Pulmonary Vein Isolation Guided By Moderate Ablation Index Targets Combined With Strict Procedural Endpoints For Patients With Paroxysmal Atrial Fibrillation

Introduction Ablation index (AI)-guided radiofrequency ablation has been increasingly used for the treatment of drug-resistant paroxysmal atrial fibrillation (AF)?but the optimal AI targets remain to be determined. We aimed to examine the efficacy and safety of catheter ablation guided by moderate AI values but more strict procedural endpoints in patients with paroxysmal AF.Methods We conducted a retrospective review of a consecutive series of patients who received their first AI-guided ablation for paroxysmal AF from 2017 to 2018. The standard procedural protocol recommends AI targets as follows: anterior: 400-450; posterior: 280-330; and roof/inferior wall: 380-430. After circumferential pulmonary vein isolation (PVI), we performed bipolar pacing along the ablation line, adenosine triphosphate (ATP)-provocation, and waited for 30 min to verify PVI. The primary clinical outcome was the rate of freedom from AF recurrence at 12 months.Results A total of 140 consecutive patients were included. The mean procedure and ablation times were 132.2 +/- 30.2 min and 24.2 +/- 7.9 min, respectively. The first-pass isolation and final isolation rates were documented in 49.3% and in 100% of the patients, respectively. At 12 months, single-procedure freedom from atrial tachyarrhythmias was observed in 92.1% of patients. No major procedure-related complications were encountered.Conclusions Moderate AI-guided catheter ablation is highly effective for the treatment of drug-refractory paroxysmal AF in real-world settings. Over 90% of patients achieved single-procedure arrhythmia-free survival at 1 year. The outcome was obtained without major complications and the procedure involved relatively short procedure and ablation times.