July 23, 2008 – Ventricular-assist devices (VADs) are getting smaller, more reliable and may someday eliminate the need for heart transplants, say doctors at the University of Michigan.
Heart transplants save the lives of more than 2,100 Americans every year. But many more patients are still waiting for a new heart to become available, and hundreds will die without ever getting a second chance at life. Meanwhile, tens of thousands more people aren’t sick enough to need a transplant, but struggle every day with severe heart failure that limits all aspects of their lives. VADs are implanted to bridge the gap until patients can receive a heart transplant, but about 5 percent of those who get VADs see improvements as their hearts repair themselves and the device can be removed.
But until VADs are good enough to make transplants obsolete, says Francis Pagani, M.D., Ph.D. a University of Michigan heart surgeon who specializes in VAD implantations and heart transplants, we can harness technology to help many people with severe heart problems survive and even thrive.
Patients like Tim Cusatis, a 50-year-old Michigan man who had never felt sick until Super Bowl Sunday 2006 — the day doctors told him his heart was failing fast. A few weeks later, they told him that he’d die within weeks without a new heart.
After seeking help from the U-M Cardiovascular Center, he and his heart received a state-of-the-art technological boost, from the HeartMate II VAD made by Thoratec, which was experimental at the time but was approved by the FDA in April.
Dr. Pagani and his team implanted it in Cusatis’ chest and attached it to his heart, and then helped him adjust to life as a “bionic man.” The HeartMate II is about the size of a D-cell battery, with a tube that pokes through the skin and connects to a battery pack. And it helped pump blood throughout Cusatis’ body, taking over for the left side of his failing heart and helping him get stronger while he waited for a transplant.
At the time, the device was still experimental.
Lucky for Cusatis, a donor heart that matched his own became available just seven weeks later. But he knows many other people wait many more months than he did, waiting for chance, and the generosity of a grieving family, to save their lives.
The device that Cusatis received is one of the latest in a series of technologies that have been tried in the past 25 years, ever since the first truly successful use of a heart-assisting device.
Pagani and his colleagues at the U-M Center for Circulatory Support – cardiologists, nurses, surgical team members and therapists – have helped test all of the new devices as they have been developed over the years. The U-M team has been helped by hundreds of patients who have volunteered for clinical trials of new devices.
U-M now offers nearly a dozen options for adults and children with heart failure. Most of the devices help the left side of the heart, the powerful pumping chamber known as the left ventricle, so they’re called left-ventricular assist devices or LVADs.
In fact, the HeartMate II is the cousin to the larger HeartMate LVAD that has been available for several years. That device was developed to help patients survive until a transplant, but later it was shown that even nontransplant candidates could get years of high-quality life with help from it.
It’s larger and louder than a HeartMate II – when he saw it, Cusatis compared the HeartMate to the water pump from an old Ford truck. Indeed, the HeartMate was too big to be used in some patients, including most women, which is part of what makes the HeartMate II an important advance.
Now, U-M and other hospitals are planning a study that will see if the HeartMate II could also be used in people with heart failure who aren’t good candidates for a transplant. That’s a question that will take several years and hundreds of volunteers to answer. In the meantime, the HeartMate II is mainly for people who are waiting for a new heart.
Evidence suggests the new device may even help some patients avoid a heart transplant. In a small minority of patients, the device gives the heart muscle such a break that the muscle can actually start to heal and get stronger. The U-M team is now studying a drug that might help accelerate this process.
But as exciting as today’s technology is, there’s even more hope on the horizon, Dr. Pagani says.
“Over the past 15 years the technology has dramatically improved. The pumps are now very small, but there’s even newer technology that is coming into clinical testing within the next year that offers dramatic improvements in the durability of these devices,” he says. “We believe that some of the devices coming into the research area now will likely have five- to 10-year durability, and that they will start competing practically with heart transplantation.”
These third generation VAD devices use magnetic fields to keep the pumping components suspended within the implanted device, to reduce friction and wear and improve the life of the device. A clinical trial of the first of these devices, called the Duraheart by Terumo Heart Inc., may begin this summer.
“I think the technology is improving to such a point that we see dramatic changes in patients’ lifestyles, compared with when they had advanced heart failure,” Dr. Pagani said. “The major issue now is reducing the side effects associated with this therapy, using transplantation as the benchmark and trying to achieve the outcomes that we can achieve with a transplant. If we can do that successfully with this technology, then it’s going to have much, much wider application.”
For Cusatis, there’s no question that having the HeartMate II and then a transplant has transformed his life. He now knows that he has to take an active role in keeping himself healthy, and has done so ever since getting the HeartMate II. He quit smoking, lost weight, and exercises every day. He reads food labels carefully, looking for lower-salt options and lower-fat choices. He ran his first five-kilometer race last fall and just ran his third one, five minutes faster than his last time.
“It’s amazing what a piece of equipment will do,” he says. “When I look back at before the LVAD, and how sick I was, I can see that it was a stepping stone to getting better. It was a bridge to a new life.”
Heart-assisting technologies are best suited for patients who are waiting for a heart transplant; between 2,000 and 4,000 Americans are on transplant waiting lists at any time. Only 2,100 heart transplants take place in the U.S. each year, and hundreds of people die while waiting for a heart.
In 1984, the first successful heart-assisting device was used. In the years since, a number of new devices have been tried in thousands of patients nationwide. The HeartMate left-ventricular assist device was approved for use in transplant candidates in 2001, and as a destination therapy for long-term use in 2003.
For more information: www.med.umich.edu/cvc, www.terumoheart.com, www.thoratec.com