The value of the ablation index in patients undergoing ablation for atrial fibrillation

Abstract

BACKGROUND Data on the results of ablation for atrial fibrillation (AF) in Poland are scarce. AIMS The aim of the study was to compare the efficacy of ablation index (AI)-guided pulmonary vein isolation (PVI) with that of conventional contact force–based PVI. METHODS Consecutive patients undergoing PVI for the first time were included in the study. A nonrandomized retrospective comparison was made between patients ablated with contact force before AI was introduced (non-AI group) and patients ablated with the use of AI (AI group). The AI threshold for the anterior wall / roof of left veins was 500 and 380 elsewhere. The maximal interlesion distance was 6 mm. The follow-up included outpatient visits and 7-day Holter monitoring 6 and 12 months after ablation. RESULTS A total of 275 patients were included in the analysis: 133 in the AI group and 142 in the non-AI group. The duration of AF ablation was slightly longer in the AI group, but the fluoroscopy time and the radiofrequency ablation time were shorter in the same group. During the 12-month follow-up period, 25.8% and 40.6% of patients from the AI and non-AI groups, respectively, experienced recurrences (P= 0.02). The log-rank test with an extended follow-up period of up to 18 months confirmed the difference between the AI and non-AI groups, both in the whole group and in the paroxysmal AF and nonparoxysmal AF subgroups (P = 0.001, P = 0.04, and P = 0.006, respectively). CONCLUSIONS The AI-based protocol provides a significant advantage over traditional contact force–based radiofrequency ablation in nonselected patients undergoing PVI.