The Value of the Ablation Index in Patients Undergoing Ablation for Atrial Fibrillation

Background

Consecutive patients undergoing PVI for the first time were included in the study.

Aim

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 (CF)-based PVI.

Methods

A non-randomized retrospective comparison was made between patients ablated with CF 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 the left veins was 500 and 380 elsewhere. The maximal interlesion distance was 6 mm. Follow-up was based on outpatient visits and seven-day Holter monitoring 6 and 12 months after ablation.

Results

A total of 275 patients were included in the analysis-133 patients in the AI group and 142 patients in the non-AI group. The duration of atrial fibrillation (AF) ablation was slightly longer in the AI group, but the fluoroscopy time and the radiofrequency (RF) ablation time were shorter in the same group. During the 12-month follow-up period, 25.8% and 40.6% of the AI and non-AI group patients, respectively, experienced recurrences (P = 0.02). A 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 non-paroxysmal AF subgroups (P = 0.001, P = 0.04, and P = 0.006, respectively).

Conclusion

The AI-based protocol provides a significant advantage over traditional CF-based RF ablation in non-selected patients undergoing PVI.