By Emily P. Walker, Washington Correspondent, MedPage Today
Published: June 13, 2012
GAITHERSBURG, Md. -- An FDA advisory panel has voted 11-0, with one abstention, to recommend expanding the indication for the Sapien Transcatheter Heart Valve to include high-risk patients with severe aortic stenosis.
The FDA's Circulatory Systems Advisory Committee agreed Wednesday that Edwards Lifesciences' Sapien valve is safe and effective for patients who are candidates for aortic valve replacement but who have an open-heart surgery mortality risk of 15% or more.
The Sapien was approved in 2011 for inoperable patients, but Edwards is seeking the broader "high-risk" indication, which would allow the device to be a treatment option for a greater number of patients.
The earlier approval was based on "Cohort B" of the company's PARTNER trial, which was the first trial to compare transcatheter aortic valve implantation (commonly referred to as TAVI) with surgery.
For this indication, the advisory committee considered data from "Cohort A" of that trial, which showed high-risk patients who underwent TAVI had virtually the same survival at 1 year as similar patients who had surgical repair.
PARTNER recruited 699 high-risk older patients with severe aortic stenosis and randomly assigned them to TAVI (n=348) or surgery. About two-thirds of the TAVI patients underwent transfemoral procedures, where the device was threaded through the femoral artery, while 103 had transapical access procedures, where the device was inserted directly into the tip of the left ventricle of the heart.
Death rates were essentially the same at 1 year for the Sapien group and the control group. When divided up by type of valve implantation compared with matched surgery controls, the death rate for Sapien implanted via a transfemoral approach was 24.2% versus 26.8% for surgery; and for the transapical approach the 1-year mortality rate was 22.2% for the Sapien group and 26.4% for the open-heart surgery group.
The panel voted 12-0 that the Sapien device is effective.
Although the death rate was very similar, TAVI patients had double the rate of stoke during the 30-day period following the procedure. With the transapical approach, there appeared to be an even greater increased risk for early stroke, which the panel chalked up to the fact that patients who received TAVI via transapical approach were sicker patients, so their outcomes were poorer than those who were implanted via a transfemoral approach.
The panel was concerned with the increased stroke rate, but as panelist Gregory Dehmer, MD, a cardiologist at Scott & White Healthcare in Temple, Texas, put it, there is always a stroke risk for cardiovascular procedures.
"It's just an accepted risk of this procedure," Dehmer said. "We'll have to make sure to do everything we can to lower the risk. But it's never going to be zero."
Panelists also were concerned with gender differences observed in the PARTNER trial -- women seemed to respond better to having the device implanted. One panelist said he thought the better outcomes in women occurred because TAVI is a better option than open-heart surgery for frail patients, and women tended to fit that category more than men. Ultimately, the panel didn't seem too concerned about the gender imbalance.
FDA wanted to get the panel's take on whether it would be necessary to add an additional section to the standard informed consent document cardiac surgery patients sign that would outline the specific risks and benefits of the Sapien device compared with standard cardiac valve surgery. But the panel had mixed views on that with several members questioning whether a detailed consent form would do much to inform patients.
"A piece of paper doesn't really mean anything," said panel chairman Warren Laskey, MD, chief of staff at the University of New Mexico School of Medicine. "It's the heart to heart conversation that matters."
The FDA does not have to follow the advice of its advisory committees, but it often does.