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.