New hope for heart patients

Implantable defibrillators gain endorsements


February 04, 2005|By Erika Hobbs | Erika Hobbs,SPECIAL TO THE SUN

Ever since Joan Hebert turned down a donor heart to replace her diseased one, doctors have struggled for 14 years to keep her heart ticking.

They boosted her standard treatment with a pacemaker to speed her heart when it slowed, and a defibrillator to shock the 73-year-old back to life in case it stopped.

Hebert's defibrillator has never been used - most people's aren't - but she's thankful for the insurance it offered in extending her life, which could have ended with the massive heart attack she had in 1991.

FOR THE RECORD - An article in the Feb. 4 Health & Science section contained incorrect information about Vice President Dick Cheney's implanted defibrillator. Cheney received his first and only defibrillator at George Washington University in 2001.
The Sun regrets the errors.

"I knew there was a chance it could save my life, and that was a chance I was willing to take," the Timonium woman said.

Hebert's case is extreme. But, like Hebert, hundreds of thousands of people may soon have a chance to beat America's No. 1 killer, sudden cardiac disease.

A landmark study, published last month in the New England Journal of Medicine, showed for the first time that patients with mild and moderate heart disease may be able to live longer with implantable defibrillators that shock chaotic heartbeats back into normal rhythms.

The study compared the use of the defibrillators and a standard drug, amiodarone, in patients with congestive heart failure. It showed that defibrillators reduced the patients' likelihood of death by 23 percent. The drug showed no significant effect on improving mortality.

As a result of the study, the Centers for Medicare and Medicaid Services announced last month that it will cover defibrillators in an additional 200,000 people with heart failure. More than a half million people will qualify for the new coverage.

In the past, doctors used defibrillators largely to treat patients who already experienced a potentially lethal problem - those with certain arrhythmias and those who had survived heart attacks and cardiac arrest. Defibrillators have been the best treatment for those patients, saving lives 98 percent of the time, explained Hugh Calkins, director of the Arrhythmia Service at Johns Hopkins Hospital and Health System.

Now, doctors can use them to treat people with heart failure and weak hearts before a traumatic event occurs.

"Now we can use them as prevention," said Rafique Ahmed, a cardiologist with St. Joseph Medical Center in Towson.

Vice President Dick Cheney may be the most famous American with an implantable defibrillator. In 2001, he replaced his old model with a new one at Hopkins.

Heart failure, a progressive disease that causes the heart to inefficiently pump blood, is pervasive. According to the American Heart Association, about 5 million Americans have it. That group is almost nine times more likely to suffer sudden cardiac arrest than the general public. About half die from it, the AHA said.

The terms can be confusing. A cardiac arrest is not the same as a heart attack. Sudden cardiac arrest is caused by a problem with the heart's electrical system; heart attacks are caused by blockages to the coronary arteries. Heart failure can be caused by a number of things, including heart attack, hypertension or high blood pressure, and can lead to cardiac arrest.

"You often hear of people stepping off a curb and dying suddenly of a `massive heart attack,' " said R.E. Hood, an assistant professor of medicine at the University of Maryland. "Most of the time ... they died of fatal arrhythmia."

Sudden cardiac death kills more Americans than any other disease, claiming nearly a half million lives each year.

Fewer than 10 percent who experience sudden cardiac arrest survive it.

Hopkins researchers led by Michel Mirowski, developed and implanted the first defibrillator in the early 1980s in a California woman who experienced several life-threatening arrhythmias.

Last month's study was sponsored by the National Institutes of Health's National Heart, Lung, and Blood Institute in Bethesda with funding from defibrillator manufacturer Medtronic Inc. and drugmaker Wyeth Ayerst. Both Johns Hopkins University and the University of Maryland, Baltimore were test sites for the study.

Due in part to the Medicare changes, analysts expect U.S. defibrillator sales to jump about 20 percent over the next four years. In 2003, sales of implantable defibrillators totaled $2.8 million, said research analyst Vaishnavi Ananthanarayanan of Frost & Sullivan in San Antonio, Texas. They cost roughly $30,000 each.

Most people are familiar with a type of defibrillator often shown on television: Doctors place electric paddles on a victim's chest and shock him back to life. Implantable defibrillators work almost the same way, but they are inserted near the heart.

They work because the heart is controlled by an internal electrical system, which controls the speed of heartbeats. The heart beats faster with exercise, for example, and slows with rest. An abnormal rhythm - too fast or too slow - can be dangerous.

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