An ablation index operator-independent approach to improve efficacy in atrial fibrillation ablation at 24-month follow-up : a single center experience

Purpose: Since the introduction of catheter ablation as a mainstream treatment for atrial fibrillation (AF), several technical improvements have been put forward. In this contest, Ablation Index (AI) is an accurate ablation quality marker by incorporating power, delivery time, contact force (CF), and catheter stability in a weighted formula. The aim of our study is to evaluate the efficacy of AI-guided AF ablation over 24 month follow-up. Methods: We evaluated 72 consecutive patients with drug-refractory paroxysmal (66.7%) and early-persistent AF (33.3%) undergoing AI-guided ablation, compared to 72 propensity-matched control patients who underwent CF-guided procedure. All procedures were performed by three skilled operators. Data concerning procedural characteristics and long-term freedom from AF recurrence were analyzed. Results: At 24-month follow-up, Kaplan-Meier curves of AF recurrence were significantly lower in AI group than in CF group (15.5% vs. 30.6%; p 0.042). These findings were confirmed in a sub analysis regardless of the continued use of antiarrhythmic drugs in the follow-up (42.2% in AI-guided group and 66.7% in CF-guided group, p 0.004). At 24-month follow-up, a positive trend in the decrease of arrhythmia recurrences was observed in AI-guided ablation for all operators. Conclusions: AI-guided ablation results more effective than CF-guided ablation as demonstrated by a lower incidence of AF recurrences regardless of the use of antiarrhythmic drugs in the follow-up. Each operator seems to improve the long-term success using an AI-guided ablation, thus showing both the efficacy and the reproducibility of this approach.