Clinical Benefit and Safety of Ablation Index -Guided Higher-Power Ablation Protected by Impedance Spike Cut-off in Patients with Atrial Fibrillation

Aims: To evaluate the procedural effectiveness, efficiency and safety outcomes when using ablation index-guided higher-power ablation protected by impedance spike cut-off for atrial fibrillation (AF) up to 12-month follow-up in China. Methods： 132 patients were consecutively enrolled. The endpoints included freedom from any atrial arrhythmia during 12-month follow-up, first-pass pulmonary vein isolation (PVI) rate, RF ablation time, procedure time and fluoroscopy time. Results: All patients achieved acute PVI and first-pass PVI rate was 87.9%. During 12-month follow-up, the overall success rate was 82.6%. The mean procedure time, total RF ablation time, baseline impedance value and fluoroscopy time were 55.3±11.3min, 36.0±8.5min, 118.5±9.4Ω and 7.1±3.6min, respectively. The spike cut-off occurred in 72 (54.6%) subjects and mostly during PVI at the anterior carina of right pulmonary vein (RPV) (25.8%), ridge between left atrial appendage and left pulmonary vein (22.0%), and inferior of RPV (16.7%). The overall major adverse event rate was 0.8%. The result of Cox regression analysis showed that gender, baseline impedance value and contact force were independent prognostic factors for recurrence. Conclusion: AI-guided higher-power ablation with impedance spike cut-off appears to be a safe and effective ablation technique for AF and leads to a high overall success rate at 12 months.