Implantable Defibrillators Save Lives in Many With Heart Failure

Armen Hareyan's picture

CHARLESTON -- Implantable cardioverter-defibrillators (ICDs) reduce death by 23 percent in people with heart failure whose hearts don't pump blood efficiently, according to a study appearing in the Jan. 20, 2005 issue of The New England Journal of Medicine. The MUSC Medical Center was one of 150 medical centers participating in the study.

The findings from the National Institutes of Health-sponsored Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) suggest that approximately 600,000 Americans with this heart condition could be at risk for sudden cardiac arrest (SCA) and should be protected by an ICD. This device, implanted beneath the skin in the upper chest, delivers an electrical pacing impulse, or shock, to stop a rapid, chaotic heart rhythm that otherwise often leads to death within minutes.

The study compared the lifesaving benefits of ICDs and amiodarone, a commonly used heart medication, in 2,521 patients with moderate heart failure and poor heart pumping function who had not experienced a prior episode of sudden cardiac arrest. In addition, economic study data presented at the 2004 American Heart Association Scientific Sessions indicate that ICDs are a cost-effective therapy in this heart failure population. The Centers for Medicare and Medicaid Services (CMS) has said it intends to increase the Medicare beneficiaries eligible for an ICD based on the SCD-HeFT results.

Eleven heart failure patients participated in the study at the MUSC Medical Center, where Robert Leman, M.D., was principal investigator. "The study emphasizes the need for ICD treatment as a preventive therapy in patients with congestive heart failure," said Leman.


Implantable defibrillators have been approved for use since the late 1980s, but primarily for the 5 percent of people who had already survived an episode of sudden cardiac arrest. Recent studies, however, have demonstrated that ICDs can be used as a preventive therapy to save lives from SCA in many patients with a history of heart attack, even if they haven't experienced cardiac arrest. Now, this has been extended to many more patients who have heart failure.

Heart failure is a progressive condition that limits the lower chambers of the heart from to pumping sufficient blood to meet the needs of the circulatory system. According to the American Heart Association, sudden cardiac arrest occurs six to nine times more frequently in the 5 million Americans who have heart failure than in the general population.

SCA is one of the nation's leading killers. Approximately 1.6 million Americans are at risk for SCA and are eligible to receive an ICD. Despite the proven benefit of ICDs, they remain vastly underutilized. Less than 20 percent of the patients at risk for SCA are protected with an ICD.


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