The June 17 recall of nearly 50,000 implantable defibrillators for potential malfunctions, including short-circuiting that was tied to two patient deaths, has unsettled many patients and doctors. People with the defibrillators -- surgically installed devices that monitor the heart's rhythm and shock the organ if it begins to beat irregularly -- have been anxiously seeking advice on whether to replace the three suspect models. Doctors also report fielding calls from worried cardiac patients with units that have not been recalled.
The announcement Friday by Guidant Corp. that a faulty switch might impair the function of five additional models -- affecting another 44,700 devices -- added to concern. The Food and Drug Administration (FDA) hasn't yet classified the new problem as a recall. We spoke with medical experts about the recall and some of the questions it poses.
How are patients reacting?
"People see this stuff and get nervous," said Adam Strickberger, an electrophysiologist at Washington Hospital Center who treats people with defibrillators. Some patients met at the hospital Thursday to put their questions directly to representatives from device makers Guidant and Medtronic. "Some people were very unhappy," Strickberger said.
Strickberger said he plans to contact all of his affected patients this week and have them schedule appointments if necessary to discuss what to do. He anticipates recommending that relatively few of the devices be replaced, unless a patient is very upset. Patients whose defibrillators have fired to correct a heart rhythm problem or whose devices are nearing the end of their normal battery life -- about five years -- will be advised to consider replacement more seriously.
Which defibrillators are involved and just what is wrong with them?
Nearly 29,000 of the recalled defibrillators have the potentially life-threatening short-circuit risk. Units associated with the deaths were the Ventak Prizm 2, model 1861 (unless made after April 16, 2002) and the Contak Renewal, model H135 (unless made after Aug. 26, 2004). The Contak Renewal 2, model H155, while not tied to a death, was also included in the recall because models made on or before Aug. 26, 2004 are vulnerable to the same problem, according to Guidant: The deterioration of a wire insulator could disable the device's ability to deliver a shock when needed.
The other 21,000 or so other recalled devices (with other model names) have a less grave problem that, in theory, can be fixed by noninvasive reprogramming, Guidant said.
The five additional devices Guidant advised doctors to stop implanting because of a faulty switch are the Contak Renewal 3 and 4, Renewal 3 and 4 AVT, and Renewal RF.
What are the biggest risks in replacing an implantable device?
Deciding whether to replace a recalled device can be agonizing for patients and physicians. Doctors said they weigh the possibility of device failure against the risks associated with replacing the device, including the chance of infection or injury during replacement surgery.
The calculus varies from patient to patient. Defibrillators are implanted in the chest, near the left armpit. Candidates for defibrillators include people with coronary artery disease and heart rhythm disorders, and people who have experienced cardiac arrest.
Infection occurs in 1 percent or less of operations, several physicians said. But patients with certain conditions, such as a weakened immune system, or who take certain drugs, such as blood thinners, may face a higher than average risk of infection, serious bleeding or other problems.
But don't patients take a bigger chance by not replacing a faulty unit?
William H. Maisel, a cardiologist at Brigham and Women's Hospital in Boston, said most patients with implanted defibrillators have received them as a precautionary measure. Each year only 5 or 6 percent of those patients have a potentially lethal heart arrhythmia that triggers the device to fire, so even if their device is defective, it won't likely kill them. Replacement should be considered more seriously by the minority of people who already have experienced an arrhythmia, said Maisel, who has published several studies on pacemaker and defibrillator recalls.
Have general guidelines been issued to help patients with their decision?
No. In the Guidant case, the FDA said it will make no specific recommendation to patients except that they consult their physicians.
Has there been any research on patient outcomes for those who leave devices in versus those who elect to take them out?
No, Maisel said.
How unusual is this kind of recall?
Not very. In February, Medtronic -- a competitor of Guidant -- recalled about 100,000 defibrillators because of faulty batteries. That recall drew less attention in part because the problem wasn't tied to any patient deaths and the FDA regarded it as a less serious matter.
Because of their complexity, defibrillators are frequently recalled, say several physicians who deal with such devices. "Every manufacturer has had problems," said Strickberger. "If there's some glitch in the software," he said, "new software gets downloaded into the patient's machine" without surgery. But he added, fixing "a hardware glitch is more difficult," requiring surgical replacement.
But as technology improves, aren't such problems decreasing?
The average number of patients affected by each defibrillator recall has risen over time, as the number of patients using such devices has grown, said interventional cardiologist Douglas P. Zipes of Indiana University School of Medicine. Yet most device recalls occur with relatively little public fanfare, he said.
What other kinds of implantable devices are subject to recall?
Any device -- from pacemakers to artificial hips and knees -- could develop problems, but simpler devices are less apt to malfunction in a way that requires a recall, said Zipes.
How will I know if my device has a potential problem?
In general, Maisel said, "patients get notified directly by their physician when a device is recalled" after the product maker contacts physicians.
In some cases, a patient who has changed doctors or is for some other reason no longer in touch with the original physician may slip through the cracks. Of course, a patient could call his physician and seek information from the product maker, the FDA or an organization such as the American College of Cardiology or the Heart Rhythm Society.
If I decide to have my Guidant defibrillator replaced, what should I replace it with?
The latest model of a similar type could be the best replacement, physicians said. After a recall, Maisel said, patients "may lose confidence in an individual company." But data on which manufacturer's devices perform best aren't readily available, he said.
"I think Guidant has corrected their problem," said Zipes, who consults for Medtronic and also receives research funding from that company. "They manufacture a good device. I don't see any reason to change companies."
Who pays for the removal of a recalled device?
That's up to the manufacturer. Insurance may pay for some of the cost of replacement, and product makers often pick up any remaining tab, Maisel said. In the June 17 case, Guidant has stated that it will provide replacement products but not cover the full cost of the surgery.
What resources can patients consult?
The Heart Rhythm Society has published general information about defibrillators and recalls at www.hrsonline.org.
Doctors or patients who've experienced a problem with a defibrillator can also file a report with the FDA's MedWatch program (http://www.fda.gov/medwatch).
Guidant may also post more information on its Web site, www.guidant.com.
The FDA lists some recent recalls of medical devices, including implantable ones, at www.fda.gov/cdrh/recalls/. The agency more comprehensively lists recalls of medical products in weekly enforcement reports, which are archived and searchable at www.fda.gov/opacom/Enforce.html.
Ben Harder reports on medicine and health for Science News.