Brian Herron reports on a trial of CRT-Ds, devices that can benefit patients in the early stages of heart failure
New international research has shown that cardiac resyn-chronisation Therapy defibrillators (CRT-D), when implanted in patients in early stages of heart failure, can have significant benefits for patients’ long-term health.
CRT-D devices are generally implanted in patients with a New York Heart Association (NYHA) heart failure severity class of three or four, meaning that the disease has a major impact on a patient’s everyday activities.
CRT-Ds are usually implanted in vulnerable patients with a low ejection fraction — below 30 per cent — and who may have already suffered a heart failure event. The implant paces the heart, and works in synchrony with both the left and right ventricles to improve effective pumping action. In contrast, pacemakers and implantable cardioverter defibrillators (ICDs) stimulate only the right side of the heart.
But the new study demonstrates that implanting a device in the early stages of heart failure could reduce the chance of hospitalisation dramatically. In comparison with an ICD — the implant that is generally used in early stages of heart failure — the risk of a patient suffering a heart failure event can be reduced by up to 41 per cent.
Better quality of life
“By preventing an event we can also prevent long-term damage to the muscles in the heart,” said Fred Colen, president of the Cardiac Rhythm Management group at Boston Scientific, the sponsors of the research. “This means a better quality of life for the patient.”
“People with an NYHA severity class of three or four are in the later stages on the conditions and have severe symptoms. Heart failure is a progressive disease, and the symptoms grow worse and worse over time. This study looks at CRT-Ds as a therapeutic and preventative measure in healthcare.”
The randomised trial took people with a severity class of one or two, who were already picked for ICD implant. They were then implanted with a CRT-D instead. Boston Scientific claims that this is the largest trial of its kind ever conducted.
“This research is showing that by implanting the CRT-D earlier, we can reduce the number of hospitalisations and therefore reduce the overall cost of providing services to patients with heart failure. It represents a tremendous benefit to both patients and healthcare services.”
In addition, the study has shown that the CRT-D can help improve the quality of the heart. Patients who had the CRT-D implanted showed an average improvement of 11 per cent in left ventricular ejection after one year; the control group given ICDs showed only a 3 per cent improvement in the same time. “Upgrading to a CRT-D does have an increased cost,” Colen acknowledges “but the patients are already candidates for an ICD so the gap in price between the devices is not prohibitively expensive.”
Heart failure is one of Ireland’s most common reasons for emergency admission to hospitals. There are 12,000 hospitalisation each year in Ireland due to a heart failure event, according to the Irish Heart Foundation. This results in 250,000 bed days in hospitals across the country.
Although the results of the research are promising, says Colen, “more studies need to be conducted.”
“This research is important, and we believe that this technology can offer real benefits to patients. But there are other questions that need to be answered, like, does this technology offer a death benefit over time? Are patients who are fitted with a CRT-D in early stages of Heart failure less likely to suffer a fatal event?”
The research, lead by Prof Arthur J Moss, Director of the Heart Research Follow-up Program at the University of Rochester, was conducted in 110 centres worldwide on 1,820 patients. Although units in several EU countries took part, including the UK, Germany and Spain, no Irish patients were included.
This, says Colen, was largely due to low-market penetration in Ireland. “When the study began four and a half years ago Boston Scientific didn’t have a significant presence in the Irish market.”
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