Burden and Long Firing of Premature Atrial Contraction Early After Catheter Ablation Predict Late Recurrence of Atrial Fibrillation.

Background: Associations between characteristics of premature atrial contraction (PAC) 6 months after catheter ablation (CA) and later recurrence are not known. We investigated the effects of PAC characteristics on long-term outcomes of initially successful atrial fibrillation (AF) ablation.

Methods and results: In all, 378 patients (mean age 61 years, 21% female, 67% paroxysmal AF) who underwent initial radiofrequency CA for AF without recurrence up to 24-h Holter monitoring 6 months after the procedure were reviewed retrospectively. The calculated number of PAC/24 h and the length of the longest PAC run during Holter recording were analyzed. After 4.3±1.2 years (mean±SD) follow-up, 123 (32.5%) patients experienced late recurrence. Patients with recurrence had significantly more PAC/24 h (median [interquartile range] 110 [33-228] vs. 42 [16-210]; P<0.01) and a longer longest PAC run (5 [2-8] vs. 3 [1-5]; P<0.01) than those without. Receiver operating characteristic curve analysis indicated 58 PAC/24 h and a longest PAC run of 5 were optimal cut-off values for predicting recurrence. After adjusting for previously reported predictors of late recurrence, frequent PAC (≥58/24 h) and longest PAC run ≥5 were found to be independent predictors of late recurrence (hazard ratios [95% confidence intervals] 1.93 [1.24-3.02; P<0.01] and 1.81 [1.20-2.76; P<0.01], respectively).

Conclusions: Six months after successful AF ablation, both frequent PAC and long PAC run are independent predictors of late recurrence.