Novel devices from Medtronic Inc. (MDT:US) and Edwards Lifesciences Corp. (EW:US) that repair damaged aortic valves without open-heart surgery safely helped patients in two of the largest and longest reviews of the technology.
Medtronic’s CoreValve eased heart-failure symptoms in a study of 1,015 patients with severe aortic stenosis, according to findings released today at the American College of Cardiology meeting in Chicago. After six months, 87.2 percent were alive with few complications, a reassuring result given their age and illness, said Axel Linke, professor of cardiology at the University of Leipzig Heart Center in Germany.
A review of 399 patients given Edwards’ Sapien device found a 10 percent death rate within a month of treatment, with the majority of survivors subsequently dying from non-cardiac causes. The review from 2005 to 2009 is among the longest on the durability of the valves and the patients’ fate.
“This technology works and evidence is accumulating that it can be done safely and effectively,” said Murat Tuczu, an interventional cardiologist and vice-chair of cardiovascular medicine at the Cleveland Clinic in Ohio. “For many patients, they didn’t have any other options. We have to be careful in monitoring these people.”
The reports provide a window into the technology that is gaining popularity among heart doctors, even as the first rigorous, controlled studies are only now providing information about long-term safety and effectiveness.
About 200,000 Americans suffer from narrowing and stiffening of the aortic valve, the three-flapped spigot between the heart’s main pumping chamber and the artery that carries oxygen-rich blood to the body.
Potential $2.5 Billion Market
Edwards, based in Irvine, California, and Minneapolis-based Medtronic introduced the valves in Europe in 2007 based on early indications of safety and split the $700 million market. The U.S. market may be as much as $2.5 billion, said Jason Mills, an analyst with Canaccord Adams Inc. in San Francisco.
Edwards has U.S. regulatory approval for Sapien for patients who can’t withstand open-heart surgery and is awaiting a decision on broader use. The two-year findings from its study of the device in high-risk surgery patients will be presented on March 26.
Medtronic’s studies are expected to conclude next year and the company forecasts approval in 2014.
“We have experience now for seven years with the valve, and I haven’t seen a single case of deterioration in this time,” Linke said of his work with Medtronic’s CoreValve “But the experience is limited to a few hundred patients that I have personally seen. We need information from a wide variety of patients to get more information on how this valve works and if it lasts as long as we are expecting.”
The differences in mortality rates may have stemmed from the doctors’ experience with the valves that are threaded into the heart via a catheter through the femoral artery or a small slit in the chest. The study of the Edwards device was conducted at six sites in Canada after the valves were first introduced, while the Medtronic trial included only doctors who had performed at least 40 previous implants.
The Canadian study also released today at the heart association meeting shows the $30,000 valves appear durable and function well at least for the first three to four years after they are implanted, said Josep Rodes-Cabau, lead author and director of the cardiac catheterization and interventional laboratories at the Quebec Heart and Lung Institute.
The patients’ chronic health conditions other than aortic stenosis ultimately limit their benefits, he said.
“The study is reassuring because it shows the valves are stable over time,” with no structural failures or problems with blood flow, he said. “But we should pay attention to the non- cardiac disease. When they survive the intervention, what is really behind the deaths of these patients is not cardiac disease.”
After three years, 43 percent of patients treated with a Sapien or a newer version called Sapien XT died, rising to 48 percent after four years, the study found. For those who survived the first month, 67 percent subsequently died from lung disease, kidney failure, an erratic heart rate, frailty or other causes. About one-quarter died from heart disease and two patients needed re-treatment for valve infections.
The CoreValve study, funded by Medtronic, examined patients treated in a regular medical setting, rather than a controlled clinical trial. Fewer than 8 percent of the healthiest patients died after six months, compared with 17 percent of those with severe symptoms, underscoring how important it is to select the right patients, Linke said. Strokes, a feared side effect, occurred in 3.4 percent of patients within six months.
Patients with the CoreValve experienced a quick and dramatic improvement in symptoms, such as breathlessness, Linke said. While 79 percent had moderate to severe symptoms of heart failure before the surgery, just 13 percent were still struggling after six months.
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