A Low Critical Event Rate Despite a High Abnormal Event Rate in Patients with Cardiac Implantable Electric Devices Followed Up by Remote Monitoring

OBJECTIVE: Remote monitoring (RM) of cardiac implantable electric devices (CIEDs) has been advocated as a healthcare standard. However, expert consensus statements suggest that all patients require annual face-to-face follow-up consultations at outpatient clinics even if RM reveals no episodes. The objective of this study was to determine the critical event rate after CIED implantation through RM. METHODS: This multicenter, retrospective, cohort study evaluated patients with pacemakers (PMs), implantable cardioverter defibrillators (ICDs), or cardiac resynchronization therapy defibrillator (CRT-Ds) and analyzed whether or not the data drawn from RM included abnormal or critical events. PATIENTS: A total of 1,849 CIED patients in 12 hospitals who were followed up by the RM center in Okayama University Hospital were included in this study. RESULTS: During the mean follow-up period of 774.9 days, 16,560 transmissions were analyzed, of which 11,040 (66.7%) were abnormal events and only 676 (4.1%) were critical events. The critical event rate in the PM group was significantly lower than that in the ICD or CRT-D groups (0.9% vs. 5.0% or 5.9%, p<0.001). A multivariate analysis revealed that ICD, CRT-D, and a low ejection fraction were independently associated with critical events. In patients with ICD, the independent risk factors for a critical event were old age, low ejection fraction, Brugada syndrome, dilated phase hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. CONCLUSION: Although abnormal events were observed in two-thirds of the transmitted RM data, the critical event rate was <1% in patients with a PM, which was lower in comparison to the rates in patients with ICDs or CRT-Ds. A low ejection fraction was an independent predictor of critical events.