Old Habits Die Hard

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