SAN FRANCISCO – Food and Drug Administration approval of the SAPIEN XT transcatheter aortic valve for the valve-in-valve indication in high–surgical risk patients means that, officially, there are now two options for transcatheter replacement of a faulty prosthetic aortic valve.
CoreValve, the competing device for transcatheter aortic valve replacement (TAVR) in U.S. practice, received FDA approval for the valve-in-valve indication in March.
Researchers reported the data behind SAPIEN XT’s approval from two U.S. registries with a total of 197 high-risk patients at the Transcatheter Cardiovascular Therapeutics annual meeting on Oct. 16, the same day the FDA approval was announced by Edwards Lifesciences. The mortality rate was 4% after 30 days and 13% after 1 year, and the 1-year stroke rate was 4%, Dr. Danny Dvir said at the meeting.
One feature of the 1-year survival data that Dr. Dvir called “quite amazing” was the absence of any deaths during the first 30 days post TAVR with the SAPIEN XT system, and 7% at 1 year among the 100 patients treated during the final 8 months of the registry, who comprised the second half of patients enrolled in the registry. “I think we learned how to choose the right patients for this procedure,” said Dr. Dvir, an interventional cardiologist at St. Paul’s Hospital in Vancouver, B.C.
Given the risk from replacing a failed bioprosthetic valve by open surgery, “TAVR is becoming the preferred approach to valve-in-valve,” commented Dr. Ajay J. Kirtane, director of the cardiac catheterization laboratories at Columbia University in New York.
The registry results also highlighted a key limitation of the SAPIEN XT valve: patients with a bioprosthetic valve with a relatively narrow inner diameter of 21 mm or less.
Because the SAPIEN series of valves are balloon expandable and designed to sit directly in the aortic-valve annulus, the inner diameter of an existing bioprothesis can limit the TAVR options. The CoreValve, self-expanding valves sit in a supravalvular location and better fit through a narrow-frame existing valve.
This geometric limitation means that SAPIEN XT cannot work in patients with existing valves less than 21 mm in inner diameter, and the registry excluded such patients, who generally comprise about 10% of all patients with severe aortic stenosis.
In addition, among the 28% of patients enrolled in the registry who had an existing valve diameter of 21 mm, the 1-year mortality rate was strikingly high – 20% – compared with an 11% mortality rate in patients with existing valve diameters of 23 or 25 mm, Dr. Dvir reported.
“If a patient had a smaller inner diameter I’d definitely go with the supravalvular valve. For a bigger valve you have more choices,” commented Dr. Axel H.P. Linke, codirector of cardiology at the Heart Center at the University of Leipzig (Germany).
“It’s not fair to extrapolate these findings with SAPIEN XT to smaller [existing bioprosthetic] valves. There is the ability to go to lower inner diameters” using CoreValve, commented Dr. Jeffrey J. Popma, who led the U.S. CoreValve studies and is professor at Harvard Medical School and director of interventional cardiology at Beth Israel Deaconess Medical Center in Boston.
The two sequential valve-in-valve U.S. registries for SAPIEN XT ran as part of the PARTNER 2 trial, designed to test the safety and efficacy of SAPIEN XT in patients undergoing TAVR for a de novo aortic valve. The 197 patients in the full registry averaged 79 years of age, 60% were men, their average Society of Thoracic Surgeons mortality risk score was 9.7%, 50% had atrial fibrillation, 95% had New York Heart Association class III or IV symptoms, and baseline screening identified one-third of the patients as frail.
The PARTNER 2 trial valve-in-valve registry and extended registry are sponsored by Edwards Lifesciences, which markets the SAPIEN XT system. Dr. Dvir has been a consultant to Edwards and to Medtronic, the company that markets the CoreValve systems. Dr. Kirtane has received research grants from Boston Scientific, St. Jude, Eli Lilly, GlaxoSmithKline, Abiomed, and Abbott Vascular. Dr. Linke has been a consultant to Boston Scientific, St. Jude, Bard, Edwards, and Medtronic and owns equity in Claret. Dr. Popma has been principal investigator of the CoreValve studies, has been a consultant to Abbott Vascular, Boston Scientific, and Director Flow; he owns equity in Direct Flow, and he has received research grants from Abbott Vascular, Medtronic, Boston Scientific, and Cook Medical.