Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New therapies may help some end-stage heart failure patients avoid transplant

09.05.2007
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 Circulation: 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:

To help keep patients with end-stage heart failure alive until a donor heart becomes available for transplantation.

To serve as a long-term therapy for patients deemed unacceptable for a heart transplant.

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 in New York City.

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.

Yet, after 30 days on the pump, one third of the patients had a left ventricular ejection fraction greater than 40 percent (measured when the pump flow was decreased). Ejection fraction is the percentage of blood pumped out of the left ventricle with each beat. Healthy hearts typically have an ejection fraction of 55 percent to 60 percent, Maybaum said. The proportion of patients showing this degree of improvement then waned, dropping to 27 percent of patients at 60 days, 19 percent at 90 days and 6 percent at 120 days.

Patients also showed progressive improvement in exercise capacity after LVAD implantation. From day 30 to 120 there was an increase in their peak oxygen consumption and how long they could exercise.

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.

The size of the heart muscle cells, the amount of the fibrous collagen and levels of the protein TNF-alpha all decreased significantly between pump implant and heart transplant — signs of reduced heart damage.

"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.

Karen Astle | EurekAlert!
Further information:
http://www.heart.org

More articles from Health and Medicine:

nachricht Study tracks inner workings of the brain with new biosensor
16.08.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Foods of the future
15.08.2018 | Georg-August-Universität Göttingen

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>