Mar 16, 2010 10:13 PM
More than 5 million Americans have heart failure, a progressive and often lethal condition that weakens the heart and saps its pumping power. The mainstays of treatment -- including drug therapy, lifestyle modification, and surgery to implant pacemakers or defibrillators -- can be quite effective at managing symptoms of mild to moderate heart failure.
But what about the estimated 150,000 Americans who suffer from chronic, severe heart failure?
Doctors traditionally have had little to offer these patients in the way of lifesaving treatment, short of a heart transplant. But with only about 2,100 donor hearts available each year, the demand for hearts inevitably outweighs the supply. And some patients are simply too old to qualify for a transplant. For them, what's the alternative?
There's now an option that could change the outlook for many with severe heart failure: implantable mechanical pumps called left ventricular-assist devices (LVADs or sometimes simply VADs.)
These devices were once just used as a "bridge" -- a temporary stopgap to keep heart failure patients alive until they could get a heart transplant. But now, they have become so effective that doctors use them as a treatment in themselves. LVADs are now an alternative to heart transplants, permanently augmenting the action of a heart's main pumping chamber.
"With the new devices, there finally appears to be a real, practical solution to advanced heart failure," says Clyde W. Yancy, MD, president of the American Heart Association, medical director of the Baylor Heart and Vascular Institute at Baylor University Medical Center in Dallas, and a noted expert on heart failure. "This has been a 40-year pursuit of a mechanism that can take over for a heart that is failing. This is big news."
LVADs have been around in some form since the 1960s, but have been used primarily as a temporary treatment to give the patient's heart a chance to improve or to keep the patient alive long enough for a donor heart to be found.
First-generation LVADs are limited by their considerable bulk and poor durability. The large size increases the risk of implantation surgery and makes the device unsuitable for smaller patients.
Recent research has demonstrated the superiority of the newer rotary, or "continuous-flow," LVADs, which are smaller and more durable than their predecessors.
Continuous-flow LVADs consist of a pump implanted in the abdominal wall linked with tubes to the patient's aorta and left ventricle. A power cord emerging through the abdominal skin leads to a control unit worn on the belt, which, in turn, is attached to battery packs worn in a shoulder harness.
One study of 200 patients with advanced heart failure showed that both the older LVADs and the new continuous-flow LVADs improved exercise tolerance and quality of life. That's significant, Yancy says, given that even people with well-treated heart failure tend to have seriously impaired quality of life.
What's more, patients implanted with the new continuous-flow pump were twice as likely to live for at least two years following surgery, according to the report in the Dec. 3, 2009, issue of the New England Journal of Medicine. And they were four times as likely to survive for two years as patients on drug therapy alone.
In addition, the continuous-flow LVAD was associated with fewer infections and a significantly lower rate of failure.
"The continuous-flow LVAD has changed the landscape of advanced heart failure," says James C. Fang, MD, chief medical officer of the Harrington-McLaughlin Heart and Vascular Institute at University Hospitals Case Medical Center in Cleveland and the author of an editorial on LVADs that accompanied the study in the New England Journal of Medicine.
"In addition to being more durable, the new device is a lot smaller -- about the size of a D battery. It's also quiet. You can barely hear it. With the old devices, you could hear them coming down the street."
Though LVADs offer new hope to many people with heart failure, it's important to understand the drawbacks. They don't work for everyone. They also pose an increased risk of stroke. Some people with LVADs need to take anticoagulants to lower the odds of stroke.
And despite their successes, LVADs are still a new treatment. Yancy estimates that a few thousand people have received them so far. Hundreds more will get them this year. That's a small number compared to the tens of thousands who could potentially benefit. About 100 centers in the country have the expertise to implant them.
To get an LVAD, a person would also have to meet some eligibility requirements. The good news is that some older people who might not qualify for a transplant might be able to get an LVAD instead. The bad news is that others who are too sick for a transplant might also be too sick for an LVAD.
Being a good candidate for an LVAD also depends on your current treatment approach.
"Before people are eligible to get an LVAD, it is imperative that they are already getting the best possible treatment," Yancy tells WebMD. They need to be taking their medication as prescribed, getting regular checkups with doctors, and following any lifestyle advice -- like sticking to a low-sodium diet. People who aren't doing these things -- or who have other issues, like heavy alcohol use -- might not qualify for an LVAD.
If you're wondering if an LVAD might help you, talk to your doctor. See if any local medical centers are qualified to implant LVADs. And in the meantime, make sure to follow your doctor's heart failure treatment plan closely.
Yancy says that the number of people who get LVADs is likely to increase dramatically in the next few years. They might also be used in people with earlier stages of disease, when they could have an even bigger benefit.
There's some evidence that LVADs could do more than support a weakened heart -- they might be able to help heal it. Some European studies suggest that an LVAD could be implanted temporarily to assist the heart and allow it to recover. Afterward, the device could theoretically be removed.
LVADs also have the potential to work alongside possible future treatments for heart failure, Yancy says. For instance, researchers are working on stem cells and growth hormones that could help regenerate a damaged heart. Theoretically, LVADs could be implanted temporarily to help support the heart while those treatments take effect.
While these future technologies are being developed, LVADs are making a big difference in the lives of thousands of people with heart failure right now.
"What people with heart failure need to know today is that LVADs can help them feel better and live longer than previously possible," says Yancy. "These devices were only available to a few before. But now, more and more people are benefiting from them."