Montefiore News Releases
Implanted pumps improved heart function enough in a small percentage of patients awaiting a heart transplant that they were able to leave the hospital without a pump and without a new heart, according to a study in the Journal of the American Heart Association.
The heart-assist devices also significantly improved the cardiac function in many other heart failure patients.
"This suggests that, while the devices alone may not be sufficient to allow a meaningful number of patients to come off the heart pump instead of having a heart transplant, there may be other therapies that can be added to enhance recovery," said Simon Maybaum, M.D., lead author of the study.
In end-stage heart failure, the heart weakens, gets larger and shows other signs of deterioration. Implantable heart pumps, called left ventricular assist devices (LVADs), pump blood through the body, which lets the heart’s main pumping chamber rest. Pumps are currently approved for two purposes:
However, for some time, transplant specialists have debated the potential for LVADs to be used as a "bridge to recovery" for the patient’s own heart. Prior small studies have yielded contrasting results. "Some centers were reporting that up to a third of their patients implanted with a heart pump were able to come off the pump without a transplant, and some centers were saying they just did not have that experience," said Maybaum, associate professor of clinical medicine and medical director of the Center for Advanced Cardiac Therapy at the Albert Einstein College of Medicine’s Montefiore Medical Center.
To resolve these inconsistent findings, researchers from seven major U.S. heart transplant centers formed the LVAD Working Group. They enrolled 67 patients with end-stage heart failure between August 2001 and October 2003 in the first prospective, multicenter study to extensively examine how LVADs affect cardiac function and exercise capacity over several months.
Patients were recruited from these centers: Baylor College of Medicine, Houston, Texas; Cleveland Clinic Foundation, Ohio; Columbia University, New York City; University of Michigan, Ann Arbor; University of Minnesota, Minneapolis; Temple University, Philadelphia, Penn.; and the Texas Heart Institute, Houston. Four different types of LVADs were used in the study. Researchers evaluated the patients every 30 days after pump implant.
"There are two contrasting, important findings in our study," Maybaum said. "One, the ability to remove an LVAD from a patient with end-stage heart failure was low. Two, there was a high degree of improvement in heart function during the use of the assist device."
Six (9 percent) of the 67 patients had their pump removed without needing a heart transplant. Six others (9 percent) had died by May 2004, when data collection ended.
Tiny snips of heart tissue from 22 patients taken at implant and at the time of removal of the LVAD prior to transplantation found evidence of important improvements.
"We now have a much more reliable description of the natural history of the changes in heart function during LVAD support," Maybaum said. "That makes us optimistic that other strategies may allow us to further improve cardiac function."
Two novel strategies will soon be tested in clinical trials for LVAD patients in the U.S. One study will utilize the muscle bulking agent clenbuterol and the second will evaluate autologous (the patient’s own) stem cells injected at the time of LVAD implantation.
Statements and conclusions of study authors published in the American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect association policy or position. The American Heart Association makes no representation or warranty as to their accuracy or reliability.