Aug. 14, 2001 -- Mechanical heart aids such as pacemakers or implantable cardioverter-defribrillators, or ICDs, like the one implanted in Vice President Dick Cheney may not always "take a lickin' and keep on tickin'," according to a new analysis from a Harvard researcher who says the number of FDA advisories, alerts, and recalls of pacemakers and ICDs is increasing.
William H. Maisel, MD, PhD, an instructor at Harvard Medical School, and his colleagues studied FDA records over an 11-year period from January 1990 through December 2000. He says that the FDA issued 52 alerts during that period, "an average of about four a year."
The alerts, which ranged from actual recalls to advisories about very minimal problems with the programming of some devices, "have the potential of being very expensive to fix," Maisel tells WebMD. The alerts affect more than 400,000 pacemakers and more than 100,000 ICDs. "We estimate the cost of these advisories to be about $870 million."
While more pacemakers were the subjects of FDA action, Maisel says that the recall rate is actually higher for ICDs than for pacemakers, but because ICD technology is newer there are fewer devices in use and therefore a lower number of advisories.
Although malfunctions in either of these mechanical devices can be serious, Maisel says that an ICD failure has a greater potential for harm. The ICD is implanted in patients who are at risk for a dangerous heart rhythm called a ventricular tachycardia or fibrillation, conditions associated with sudden death. When this rhythm occurs, the ICD shocks the heart to restore normal rhythm. If the device fails to recognize the dangerous rhythm, the malfunction is "potentially life-threatening."
Pacemakers, on the other hand, are battery-operated devices that control the heart rate by sending electrical impulses to the heart. Some people with pacemakers are pacemaker-dependent, and in these patients a mechanical malfunction in the pacemaker can be life threatening. In patients who are not pacemaker-dependent, mechanical failure would simply mean that their hearts beat at a much slower rate, "so they will feel poorly but they won't die," says Maisel.
Maisel says that his study, which is published in this week's issue of The Journal of the American Medical Association, represents the first compilation of all reported device malfunction advisories.
Eric N. Prystowsky, MD, president of the North American Society of Pacing and Electrophysiology, which represents doctors who specialize in the use of pacemakers and ICDs, says his group welcomes Maisel's study because "it is the first attempt ... to track all these reports."
But Prystowsky says the study has to be assessed realistically. As a specialist working at St. Vincent's Hospital in Indianapolis, home of the Indiana Heart Institute, Prystowsky says he oversees the implantation of 400 pacemakers and 200 ICDs each year. He says that he is well aware of the frequency of safety alerts, yet he says, "even with all these alerts it is exceedingly uncommon to bring back patients to replace a device."
Prystowsky says that it is, therefore, unlikely that device alerts cost anywhere near $870 million, because "that figure is based on the assumption that all devices are replaced."
Most alerts require little more than more frequent office visits to better monitor the patient, says Prystowsky, who is a consultant to Guidant, a manufacturer of both ICDs and pacemakers.
Although Maisel's paper tracks the number of FDA-issued alerts, it doesn't provide any data on the health effects of those alerts and Maisel admits that he can only estimate the costs involved with the alerts. He explains that the FDA warnings are the only official records available. When an alert is issued a notice goes out to the doctor who implanted the device and the patient in whom it was implanted. It is then up to the doctor and patient to decide how to respond, says Maisel.
A better approach, according to one expert, would be some uniform recommendations -- not generated by the device industry or the FDA -- about how to handle and track potential malfunctions.
In an editorial that accompanies the study, Kim A. Eagle, MD, chief of clinical cardiology at the University of Michigan Medical Center in Ann Arbor, tells WebMD that tracking devices after they are implanted is actually "a lot more complicated than tracking side-effects of pills. It is much more challenging because the devices are more complex."
Eagle says it is time doctors themselves become involved in monitoring device safety, and he suggests that the American Heart Association, the American College of Cardiology, and Prystowsky's group join forces to produce a better tracking system.
Prystowsky says his group is already planning a conference aimed at addressing device safety concerns. "This is not a new issue for us and we are already well along in the planning process," he says.
However it is done, Eagle says its clear that better device safety monitoring is needed. "What is very clear is that the recall carries with it a certain amount of inconvenience and expense. It has a direct impact on patient safety, although the lion's share of the recalls are not life-and-death issues."