Remote monitoring of pacemaker patients improves detection of serious events

21 May 2008

Remote monitoring of pacemaker patients via the Medtronic CareLink Network detected clinically actionable events (CAEs) more quickly than routine follow-up care of transtelephonic monitoring (TTM) and in-office visit, according to a study presented last week at the Heart Rhythm 2008 congress in San Francisco.

Medtronic Inc. (NYSE: MDT) sponsored the PREFER (Pacemaker Remote Follow-up Evaluation and Review) trial, which was presented by Bruce Wilkoff, MD, Director of Cardiac Pacing and Tachyarrhythmia Devices, Department of Cardiovascular Medicine, Cleveland Clinic, and Professor of Medicine at Cleveland Clinic Lerner College of Medicine, Case Western Reserve University.

“In the trial we found that by following patients through the Medtronic CareLink Network every three months — and thus having quarterly access to device diagnostics — clinicians are able to more quickly identify the occurrence of clinically actionable events,” said Dr. Wilkoff, principal investigator for PREFER.

For example, physicians who remotely monitored patients with the Network more quickly detected new onset atrial fibrillation (AF) in patients with no known history. Untreated AF — a rapid irregular heartbeat in the upper chambers (atria) — can lead to stroke.

PREFER was a prospective, randomized, parallel, unblinded trial involving 980 pacemaker patients at 50 centres in the United States. The primary objective was to compare the rate of first diagnosis of CAEs between patients who utilize the Medtronic CareLink Network (REMOTE arm) versus patients who are followed via routine office visits augmented by TTM (TTM arm). Secondary objectives were to characterize the frequency of actions taken in response to CAEs, and to compare the rate of first diagnosis of single types of CAEs. CAEs included physiologic changes such as new onset atrial fibrillation (AF), uncontrolled ventricular rate in AF, ventricular tachycardia, and device integrity alerts affecting leads, pulse generators or batteries.

Patients in the REMOTE group had scheduled pacemaker interrogations transmitted via the Medtronic CareLink Network at 3, 6, and 9 months after enrollment, and an in-office evaluation at 12 months post-enrollment. TTM patients with a dual-chamber devices transmitted 30-second EKG strips at 2, 4, 6, 8 and 10 months after enrollment, with in-office evaluations at 6 and 12 months. TTM patients with a single-chamber pacemaker transmitted data via TTM instead of an in-office evaluation at 6 months.

PREFER demonstrated that utilization of the Medtronic CareLink Network resulted in a statistically significant improvement in the rate of first diagnosis of clinically actionable events between the 602 patients in the REMOTE arm and the 295 patients in the TTM arm (<0.0001). There were 272 patients in the REMOTE arm and 111 patients in the TTM arm in which the investigator detected an event.

“Intuitively, one might think that increased frequency of information as available via TTM would be beneficial in catching these clinically actionable events,” said David M. Steinhaus, MD, vice president and medical director of the Cardiac Rhythm Disease Management business at Medtronic. “However, despite frequency, the limited point-in-time EKG information provided by TTM didn’t uncover the potential for serious cardiac events as early as the more comprehensive data provided for the remote group. This has important implications for patient care by using remote management systems such as the Medtronic CareLink Network.”

How it works

The Medtronic CareLink Network enables patients to transmit data from their implantable device, as instructed by their physician, using a portable monitor that is connected to a standard telephone line. Within minutes, the patient’s physician and nurses can view the data on a secure website.

Available information includes arrhythmia episode reports and stored electrograms along with device integrity information, which is comparable to the information provided during an in-clinic device follow-up visit, and provides the physician with a view of how the device and patient’s heart are operating.

The system provides an efficient, safe and convenient way for specialty physicians to optimize patient care by remotely monitoring the condition of their patients and, if needed, make adjustments to medication or prescribe additional therapy.

The Medtronic CareLink Network was introduces in the United States in 2002. Today, more than 250,000 patients at nearly 2,400 clinics in 20 countries are followed remotely, saving patients' time by eliminating in-office visits, and allowing physicians to perform a complete analysis of all the device- and patient-specific cardiac data stored within Medtronic patients’ ICDs, pacemakers and CRT-D devices.

The Network has registered 1 million patient data transmissions since the service’s inception.

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