Phone it in: Remote monitoring could offer peace of mind for patients with "recalled" ICD leads

December 02, 2010


Dallas, TX - There's probably no app for it, but the technology needed to remotely monitor the activity and functions of implanted cardioverter defibrillators (ICDs) has been around for years. Remote ICD monitoring has long earned a seal of approval from the major cardiology societies, and patients with the devices are increasingly registered for the monitoring services established by the device manufacturers.

Still, many such patients aren't remotely followed, and they appear to be missing out on a process that can make life easier for both them and their clinicians. Several recent studies, including at least one large randomized trial[1], have strengthened the evidence base built primarily on large registries suggesting that remote ICD monitoring makes following device patients more efficient and potentially less costly, cuts reliance on in-office visits, and is no less safe than conventional care—scheduled device checks in the office that may be many months apart, with further visits as needed in the event of symptoms or device discharges.

Dr Leslie A Saxon

And monitoring can give many patients some welcome reassurance about having a device in the first place, a sense that they're being closely watched. "It makes them feel taken care of," Dr Leslie A Saxon (University of Southern California, Los Angeles) observed for heartwire .

Although not all patients with devices are closely followed, either remotely or in the office, it should be a routine part of their care, observed Dr Bruce L Wilkoff (Cleveland Clinic, OH). In fact, he told heart wire , "The Heart Rhythm Society [HRS] is examining the possibility of creating a quality measure that includes follow-up for defibrillators. I doubt we'd say you have to do it remotely, but we'd say you have to do it. And if you have to do it, then you're going to find the most efficient way of doing it."

Remote monitoring, he added, is more efficient than scheduled office visits for picking up the kinds of arrhythmic events that physicians want to know about. Wilkoff was a coauthor on a 2008 HRS consensus statementon monitoring of implanted cardiac rhythm devices[2] and the 2009 recommendations on lead performance policies and guidelines from the HRS, the American Heart Association (AHA), and the American College of Cardiology[3].

Dr Bruce L Wilkoff

An additional benefit, long appreciated but only recently getting a lot of play in the literature, is that remote monitoring can help address one of the most disturbing device issues for patients—that an ICD or its leads can become subject to safety advisories, which the FDA refers to as a "recall." With remote monitoring, patients with advisory devices can be followed more closely, their issues addressed more promptly, and clinicians and device manufacturers get exquisitely detailed data on how the patient is faring and the device is performing.

The ability to look at device performance data daily, according to Saxon, "gives you enormous advantages and really enhances product and patient safety. Not only can you identify a problem earlier, you can understand how frequent it is. And all that helps to advise physicians on what they can do for the patients."

That makes such monitoring profoundly suited to following devices under a safety advisory, she noted for heart wire . "It allows the companies to more accurately assess the frequency of problems, so recommendations by the FDA to us are more accurate." Saxon directs the ALTITUDE registry of patients implanted with ICDs from Boston Scientific, more than 150 000 of which have been followed remotely using the company's LATITUDE patient-management system.

A matter of TRUST

Those benefits were highlighted in the randomized Lumos-T Safely Reduces Routine Office Device Follow-up (TRUST) trial, which in its primary analysis[1], published earlier this year and reported by heart wire from the AHA 2008 meeting, found that nearly constant remote monitoring of ICD activity helped lessen the need for in-office follow-up visits.

More recently, a post hoc analysis of TRUST suggests that remote monitoring can also be effective for following ICD-lead performance issues [4]. That, its investigators concluded, could prove especially useful when leads become subject to a safety advisory, as occurred in October 2007, when the FDA issued a class 1 recall of Medtronic's hugely popular Sprint Fidelis defibrillator leads, and the company told physicians to stop implanting them.

It's worth their while to do it, and they should be doing it to get the best outcome they can with these devices. I think it's enormously important and not something that should be considered optional.

It was already known that the leads might be prone to fracture, which could potentially cause oversensing, inappropriate shocks, or failure to deliver appropriate therapy, and doctors and the FDA had already been alerted. But the actual recall came after it was concluded that such lead fractures may have contributed to five deaths.

The TRUST analysis and smaller recent observational studies[5,6] point to a role for remote-monitoring systems in sharpening and simplifying the follow-up of advisory leads like the Fidelis. Potentially, they might be able to identify signs of impending lead failure, perhaps sparing the patient a good deal of distress, or pin down lead failure as the cause of any symptoms or shocks that do occur.

In the trial, remote monitoring of generator and lead function allowed clinicians to distinguish between technical failures like lead fracture and changes in clinical condition that might require only treatment adjustments or device reprogramming. "And in the end, the number of actionable events requiring surgical [lead] revision was very much a minority," according to TRUST principal investigator Dr Niraj Varma (Cleveland Clinic, OH).

Dr Niraj Varma

"The first very important observation [from TRUST] is that [ICDs and their lead systems] are very reliable. The actual incidence of device-related problems was actually very low, and a lot of the flagged events could be managed conservatively. This should allay concerns, certainly in the public's mind given the recalls, that devices are unreliable."

The trial enrolled 1339 patients implanted with ICDs from the trial's sponsor, Biotronik (Lake Oswego, OR), who were randomized to be followed or not followed with the company's home monitoring system, in which the ICD wirelessly connects to a kind of relay station kept in the home, often at bedside. Data on device events, such as discharges, and on device functions, such as battery strength or changes in lead impedance, are stored and automatically streamed to the relay station whenever it comes into range. They're then transmitted across telephone land lines or a cellular connection, ultimately to the clinician.

Some people think , for some reason, that you're not going to pay as much attention to them if they don't come in to see you every time.

All patients were evaluated in the office within six to 12 weeks of device implantation, at which time they were assessed for "wound healing, determination of chronic thresholds, and setting of final pacing parameters." Thereafter, both groups were evaluated every three months: conventionally followed patients went to their clinicians for scheduled device checks; monitored patients had their subsequent checks remotely, except for the final check at 15 months, which was conducted in person. All patients saw their clinicians as needed because of symptoms or after significant device events, such as discharges.

In the trial's primary analysis[1], as previously reported, remotely monitored patients had 45% fewer in-office device evaluations than conventionally followed patients, and monitored patients saw their clinicians significantly sooner after significant arrhythmic events (p<0.001 for both differences).

Dr Kenneth A Ellenbogen

TRUST "is one of the best studies on the clinical applicability of remote monitoring," Dr Kenneth A Ellenbogen (Medical College of Virginia, Richmond) told heart wire . "It's probably the first study to show how useful it is and what sort of things can be picked up." Ellenbogen wasn't involved in the trial but was a coauthor on the 2008 and 2009 documents on device policies and performance.

Calling ICD remote monitoring "an incredibly powerful microscope" that could dramatically change how patients with devices are followed and managed, he observed that all the major companies marketing ICDs in North America provide and maintain comparable monitoring networks. Biotronik has a smaller share of the North American market than the three long-time players, Medtronic, Guidant/Boston Scientific, and St Jude Medical.

"There are some differences, but they all give you basically the same information about lead function, generator function, and the patient's arrhythmias," Ellenbogen said.

Saxon pointed out most ICDs "can and will do a safety check every day" that provides a limited amount of information (full data downloads are usually obtained less frequently), including data on system integrity, whether the device delivered a shock, and presence of any arrhythmias.

"The frequency of clinically actionable atrial arrhythmias is very high in patients who get defibrillators," she said. In ICD patients who develop atrial fibrillation, the yearly risk of stroke is about 10%. "If you can identify atrial fibrillation when it occurs and treat the patient with a blood thinner or other therapy to get them out of it, you can significantly reduce their risk of stroke and death. And that's something you don't want to wait three months to find out about, when they come into the device clinic."

Taking the lead

In the TRUST analysis of lead performance monitoring[4], there were 33 lead problem notifications in 46 patients across both arms of the trial, including 40 remotely monitored and six conventionally monitored patients, or 4.4% vs 1.4% of the respective groups (p=0.004) over a follow-up of about 400 days. As a result, 15 and four patients, respectively, required surgical revision of the leads, for an overall revision rate of 0.012 per patient-year.

"The study presents a device-management model in which near-continuous remote surveillance of ICD performance is combined with automatic self-declaration of system problems, enabling prompt medical decisions," according to the authors.

The lead problem is probably a more substantial problem, with more substantial risks, than the device problems ever were.

Four patients randomized to the remote-monitoring group had crossed over to the control arm when their Sprint Fidelis leads became subject to the safety advisory; the analyses were by intention to treat, however.

The remote lead-surveillance strategy received support also from the experience of 40 Sprint Fidelis recipients in an ongoing prospective Biotronik-sponsored trial, including 18 who had been randomized to remote monitoring and 22 to conventional follow-up[5].

Over a 22-month follow-up, monitoring led to unscheduled clinic visits in four patients, three of whom were shown to have fractured leads; there were no lead failures in the other 36 cases, note the authors, led by Dr Laurence Guédon-Moreau (Hospitalier Régional Universitaire, Lille, France), in a recent European Heart Journal report.

"Home monitoring allowed the early and reliable detection of three lead fractures, manifested by sensing of noise artifact, abrupt rise in pacing impedance, or both, without requiring the intervention of patients in the diagnosis or decision-making process," they write.

According to Ellenbogen, a patient with a generator or lead system that comes under an advisory would be flagged for more intensive monitoring than the others. But physicians vary in how often they look at incoming device data from individual patients, he said. "In someone with a Sprint Fidelis lead, for example, you might want to make sure the lead impedance and the RR intervals are being looked at on a daily basis."

Lessons learned

Varma pointed out that surgical revision isn't called for solely because leads become subject to an advisory. "You don't need to replace most leads, only those that declare themselves with a problem." And remote monitoring can facilitate the process of diagnosing or ruling out lead failure, he said.

That can provide more than just peace of mind; lead fractures can cause inappropriate shocks, among other problems, so remote monitoring can conceivably make them less likely.

In a 2009 retrospective look at all 54 patients from a single center who underwent surgical lead revision due to lead failure or T-wave oversensing over a six-year period[6], 11 patients had remotely monitored devices. The system's alert to clinicians was the first sign of lead failure in 10 of the 11 cases; an inappropriate shock was the first sign in the remaining patient. In nine of the 11 cases, no symptoms accompanied the first indication of lead failure.

The authors, led by Dr Sebastian Spencker (Charité-Campus Benjamin Franklin, Berlin, Germany), conclude that remote-monitoring technologies "may be of value for saving patients with potentially life-threatening malfunctions and inappropriate shocks."

That ability would have been valuable in five years ago, notes Wilkoff, when Guidant (later purchased by Boston Scientific) recalled close to 50 000 ICDs that appeared to be at increased risk of shorting out. As chronicled by heart wire then and over the next few years, it was a global event that shook patients and physicians and ultimately led to major reforms in ICD performance and safety monitoring and, especially, how companies communicate recall issues to patients. For the public and many patients, the protracted recall saga—and the resulting intensified scrutiny of device safety—brought the once-sterling image of ICDs down a few notches.

Many of the devices falling under the advisory were removed from patients and replaced, in most cases without having shown signs of failure. Wilkoff observed that "the rates of failure were in the order of a quarter of 1%." The Guidant ICD at the center of the recall "was one of their longest-lived devices ever. It lasted [in patients] for seven or eight years, so the tragedy of taking a third to 40% of them out, when they were going to behave so well, at a 5% to 7% complication rate [associated with change-out surgery], in hindsight really makes us look bit foolish. A more appropriate, more targeted way of following these patients—watching them, [remotely] monitoring them, and only responding when there's a potential problem—is clearly the way to do it."

Fewer of those devices would have been replaced, he said, had remote ICD monitoring been more common then. "This remote monitoring was just sort of emerging at that time. Medtronic did have it, but they probably did not have enough of the [CareLink] telemetry systems to give out to all of the patients. I don't think even they realize how much better it would have been if they had approached it that way."

Things are different now, he said. Largely as a result of the Guidant recall and the reforms that followed, "our understanding of how to manage a safety alert or recall has evolved."

That helped later when Medtronic issued its Sprint Fidelis advisory; replacement of subcutaneous ICD units is easier than transvenous lead revision. "The lead problem is probably a more substantial problem, with more substantial risks, than the device problems ever were, and it's good that it happened in this order," Wilkoff said. Had the lead issues emerged before the learning experience of the ICD recall, "I think we would have had chaos."

Why isn't it used more?

Saxon said she hopes the TRUST analyses encourage physicians to make sure their ICD patients join the device company's remote-monitoring network. "Contemporary data show that about 50% of implanting physicians are not enrolling patients on the network, even though it's there and isn't at an additional cost," she said. "It's worth their while to do it, and they should be doing it in order to get the best outcome they can with these devices. I think it's enormously important and not something that should be considered optional."

There can be administrative advantages to it, as well. At Wilkoff's center, he said, "I think we did about 14 000 defibrillator checks last year, about half in person and half remotely." There are dedicated personnel to support its current home-monitoring program, but "if we had to do those remote checks all in person, we would not have had room to support the people or the time to do it."

Why aren't more patients with ICDs remotely followed? "Virtually all of them are offered it, but not everybody wants to be monitored in this way," he said. "Some people think, for some reason, that you're not going to pay as much attention to them if they don't come in to see you every time."

Also, "some patients need to come in and talk to someone and just aren't comfortable with the technology."

Still, the proportion of ICD patients enrolled in remote-monitoring networks is rising, and Ellenbogen says it's probably the electrophysiologists driving the growth. Fewer nonelectrophysiologist implanting physicians use it. "It's one of the big disadvantages of having nonelectrophysiologists able to implant devices," he said. "In my opinion, they are probably less aware of and less interested in really optimizing the use of the [remote-monitoring] technology."

TRUST was sponsored by Biotronik. Varma reports receiving research grants and honoraria from Biotronik, St Jude Medical , Boston Scientific, Medtronic, Sorin, and Sanofi-Aventis . Of his coauthors, Dr Justin Michalski is an employee of Biotronik ( Lake Oswego, OR); Dr Andrew E Epstein ( University of Pennsylvania , Philadelphia ) reports receiving research grants and honoraria from Biotronik, Boston Scientific, Medtronic, and St Jude and serving on committees for Boston Scientific and St Jude ; and Dr Robert Schweikert ( Akron General Medical Center, OH) reports receiving research grants and honoraria from Boston Scientific, St Jude , GlaxoSmith Kline, and Sanofi-Aventis . Wilkoff has reported serving as an advisor or consultant for Medtronic, Lifewatch, and Spectranetics and receiving royalty payments from Medtronic . Saxon has disclosed serving as an advisor or consultant for Boston Scientific and St Jude and receiving r eceived grants from St Jude, Boston Scientific, and Medtronic . Ellenbogen has disclosed receiving research grants from Boston Scientific, Medtronic, St Jude, Biosense Webster, and Sanofi-Aventis and consulting for Cardionet, Atricare, and EBR Systems .


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