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.
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. Indeed, at one-year
follow-up most patients who had received a CRT device considered their
symptoms were better than their pre-implant assessment.
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.
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.
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). 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.
