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 A promising target for kidney fibrosis
21.04.2017 | Brigham and Women's Hospital

nachricht Stem cell transplants: activating signal paths may protect from graft-versus-host disease
20.04.2017 | Technische Universität München

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>