"Home monitoring" for early detection of implantable cardioverter-defibrillator failure: a single-center prospective observational study.

Background: Telemedical ICD monitoring has the potential to enhance patient safety. The "home-monitoring" (HM) feature transmits selected device-related data to a service-center via mobile phone network. In case of a potential emergency situation, event reports are generated automatically. This prospective observational study was designed to test whether HM is effective and reliable in early detection of device failure.

Methods: Consecutive patients receiving ICD, CRT-D or CRT pacemaker systems with HM feature were included. Regular follow-up visits were performed 1, 3, 6, 9 and 12 months after implantation in the first year, and every 6 months thereafter. All event reports transmitted by HM were analyzed and severe device-related events (serious lead or device dysfunction, hospitalization, death) were documented including timing, type and mode of detection.

Results: Sixty-nine patients were included and followed for 18 +/- 9 months. A total of 206 event reports were transmitted, prompted by VF/VT-episodes (n = 193), ineffective ICD shocks (n = 7), abnormal pacing impedance (n = 4) or battery depletion (n = 2). 8 SAEs were observed (RV lead fracture; n = 5, connector defect; n = 1, sensing defect, n = 1, RV lead dislodgement, n = 1). There was no device-related death. 6 out of 8 SAEs were discovered by HM (sensitivity, 75%). Without HM, these events would have been detected with a theoretical delay of 1.9 +/- 0.5 months in the first year (3 monthly FU) and 4.9 +/- 0.5 months in the following years (6 monthly FU).

Conclusions: This pilot study demonstrates that HM enables early detection of ICD failure and appears to enhance patient safety.