Long-term effectiveness and safety of ablation index– guided high-power ablation combined with impedance spike cut-off in patients with atrial fibrillation

Introduction
High-power, short-duration radiofrequency ablation (RFA) is considered an effective treatment for atrial fibrillation (AF) patients.

Aim
This study aimed to evaluate long-term outcomes over a follow-up period up to 3 years.

Material and methods
This was a single-center, retrospective real-world study. 132 patients were consecutively enrolled. The effectiveness endpoints included freedom from any atrial arrhythmia during 1-year and 3-year follow-up. The efficiency endpoints included first-pass pulmonary vein isolation (PVI) rate, RFA time, procedure time, and fluoroscopy time. The main safety endpoint was the incidence of acute pericardial tamponade and steam pop.

Results
All patients (n  =  132, mean age: 60.1 ±9.7 years, male: 65.9%, left ventricular ejection fraction: 64.3 ±7.8%, persistent AF: 50.8%) achieved acute PVI, and the first-pass PVI rate was 87.9%. During 1-year follow-up, the overall success rate was 82.6%, and the overall success rate was 77.06% in a 3-year follow-up. The mean procedure time, total RFA time, baseline impedance value, and fluoroscopy time were 55.3 ±11.3 min, 36.0 ±8.5 min, 118.5 ±9.4 Ω, and 7.1 ±3.6 min, respectively. Seventy-two (54.6%) patients experienced impedance spike cut-offs during RFA, mostly during PVI at the anterior carina of the right pulmonary vein (RPV) (25.8%), the ridge between the left atrial (LA) appendage and left pulmonary vein (LPV) (22.0%), and the inferior region of the RPV (16.7%). The overall major adverse event rate was 0.8%. The results of Cox regression analysis showed that sex (female), baseline impedance value, and contact force were independent prognostic factors for recurrence during 1-year follow-up.

Conclusions
Ablation index–guided high-power (AI‑HP) RFA combined with impedance spike cut-off appears to be a safe and effective ablation technique for AF.