Background: Paroxysmal atrial fibrillation (PAF) is defined as recurrent AF terminating spontaneously within 7 days. This definition allows the consideration of any AF occurrence lasting < 7 days as paroxysmal, irrespective of the frequency and duration of episodes. The aim of this study was to investigate symptomatic AF burden (AFB) defined as total duration of symptomatic AF episodes within 3 months prior to abalation, for prediction of outcome after pulmonary vein isolation (PVI).
Methods: A total of 320 consecutive patients with symptomatic AF (PAF=244, men=214, age=58 y) were enrolled. AFB in patients with PAF was defined as time spent in AF within 3 months prior to PVI. After the AFB cut-off point was optimized at 500 h, patients with PAF were categorized into 2 groups: Group 1 - patients with AFB< 500 h (n=192), Group 2 - patients with AFB> or = 500 h (n=52). Patients with persistent AF (PersAF, n = 76) comprised control group (Group 3). PVI was performed either with irrigated tip catheter (n=215) or using cryoballoon (n=105). The endpoint of study was first documented recurrence of AF >30 sec.
Results: Symptomatic AFB was found to be appropriate for prediction of outcome after PVI. The freedom from AF within 2 years was observed in 69%, 31%, and 43% patients in Group 1, 2 and 3, respectively (Group 1 vs. Group 2, p < .001; Group 1 vs. Group 3, p< .001; Group 2 vs. Group 3, p = 0.46).
Conclusions: Low AFB < 500 h /3 months was associated with better outcome after PVI. Patients with PAF and high AFB should be treated as patients with PersAF.
Keywords: atrial fibrillation; atrial fibrillation burden; catheter ablation; outcome; prediction; pulmonary vein isolation.