New Device Jump-Starts Failing Hearts
Combo Pacemaker-Defibrillator Helps Many With Heart Failure
June 28, 2002 -- Yesterday, the FDA approved a new device that may improve the quality and length of life for more than a million people in the U.S. with heart failure.
That device, called the InSync ICD system, is, in fact, a combination of two other revolutionary devices -- a highly specialized pacemaker and a defibrillator -- both of which have proven to benefit many with this life-threatening condition.
"We think it's an important advancement in this emerging technology," says David DeLurgio, MD, director of the electrophysiology laboratory at Emory University School of Medicine in Atlanta.
He and his colleagues at Emory have been involved in studies of both devices.
Heart failure occurs when the heart's pumping action grows weaker and weaker, and needs to work harder to keep blood flowing through the body. When the heart is not pumping properly, even mild activity can cause shortness of breath or difficulty breathing.
A pacemaker device approved late last year -- called cardiac resynchronization therapy -- helps the heart's main pumping chambers fall back in step with one another. It calls for tiny electrodes to be threaded through veins into two chambers of the heart.
The InSync ICD takes that concept a step further, adding a defibrillator to the CRT system to jump-start a heart that is at risk of going into cardiac arrest.
Medtronic Inc., the maker of the device, is a WebMD sponsor.
"The original device is essentially a pacemaker that stimulates the heart continuously -- but it does not provide any protection against cardiac arrest [or sudden heart death]," DeLurgio tells WebMD.
Studies of the original InSync cardiac resynchronization therapy (CRT) have yielded encouraging long-term results. In one study reported recently, 500 patients received the device. Half the patients had the device turned on, the others didn't. After six months, all patients were switched on. The results:
- CRT patients had worsening heart failure only half as often.
- The risk of death or worsening heart failure dropped by 40% in the CRT group.
- CRT patients had a 57% lower chance of worsening heart failure requiring intravenous heart medication.
However, some patients with heart failure -- especially those who have had a heart attack -- are at higher risk for sudden cardiac arrest and death, says DeLurgio.
In tests of that original device, some patients also died, says DeLurgio. "There were people that the CRT couldn't protect. Since then, there's been a growing awareness that a defibrillator added to the device would be beneficial."
That's where the defibrillator comes in. Implanted cardioverter-defibrillators (ICDs) are often used in people with moderate to severe heart failure to prevent the onset of deadly heart rhythm problems or arrhythmias that can cause sudden death.
A recently published study of the InSync ICD device showed that patients who had a heart attack in the past -- and had reduced heart strength -- had improved survival rate because of the defibrillator.
"This was even if they had never had arrhythmia or a cardiac arrest episode," he tells WebMD. "There was a definite protective effect."