Patients with dyssynchronous yet viable ventricles are most likely to benefit from cardiac resynchronization therapy combined with defibrillation, concludes the latest analysis of the MADIT CRT trial. The CRT-MADIT-CRT trial - presented at the Heart Failure Congress 2011, organized by the Heart Failure Association of the European Society of Cardiology (ESC) in Late Breaking Session 1 - showed that CRT produced improvements in both synchrony and contractile function, and that the extent of this benefit relates to subsequent outcomes.
The Multicentre Automatic Defibrillator Implantation Trial-CRT (MADIT-CRT) set out to determine whether patients with mild heart failure (NYHA class I or II) would do better if they got implanted with a CRT-D device (which combines cardiac resynchronization therapy with defibrillation), than if they only received the traditional ICD defibrillation. In earlier studies CRT-D devices had been approved for use in patients with severe heart failure (NYHA class III/IV).
In the MADIT-CRT study, funded by Boston Scientific, 1820 patients with Class I and II heart failure, wide QRS and left ventricular dysfunction were randomized 3:2 to receive CRT-D (n=1089) or ICD alone (n=731). Results, presented at the 2009 ESC Annual Conference in Barcelona after a follow period averaging 2.4 years, demonstrated a greater than 40% reduction in the primary endpoint of death or heart failure in patients receiving CRT-D. However, in virtually all studies of CRT-D approximately 30% of patients do not respond to therapy.
In the current study, Dr Scott D Solomon (Brigham and Women's Hospital, Boston, MA) and colleagues set out to investigate whether the degree of synchrony – the extent to which the walls of the left ventricle contract in unison – might influence the likelihood of patients responding to CRT-D. "It's important to target patients in whom CRT-D works well because the technology is quite expensive," explained Solomon.
In this latest analysis of MADIT-CRT, investigators analyzed echocardiograms from 1077 patients enrolled in MADIT-CRT (CRT-D n=66; ICD, n=416) who had echocardiographic images of sufficient quality to allow analysis of synchrony and contractile function. Researchers were blinded to the randomization and study outcomes.Results showed that patients with mild to moderate dyssynchrony at baseline (defined as a time-to peak transverse strain SD of 142-230 ms) and greater baseline contractile function (longitudinal strain
The study showed that over a year each 10 ms decrease in LV dyssynchrony was associated with a 3% reduction in the primary outcome of death or heart failure, and each 5 point absolute increase in LV strain was associated with a 75% reduction in the primary outcome.
"These results suggest that the patients who are most likely to benefit from CRT-D are those with at least some dyssynchrony who have relatively preserved contractile function," said Solomon, adding that the observation that improvements in synchrony and contractile function were associated with reduced death and heart failure events, suggests that the benefits delivered by CRT relate to improvements in these factors. "Future studies will continue to try to identify the patients who are most likely to benefit from this expensive but highly effective therapy," he said.
Jacqueline Partarrieu | EurekAlert!
Mice provide insight into genetics of autism spectrum disorders
28.06.2017 | University of California - Davis
Correct connections are crucial
26.06.2017 | Charité - Universitätsmedizin Berlin
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
28.06.2017 | Power and Electrical Engineering
28.06.2017 | Life Sciences
28.06.2017 | Awards Funding