Home Defibrillators Fail to Boost Survival Rates

TUESDAY April 1, 2008 -- Putting external defibrillators in the homes of people after they had a heart attack didn't improve their survival rate, a new study found.

But, the leader of the study still sees plenty of encouraging news in the research and is not necessarily ruling out the use of those heart-shocking devices in the home.

In a 37-month trial, half of 7,001 heart attack survivors had defibrillators put in their homes, while the other half got standard instructions to call for emergency help if a second heart attack occurred. But, the death rate for both groups was just about the same -- 222 of the people given defibrillators and 228 of those not given the devices, said study leader Dr. Gust H. Bardy, director of the Seattle Institute for Cardiac Research.

The findings were to be presented Tuesday at the American College of Cardiology annual meeting, in Chicago, and were published in the April 1 online edition of the New England Journal of Medicine. The results were also expected to be published in April 24, 2008, print issue of the journal.

People in the study weren't considered suitable for implanted defibrillators. The devices they took home were identical to those now found in many public places for use in cardiac emergencies.

"It really amazed me that the survival prospects for this group were so promising," Bardy said. "A 2 percent-a-year death rate for 60-year-old patients, that surprises me."

Most of the deaths in the defibrillator group were due to non-cardiac causes, Bardy noted. "The event rate was so low," he said of cardiac deaths, "and the usage of the defibrillators is less than it should be. It's not that the devices are ineffective. When they were used, they did real well."

The defibrillators, which deliver an electric shock to restart an arrested heartbeat, were used 18 times, and six of those people survived, Bardy said. "Long-term survival of one out of three is not bad," he said.

Partly because of the high cost of external defibrillators, their home use should not be encouraged, said an accompanying editorial in the journal by Dr. David J. Callans, professor of medicine at the University of Pennsylvania. "Future efforts should turn toward education, modification of risk factors and other methods for primary prevention of heart disease," Callans said in a statement.

But Dr. Robert Femia, chairman of emergency medicine at Lenox Hill Hospital in New York City, disagreed with Callans. "Early defibrillation offers the best chance for survival," Femia said. "My point is that there may be a role for a defibrillator as part of a plan developed by your physician on an individual basis."

Such a plan usually is lacking after a heart attack, Bardy said. "One thing that is not standard practice is consciousness-raising," he said. "Most post-myocardial infarct [heart attack] patients don't have a discussion of mortality, don't have a discussion of cardiac arrest, don't have a discussion of what to do if there is a cardiac arrest."

Any discussion with a doctor after a heart attack should include advice about carefully taking any medications that are prescribed, Bardy said, and about other medical measures needed to keep arteries clear.

When such steps are taken, he said, "the patient may or may not choose an external defibrillator. I see no downside for an external defibrillator. Whether or not it will help in the long run, I don't know."

More information

The facts about external defibrillators are available from the U.S. Food and Drug Administration.

Posted: April 2008


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