November 11th, 2011
Shaky Start Ends STACCATO
The STACCATO trial planned to randomize 200 low-risk patients to transcatheter aortic heart valve implantation (TAVI) via the transapical approach (with the Sapien valve from Edwards Lifesciences) or surgical aortic valve replacement (AVR). The primary endpoint was a composite of death, stroke, and renal failure at one month. After enrolling only 70 patients (34 TAVI and 36 surgical AVR), the study was stopped prematurely by the data safety and monitoring board because of an excess of events in the TAVI arm. The primary endpoint was met in five patients in the TAVI group (2 deaths, 2 strokes, and 1 case of renal failure) and one patient (stroke) in the AVR group.
It is distinctly unusual to stop a study prematurely after only one third of the enrollment has occurred.
What went wrong?
2) Were the physicians inadequately trained or inept?
3) Were the patients selected for TAVI unsuitable for it?
4) Is application of TAVI to low-risk patients inappropriate?
As a condition of FDA approval of the Sapien valve, Edwards Lifesciences committed to monitoring the outcomes with the valve through a national registry on transcatheter valve therapy. The American College of Cardiology and the Society of Thoracic Surgeons have been working with the FDA and the Centers for Medicare and Medicaid Services to create this national registry, which will serve as a platform for post-market evaluation of the Sapien valve and future transcatheter devices.
However, STACCATO sends a clear message. To quote our NASA friends, “Houston, we have a problem.”
It’s critical that we find out what went wrong in STACCATO before Edwards embarks on its ambitious efforts to roll out TAVI to 150-250 sites in the first year of commercialization.