Diagnostics & Imaging Week Executive Editor

SAN FRANCISCO — If there was anything particularly new at this year's scientific sessions of the Heart Rhythm Society (HRS; Washington) besides a series of first-time guidances related to electronic implanted devices it probably was an increased emphasis on the remote monitoring of these devices.

Getting a very large spotlight among a variety of reports on the remote assessment of implanted electronics was data presented from the Pacemaker Remote Follow-up Evaluation and Review (PREFER) Trial, comparing two types of new monitoring technologies to track data gathered from pacemakers: in-person programming evaluations augmented by remote interrogation vs. in-person programming evaluations augmented by what was termed transtelephonic monitoring (TTM), also called TTM rhythm strip evaluations.

As reported by Bruce Wilkoff, MD, lead author of the PREFER report and director of cardiac pacing and tachyarrhythmia devices at the Cleveland Clinic, the remote monitoring technique was far superior to TTM evaluation in identifying what were termed "clinically actionable events," the trial's primary endpoint, which he defined as "things that we could identify going on with the patient, being important to know" and then act upon.

At the end of 12-month follow-up, the remote monitoring method detected 60% of all clinically actionable events, Wilkoff said, while TTM detected just 2% of these.

TTM patients included those implanted with a dual-chamber device which transmitted 30-second ECG strips at two, four, six, eight and 10 months after enrollment, with in-office evaluations at six and 12 months; and also TTM patients with a single-chamber pacemaker, which transmitted data via TTM instead of an in-office evaluation at six months. There were a total of 296 patients in this group.

The other group the REMOTE group, of 605 enrollees, thus a roughly 1-to-2 ratio of a total of 897 patients were interrogated via the CareLink Network from Medtronic (Minneapolis) at three, six and nine months and in-office evaluation at 12 months.

Medtronic explained the difference in the results by comparing the use of "frequency of information" vs. more comprehensive data.

David Steinhaus, MD, VP and medical director of the Cardiac Rhythm Disease Management business at Medtronic, said in a company statement, "Intuitively, one might think that increased frequency of information as available via TTM would be beneficial in catching these clinically actionable events. However, despite frequency, the limited point-in-time ECG 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."

The findings are an obvious boon for Medtronic, and the company reports that CareLink introduced in the U.S. six years ago now follows 250,000 patients in 20 countries at nearly 2,400 clinics and "has registered 1 million patient data transmissions."

Medtronic touts the network as providing earlier signaling of potential problems, such as clots, arrhythmias and other events that may lead to more serious events, and Wilkoff agreed with this assessment.

As he put it (via some rather circuitous syntax), "There is a substantial increase in the shortening of the time for event to detection of event if you use remote interrogation."

He said that the trial did not evaluate whether this earlier detection resulted in a superior clinical outcome, and that this would be the next thing to study using the CareLink Network.

The trial also did not develop data on the comparative costs of the two types of monitoring, or to compare the costs of these remote monitoring methods to in-office visits. (Overall, remote monitoring studies have shown improved clinical results but higher costs related to the technologies.)

That faster diagnosis produces faster treatment was presented in another study concerning the use of cell phones in emergency situations

In another study reported at HRS, researchers presented data from the Synthesized Twelve-lead ST Monitoring & Real-time Tele-electrocardiography (ST SMART) study on the use of special ECG devices modified to wirelessly transmit an ECG reading to the hospital through mobile phone technology while continuously monitoring the patient's status and re-transmitting information to the hospital if changes were detect. The devices were placed in all paramedic vehicles in Santa Cruz County, California, beginning in 2003.

The findings: Patients randomized to the experimental group with pre-hospital ECG cell phone transmission had an initial ECG reading 50 minutes earlier than patients randomized to the control group with their first ECG reading at the hospital.

In addition, patients who received a pre-hospital ECG had an average door-to-balloon time of 79 minutes, 37 minutes faster than those who did not receive a pre-hospital ECG.

These systems require considerable patient or provider human interaction, and Transoma (St. Paul, Minnesota), heretofore focused on providing tiny implanted blood pressure monitors in animals for drug reactions, presented at a breakfast meeting its new Sleuth implantable monitoring system providing continuous monitoring for diagnosis of syncope.

FDA-cleared this past October, the Sleuth is implanted in just a few minutes under local anesthetic and is currently being rolled out by the company, Nestor Jaramillo, VP of sales and marketing for Transoma, told Diagnostics & Imaging Week. He said the company is looking to file with the FDA for other indications, such as the detection of atrial fibrillation, with an advanced generation of the device.

Presenting much of the information about the Sleuth was Randy Lieberman, MD, of Heart Care Cardiology (Detroit), who billed Sleuth as very different from the "old paradigm," of remote monitoring which he said required accessing of the monitored data by the physician.

Sleuth, he said, delivers the data continuously and updates the physician, when necessary, via fax or other message systems.

Lieberman was voluble in emphasizing the need for this type of monitoring, saying that syncope is too often over-looked.

"It's absolutely amazing how we approach [this] problem, if we bury it under the carpet. Then [the patient] will have a stroke or wreck the car because we couldn't guess the moment when we should put the Holter [monitor] on."

While presenters referred to the Sleuth as completely automatic, Jaramillo told D&IW that a key action patient is necessary: after awaking from a syncope, the patient pushes a button and the monitor then backs up and collects several minutes of data before the fainting spell and delivers it on.

Jaramillo said that Transoma is not positioning itself to compete against Medtronic in this sector, but simply to first become a participant in it, given the size of the market being continuously boosted by aging demographics.

D&IW asked a clinician leaving the breakfast session, if all of this works as effectively and cost-effectively as the Transoma people claimed.

"We'll see," she responded, "I'm doing a study."