In addition, "being trained in both areas will take out the financial and political battles," he said. "It will help you become the least biased decision maker."
The approval of the Edwards Sapien valve was based the results from PARTNER's Cohort B, comprising inoperable patients with severe aortic stenosis, the proportion of survival at 1 year was 50.3% for the 179 control patients and 69.3% for the 179 patients assigned to the Sapien device, a significant difference. The median survival in years was 0.97 in the control group and 2.18 in the treated group, also a significant difference. These results swayed the FDA’s Circulatory System Devices Panel to recommend the Sapien model 9000TFX, sizes 23 mm and 26 mm, for approval, despite a high neurologic event rate (stroke and transient ischemic heart attack). In anticipation of an FDA approval, the Centers for Medicare and Medicaid Services has already opened a national coverage determination analysis for TAVI and is expected to issue its decision in March 2012.
Meanwhile, inoperable aortic stenosis patients are being enrolled in the PARTNER II trial of the next-generation Sapien XT valve, which has already supplanted the first-generation Sapien in Europe.
But while Heart Teams are excited about the potential of stent-valve systems, they are aware of some apprehension, especially among some cardiovascular surgeons who have long been the gatekeepers for valve replacement surgeries.
"The rationale for having both the cardiologist and surgeon involved is that one acts as the check for the other. So that every time the cardiologist says I can stick one of those in there, it wouldn’t be easy. It takes judgment, precision, preparation, work-up and evaluation. It takes a very takes a very long time," said Dr. Alan H. Markowitz, director of the Heart Valve Center at the University Hospitals Case Medical Center, Cleveland. His center is participating in the Medtronic CoreValve U.S. Pivotal Trial. "Surgeons have to understand it, get involved in it, or it will pass them by."
Some experts outside the TAVR realm are skeptical that the interdisciplinary teams will change the trajectory of cardiology. "The collaboration that these cardiovascular specialists are enjoying is generated by the trial protocol itself. So whether this collegiality will spill over into cardiovascular science in a larger sense remains to be seen," commented Dr. Sidney Goldstein, professor of medicine at Wayne State University and division head emeritus of cardiovascular medicine at Henry Ford Hospital, both in Detroit. Regarding the merits of the new treatment, "TAVR represents an important step in treating high risk aortic patients. It does carry a significant risk of stroke, and its performance against standard AVR in less critically ill patients has not been determined."
The two valves in U.S. trials have more than one route of implantation. The Edwards Sapien valve can be implanted through a transfemoral or transapical route. The CoreValve routes include transfemoral, subclavian, and direct aortic access. A cardiac surgeon and interventional cardiologist collaborate and are present during all procedures.
There are still many unknowns, among them the durability of the devices or whether the patient criteria will expand beyond the "sickest of the sick," as it already has in Europe.
"This is just the very beginning," said Dr. Paul Joseph Corso, director of cardiac surgery at Washington Hospital Center and the co-principle investigator for the PARTNER trial. "We’re not going to have turf wars that will be to the detriment of the patients."
Dr. Holmes, Dr. Mack, and Dr. Zoghbi said they had no relevant disclosures. Dr. Williams, Dr. Corso, and Dr. Pichard are involved in the PARTNER trial; Dr. Pichard has received honoraria from Edwards Lifesciences as a proctor for percutaneous aortic valves. Dr. Markowitz is involved in the CoreValve trial.