October 15, 2020
Symetis Acurate Neo TAVR Device Fails to Show Noninferiority in SCOPE II Trial
October 15, 2020—In the randomized SCOPE II clinical trial, a new self-expanding bioprosthetic valve used in transcatheter aortic valve replacement (TAVR) failed to demonstrate noninferiority compared to an existing self-expanding valve. The trial was designed to compare the clinical outcomes of the Symetis Acurate Neo self-expanding transcatheter heart valve (Boston Scientific Corporation) and the CoreValve Evolut R TAVR system (Medtronic). CERC, the Cardiovascular European Research Center in Massey, France, sponsored the trial.
The SCOPE II findings were presented at TCT Connect, the 32nd annual Transcatheter Cardiovascular Therapeutics scientific symposium of the Cardiovascular Research Foundation held online October 14–18, 2020. The study was simultaneously published online by SCOPE II principal investigator Corrado Tamburino, MD, et al Circulation.
“TAVR with the Acurate Neo valve did not meet noninferiority compared with the CoreValve Evolut bioprosthesis with respect to a composite of death or stroke at 1 year,” commented Dr. Tamburino in the TCT Connect announcement. “In a secondary analysis with limited statistical power, cardiac death was increased at 1 year in patients who received the Acurate Neo valve. The two valves also differed with respect to technical characteristics such as degree of aortic regurgitation and need for new permanent pacemaker implantation.”
According to TCT press release, SCOPE II was composed of 796 patients, aged ≥ 75 years, with symptomatic severe aortic stenosis and an indication for transfemoral TAVR as agreed by the Heart Team. The patients were recruited at 23 tertiary heart valves centers in Denmark, France, Germany, Italy, Spain, and the United Kingdom. The patients were randomly assigned (1:1) to receive treatment with the Acurate Neo (n = 398) or the CoreValve Evolut (n = 398).
The primary safety endpoint, powered for noninferiority of the Acurate Neo valve using a noninferiority margin of 6%, was the composite of all-cause mortality or stroke at 12 months. The primary efficacy endpoint, powered for superiority, was new permanent pacemaker implantation at 30 days. Secondary endpoints included clinical efficacy and safety endpoints at 30 days and 12 months.
As summarized in the TCT announcement, the intention-to-treat analysis found that the rate of death or stroke at 1 year was 15.8% in the Acurate Neo group compared to 13.9% in the CoreValve Evolut group. In the per-protocol analysis, the rate of death or stroke was 15.3% for Acurate Neo versus 14.3% for CoreValve Evolut. Noninferiority of the Acurate Neo was not met for the primary endpoint in the intent-to-treat analysis, while it was met in the per-protocol analysis. Because of these inconsistent results, noninferiority was not established for the primary endpoint based on the prespecified statistical plan, concluded the investigators.
Acurate Neo versus CoreValve Evolut demonstrated the following secondary endpoints:
- New pacemaker implantation at 30 days was 10.5% verus 18.0% (risk difference, -7.5%; 95% CI, -12.4 to -2.60; P = .0027)
- Cardiac death was 2.8% versus 0.8% (P = .03) at 30 days and 8.4% vs 3.9% (P = .01) at 1 year
- Rate of moderate-severe aortic regurgitation was 9.6% versus 2.9% (P < .0001) at 30 days and 4% versus 3.3% (P < .0001) at 1 year.