Insertable Cardiac Monitor-Guided Early Intervention to Reduce Atrial Fibrillation Burden Following Catheter Ablation (ICM-REDUCE-AF Trial) PI: Ilan Goldenberg, MD, University of Rochester Medical Center, Rochester, NY Percutaneous catheter ablation (CA) to achieve pulmonary vein electrical isolation is an effective and recommended treatment for drug-refractory paroxysmal and persistent atrial fibrillation (AF). Nevertheless, recurrence rates after a single AF ablation procedure are in the range of 30%-50%. Accordingly, more measures are needed to improve success rates following CA of AF. To date, conventional management after CA ablation has mostly been based on intervention for clinical AF recurrence. Continuous recording with insertable cardiac monitors (ICMs) can now be used to detect early recurrences of subclinical AF (SCAF) and patients-triggered mobile app transmissions post ablation. We hypothesize that early intervention following CA can prevent substrate progression that promotes the onset and maintenance of atrial arrhythmias. We therefore propose a randomized, double-blind (to SCAF data), single center, clinical trial in which 120 patients with drug-refractory paroxysmal AF or persistent AF planned to undergo CA with an ICM, will be randomized to: an intervention arm (n=60) consisting of ICM-guided early intervention based on SCAF and patient-triggered mobile app transmissions vs. a control arm (n=60) consisting of a standard intervention protocol based on clinical AF recurrence validated by the ICM. We believe that ICM-guided early intervention management provides a novel personalized approach and a paradigm shift in post-AF ablation management that will result in a significant reduction in AF burden and healthcare utilization in this expanding population, with corresponding improvements in functional capacity and quality of life, compared with conventional follow-up after AF ablation. In the proposed clinical trial, Aim 1 is to evaluate whether ICM-guided early intervention based on SCAF detection and symptom-triggered mobile app transmissions will be associated with a significant reduction in AF burden following CA for AF compared with the standard strategy of treatment upon the development of clinical AF recurrence. AF burden will be assessed from ICMs at 15 months post-AF ablation (excluding the 3-month blanking period). Aim 2 is to evaluate whether ICM-guided early intervention management will be associated with a reduction in in healthcare utilization (defined as unplanned hospitalizations, emergency department visits, cardioversions, and unplanned office visits) compared with a conventional management strategy. Aim 3 is to evaluate whether ICM-guided early intervention management will be associated with improvement in functional capacity and quality of life compared with a conventional management strategy following CA for AF.