Pulse
Tune-Ups
Implantable cardiac device manufacturers are looking for better ways to monitor their products’ functionality. But is it making a difference?
For companies that make implantable cardiac devices, the past 18 months will probably go on record as a time of unprecedented tribulation. In March of 2005, 21-year-old Joshua Oukrop died while biking near Moab, Utah, when his VENTAK Prizm 2 DR implantable cardioverter defibrillator (ICD) short-circuited as it tried to send a life-saving shock to his heart.
Officials from St. Paul–based Guidant Corporation, which manufactures the defibrillator, later acknowledged that they knew about the potential for problems with the device, as 25 others that were made between 2000 and mid 2002 had failed. One month before Oukrop’s death, Medtronic, headquartered in Fridley, had voluntarily recalled its Marquis line of defibrillators because the batteries exhibited the potential to drain prematurely.
In the wake of these occurrences—Guidant’s, in particular—independent panels convened to address how medical device malfunctions could be better documented and disclosed and notice of possible problems conveyed to physicians. Meanwhile, a meta-analysis published in the Journal of the American Medical Association in April 2006 brought still more sobering news: Pacemaker reliability had improved since the mid 1980s, but the malfunction rate of ICDs had increased almost every year except the last two (2003 and 2004).
Those statistics must be viewed in context, says William T. Katsiyiannis, M.D., a cardiologist at Abbott Northwestern Hospital’s Minneapolis Heart Institute in Minneapolis. “I don’t really think that this means the malfunctioning rate is worsening,” he says. “Anytime you have a problem that hasn’t been scrutinized before, you are going to uncover things that simply have not been documented. But just because we are looking harder doesn’t mean that the devices are getting worse or are just not reliable.”
Katsiyiannis notes that both pacemakers and defibrillators have a greater-than-99-percent rate of saving a person’s life. (According to consumeraffairs.com, such devices must be replaced every five to six years because the batteries run down.) But what concerns him are what he describes as “known component failures” that manufacturers may not be revealing in a timely manner.
“The positive that has come out of the recent component failures is that the industry has more pressure to inform us of trends they are seeing through the follow up on their devices. Now, they are expected to bring that to our attention.”
Uncovering the Story
Expected, maybe. Required, not entirely. Under the Medical Device Reporting Act of 1984 and the subsequent Safe Medical Device Act of 1990, manufacturers and “user facilities” (eg, hospitals and nursing homes) must report device-related injuries and deaths to the Food and Drug Administration (FDA). That system is hardly fail-safe, however, notably because hospitals, nursing homes, and other facilities need only file annual reports of malfunctions. Also, the FDA does not require manufacturers to submit malfunction incidents that are not associated with death or injury immediately after they come to their attention.
Thus, while patients are relying on physicians to alert them to problems that may crop up with their own devices, physicians are counting on implantable device manufacturers—through the FDA—to keep them in the know about general defects and malfunctions. That process does not always happen fast or often enough.
At least part of it—physicians’ monitoring of individual patients’ implantable devices—is becoming easier. Typically, patients see their electrophysiologist quarterly to ensure that their pacemakers and defibrillators are running smoothly. During each visit, the physician boots up a small laptop-sized programmer and holds a mouse-like “programmer head” over the patient’s ICD or pacemaker to gather data about whether the leads are connected properly and whether the battery is still strong.
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A Step toward Better Surveillance
In the wake of the recent recalls of several implantable cardioverter defibrillators, the Heart Rhythm Society released recommendations for surveillance of implantable cardiac devices and reporting of malfunctions. Its report can be found in its entirety at www.hrsonline.org.
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Going the Distance
All that is changing, thanks to remote monitoring capabilities and the advent of wireless technology. In 2002, for example, Medtronic created CareLink, a system that enables patients to transmit information about their device over analog phone lines. In the comfort of their home (or hotel room or Florida condo, for that matter), patients turn on a portable monitor that hooks up to a phone jack. They wave an antenna over their device, press a button, and the data is sent to a database that physicians can access on line.
More recently, Medtronic and other device manufact-urers have taken remote monitoring technology a step further by introducing wireless in-home, bedside monitors that physicians preprogram to be activated during a time when patients are within close range of the unit (eg, while sleeping). Guidant’s Contact Renewal 3RF CRT-D and Medtronic’s Virtuoso ICD and Concerto CRT-D systems are examples of devices that can be monitored using the wireless technology. In some cases, remote monitoring may decrease in-office patient visits by up to 75 percent (from quarterly visits to one annual visit), according to Tracy McNulty, a spokesperson for Medtronic’s Cardiac Rhythm Disease Management Division. In addition to saving time for both doctor and patient and making patient compliance easier, these new monitoring products are reducing invasive and potentially risky interventions. “Replacing a device comes with its own set of concerns—including infection and other complications—and what drove replacement is that you never knew when or if the device was going to fail,” explains David M. Steinhaus, M.D., vice president and medical director of Medtronic’s Cardiac Rhythm Disease Management Division. “Now, if you have a device that checks itself every day, it will give people a lot more peace of mind about the ability and reliability of their devices. We can all have more confidence that if there is a failure, it will get picked up quickly.”
All told, it’s difficult to tell whether these technological improvements will translate to statistically significant reductions in malfunction rates. “If you have one death every two years related to a device—or something in that ballpark—it is going to be kind of hard to prove that you are making a difference,” Steinhaus says. “Having said that, we do believe that the newer technologies will make a difference.”
Says Abbott Northwestern’s Katsiyiannis: “The risk of a device failing cannot be avoided, but consumers and physicians should be reassured that the risk of failure is a fraction of the risk that comes from not having one of these devices when you need one. Certainly, we would like to hope that everyone getting a pacemaker or defibrillator benefits substantially from getting the device. That’s something we should not lose sight of.”
—J. Mettner