Performance of alert transmissions from cardiac implantable electronic devices to the CareLink network: A retrospective analysis

BACKGROUND: Remote monitoring of cardiac implantable electric devices improves patient outcomes and experiences. Alert-based systems notify physicians of clinical or device issues in near real-time, but their effectiveness is contingent upon device connectivity. OBJECTIVE: To assess patient connectivity by analyzing alert transmission times from patient transceivers to the CareLink network. METHODS: Alert transmissions were retrospectively gathered from a query of the United States de-identified Medtronic CareLink database. Alert transmission time was defined as the duration from alert occurrence to arrival at the CareLink network and was analyzed by device type, alert event, and alert type. Using data from previous studies, we computed the benefit of daily connectivity checks. RESULTS: The mean alert transmission time was 14.8 hours (median = 6 hours), with 90.9% of alert transmissions received within 24 hours. Implantable pulse generators (17.0 ± 40.2 hours) and cardiac resynchronization therapy-pacemakers (17.2 ± 42.5 hours) had longer alert transmission times than implantable cardioverter-defibrillators (13.7 ± 29.5 hours) and cardiac resynchronization therapy-defibrillators (13.5 ± 30.2 hours), but the median time was 6 hours for all 4 device types. There were differences in alert times between specific alert events. Based on our data and previous studies, daily connectivity checks could improve daily alert transmission success by 8.5% but would require up to nearly 800 additional hours of staff time on any given day. CONCLUSION: Alert transmission performance from Medtronic devices was satisfactory, with some delays likely underscored by patient connectivity issues. Daily connectivity checks could provide some improvement in transmission success at the expense of increased clinic burden.