However, large-scale clinical trials have highlighted the beneficial effect of cardiac resynchronisation therapy (CRT) in the improvement of symptoms and reduction of mortality, and CRT is now recommended in the major European and American guidelines for the treatment and prevention of heart failure.(1)
Clinical trials, however, are performed in carefully selected subjects and their results are not always applicable to the general population. Large-scale registries or surveys, on the other hand, capture data from a much more heterogeneous population and are closer to everyday clinical practice (although the applicability of the sample may be a concern).
Now, the European CRT Survey, whose follow-up results are published today in the European Journal of Heart Failure, suggests that CRT does indeed reduce rates of death and re-hospitalisation among heart failure patients.(2) Indeed, at one-year follow-up most patients who had received a CRT device considered their symptoms were better than their pre-implant assessment.(3)
The survey - a joint initiative of the Heart Failure Association and European Heart Rhythm Association of the European Society of Cardiology (ESC) - gathered information on more than 2000 patients at 141 centres in 13 European countries. Its aim was to assess the effect of CRT on symptom severity, cardiovascular re-hospitalisation, and survival. The study population included subjects poorly represented in clinical trials but commonly admitted as heart failure patients - including the very elderly, those with atrial fibrillation, and those previously treated with a pacemaker or other cardiac device.
Analysis of the survey data showed that at, one year (average) follow-up, 81% reported a self-assessed improvement in their symptoms (with 16% no change and 4% a deterioration).
The survey also found that almost 25% of the subjects had died or been re-hospitalised within the 12-month follow-up period. This poor outcome (whose rate is consistent with that found in clinical trials - was directly associated with the diagnostic severity of the heart failure, the pre-existence of atrial fibrillation (or other heart disease), and the type of resynchronisation cardiac device implanted. Patients implanted with a pacing device only (CRT-P) had higher rates of mortality than those whose device had an additional defibrillator (CRT-D).
First author Dr Nigussie Bogale from Stavanger University Hospital in Norway said: "This is the largest study reporting a difference in outcome between CRT-D and CRT-P. Most patients with an indication for CRT have also an indication for a defibrillator. So unless they have contraindicating co-morbidities, it is now our belief that these patients should be considered for CRT-D implantation."
The use of advanced CRT devices has gained increasing acceptance in recent years and they are now being implanted on a large scale as an adjunct to conventional drug treatment. Indeed, some reports have described the two types of devices (CRT-P and CRT-D) as a revolution in heart failure. One important study cited in the most recent guidelines on heart failure suggested implantation of an ICD was associated with a 23% reduction in all-cause mortality.(4)
One study reporting in 2009 found that throughout 15 European countries the number of CRT implantations increased substantially, from 46/million in 2004 to 99/million in 2008, an increase of 115%. This was mainly explained by an increase in use of CRT-D devices. One study cited by many recent guidelines (MADIT-CRT) found that CRT-D decreased the risk of heart-failure events even in relatively asymptomatic patients (with a 34% reduction in the risk of all-cause mortality or heart failure).(5) This European CRT Survey now suggests that benefits of this nature - in both symptoms and survival - can be replicated in routine everyday practice.
However, despite the benefits and the recommendations, other studies show there is still a wide gap between those who meet the criteria for CRT and those who actually have a device implanted.
Notes to editor
(1) Cardiac resynchronisation pacemakers (CRT-P) and defibrillators (CRT-D) for treating heart failure, which have evolved from conventional pacemakers, aim to correct abnormal contractions of the heart's ventricles. More than half of the mortality associated with heart failure is because of sudden cardiac death - and the most important predictor of SCD is left ventricular dysfunction, the underlying cause of heart failure. The use of CRT aims to correct dyssynchrony and prevent sudden cardiac death.
(2) Bogale N, Priori S, Cleland JGF, et al. The European CRT Survey: 1 year (9-15 months) follow-up results. Eur J Heart Fail 2011; doi:10.1093/eurjhf/hfr158.
(3) The main symptoms of heart failure are breathlessness (dyspnoea), tiredness and weakness, and oedema (swelling in the legs and ankles).
(4) Moss AJ, Hall WJ, Cannom DS, et al. Cardiac-resynchronization therapy for the prevention of heart-failure events. N Engl J Med 2009; 361: 1329-1338.
(5) Van Veldhuisen DJ, Maass AH, Priori SG, et al. Implementation of device therapy (cardiac resynchronization therapy and implantable cardioverter defibrillator) for patients with heart failure in Europe: changes from 2004 to 2008. Eur J Heart Fail 2009; doi:10.1093/eurjhf/hfp149.
* The European Journal of Heart Failure is a journal of the European Society of Cardiology.
* Heart failure is by far the single biggest reason for acute hospital admission. Around 30 million people in Europe have heart failure and its incidence is still increasing: more cases are being identified, more people are living to an old age, and more are surviving a heart attack but with damage to the heart muscle.
The 2010 Focused Update of ESC Guidelines on device therapy in heart failure can be seen in various formats
More information on this press release and a PDF of the paper is available from the ESC's press office firstname.lastname@example.org
ESC Press Office | EurekAlert!
Millions through license revenues
27.04.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn
New High-Performance Center Translational Medical Engineering
26.04.2017 | Fraunhofer ITEM
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...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences