Featured Research

from universities, journals, and other organizations

Patients who receive greatest benefit from heart failure treatment identified

Date:
March 1, 2011
Source:
University of Rochester Medical Center
Summary:
Mild heart failure patients with a particular condition that results in disorganized electrical activity throughout the heart benefit substantially from cardiac resynchronization therapy with defibrillator (CRT--D), according to a new study. In patients with the condition, known as left bundle branch block (LBBB), CRT-D therapy reduced heart failure progression and the risk of ventricular tachyarrhythmias, fast and potentially life-threatening heart rhythms. Heart failure patients without LBBB did not benefit from the therapy.

Cardiac resynchronization therapy with defibrillator (CRT–D)
Credit: Image courtesy of University of Rochester Medical Center

Mild heart failure patients with a particular condition that results in disorganized electrical activity throughout the heart benefit substantially from cardiac resynchronization therapy with defibrillator (CRT-D), according to a study published in the American Heart Association journal Circulation.

Related Articles


In patients with the condition, known as left bundle branch block or LBBB, CRT-D therapy reduced heart failure progression and the risk of ventricular tachyarrhythmias, fast and potentially life-threatening heart rhythms. Heart failure patients without LBBB did not receive any benefit from the therapy.

The analysis, based on the major study which tested the device -- the MADIT-CRT trial -- led the FDA to extend the approval of the CRT-D in September 2010 to patients with mild heart failure and LBBB to prevent progression to advanced heart failure. The device, developed by Boston Scientific, was originally approved to treat patients with severe heart failure.

"This study allowed us to identify the specific set of patients that receive the greatest benefit from this device," said Wojciech Zareba, M.D., Ph.D., lead study author and director of the Heart Research Follow-up Program at the University of Rochester Medical Center. "Our analysis highlights the fact that this therapy is not equally effective in all mild heart failure patients and was the basis of the FDA's approval of the therapy only in patients with left bundle branch block."

Zareba's team found that patients with LBBB who received CRT-D therapy had a significant 53 percent reduction in the risk of a heart failure event, such as being hospitalized with heart failure symptoms, or death, compared to LBBB patients who only received an implantable cardioverter defibrillator (ICD). The risk of ventricular tachyarrhythmias was also considerably less in LBBB patients with CRT-D.

CRT-D therapy combines an ICD, which senses dangerous abnormal heart rhythms and attempts to shock the heart back into a normal rhythm, with cardiac resynchronization therapy (CRT), which coordinates the beating of the heart so it can pump blood throughout the body more effectively.

The study included 1,817 patients and researchers analyzed electrocardiograms -- maps of the heart's electrical activity -- to determine which patients had electrical disturbances and what type. Seventy percent of study participants had LBBB. LBBB patients were more often female and had higher rates of non-ischemic heart disease, a disorder typically characterized by inflammatory scarring of the heart muscle.

Study authors evaluated the effects of CRT-D versus ICD therapy in patients with and without LBBB. They found that in LBBB patients, CRT-D therapy effectively prevented deterioration of the heart, otherwise known as cardiac remodeling, by preventing enlargement of the heart with more effective contraction of the heart.

"We believe this therapy is so effective in patients with LBBB because their hearts don't contract in a synchronous way, rather, the pumping action is quite out of sync," noted Zareba. "CRT-D therapy paces the heart and makes these patients much better very quickly."

Beyond mild heart failure patients, the results are leading experts to rethink current guidelines recommending the use of CRT-D therapy for all advanced heart failure patients. In this age of personalized medicine, as treatments are continually directed towards subsets of patients with particular characteristics or biologic markers, the group of advanced heart failure patients that receive CRT-D therapy may be narrowed to those with LBBB, as well.

The MADIT-CRT trial, led by Arthur J. Moss, M.D., cardiologist at the University of Rochester Medical Center, was supported by a research grant from Boston Scientific to the University of Rochester. The sub-analysis, led by Zareba, was also sponsored by Boston Scientific.


Story Source:

The above story is based on materials provided by University of Rochester Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Wojciech Zareba, Helmut Klein, Iwona Cygankiewicz, W. Jackson Hall, Scott McNitt, Mary Brown, David Cannom, James P. Daubert, Michael Eldar, Michael R. Gold, Jeffrey J. Goldberger, Ilan Goldenberg, Edgar Lichstein, Heinz Pitschner, Mayer Rashtian, Scott Solomon, Sami Viskin, Paul Wang, Arthur J. Moss on behalf of the MADIT-CRT Investigators. Effectiveness of Cardiac Resynchronization Therapy by QRS Morphology in the Multicenter Automatic Defibrillator Implantation Trial–Cardiac Resynchronization Therapy (MADIT-CRT). Circulation, Feb 2011 DOI: 10.1161/CIRCULATIONAHA.110.960898

Cite This Page:

University of Rochester Medical Center. "Patients who receive greatest benefit from heart failure treatment identified." ScienceDaily. ScienceDaily, 1 March 2011. <www.sciencedaily.com/releases/2011/03/110301142016.htm>.
University of Rochester Medical Center. (2011, March 1). Patients who receive greatest benefit from heart failure treatment identified. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2011/03/110301142016.htm
University of Rochester Medical Center. "Patients who receive greatest benefit from heart failure treatment identified." ScienceDaily. www.sciencedaily.com/releases/2011/03/110301142016.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Doctor in NYC Quarantined With Ebola

Doctor in NYC Quarantined With Ebola

AP (Oct. 24, 2014) An emergency room doctor who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus. He's quarantined in a hospital. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins