Two heart societies, a device maker, and two federal agencies have collaborated to develop a trial for transcatheter aortic valve replacement, once again extending the concept of teamwork, which is the cornerstone of this technology, far beyond the operating room walls.
During the past year, the Society of Thoracic Surgeons and the American College of Cardiology worked with the Food and Drug Administration, the Centers for Medicare and Medicaid Services (CMS), and Edwards Lifesciences to develop a trial that assesses the safety and efficacy of nontransfemoral approaches for TAVR, using the already-approved Edwards SAPIEN valves.
Copyright ACC
Dr. William Zoghbi
"What makes it unusual is, to the best of our knowledge, this is the first investigational device exemption [IDE] granted by the FDA to medical societies who operate national clinical registries," said ACC President Dr. William Zoghbi.
The societies will run the trial with funding from Edwards, and Medicare will pay for the procedures.
"This allows physicians to get reimbursed for off-label use," said Dr. Michael J. Mack, past president of STS and chair of the STS/ACC TVT (Transcatheter Valvular Therapy) Registry Steering Committee. "And it also allows for controlled off-label use, in which the outcomes can be captured and the sites can be paid while this information is being captured. People should be excited about it."
The goal of the trial is to expand the field and to extend TAVR to a broader group of patients, the societies said.
"A similar mechanism has been used in the past for the implantation of ICDs [implantable cardioverter-defibrillators] for patients who met particular criteria and get the funding as the registry moves forward," said Dr. Sidney Goldstein, professor of medicine at Wayne State University in Detroit, who is not involved in the trial or registry.
But currently, "the ICD Registry is not conducting an IDE to evaluate and reimburse for other possible indications of ICDs," said Dr. Zoghbi.
In the United States, an estimated one in four inoperable patients with severe aortic stenosis is not eligible for TAVR through a transfemoral or transapical approach because of vessel size, vessel disease, or other anatomical restrictions, according to the societies. Alternative routes, such as the transaortic approach, could provide an option for them.
STS and ACC are also working to get FDA approval for two more studies.
"The collaboration and use of registries for research in this pilot can be a model for specialty societies, industry, and federal regulators," Dr. Zoghbi said in a statement. "We have aligned our efforts to ensure patient access to a new technology in a safe and cost-effective way."
The study also stands out in the list of TAVR clinical trials approved by CMS, which began covering TAVR in May 2012: The other five are sponsored by Edwards or Medtronic.
The earlier collaboration of the entities that have developed this trial resulted in the STS/ACC TVT Registry, which captures TAVR-related patient demographics, procedure details, and facility and physician information.
The observational study is conducted in the TVT Registry, and will follow 1,000 patients. Any of the nearly 180 sites using the TVT Registry can participate in the study.
The trial will gather 30-day safety endpoints for patients who undergo alternative access approaches such as transapical and transaortic routes. The lumped data will then be compared with the 30-day outcomes of the transapical approach reported in Cohort A of the PARTNER trial.
Because the trial is covered by Medicare, it has to adhere to conditions set by the agency. The requirements will ensure better patient care, Dr. Jeffrey B. Rich, the STS immediate past president, said in a statement, because the "preoperative evaluation, interoperative deployment of the valve, and postoperative care must be jointly shared by cardiologists and cardiothoracic surgeons, utilizing the heart team approach."
Dr. Michael J. Mack
Alternative access approaches in the trial include the left ventricular apex (transapical), ascending aorta, subclavian and axillary arteries, and distal aorta, as well as retroperitoneal access to the iliac artery.
The approaches have several advantages, according to the societies. For one, the risks associated with inserting large-caliber catheters into small, diseased femoral arteries are reduced. Also, nonfemoral access sites can provide for better catheter control and safer closure of the access site.
But since some of the alternative approaches, such as the transaortic approach, have not been approved, the operator training lags behind the already-approved transfemoral and transapical approaches. To address this, the societies and Edwards will probably have to create a contract to train the surgeons and cardiologists for the specific purpose of this trial, said Dr. Mack.