Abstract 4136952: The Clinical Importance of Arrhythmia Notifications During Use of Wearable Cardioverter Defibrillator

Introduction: Wearable cardioverter defibrillators (WCDs) record continuous ECG data for the purpose of delivering treatment for lethal arrhythmias, but occasionally capture non-treatable arrhythmias that may be of clinical value. The purpose of this study was to evaluate the usefulness to health care providers (HCPs) of evaluating and reporting these other recorded ECGs and the impact on additional arrhythmia detection and clinical management decisions. Research Questions: Do clinicians find arrhythmias identified during routine WCD useful? What arrhythmias are observed? Can the identification of these arrhythmias, validation through ZOLL’s Independent Diagnostic Testing Facility (IDTF) and notification to the provider lead to changes in clinical management? Methods: A multi-center, observational study of 52 US HCPs enrolled 474 patients with commercial LifeVest prescriptions and followed them for up to 3 months. All routinely transmitted LifeVest ECG strips (corresponding to Baseline, Patient Initiated, or other automatic event recordings) during this period were analyzed by ECG technicians at the IDTF within ZOLL. These arrhythmias were reported to the HCP who completed a questionnaire assessing the utility (scored 1 to 5) and clinical impact (medication changes, tests, and procedures ordered) of these events. Results: At the conclusion of the study, 22% of patients (105/474) monitored had 112 reportable, unique arrhythmia events that were sent to 34 providers who completed questionnaires regarding report utility and clinical management decisions. A significant proportion of reports led to medication changes (40%), additional testing (32%) and procedural interventions (23%). The average usefulness of the reports was 3.63/5 with atrial fibrillation representing the most common arrhythmia, but many variations of ventricular ectopy were also captured which tended to be more clinically useful and impactful. Conclusions: WCD patients experience a high burden of actionable arrhythmias. Monitoring and reporting these arrhythmias over the course of normal wear provides additional clinical value to providers. Those arrhythmias that lead to changes to clinical management are the most useful.