Comparison of the efficacy between impedance‐guided and contact force‐guided atrial fibrillation ablation using an automated annotation system

BACKGROUND: This study compared the efficacy of catheter ablation of atrial fibrillation (AF) between impedance (IMP)‐guided and contact force (CF)‐guided annotation using the automated annotation system (VisiTag™). METHODS: Fifty patients undergoing pulmonary vein isolation (PVI) for AF were randomized to the IMP‐guided or CF‐guided groups. The annotation criteria for VisiTag™ were a 10 second minimum ablation time and 2 mm maximum catheter movement range. A minimum CF of 10 g was added to the criteria in the CF‐guided group. In the IMP‐guided group, a minimum IMP drop of over 5 Ω was added to the criteria. RESULTS: The rates of successful PVI after an initial ablation line were higher in the CF‐guided group (80% vs 48%, P = .018). Although average CF was similar between two groups, the average force‐time integral (FTI) was significantly higher in the CF‐guided group (298.3 ± 65. 2 g·s vs 255.1 ± 38.3 g·s, P = .007). The atrial arrhythmia‐free survival at 1 year demonstrated no difference between the two groups (84.0% in the IMP‐guided group vs 80.0% in the CF‐guided group, P = .737). If the use of any antiarrhythmic drug beyond the blanking period was considered as a failure, the clinical success rate at 1 year was 52.0% for the CF‐guided group vs 56.0% for the IMP‐guided group (P = .813). CONCLUSIONS: Atrial fibrillation ablation using an automated annotation system guided by CF improved the success rate of PVI after the initial circumferential ablation. An IMP‐guided annotation combined with catheter stability criteria showed similar clinical outcomes as compared to the CF‐guided annotation.