AHA 2008: Remote ICD Monitoring Safely Cuts Clinic Visits in Large Randomized Trial

November 24, 2008

November 24, 2008 (New Orleans, Louisiana) — Websites and ads for implantable cardioverter defibrillators (ICDs) tout systems for remote monitoring of their performance and for tracking arrhythmic events, propping them with alluring claims that they can streamline the care of patients, cut down on their clinic visits, and provide more effective protection against life-threatening arrhythmias. Until recently, however, data from a large randomized trial to lend substance to the marketing sizzle had been lacking.

In a comparison of two ICD follow-up strategies, automatic wireless remote monitoring or device interrogation at regular in-office visits, conducted in >1300 patients, the automated approach reduced clinic visits by >40% over 12 months, but safety as gauged by mortality and clinical events was comparable in both groups [1].

The study, called TRUST and reported by Dr Niraj Varma (Cleveland Clinic, OH) recently at the American Heart Association 2008 Scientific Sessions, also raised some provocative issues about the behavior of patients during the first year after ICD implantation as well as the clinicians and other providers watching over them.

All the major players in the field offer home monitoring with their implantable devices; all work somewhat differently from each other. Medtronic has its Carelink network, Guidant/Boston Scientific its Latitude Patient Management system, and St Jude Medical its Medical Housecall Plus system. In TRUST, patients were implanted with Lumos and Lumax single- and dual-chamber ICDs from Biotronik, which used the company's Home Monitoring System.

With Biotronik's system, the scheduled follow-ups consist of a condensed report of performance data and arrhythmic-event trends based on a scheduled transmission from the ICD. The device itself sends the data to a cell-phone–like wireless communicator that the patients can keep by the bedside or carry with them, which in turn automatically connects with a computer at the office, according to Varma.

Round-the-clock monitoring is achieved through automatic daily transmissions to the clinic, which can be programmed to occur in the middle of night, for example, and cover the preceding 24 hours. If the ICD observes an important event, the system can report to the clinic right away, he explained.

But there are few prospective data supporting the strategy, observed Varma for heartwire , and there had been concerns that remote ICD monitoring in lieu of scheduled in-office follow-ups might greatly increase the number of unscheduled clinic visits, expose patients to increased risk, or flood providers with more performance and event data than they can handle.

A 155-patient pilot study for TRUST, called REFORM and reported by heartwire from Cardiostim 2008 in June, was promising in that it saw a nearly 50% drop in office visits among ICD patients followed remotely.

I think we will see patients who need to be seen, and we will see them more quickly. That's a big advantage for patients and for us.

Varma said his center has legions of ICD patients coming in every three months for routine reviews, and in only 10% of cases does device interrogation lead to a clinically actionable event, such as drug-dose adjustment, programming changes, or lead revision. "So 90% of in-office visits are a waste of the patient's time and of our time."

Unscheduled clinic visits initiated by the patient are actionable more often, about 40% of the time, he said, so those visits are more important. Yet some practices may view them as an extra burden on the already-busy clinic schedule, Varma observed. Remote monitoring has the potential to change that by making follow-ups more efficient and, perhaps, safer: "I think we will see patients who need to be seen, and we will see them more quickly. That's a big advantage for patients and for us."

In TRUST, conducted at 105 centers in the US, patients were randomized within 45 days of implantation to having their ICD's remote-monitoring function disabled and coming into the clinic every three months for a year or to using the monitoring system, coming into the clinic after three months, but from then on having their devices remotely interrogated every three months.

The 898 conventionally followed and 414 remotely monitored patients were similar with respect to demographics, ICD indications, LVEF, and extent of treatment with beta blockers (80% and 76%, respectively) or amiodarone (about 14% in both groups).

Mean Number of Scheduled and Unscheduled Office Visits Per Patient Year in TRUST (Primary Efficacy End Point)

Randomization group Scheduled Unscheduled Total
Remote monitoring 1.3 0.7 2.0
Conventional follow-up 3.0a 0.5b 3.5a

size="1">a. p<0.001 vs remote monitoring b. p=0.034 vs remote monitoring

Remote monitoring, the study found, cut the overall number of clinic visits (the study's primary efficacy end point) and raised the number of unscheduled visits but also didn't entail higher clinical risk. The cumulative rate of survival free from death, stroke, or surgical intervention at one year (the primary safety end point) was 90.1% for remote monitoring and 91.3% for the conventional follow-up group.

One of the study's surprising secondary findings, Varma said, was the apparent delay between arrhythmic events and the physician's evaluation of the event, not only for conventionally followed patients but also in the remote-monitoring group.

Mean Number of Days Between Arrhythmia Onset and Clinician Evaluation of First Arrhythmic Event in TRUST

Randomization group VF VT SVT AF
Remote monitoring (d) 10.5 12.9 16.6 25.2
Conventional follow-up (d) 45 45.6 42.1 46.8*

size="1">*p=0.005 vs remote monitoring; all other differences between groups p<0.001; VF=ventricular fibrillation; VT=ventricular tachycardia; SVT=supraventricular tachycardia; AF=atrial fibrillation

Interestingly, the clinician-evaluation delay for VF events in the remote-monitoring group averaged a surprising 10.5 days. "This tells me there are some centers that don't evaluate for several weeks," Varma said, "which means they're not paying attention to [the remote-monitoring system]."

The delay times appear to vary from center to center and might reflect some clinicians' inexperience with the system, according to Varma. Still, their data suggest "that many of these arrhythmias, and this includes lead and device problems, are not evaluated quickly. The remote monitoring accelerated that time, but it's still longer than we'd have imagined."

He noted that the delay is about 45 days in the conventional arm, which means that most problems go unevaluated in conventional follow-up.

TRUST provided unexpected insights about the patients, as well. For one, fewer than expected in the remote-monitoring group completed their follow-up evaluations at six, nine, and 12 months,despite their not requiring a clinic visit.

Patient Adherence to Scheduled Follow-Ups, Whether Remotely or in-Office, in TRUST

Randomization group 3 mo 6 mo 9 mo 12 mo
Remote monitoring (%) 88 90 88 84
Conventional follow-up (%) 91 78* 73* 65*

size="1">*p<0.001 vs remote monitoring

Varma said some patients may have ventured beyond the ICD-to-communicator transmission range of about 3 m for longer than the prespecified (and strictly enforced) device-check time window as if, perhaps, they went on vacation and left the external device at home. That's in a study, he said; in practice, there is more flexibility as to when the scheduled transmission can occur.

Also, in the conventionally followed group, attendance was high at the three-month visit but thereafter steadily dropped off. "It tells us that patients are reluctant to come in for in-office visits. That was remarkable; we didn't expect that, particularly in the first year, and particularly under clinical-trial conditions."

TRUST was sponsored by Biotronik. Varma discloses that he consults for the company.

  1. Varma N. Evaluation of efficacy and safety of remote monitoring for ICD follow-up: The TRUST trial. American Heart Association 2008 Scientific Sessions; November 11, 2008; New Orleans, LA. New Trials in Electrophysiology and Pacing.


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