A prospective comparison of remote monitoring systems in implantable cardiac defibrillators: potential effects of frequency of transmissions.

Purpose: Currently, cardiac implantable electronic devices allow remote monitoring (RM) based on periodic (Boston Latitude [LAT], Medtronic Carelink [MCL], St. Jude Merlin [SJM]) or daily transmissions (Biotronik Home Monitoring [BHM]). The aim of this study was to compare all the current RM systems in normal practice and investigate the effect of periodicity of RM transmissions on early detection of clinical and device-related events.
Methods: Two hundred eleven ICD patients (mean age 69±11 years, 158 males), were remotely followed up for 1 year (61 with BHM, 49 with LAT, 65 with MCL, 36 with SJM). Remote follow-ups were configured quarterly, except for the BHM (daily transmissions).
Results: The event-free rates were 49% with BHM, 57% with LAT, 57% with MCL, and 58 % with SJM (long-rank, p=0.23). BHM generated 304 (interquartile range, 184–342) transmissions per patient in a year, LAT 9 (8–11), MCL 7 (5–10), and SJM 8 (7–14) (p<0.000001). Eighty actionable events occurred at 1 year follow-up, 69 (86%) with RM systems: BHM was associated with a higher cumulative rate of actionable events. At a multivariate analysis, daily transmissions were independently associated with an increased probability of event detection as compared to periodic transmission systems. The chance of event detection is reduced by 20% (p=0.036) for a 1-month increase of the between-transmission interval (27 % for actionable events, p=0.004).
Conclusions: Although all RM systems effectively detected major events, daily transmission was associated with a higher probability of early event detection.