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

BackgroundThis 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). MethodsFifty 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 10second minimum ablation time and 2mm maximum catheter movement range. A minimum CF of 10g was added to the criteria in the CF-guided group. In the IMP-guided group, a minimum IMP drop of over 5 was added to the criteria. ResultsThe 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 (298.365. 2g<bold>s vs </bold>255.1 +/- 38.3g<bold>s</bold>, P=.007). The atrial arrhythmia-free survival at 1year 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 1year was 52.0% for the CF-guided group vs 56.0% for the IMP-guided group (P=.813). ConclusionsAtrial 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.