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.
Cardiac resynchronization therapy with defibrillator (CRT–D)“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.
Arthur J. Moss, M.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.For Media Inquiries:
Emily Boynton | EurekAlert!
A promising target for kidney fibrosis
21.04.2017 | Brigham and Women's Hospital
Stem cell transplants: activating signal paths may protect from graft-versus-host disease
20.04.2017 | Technische Universität München
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...
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...
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...
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...
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...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Physics and Astronomy
25.04.2017 | Materials Sciences
25.04.2017 | Life Sciences