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%, =.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, =.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, =.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 (=.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.