FDA panel hints at how U.S. TAVI landscape could pan out
While the FDA’s Circulatory System Devices Panel voted July 20 in overwhelming favor for the FDA to clear the Sapien transcatheter heart valve (Edwards Lifesciences), the discussion throughout the day hinted at certain practice management challenges, such as patient selection, that the technology may face if approved.

During her presentation, Jodi Akin, vice president of global clinical affairs at Edwards, cited that ACC/AHA guidelines for aortic replacement (AVR) is a Class I indication for severe aortic stenosis (AS). Then, she reported the U.S. patient population that this would include: between 30 to 50 percent of patients with severe AS are “untreated,” and the approximate total U.S. population of patients with severe AS is 360,000. Of this overall patient population, 40,000 are candidates for isolated surgical AVR and 20,000 patients are inoperable, according to Akin. Thus, the expected population for this device, if approved, would be 20,000 patients in the U.S.

The panel solely assessed the inoperable patient population that was assessed in the PARTNER Cohort B trial, and oftentimes, the concept and concern over the potential for “indication creep” was raised throughout the day. Namely, if the procedure is available in U.S. clinical practice, practitioners could utilize the technology in an off-label manner, such as valve-in-valve, or treat patients outside the bounds of the FDA indication.

“This is an important, new technology that provides a good option for patients to improve quality of life and survival, but it is a high-risk procedure,” Panel Chair Richard L. Page, MD, told Cardiovascular Business. “Therefore, if FDA approved, physicians need to ensure that the technology is utilized in the appropriate patient population—those who are truly inoperable. The technology likely will be rolled out more broadly, but we need to make sure that appropriate patients are selected.”

Thus, Page suggested that a well-designed post-approval study needs to be conducted, with monitored data collection. In addition, he recommended the use of registry to track how these procedures are conducted in real-life clinical practice.

During the meeting, David R. Holmes, MD, president of the American College of Cardiology (ACC), and Michael J. Mack, MD, president of the Society for Thoracic Surgery (STS), proposed expanding their national databases to include U.S. patients treated with TAVI.

“The STS database and the ACC’s National Cardiovascular Data Registry already have the mechanisms to collect these data,” said Page, who is past-president of the Heart Rhythm Society. “It is positive for the field that surgeons and cardiologists are collaborating to set standards and registries.” 

Since TAVI requires the involvement of both cardiac surgeons and interventional cardiologist for decision-making, many of the panel members lauded the collaborative nature of the procedure and the trial design.

However, several of the panel members, including Valluvan Jeevanandam, MD, a thoracic surgeon from the University of Chicago, suggested that two cardiac surgeons, instead of just one cardiac surgeon, should decide whether the intervention should be percutaneous. This is how PARTNER was designed, but there is no mention of that in the recommended FDA indication.

“In order to ensure the appropriate patients are treated with the device, I recommend having two surgeons involved with the decision making—as demonstrated in the [PARTNER] study—as well as additional warning labels on the device that indicate the increased incidence of stroke,” Jeevanandam said after his vote.

Another patient selection issue that was raised was how sick an inoperable patient is when he receives the device. Panel member Richard A. Lange, MD, MBA, from the University of Texas Health Science Center in San Antonio, suggested that the physicians should have a reasonable assurance that the patient will survive for one year or more beyond the procedure, barring unforeseen events. While that stipulation was not rolled into the recommended FDA indication, many of the panel members agreed that this seemed a reasonable method.

“Some patient selection decisions will come down to clinical judgment,” Page explained. “However, as an electrophysiologist, I placed pacemakers, a procedure that has no age limit. Physicians need to be assured that the patient will benefit from this procedure.” He also recommended avoiding “hard and fast rules, particularly age, which could potentially ration care.

“While patient-centered outcomes research—the new term for comparative effective research—needs to be performed, this new technology is truly beneficial for patients who had a previously had no treatment solution,” Page summarized.