Pumps implanted into the chest to maintain circulation can significantly extend the lives of the sickest patients in end-stage heart failure who are not candidates for heart transplantation, according to the results of a clinical trial led by Duke University Medical Center cardiologists.
The pumps, known as left ventricular assistant devices (LVADs), are employed when the heart's left ventricle – the chamber of the heart that pumps blood throughout the body – is too weak to pump enough blood to nourish the body's tissues. LVADs have been used as successful short-term "bridges to heart transplant" and are increasingly being considered as a long-term heart failure destination therapy, said the researchers.
In the current trial, the researchers found that patients who received LVADs had an average survival time of 10.3 months, compared to 3.1 months for those who did not receive the device. In this group of end-stage heart failure patients, 78 percent died within six months and 90 percent within a year.
"The patients who received the devices not only had a lengthened quantity of life, but they appeared to have an improved quality of life," said Duke cardiologist Joseph Rogers, M.D., who presented the results of the trial Nov. 14, 2005, at the annual scientific session of the American Heart Association meeting in Dallas. "We had patients who were doing the normal activities of life, such driving cars, fishing and golfing."
Patients who were on the LVADs scored significantly higher on standard measures of quality of life than patients in the control group, Rogers said.
"This is a remarkably ill group of patients," Rogers continued. "When you look at the control group, which was receiving the best care medicine has to offer, we can only keep ten percent of them alive after one year. We need to focus on this as a group of patients, since most are still in the prime of life and can still be quite productive."
To be considered for the trial, patients had to be taking powerful intravenous drugs in the hospital just to keep their hearts pumping, and they were also too sick to be considered for a heart transplants. Most were in intensive care units.
"Despite the shortcomings of the device, the results of this trial speak to our ability to improve the functionality for a very sick group of patients," Rogers said. The major complications of LVADs, said the researchers, include stroke, bleeding episodes and infections, especially at the site in the side of the body where the pump is connected to an external power source and computer.
"We already had a lot of data on the device when it was being used as bridge to transplantation," he continued. "We knew it could go for extended periods without problems, and that was the most compelling argument to use for implanting the device in patients who have no other options."
For the trial, researchers enrolled 55 patients from 2000 to 2003. Thirty-seven patients received the device and 18 did not. Patients were on average of 59 years old and as a group their hearts beat at only 14 percent of normal strength. The pump tested in the trial was the Novacor device, which is produced by WorldHeart, Oakland, Calif.