Impact of Catheter Ablation on Arrhythmia Burden in Patients With Shock-Resistant Persistent Atrial Fibrillation

Abstract

Background: Persistent shock-resistant atrial fibrillation (AF) is a challenging entity, with modest results from catheter ablation according to conventional survival analysis.

Objectives: The aim of this study was to determine the effect of catheter ablation on atrial tachyarrhythmia (ATA) burden in persistent AF patients undergoing first-time ablation with the use of an implantable cardiac monitor (ICM).

Methods: Patients with drug-resistant ongoing persistent AF and at least 1 previous failed cardioversion were implanted with an ICM 2 months before the procedure. All patients underwent pulmonary vein isolation with or without additional substrate ablation depending on the presence of self-terminating AF on ICM and left atrium size. Median AF burden before and after ablation, off antiarrhythmic medication, was determined from ICM recordings after review by 2 independent investigators.

Results: Sixty patients were recruited (mean age 66 ± 9 years, 70% male). Mean left atrial diameter was 48 ± 6 mm and median CHA₂DS₂VASc score was 2. Ten patients (17%) unexpectedly demonstrated self-terminating AF before ablation. The median burden of ATA before ablation was 100% (95% CI: 19.6%-100%), decreasing to 0% (95% CI: 0%-95.8%) after ablation during the post-blanking follow-up period (median reduction 100%; 95% CI: 4%-100%; P < 0.001). Twenty-seven patients (45%) experienced recurrent ATA during 12-month follow-up. In these patients, median burden before ablation was 100% (95% CI: 26.9%-100%), decreasing to 11.4% (95% CI: 0.35%-99.7%) after ablation (P < 0.001). Quality of life improved significantly from baseline, driven by lack of recurrence.

Conclusions: Patient-tailored catheter ablation results in a significant reduction in ATA burden (off antiarrhythmic medication) in shock-resistant persistent AF patients using ICMs implanted 2-months pre-procedure. These data suggest that conventional arrhythmia-free survival analysis does not capture the true impact of catheter ablation in this challenging cohort.

Keywords: atrial tachyarrhythmia burden; catheter ablation; implantable cardiac monitor; persistent atrial fibrillation; quality of life.