Electrical Cardioversion of Persistent Atrial Fibrillation: Acute and Long-Term Results Stratified According to Arrhythmia Duration.

Background: Current definition of persistent atrial fibrillation (PAF) enrolls a heterogeneous population with different atrial fibrillation (AF) exposure and degree of atrial substrate. Study aims were to evaluate acute and long-term results of electrical cardioversion (ECV) and to identify temporal cutoff of previous AF exposure to reclassify PAF in subgroups with different chance of sinus rhythm (SR) maintenance. Methods: Five hundred twenty-one patients (66% men; age 69 ± 10 years) with PAF undergoing ECV, were divided in four groups according to AF duration at the time of ECV: group A with AF ≤2 months (141 patients); group B with AF >2 and ≤4 months (176 patients); group C with AF >4 and ≤6 months (89 patients); and group D with AF >6 months and <1 year (115 patients). Results: There was no difference in term of acute success among groups (98.5% vs 97.1% vs 98.9% vs 96.5%, respectively, P = 0.95). At 5-year follow-up, 198 (41%) patients were in SR: 50% in group A, 44% in group B, 42% in group C, and 25% in group D (P < 0.001). At the multivariate analysis, previous ECV (hazard ratio [HR] 1.55, P < 0.001), left atrium enlargement (HR 1.39, P = 0.013), and AF duration >6 months at time of procedure (HR 1.59, P = 0.001) independently predict ECV failure. Conclusion: ECV is associated with high acute success rate and low complications rate. Long-term results are strongly related with AF duration at time of ECV: a cutoff of >6 months helps in selecting patients that can take greater advantage of the procedure. (PACE 2012; 35:1126-1134) [ABSTRACT FROM AUTHOR]