Reduction of inappropriate shocks through remote monitoring in the ECOST study

Abstract

Purpose: Avoiding the inappropriate shocks represent one of the most challenging aspects of ICD management. Automatic daily wireless remote monitoring (RM) of implantable cardioverter defibrillators (ICD) provides early notification of inappropriate detections which may lead to inappropriate shocks. This topic was investigated in the ECOST trial as a secondary end‐point. Methods: Patients (n=433) were randomly assigned to RM follow‐up with Biotronik Home Monitoring ® (active group) versus ambulatory follow‐up (control group). Patients assigned to active group were seen once a year, unless RM reported an ICD dysfunction or a clinical event requiring an ambulatory visit. Patients in the control group underwent ambulatory visits every 6‐month. The number and causes of inappropriate shocks were compared between groups. Results: The characteristics of the study groups were similar including the use of cardiovascular medications (88% male, 62±13 years, 53.6% primary prevention ICD indication, 69.7 single chamber implants and 30.3% dual chamber implants, 85.3% first implantation). Over a follow‐up of 24.2±7.3 months, the proportion of patients who received inappropriate shocks was 52% lower in the active than in the control group (5.0% vs. 10.4%; p=0.03). The total number of inappropriate shocks was much lower in the active group (28 vs. 283). The inappropriate shocks were caused by supraventricular arrhythmia (in 48.5% of the patients), T‐wave oversensing (in 15.2%), noise oversensing (in 21.2%) or lead dysfunction (in 15.2%). The numbers of inappropriate shocks delivered per patient, related to supraventricular arrhythmia and to lead dysfunction were respectively 74% and 98% lower in the active group. In the active group, 7/8 lead dysfunctions could be managed before the delivery of any inappropriate shock whereas in the control group, among 5 lead dysfunctions, 4 patients received several inappropriate shocks. Conclusion: Remote monitoring is a powerful tool to prevent inappropriate shocks, whatever the cause, during long term follow‐up.