Standard versus strict stability criteria in radiofrequency paroxysmal atrial fibrillation ablation using ablation index

Purpose: To compare the outcome of paroxysmal atrial fibrillation (AF) ablation via pulmonary vein isolation using Ablation Index (AI) with strict or standard stability criteria. Methods: We enrolled 130 consecutive naive patients affected by paroxysmal AF who underwent PVI at two high-volume centers. AI target was ≥380 at the posterior wall and ≥500 at the anterior wall. Strict versus standard stability criteria were set for Group 1 (65 patients) and Group 2 (65 patients), respectively. We compared those strategies with a historical cohort of 72 consecutive patients treated at same centers in the VISITALY study, using average force ≥10 g and strict stability criteria as target parameters. Interlesion distance target was <6 mm. Recurrence was defined as any AF, atrial tachycardia (AT) or atrial flutter (AFL) during the 12 months after ablation, excluding a 90-days blanking period. Results: Procedure duration (224.05 ± 47.21 vs. 175.61 ± 51.29 min; p <.001), fluoroscopy time (11.85 ± 4.38 vs. 10.46 ± 6.49 min; p =.019) and pericardial effusion rate (9.23% vs. 0%; p =.01) were higher in Group 1 than in Group 2. Freedom from AF/AT/AFL at 12 months was not significantly different (Group 1: 86.15%; Group 2: 90.77%; p =.42). Compared to VISITALY study, there were not significant differences in terms of recurrences. Conclusion: A strategy of PVI using AI with standard stability criteria performed the best in terms of procedure efficiency and safety. Twelve-months arrhythmia-free survival rate was comparable with other strategies pursuing an interlesion distance target <6 mm, regardless of the use of AI