Transcatheter valves starting from top left (clockwise): Sapien 3; Direct Flow Medical; CoreValve; Portico; and Lotus. These valves are currently not approved by the FDA. Pictures reprinted with permission.
With the November 2011 FDA approval of the Sapien valve, transcatheter aortic valve replacement became available in the United States, offering a less invasive alternative — and hope for improved quality of life — to patients with inoperable aortic stenosis. Then, less than a year after this development, the FDA approved an expanded indication for the Sapien device to include the treatment of high-risk surgical candidates.
Since becoming an option for high-risk patients, TAVR has increasingly become the preferred treatment in this patient population, according to Howard C. Herrmann, MD, director of the Interventional Cardiology Program and Cardiac Catheterization Labs at the Perelman School of Medicine at the University of Pennsylvania, Philadelphia.
“When given a choice, patients who are in the high-risk category and are eligible for TAVR invariably choose TAVR,” Herrmann said. “Using the baseball analogy of ‘tie goes to the runner,’ in this case, tie goes to the less invasive therapy.”
Robert Kipperman, MD, associate director, Advanced Interventional Therapeutics Program, Morristown Medical Center, Morristown, N.J., agreed. “Over time, the volume has increased and I do feel TAVR is the preferred treatment,” he said. “As the word has gotten out, many patients are being treated who would have not been referred in the past.”
The appeal of a less invasive procedure, along with promising clinical trial data, continues to drive the momentum toward the increased use of TAVR in treating patients with aortic stenosis (AS). Surgery is still considered superior in low- and moderate-risk patients with AS, and TAVR has been linked to increased stroke, vascular complications and paravalvular leak. However, the promise of a less invasive alternative has spurred device manufacturers to rectify these flaws through next-generation TAVR devices. These investigational devices, which include the second-generation Sapien XT (Edwards Lifesciences) and third-generation Sapien 3, are designed to improve upon the technology of the original Sapien.
Faisal G. Bakaeen
“The future devices are going to be lower profile, retrievable, and with more versatility in terms of access and positioning,” said Faisal G. Bakaeen, MD, chief of cardiothoracic surgery at the Michael E. DeBakey VA Medical Center and associate professor of surgery at Baylor College of Medicine, Houston. “There are going to be less paravalvular leaks and access complications.”
According to Bakaeen, it is not yet clear which of the investigational valves is superior, or which will ultimately prevail in the race for FDA approval.
“It is a horse race,” he said. “Obviously, [Sapien XT] and CoreValve are ahead of the game, but the competition is fierce. Product quality and ease of use are going to be important considerations.”
Besides receiving FDA approval for inoperable and high-risk surgical candidates, the Sapien valve can also be implanted via the transfemoral and transapical access routes. Initially approved for transapical access in October 2012, the FDA approved an update to the Ascendra transapical delivery system, Ascendra 3, in July. The Ascendra 3 system can be used with Sapien and features a nose cone, improved user controls, shorter working length and an ergonomic sheath.
“This new technology will greatly enhance our ability to deliver the Sapien transcatheter heart valves to our patients,” Bakaeen said.
Although not yet FDA approved, the Sapien XT valve marks the next step in the development of Sapien transcatheter valve, utilizing the lower-profile 18F Novaflex transfemoral delivery system. It has a balloon-expandable cobalt chromium frame and bovine pericardial tissue leaflets. The Sapien XT treats an annulus size range of 18 mm to 27 mm, and all valve sizes are available for transapical or transfemoral delivery. The Sapien XT has gained a CE mark, but remains investigational in the United States.