Same-day discovery of implantable cardioverter defibrillator dysfunction in the TRUST remote monitoring trial: influence of contrasting messaging systems

AIMS: Assess whether automatic remote home monitoring (HM) permits same-day evaluation of implantable cardioverter defibrillator (ICD) system dysfunction. METHODS AND RESULTS: Compromised ICD system integrity (generator/lead) demands prompt evaluation. Home monitoring promises earlier discovery but may be limited by technological differences and follow-up mechanism. We tested whether HM enabled event review within 24 h, and contrasted differing messaging mechanisms. Nine hundred and eight patients in the TRUST prospective multicentre trial were followed by HM for 15 months. ICD system problems automatically triggered notifications: repeatedly ('redundant') for impedance deviations and elective replacement indication (ERI), but only a single transmission for '30 J ineffective'. Detection time from event onset to physician evaluation was measured. Forty-three system-related alerts occurred; 42% were asymptomatic, 42% were actionable, and 22 of 43 (51%) were viewed within 24 h. Redundant notifications were: 1 ERI, 9 shock impedance, 2 ventricular and 6 atrial pacing impedance. Most (11/18; 61%) were detected in <24 h. Others elicited daily notifications without interruption until resolution. For single transmissions, 11 of 25 (44%) events were detected on the same day. Most (56%, 14/25) were detected between 1 and 39 days (mean 10.0 ± 13.0 days). Ten of 14 events were detected by HM and 4 at the time of office visits. These observations suggest single transmissions were vulnerable to detection failure. Mean detection time of redundant events was 1.1 ± 1.8 vs. single transmission 5.6 ± 10.9 days (P = 0.05). Hence, redundant notification avoided late detection. CONCLUSION: Same-day discovery of ICD dysfunction, even if asymptomatic, was achievable. For those events not evaluated within 24 h, repetitive messaging promoted earlier discovery. Reorganization of clinical follow-up methods may maintain early reaction ability.