WASHINGTON (AP) -- Implanted defibrillators could protect the lives of at least 3 million heart attack survivors, the Food and Drug Administration said Thursday in a ruling that allows the devices to help far more people than ever.
Until now these heart jump-starters have been reserved for the relatively few patients revived after cardiac arrest or who are at high risk for that.
But the FDA ruled Thursday that Guidant Corp. had proved its defibrillators cut the risk of dying by one-third when they were implanted in people who had survived a heart attack and were left with a moderately weakened heart.
``If you've had a heart attack and you have suppressed heart function ... you should discuss with your physician whether you're a candidate for one of these devices,' said FDA medical officer Dr. Helen Barold.
Each year, about 220,000 Americans collapse and die of cardiac arrest -- when the electrical signals that pump the heart go haywire and heartbeat stops.
Only a defibrillator can restart the heart, by electrically jolting it. External versions that bystanders can use to save cardiac arrest victims now are popular in places such as airports and shopping malls.
Implanted defibrillators -- like the kind given to Vice President Dick Cheney last year -- constantly check for abnormal beats and automatically zap the heart back into rhythm in case of cardiac arrest.
A heart attack is different -- blood flow is blocked to the heart. But a major heart attack or several smaller ones can leave the heart permanently weakened, making the survivor more vulnerable to cardiac arrest later.
That is the FDA ruling, prompted by the Guidant-sponsored study of 1,200 heart attack survivors, comes in.
If every heart attack survivor with the required amount of heart weakness were to get a defibrillator today, that would come to 3 million to 4 million people, Barold said. With more people living longer with heart disease, as many as 400,000 people more a year might qualify, she said.
``This is huge,' she said.
Some doctors already had begun implanting defibrillators in heart attack survivors after Guidant's study made headlines last spring; they note that different defibrillator brands should have the same effect.
The ruling means Guidant now can advertise the added defibrillator benefit, which promises to spread the new use faster.
But qualifying does not mean it's best that all these people get a defibrillator, said University of Chicago cardiology chief Dr. David Faxon, past president of the American Heart Association. Scientists are trying to determine who would be top candidates, examining risk factors such as irregular heartbeat tendency and EKG abnormalities.
``The way I approach it with my patients is we're waiting for more information about who really benefits the most,' he said. ``We really want to choose wisely' before implanting such an expensive device too widely.
With surgery and a one-night hospital stay to install the defibrillator, the total cost is about $40,000.
To qualify, heart attack survivors should have ``ejection fractions' that are 30 percent or less. That is a measure of the amount of blood pumped from the heart with each beat. Typically, it is measured with an echocardiogram, a noninvasive imaging scan. Normal ejection fraction is 50 percent or more.
Defibrillators are implanted under the collarbone; one or more wires are threaded into the chambers of the heart.
The FDA had one more piece of good news: The heart attack survivors do not need the invasive electrophysiological testing -- where doctors snake a catheter inside the heart to trigger an irregular beat -- that was once routine for most defibrillator candidates.
