SAN FRANCISCO — Remote interrogation of pacemakers detected more cardiac events that might require a clinical response, compared with traditional pacemaker follow-up, but did not alter clinical response rates in a study of 897 patients.
The results suggest that remote interrogation of pacemakers has the potential to identify problems earlier and to reduce the time to starting therapy if needed, but further studies are necessary to verify whether enhanced detection affects clinician response, Dr. Bruce L. Wilkoff said at the annual meeting of the Heart Rhythm Society.
Internet-based remote monitoring systems have been studied in patients with implantable cardioverter defibrillators, but this is one of the first studies of remote interrogation in patients with pacemakers.
The prospective Pacemaker Remote Follow-Up Evaluation and Review (PREFER) trial randomized 295 patients with pacemakers to conventional monitoring using transtelephonic rhythm strip evaluations and 602 patients to remote interrogation of pacemakers over a 12-month period. Remote interrogations were done at 3, 6, and 9 months, with a live visit at 12 months. Transtelephonic monitoring was performed every 2 months, with live visits at 12 months for patients with single-chamber pacemakers and at 6 and 12 months for patients with dual-chamber pacemakers.
During the 1-year follow-up, a total of 45% of patients in the remote interrogation group and 38% in the transtelephonic monitoring group had evidence of one or more predefined “clinically actionable events.” These were events that would be likely to trigger clinician response, such as nonsustained ventricular tachycardia, new onset of atrial tachyarrhythmias or atrial fibrillation (AT/AF), electric replacement of the pacemaker indicated, or end of life of the device.
Remote interrogation identified 66% of the clinically actionable events before the live follow-up visit, compared with only 2% of clinically actionable events identified remotely by transtelephonic monitoring (and the rest identified later at live follow-ups), reported Dr. Wilkoff, director of cardiac pacing and tachyarrhythmia devices at the Cleveland Clinic, and his associates.
Early detection of new onset AT/AF was significantly more likely with remote interrogation than with transtelephonic monitoring, which could lead to earlier initiation of therapy and a reduction in risk for stroke, Dr. Wilkoff said.
In this study, however, the significant difference in remote detection of events did not lead to a significant difference in overall clinical response. Of events detected, clinicians acted on 19% in the remote interrogation group and on 15% in the transtelephonic monitoring group.
The study was funded by Medtronic Inc., which makes the remote interrogation system used in the study. Dr. Wilkoff is a consultant for Medtronic. He also has received research funds from or is a consultant to several device makers.
Because of its low yield, “The value of transtelephonic monitoring is limited and may be of clinical significance mostly for the detection of battery depletion,” Dr. Wilkoff suggested. With remote interrogation, in contrast, “rate, duration, electrograms—everything that's in the pacemaker, you can see,” he explained.
He did not have data on the specificity of remote interrogation and how many detected events led to further work-ups that were not necessary.
Dr. Wilkoff noted that the pacemaker monitoring technology is only a part of follow-up plans, which should emphasize communication with patients. By communicating more detailed information to patients with each remote interrogation, “we don't have less of a relationship with them. We actually have more of a relationship.”
The newer remote interrogation technology seemed as acceptable to patients as the older transtelephonic monitoring technology, which has been in use since the 1970s, he added.
Remote interrogation has the potential to identify problems earlier and to reduce the time to therapy, if needed. DR. WILKOFF