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Study says Implantable defibrillators save lives in many people with heart failure

Houston, TX - 1/19/2005

Implantable cardioverter-defibrillators (ICDs) reduce death by 23 percent in people with heart failure, a condition where heart muscle is too weak to adequately pump blood efficiently, according to a study appearing in the January 20th issue of The New England Journal of Medicine.

The Methodist Hospital in Houston 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 current to stop a rapid, chaotic heart rhythm that otherwise often leads to death within minutes.

“This study adds significantly to our understanding of the role of this life-saving therapy in patients with heart disease, said Dr. Nadim Nasir Jr., one of the co-investigators at The Methodist Hospital and Director of the Methodist Debakey Heart Center Electrophysiology Lab. 

“Until recently, this therapy was used in specific patient populations: those patients who had survived an episode of SCA, those with underlying heart disease and prior heart attacks with depressed heart function, or those who had been evaluated and found to have high risk of SCA,” said Nasir.  “Now we can offer this therapy to many more patients.  We at the Methodist Debakey Heart Center are gratified that this and other studies done here and throughout the country continue to advance the progress of medical science.”

The study compared the lifesaving benefits of ICDs versus amiodarone, a powerful and often used heart rhythm 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. A third group of patients were treated with only with optimal medical therapy. 

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.

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.

“ICD therapy may not be for every patient but individuals with significant heart disease should talk to their physicians about whether they ought to be considered for this therapy,” added Nasir. “If it is found that this is the right treatment for them, a referral to a qualified cardiologist can then be made.”

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 five 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. Not to be confused with a heart attack or myocardial infarction, SCA is a condition involving the heart’s electrical circuitry rather than the coronary arterys, though most patients in the USA have disease heart muscle on the basis of coronary artery disease which then places them at risk for the da