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?
Heart failure is a condition in which the heart can't pump blood effectively to the lungs or the rest of the body.
This can be because the person has developed a weakened heart muscle or because the heart muscle has thickened or stiffened, making it difficult to fill the heart and backing up blood into the lungs.
With heart failure, the weakened heart pumps less blood than usual, causing the kidneys and adrenal glands to produce chemicals that help the body to hold onto salt and water.
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."
The Evolution of LVADs
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.