National trial aims to help heart failure patients survive until transplant, and may offer lower clot risk and less blood damage than earlier heart devices
ANN ARBOR, Mich., Aug. 5 /PRNewswire-USNewswire/ -- Anthony Shannon made history on July 30. That's when he became the first person in the United States to receive a new type of experimental and very high-tech heart-assist device. Called a DuraHeart, it was implanted in his chest, and connected to his failing heart, to help pump his blood and keep him alive.
Shannon, a 62-year-old from Livonia, Mich., is doing well less than one week after the operation, which was performed by a team led by surgeon Francis Pagani, M.D., Ph.D. at the University of Michigan Cardiovascular Center. Shannon is the former director of homeland security and emergency management for Wayne County, Mich., and holds a Ph.D., in public administration.
The DuraHeart, made by an Ann Arbor, Mich.-based company called Terumo Heart Inc., uses advanced magnetic-levitation technology. This "maglev" approach, as it is called, means that a crucial, constantly revolving part within the hockey puck-sized implanted device never touches the walls of the pumping chamber.
Instead, it levitates in the middle, suspended in a magnetic field and pushing blood along. The battery-powered device pushes blood from the heart to the body, taking over most of the function of the left side of a severely weakened heart.
As a result, DuraHeart may cause less damage to blood cells and be less likely to allow dangerous blood clots to form, compared with other heart-assisting devices that use mechanical pumps. It has already been used in 70 patients in Europe, where it received approval for commercial use in 2007 after a clinical trial.
Now, heart failure patients at U-M and other centers across the U.S. will have the opportunity to volunteer for a clinical trial of the DuraHeart, which is being co-led by Pagani and by Yoshifumi Naka, M.D., Ph.D., from Columbia Presbyterian Hospital in New York. U-M is the national training center for the trial, which is funded by Terumo Heart, and teams from Columbia and the University of Louisville have already traveled to Ann Arbor to learn how to implant the device.
"The DuraHeart gives us a new, third-generation option for patients with advanced heart failure who need help to allow them to survive until they can receive a heart transplant," says Pagani, who leads the U-M Center for Circulatory Support.
He has led other national clinical trials of heart-assist devices, including the HeartMate II, which in April received approval from the U.S. Food and Drug Administration after a clinical trial. U-M now offers heart failure patients nearly a dozen different options to support their heart function, including heart transplants.
"This trial will test the DuraHeart's potential to overcome some of the issues that have been seen with other devices, including hemolysis caused by shear stress on red blood cells, and clotting risk caused by blood that does not circulate rapidly enough from all areas of the chamber," Pagani explains. "It also remains to be seen if this device offers superior durability, which might make it useful as a destination therapy that could remove the need for a heart transplant."
Shannon, whose heart has been weakening for nearly 20 years after a heart attack and clogged arteries damaged part of his heart muscle, is one of 5.3 million Americans with heart failure.
Although not all heart failure patients are candidates for a heart-assist device or a heart transplant, tens of thousands could be. At any given time, as many as 4,000 Americans are on the waiting list for a heart transplant, but only 2,100 people receive new hearts in the U.S. each year because of a shortage of suitable donor organs. Hundreds of people each year die while waiting for a heart.
In the past 20 years, many devices have been developed to help the heart pump. Most have been left-ventricular assist devices or systems, sometimes referred to as LVADs or LVASs. But others have assisted the right side of the heart or both sides - collectively, such devices are called VADs.
The therapy has become common enough that hospitals can now apply for accreditation as certified VAD centers, an indication of their experience in implanting the devices and taking care of patients before and after they receive their device. This spring, U-M became one of the first few such accredited VAD centers in the nation.
The DuraHeart was invented and developed by a team led by Chisato Nojiri, M.D., Ph.D., the chief executive officer of Terumo Heart. More than a decade of research and development has led to this clinical trial and the trial in Europe, as well as a trial in Japan that may begin later this year. Pagani serves as an unpaid consultant to Terumo Heart.
The clinical trial will enroll 140 patients in a prospective, non-randomized fashion, and up to 40 hospitals may eventually take part. All of the devices are being made in Ann Arbor at Terumo Heart.
To implant a DuraHeart device, the surgeon diverts blood flow from the ailing left ventricle of the heart into a titanium tube that leads into the pumping chamber. The magnetically levitating impeller, a flat magnetic disc, acts as a paddlewheel, turning constantly as it is magnetically attracted to the turning motor within the pump housing. This pushes blood into a flexible artificial blood vessel, which is connected to the large blood vessel called the ascending aorta.
By assisting the weak left ventricle, which is the heart chamber most commonly affected by heart failure, the DuraHeart allows the heart muscle to rest. It also provides better blood flow to the body, brain and organs than a weak heart ever could - which helps patients prepare for the arduous surgery of a heart transplant.
Devices such as the HeartMate II and its predecessor HeartMate XVE, and potentially the DuraHeart, may become substitutes for heart transplants over time. They may allow patients to live for years with help from the device, or to recover enough heart function that they no longer need either a device or a transplant. The HeartMate XVE is already approved for this type of "destination" use, and the HeartMate II is currently in a clinical trial for this purpose.
The DuraHeart may hold the same potential, says Pagani, but first it must be tested as a bridge to transplantation. With Anthony Shannon as the pioneer, that test has now begun.
For information on the U-M Cardiovascular Center, visit http://www.umcvc.org or call 1-888-287-1082. For more on the DuraHeart trial, visit http://www.umms.med.umich.edu/engage/detail_pub_study.do?id=3158.
|SOURCE University of Michigan Health System|
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