Implantable cardioverter-defibrillators (ICDs) reduce sudden death by 23 per cent in people with congestive heart failure, according to a study appearing in the Jan. 20 issue of The New England Journal of Medicine.

"By participating in this clinical trial, OHSU provided dozens of heart failure patients with access to ICD technology at little or no cost. Simultaneously, we raised the standard of health care in the state by perfecting our own clinical expertise," said Ray Hershberger, director of OHSU's heart failure and cardiac transplant programme and professor of medicine (cardiology) in the OHSU School of Medicine. Oregon Health & Science University was one of 150 medical centres participating in the nationwide study and the only study site in Oregon.

The study also showed that amiodarone, a common anti-arrhythmia drug once considered a gold-standard treatment to prevent sudden cardiac death, has no favourable effect on survival.

While heart failure is a serious disease, thousands of these people live well with the condition. However, some patients are at risk of sudden death from arrhythmia (rapid heart rate) due to the severity of their disease. For patients and physicians alike, this situation is particularly vexing because no one understands what will trigger a life-threatening event. Sudden cardiac arrest (SCA) kills approximately 250,000 people each year in the United States and an estimated 95 percent of those die before reaching a hospital.

The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) compared the lifesaving benefits of ICDs, amiodarone and a placebo in 2,521 patients with moderate heart failure and poor heart pumping function who had not experienced a prior episode of sudden cardiac arrest. Over the course of the study (the median time was 45.5 months), a total of 666 patients died: 244 deaths (29 per cent) in the placebo group, 240 deaths (28 per cent) amiodarone group but only 182 deaths (22 per cent) in the group undergoing ICD therapy. The National Heart Lung and Blood Institute of the National Institutes of Health (NIH) sponsored the study.

An ICD is surgically implanted beneath the skin in the upper chest. When a patient's heart rhythm accelerates, the device delivers an electrical current to stop the otherwise deadly rapid and chaotic heartbeat. Approved for use since the late 1980s, ICDs have been prescribed primarily for the 5 per cent of people who had already survived an episode of sudden cardiac arrest. This study indicates this clinical option should be considered for the many patients who have advanced heart failure but no specific history of cardiac arrest.

While not every heart failure patient is a candidate for an ICD, the study indicates that most heart failure patients should be evaluated for the procedure after first receiving optimal conventional medical therapy, such as ace inhibitors and beta blockers, said Hershberger.