Results of a randomized trial presented at TCT 2019 and simultaneously published in The Lancet, showed that TAVR with the self-expanding ACURATE neo (Boston Scientific) did not meet non-inferiority compared to the balloon-expandable SAPIEN 3 (Edwards Lifesciences) in terms of early safety and clinical efficacy outcomes.
SCOPE I is the first randomized clinical trial to look for the difference between ACURATE neo and SAPIEN 3 in terms of safety and efficacy. Jonas Lanz, MD of Bern University Hospital, Switzerland, presented the results at TCT 2019 that provide enough incentives to conduct more trials targeting TAVR.
In an interview with Dr. C. Michael Gibson, Dr. Lanz expressed, “TAVR has been an incredible success story, and with the low risk trials, it is now a valid option across the whole spectrum of surgical risk. And as findings of these landmark trials may not be applicable to all the other devices which are out there commercially available (because they have large differences in their properties), the next logical step would be, head-to-head trials. And that’s what we did.”
The Trial
A randomized non-inferiority trial conducted over a period of 2 years (from February 2017 to February 2019) at 20 tertiary heart valve centers in Germany, the Netherlands, Switzerland, and the UK, recruited 739 participants (aged ≥ 75 years with a mean age of 83 years) undergoing transfemoral TAVR for the treatment of symptomatic severe aortic stenosis, and who were considered to be at increased surgical risk. Major exclusion criteria involved congenital anomaly of aortic valve, left ventricular-ejection fraction < 20%, planned procedures, or stroke/MI in the last 30 days.
The primary composite safety and efficacy endpoint comprised all-cause death, any stroke, life-threatening or disabling bleeding, major vascular complications, coronary artery obstruction requiring intervention, acute kidney injury (stage 2 or 3), rehospitalization for valve-related symptoms or congestive heart failure, valve-related dysfunction requiring repeat procedure, moderate or severe prosthetic valve regurgitation, or prosthetic valve stenosis within 30 days of the procedure.
Within the follow-up of 30 days (available for 99% of the participants from both ACURATE neo [367 of 372] and SAPIEN 3 [364 of 367] groups), the primary endpoint occurred in 23.7% of the participants in the ACURATE neo and in 16.5% in the SAPIEN 3 group; thus, non-inferiority of the ACURATE neo was not met (absolute risk difference 7·1% [upper 95% confidence limit 12·0%], p = 0·42) and the FDA approved SAPIEN 3 appeared superior (95% CI for risk difference −1·3 to −12·9, p = 0·0156)
The constraints on this study that can highlight the reason why ACURATE neo could not perform well can involve the fact that the study was not powered for individual clinical endpoints, it was single-blinded, there was lack of pre-assessment of aortic root CT angiographies by a central core laboratory, and there was limited evaluation of device differences due to an early primary endpoint.
Point of View
Transfemoral Transcatheter Aortic Valve Replacement (TF-TAVR) has absolutely become an indispensable treatment modality for symptomatic severe aortic valve stenosis. The testing of a valuable question, to assess the differences between a novel self-expanding TAVR prosthesis and a balloon-expandable one, indeed makes the case for further head-to-head trials addressing various devices that are commercially available.