Data from multiple registries presented last week at the EuroPCR conference in Paris offered no major trouble spots for European cardiologists looking to expand use of transcatheter aortic heart valves and U.S. doctors anxiously awaiting their approval.

And some results from the meeting suggest that outcomes are improving over time as practitioners get more comfortable with the novel minimally invasive procedures.

"Overall, the data is extremely encouraging" for both Edwards Lifesciences' Sapien and Medtronic's CoreValve , said Ganesh Manoharan, an interventional cardiologist at the University of Ulster, Belfast, in an interview. "People have learned a lot over the last four years."

Some of the most closely watched EuroPCR data came from the SOURCE registry, which tracks outcomes from the European commercial experience with the 2007-launched Edwards' Sapienvalve. Patients treated with transcatheter valves in Europe are high-risk or non-candidates for traditional open-heart valve surgery.

One-year results from 1,038 patients were presented May 25 by Martyn Thomas, M.D., Kings College Hospital, London, who reported an 81.1% survival rate in patients who received Sapien via the femoral artery and a 72.1% survival rate in those that got the device transapically, or through the rib cage.

These outcomes are better than data previously collected in Europe, suggesting progression along what is considered to be a steep procedural learning curve, Thomas noted.

In his presentation, Thomas included a pooled analysis from four prior studies, showing a transfemoral survival rate of 74.9% and a transapical survival rate of 58.1%.

Cardiologists in particular noted during the meeting the marked improvement in patients treated with the transapical procedure, which is typically performed on higher risk patients and is more invasive than the transfemoral route.

Going into the EuroPCR meeting, Edwards Lifesciences underscored the importance of the SOURCE registry by emphasizing that it could serve as a preview of highly anticipated data from the firm's U.S. pivotal PARTNER trial, expected out in September at the Transcatheter Cardiovascular Therapeutics conference.

The company points out that the patients in the SOURCE registry received their valves during about the same time period as PARTNER trial implants.

SOURCE "is the closest comparison we have" to PARTNER, Edwards' CEO Michael Mussallem said during the firm's April 20 first-quarter earnings call.

In September, data from only one segment of the PARTNER trial will be reported, comparing Sapien, implanted transfemorally, to medical management in patients who are not candidates for open surgery.

"The strong one-year mortality results in SOURCE increase the likelihood that Sapien will show a significant mortality benefit over medical management in Cohort B of the pivotal PARTNER trial," Larry Biegelsen, an industry analyst with Wells Fargo, notes in a May 25 research report.

Although, he writes, the PARTNER enrollees appear to have a slightly higher level of co-morbidities, which could lead to slightly reduced survival results.

Edwards is aiming for FDA approval of Sapien for non-surgical candidates by the end of 2011. It plans on releasing data comparing Sapien to surgery next year, with hopes for 2012 approval for that indication.

Medtronic's CoreValve Also Addressed

SOURCE was not the only transcatheter valve data reported at the meeting. During the same Tuesday morning session, five distinct individual European country registries were also presented.

Four of the registries, from Belgium, France, Germany and the United Kingdom, included a mix of Sapien and its only competitor, Medtronic's CoreValve device. An Italian registry included data only from patients treated with CoreValve.

CoreValve is ahead of Sapien in overall aortic transcatheter valve market share, Medtronic affirmed during its May 25 earnings call. But the device is well behind Sapien in gaining FDA approval in the U.S.

The country registries, which included almost 3,000 patients in total, reported procedural success percentage rates in the high 90s, and relatively low mortality rates.

The one-year survival rate among the 772 patients included in the Italian CoreValve registry was 85.1%, though the patients appeared to be slightly less sick going into the treatment compared to the SOURCE cohort based on cardiac surgery risk scores. CoreValve is delivered through the transfemoral route only.

Also at EuroPCR, on May 26, researchers reported two-year follow-up results from the CoreValve 126-patient European prospective pivotal study. The two-year survival rate was 59.7% in that study.

One potential trouble spot for Medtronic, however, was the relatively higher rates of new pacemaker implantations required in CoreValve patients following the valve procedure.

In the Italian registry, 18.5% of patients required a new pacemaker, compared to 6.9% in SOURCE.

Manoharan, who has served as a consultant for Medtronic, stressed that it is inappropriate to compare data from the different registries because the procedures were performed over different timelines and at different centers in different countries. Nonetheless, the pacemaker implantation rates in the CoreValve patients need further explanation, he said.

"At the moment we do not know if it is valve-related, balloon-related, wire-related or patient-related," he said.

But he did cite "frequent" anecdotal reports from physicians involved in the registries suggesting that some physicians are more likely than others to implant a pacemaker in this very sick patient population out of caution during a valve procedure.

"I have a very low threshold to putting in a pacemaker into the very elderly, fragile patients," he noted as an example.

Medtronic is planning a prospective European study aiming to characterize best practices in CoreValve implant procedures, "including the impact of various procedural steps like valve deployment location and valvuloplasty on heart condition disturbances," according to a company spokeswoman.

Manoharan suggested the study would provide clarity on the pacemaker implant data.

It is too soon to tell if this issue will be a major factor in device selection going forward. But Edwards is making a run to overtake CoreValve in Europe with the recent launch of Sapien XT , a thinner version of the original to match CoreValve's 18-French design (¹ Also see "Edwards: Surgical Valve Sales Slow As Transcatheter Valve Ramps Up" - Medtech Insight, 26 April, 2010.).

CoreValve accounts for about 75% of Europe's transfemoral aortic heart valve procedures, in part because the 18-French design is accessible to a greater proportion of anatomies (² Also see "Edwards Looks To Smaller-Diameter Transcatheter Valve In 2010" - Medtech Insight, 27 July, 2009.).

Both Edwards and Medtronic have near-term plans to launch additional revisions to their valves and delivery systems to make them more broadly usable.

"These are all encouraging changes that are going to come in a very, very short timeline," Manoharan said.

Start-Up Valve Efforts

Smaller firms looking for long-term opportunities in the transcatheter valve space also reported progress at the meeting.

Start-up JenaValve Technology announced first-in-man results May 25 from nine patients implanted with its transapical transcatheter aortic valve. Each of the nine cases achieved procedural success and passed the 30-day survival endpoint, according to the firm.

Munich-based JenaValve raised about $20 million earlier this year in a "Series B" financing to help it move closer to European market entry.

At an even earlier stage, California start-up CardiAQ reported May 25 the first successful animal model for a transcatheter implant of a mitral valve replacement device in a pig.

- David Filmore ( ³ d.filmore@elsevier.com )

Transcatheter Valve Data Gets Top-Line Attention At EuroPCR

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