BACKGROUND: Implantable cardiac monitors (ICMs) provide valuable insights into managing atrial fibrillation (AF). Data suggest that ICMs increase AF detection, but their impact on management is still uncertain. OBJECTIVE: We aimed to evaluate and to compare the impact of ICMs on the clinical management of AF. METHODS: MONITOR-AF (NCT06352060) was a retrospective, multicenter study of patients with AF who received an ICM or routine monitoring with electrocardiograms or long-term monitoring between 2018 and 2021. Patients were observed for 12 months, with note made of AF-related clinical outcomes. RESULTS: There were 2293 patients who received an ICM (n = 1115) or routine monitoring (n = 1178). Although comorbidities were significantly different between ICM and non-ICM groups, none of the AF-related characteristics were significantly different. Patients in the ICM group had more attempts at rhythm control with antiarrhythmic drugs (100% vs 59.9%
P <
.001) and catheter ablation (91.7% vs 59.7%
P <
.001). This led to higher freedom from AF at 12 months (86.0% vs 61.8%
P <
.001) and freedom from antiarrhythmic drug (75.9% vs 39.4%
P <
.001) and oral anticoagulation (69.6% vs 39.4%
P <
.001) use and was associated with reduced rates of stroke (0.3% vs 1.6%
P <
.001) and major bleeding (1.6% vs 2.9%
P <
.001). CONCLUSION: Dynamic monitoring with ICM is associated with beneficial AF outcomes with improved freedom from AF at 12 months and fewer complications. Thus, ICM use should be considered for the management of chronic AF.