Apr 7:[Epub ahead of print].

Presented by Dr. Howard C. Herrmann at the American College of Cardiology Annual Scientific Session (ACC.24), Atlanta, GA, April 7, 2024.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease

Keywords: ACC24, ACC Annual Scientific Session, Coronary, Peripheral, and Structural Procedures, Valvular Diseases


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