Remote monitoring of cardiac implantable electronic devices and disease management

Abstract

This reviews the transition of remote monitoring of patients with cardiac electronic implantable devices from curiosity to standard of care. This has been delivered by technology evolution from patient-activated remote interrogations at appointed intervals to continuous monitoring that automatically flags clinically actionable information to the clinic for review. This model has facilitated follow-up and received professional society recommendations. Additionally, continuous monitoring has provided a new level of granularity of diagnostic data enabling extension of patient management from device to disease management. This ushers in an era of digital medicine with wider applications in cardiovascular medicine.

Keywords: Defibrillators; Follow-up; Guidelines; Patient monitoring; Remote monitoring.

Figure 1

(Left) Event notifications suggestive of AF (top) but accompanying wirelessly transmitted intra-cardiac electrograms indicate that the abnormality was caused by lead noise (likely fracture-related) permitting the diagnosis of a false positive mode switch. (Right) Event notification received for an aborted shock (7:16 p.m.) with an automatic wirelessly transmitted electrogram showing non-physiological signals due to electromagnetic interference. The subject was asymptomatic but, in response to the notification, was seen in office within 24 h (compiled with permission from Varma et al.).

Figure 2

Implantable cardioverter-defibrillator generator with automatic wireless remote monitoring coupled to a Fidelis (MDT 6949) lead. Two event notifications that were transmitted immediately on occurrence of lead fracture, occurring silently during sleep at 4:43 a.m., 6 weeks after last clinic follow-up on 14 November. (Left panel) Wirelessly transmitted electrograms demonstrated irregular sensed events (coupling intervals as short as 78 ms) with VF detection (marked). No therapy was delivered. (Right panel) A separate notification for the same event indicating a lead impedance alert. Electrogram definition was modest in first-generation device (compiled with permission from Varma).

Figure 3

Event free survival rates in HM compared with conventional care in the TRUST cohort. Protocol required event notifications were system related (end of service, elective replacement indicator, atrial impedance <250 or >1500 Ohm, ventricular impedance <250 or >1500 Ohm, daily shock impedance <30 or >100 Ohm, and shock impedance <25 or >110 Ohm); arrhythmia-related events (atrial burden > 10%, supraventricular tachycardia detected, VT1 detected, VT2 detected, and VF detected), and ineffective ventricular maximum energy shock (notified on first shock of any sequence in a given episode) (compiled with permission from Varma et al.).

Figure 4

Days to detection of ICD problems in patients assigned to remote home monitoring. Overall, 22/43 (51%) were detected within 24 h (compiled with permission from Varma et al.).

Figure 5

Conventional follow-up based on intermittent calendar-based care is likely to be replaced by digitally driven alert based care (left) to identify subjects needing care promptly and reducing the non-actionable work performed by clinics, thus easing workflow (compiled with permission from Varma et al.).