November 20, 2009
Life dealt Ruth Schuenke a tough hand last year.
After her husband passed away in May following years with Alzheimer's disease, the 84-year-old Burnsville resident saw her own health steadily decline due to a failing heart valve.
On Christmas Eve, Schuenke was so fatigued and short of breath that she wound up at the hospital, where doctors offered a grim prognosis: Without a risky open-heart surgery, she would have just a few weeks to live.
But then, Schuenke drew a wild card — one that landed her in the middle of a high-stakes competition to develop the next generation of replacement heart valves.
A doctor visiting from the Mayo Clinic happened to be working at the hospital the next day and mentioned that the Rochester hospital was part of a study that gave patients the chance at a replacement heart valve without major surgery. Schuenke underwent the procedure in January and was home feeling better in two weeks.
"I'm independent," said Schuenke, whose three adult children and many grandchildren live in the Twin Cities. "I still drive, I get my own groceries and I've resumed my social life — including playing bridge."
Schuenke's story helps illustrate why medical companies and their investors have sized up devices known as "transcatheter" heart valves as one of their best hopes for growth: The devices not only target patients who lack treatment options, but they also eventually could migrate in to a much larger group of healthier patients who need valves but want to avoid open-heart surgery.
Earlier this year, Fridley-based Medtronic made a $1 billion bet on the new valves by acquiring two small companies that were developing the technology.
"This is a real opportunity for them," said Jan Wald, an analyst with Noble Financial. "The favorites of the past — cardiac rhythm management devices and heart stents — are sort of old news."
Schuenke's new heart valve is not made by Medtronic but instead comes from a California company called Edwards Lifesciences.
For now, Edwards is the lone manufacturer with U.S. approval for a pivotal study for one of these next-generation heart valves. Edwards hopes results from this study — which finished enrolling patients this summer — will be strong enough to win approval for the device from the Food and Drug Administration in 2011.
Medtronic wants to be close on Edwards' heels.
One of the firms Medtronic acquired this year — California-based CoreValve Inc. — won approval to sell transcatheter heart valves in Europe beginning in 2007. Medtronic does not regularly report revenue from sales of the device; but this summer, the company suggested it was selling CoreValve at a rate that would generate revenue of about $100 million per year.
The next big step for Medtronic: launching a pivotal study in the U.S. for CoreValve. Pending FDA approval for the design of such a study, Medtronic expects to begin the clinical trial in summer with a potential U.S. launch of the product in 2014.
Even before its start, the study is attracting a lot of attention among heart doctors — and not always in ways Medtronic might like.
Last month, a doctor in Boston filed a lawsuit claiming his former medical group dismissed him in part because he resisted pressure to use more Medtronic heart stents. Leaders of the medical group, the doctor claimed, wanted to use more Medtronic products so their hospital "could participate in clinical trials for CoreValve," the lawsuit stated.
Dr. John Liddicoat, vice president and general manager of Medtronic's heart valve business, said the company is looking into the allegations. But Medtronic's process to select potential clinical research sites "was designed to be fair, objective and independent of commercial interests," he said.
Medtronic and Edwards roughly split the European market for next-generation heart valves. While Medtronic is lagging in the race to launch such a product in the U.S., the local company thinks it can catch up — and even take the lead — because of technical differences in how CoreValve is placed in the heart.
"We believe that the very qualities of CoreValve that lead European customers to choose it for the vast majority of their patients requiring a transarterial procedure will also be evidenced in the United States when CoreValve is on the market here," Liddicoat said. "We are confident in the superiority of our technology."
More than 75,000 patients in the U.S. underwent aortic valve replacement surgery during 2008, according to Millennium Research Group. The Toronto-based market research firm said the U.S. market for replacement valves was worth $620 million last year.
The aortic valve is a critically important structure in the heart. It regulates the flow of blood from the heart's main pumping chamber to the aorta — the biggest artery in the body.
As patients get older, they commonly experience a condition called "aortic stenosis," in which the valve leaflets — flaps meant to open and close with each heart beat — become stiff and stop working as intended. The valve problem makes it harder for the heart to efficiently pump blood, and patients may experience chest pain, shortness of breath or passing out.
"There's no medication that will fix it — the only definitive treatment we've had is an open-heart procedure for valve replacement," said Dr. Charanjit Rihal, a cardiologist at the Mayo Clinic. "On the other hand, elderly patients with multiple medical problems may not be able to safely undergo surgical valve replacement."
Those patients are the ideal candidates for the next-generation heart valves.
Rather than cracking open the chest to install a surgical heart valve, doctors using transcatheter valves make a small incision in the leg near the groin. Through this cut, doctors insert a tube into the femoral artery and feed it up through the circulatory system to the heart.
With the Edwards device, "these tubes are basically the size of your middle finger, or larger, so they're not always easy to get up the leg artery," Rihal said.
The heart valve itself is sewn inside a metal mesh tube called a stent, which is compressed to a small size as doctors pass the device to the heart. Once the new valve is in place, doctors expand the stent so the device basically eclipses the old valve.
"It's a great idea, but what ultimately will determine whether or not these valves are useful is how long they last," Rihal said. "If they last only three months, they won't be of much use to anyone. If they last 10 years, I think it will be a huge advance."
A key selling point thus far for the Medtronic device has been its small size when compressed and passed through the tube; the Edwards valve, by contrast, requires a larger tube to make it to the heart, doctors say. Heart specialists talk about this feature in terms of the "profile" of each device.
"The smaller the profile, the more patients that you'll be able to treat," said Dr. Carlos Ruiz, a heart specialist at Lenox Hill Hospital in New York City who has used CoreValve in Europe.
Edwards, however, plans to launch a lower profile version of its heart valve in Europe next year.
Initiation of the CoreValve study in the U.S. apparently has been slowed by questions about the nickel titanium frame used in the Medtronic device, doctors say. Ruiz pointed out no valves have used nickel titanium on the frame, and he suggested that regulators likely are concerned about the potential for fractures.
There's another question about the CoreValve product: Doctors say an unusually high rate of patients who received the implant subsequently needed pacemakers. Those concerns came to the forefront this fall at a meeting in San Francisco.
Medtronic says fewer patients likely will experience the problem as doctors get better at sizing and placing the CoreValve product.
To Dr. Wesley Pedersen, a heart specialist at Abbott Northwestern Hospital in Minneapolis, the points of differentiation between the devices are clear.
In arguing for its product, Edwards can stress the potential pacemaker issues with CoreValve, he said. But Medtronic can stress technical features that could make it easier to place the CoreValve in the heart.
For now, doctors and hospitals are focused on the competition to be part of the Medtronic study, Pedersen said.
The clinical trial will be high-profile and attract patients to any participating hospital, he said. Plus, all heart doctors have patients like Ruth Schuenke — the Burnsville woman who received the Edwards heart valve earlier this year at the Mayo Clinic.
"They aren't good candidates for surgery," Pedersen said, "and they just die."
Return to In the News