By AMANDA PEDERSEN
Medical Device Daily Senior Staff Writer
MIAMI BEACH Medical technology companies love being the first up to bat with a new technology, as Edwards Lifesciences (Irvine, California) was with its Sapien valve in the transcatheter aortic valve replacement (TAVR) space. But some would argue that it's better to be the first company to bring a second-generation device to the playing field.
TAVR, also known as the transcatheter aortic valve implant (TAVI) market, is a perfect example of a space where newer is, in fact, likely to be better. Many companies that had been relatively quiet about their second-generation TAVI/TAVR devices stepped up to the plate in Miami last week at the annual Transcatheter Cardiovascular Therapeutics (TCT) meeting and talked about how their devices overcome the design limitations of the first generation TAVR technology currently on the market in the U.S. and in Europe.
One such company, Direct Flow Medical (Santa Rosa, California), reported at TCT that its DISCOVER CE mark trial met its primary mortality endpoint (freedom from all-cause mortality from procedure to 30 days) and demonstrated that greater than 95% of patients had mild or less aortic regurgitation, and no patients experienced vascular complications.
"What we saw with the first-generation valves was extremely exciting," Charles Davidson, MD, the chief medical officer at Direct Flow Medical and the clinical chief of cardiology at Northwestern Memorial Hospital (Chicago), told Medical Device Daily. Davidson has extensive experience both with Edwards' Sapien technology through his participation in the PARTNER I and PARTNER II trials, and the second-generation TAVR device that Direct Flow is developing. "Like with any first generation device, we saw certain limitations with the technology which came front and center really with the long-term PARTNER data."
In particular, paravalvular regurgitation has been a big concern among physicians who have used the Sapien valve, and the complication has had a significant impact on late mortality. Another limitation of the first-generation technology that has been noted is the inability to reposition or retrieve the device, if necessary, for optimal placement. These are the limitations that many of the newer TAVR players are trying to address with second-generation devices.
Davidson said that what sets Direct Flow's device apart from other TAVR devices is its ability to be repositioned, recaptured, and "virtually eliminate" regurgitation.
Direct Flow's TAVR device takes a significantly different approach compared with competing devices, both first and second generation. The system utilizes an inflatable cuff with a conforming polymer support structure. Inflatable rings at the top and bottom of the valve are designed to conform and seal above and below the native valve to virtually eliminate regurgitation, according to Direct Flow. The lack of a metallic frame allows for a low profile, flexible, fully-sheathed system with the potential to reduce bleeding and vascular complications, particularly in patients with tortuous and variable anatomy. Full-thickness bovine pericardial leaflets are incorporated in the valve design for durability. The valve can be repositioned even after the implant is fully expanded to its final configuration.
The system also allows the physician to fully assess the position of the valve before deployment of the device, Davidson explained.
All of the second generation devices offer some degree of assessment, he said, but not full-assessment prior to deployment like the Direct Flow valve offers.
The learning curve for the Direct Flow system is fairly short, he added. The physician is proctored during the first three cases with the device and then they are generally ready to perform procedures with the system independently.
In the DISCOVER trial, freedom from all-cause cardiovascular mortality at 30 days was 100%, Davidson said, "which, considering how sick these people are to start with, is pretty astounding."
Direct Flow plans to submit for a CE mark within the next week, Davidson said, and expect to be initiating an investigational device exemption trial in the U.S. sometime in early 2013.
Boston Scientific (Natick, Massachusetts) also has a second-generation TAVR device in the pipeline that is designed to allow the physician to retrieve and reposition the device, and at TCT last week, Medical Device Daily had an opportunity to get hands-on experience with the company's Lotus aortic valve system. The Lotus is a pre-loaded, stent-mounted tissue valve prosthesis and catheter delivery system for guidance and percutaneous placement of the valve.
Dennis Fiedler, VP of new product management in the cardiology, rhythm & vascular group at Boston Scientific, told MDD that the TAVR space represents a significant growth opportunity for the company, which had been a major player in the no-longer-growing stent market.
Boston Scientific reported last week at the meeting that its REPRISE I feasibility trial last April demonstrated successful deployment of the Lotus system in all patients, with "virtually no" paravalvular regurgitation through three months. The trial results, presented by Ian Meredith, PhD, professor and director, Monash Heart, Monash Medical Centre and Southern Health Melbourne (Australia), highlighted the predictable and precise placement of the Lotus and a unique Adaptive Seal feature designed to minimize the incidence of paravalvular leakage. These features will be further tested in the REPRISE II study (CE mark trial) which began enrollment this month, Boston Scientific said.
What sets the Lotus system apart from current technology like the Sapien is the ability for the physician operator to control all aspects of the procedure. The ability to get precise placement with the device was a crucial aspect of the system's design. Like the device that Direct Flow is developing, the Lotus is designed to be repositionable and retrievable if necessary.
Because physicians have that peace of mind of knowing that they can reposition the device if necessary, unlike the Sapien valve where they really only have one shot to get it right, it "takes a lot of the stress out of the procedure," Fiedler said.
Another aspect of the Lotus design that is an improvement over first-generation TAVR technology, according to Fiedler, is the fact that the device is pre-loaded onto the delivery system so that physicians are not standing around waiting for the device to be set up for use. "It adds to the convenience factor, particularly if you have to use a second device mid-procedure," he said.
By reducing the procedure time in this way and reducing the percentage of poor outcomes, the device offers cost-savings benefits both short and long-term, Fiedler said.
If all goes according to plan the system could be available in Europe by the third or fourth quarter of 2013, and the company expects to start a U.S. trial in 2014.
Amanda Pedersen, 912-660-2282;
Published October 30, 2012