Home defibrillators do not increase survival

CHICAGO (Reuters) - Having a defibrillator at home does not protect heart attack survivors against a cardiac arrest any better than having someone at home with good cardiopulmonary resuscitation training, U.S. researchers said on Tuesday.

They presented the results of their study of devices known as automated external defibrillators or AEDs used in the home at a meeting of the American College of Cardiology in Chicago.

When stationed in public places such as airports, AEDs have helped people survive sudden cardiac arrest, when the heart stops pumping blood. Without immediate treatment with a defibrillator or a bystander who knows CPR, most die within minutes.

As about 80 percent of sudden cardiac arrests occur at home, researchers wanted to see if putting defibrillators in the home could save lives.

High-risk patients often are treated with implantable defibrillators, which can detect dangerous rhythms and deliver a life-saving shock.

Dr. Gust Bardy of the Seattle Institute of Cardiac Research and colleagues studied 7,001 people at moderate risk of sudden cardiac arrest, each of whom had a spouse or home companion willing and able to perform CPR and use an AED.

One group was told to call an ambulance and perform CPR, while the other group was told to use the defibrillator first, then seek emergency help. They were followed for three years.

“There was no mortality benefit,” said Dr. Gust Bardy of the Seattle Institute of Cardiac Research, whose study was published in the New England Journal of Medicine.

Out of 123 arrests, just 63 of those were witnessed and a defibrillator was used in just 32 people. The device, which can assess a patient’s rhythm, called for a shock to be delivered in just 14 patients, and only four survived long enough to be discharged from the hospital.

Bardy told reporters the rate of cardiac arrests occurring at home was lower than expected, and many occurred when the victim was alone.

And he noted that patients’ spouses and companions in the control group had been well educated in how to respond to a heart-stopping event, something that could have improved survival in the group that did not have an AED.

Interestingly, the devices were also used by neighbors who borrowed one of the defibrillators to revive a family member. Two out of 7 of those people survived. Bardy said whenever the devices were used, they worked well.

AEDs for use at home cost $1,200 to $2,000 per unit. AEDs used in the study were made by Philips Medical Systems, a unit of Royal Philips Electronics, which are the only AEDs available without a prescription. Other companies, including Zoll Medical and Cardiac Science, make AEDs that can purchased with a prescription.

Bardy said most of the devices are purchased by the “worried well,” and confessed to personally owning four.

He said he was able to use one of the publicly available devices to revive a person in a Denver airport. “I managed to defibrillate the patient and still make my connection,” he said.

“In light of the study findings and the high cost of the devices, future efforts should turn toward education, modification of risk factors and other methods for primary prevention of heart disease,” said Dr. David Callans of the University of Pennsylvania, who wrote a commentary on the findings.

Editing by Maggie Fox and Mohammad Zargham