Yenra : Medical : Implantable Defibrillators : ICD devices monitor the heart to stop rapid, chaotic heart rhythms that lead to sudden cardiac arrest


The use of an implantable cardioverter-defibrillator (ICD) in people with heart failure whose hearts don't pump blood efficiently reduces failure by twenty-three percent, according to a study in The New England Journal of Medicine.

The findings 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, which shocks the heart out of a rapid, chaotic heart rhythm that otherwise can lead to trouble within minutes.

The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) 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 data from SCD-HeFT 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.

A total of 150 medical centers in the United States, Canada and New Zealand enrolled patients in SCD-HeFT, the largest and longest study of ICD therapy. The National Institutes of Health sponsored the study, with funding and therapy donations from Medtronic and Wyeth Pharmaceuticals. Upon completion of the study, Medtronic offered ICDs at no cost to any interested participants who had been randomized to a non-ICD study arm.

Implantable defibrillators have been approved for use since the late 1980s, but primarily for the five 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.

"The highly significant SCD-HeFT results, combined with the rigorous study design and implementation, lead to a clear but not unexpected conclusion: Implantable defibrillators can save many, many lives," said Steve Mahle, president of Medtronic Cardiac Rhythm Management. "Medtronic is proud to be associated with this study that will bring hope to so many families throughout the world. We look forward to protecting many more patients so they can live long, productive lives."

"People with heart failure can be evaluated with a simple test called an echocardiogram to determine if they are at risk for sudden cardiac arrest," added Dr. Luceri. "This test and a discussion with a heart rhythm specialist are important steps in identifying whether a person is a candidate for an ICD."

According to Florida business owner Elizabeth Johnson, who is also a SCD-HeFT participant and patient of Dr. Luceri, "If I hadn't received an ICD in this clinical trial, I believe that I wouldn't be alive today. I would have been dead two years ago from sudden cardiac arrest, so life is a gift to me. I look forward to getting up every day and enjoying life."

Heart failure is a progressive condition that limits the lower chambers of the heart from 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.

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 twenty percent of the patients at risk for SCA are protected with an ICD.

Medtronic develops medical technology for people with chronic disease.