Relationship between the CHADS₂ score and risk of very late recurrences after catheter ablation of paroxysmal atrial fibrillation

Background: Catheter ablation of paroxysmal atrial fibrillation has been performed for more than 10 years. However, data about the long-term results were limited. Objectives: To evaluate the long-tem efficacy following paroxysmal atrial fibrillation ablation and to investigate whether there were different patterns of recurrences in patients with different CHADS₂ scores. Methods: A total of 238 patients with paroxysmal atrial fibrillation who received a catheter ablation from 2004 to 2007 were enrolled. Free of recurrence was defined as the absence of atrial arrhythmias without using any antiarrhythmic agents after ablation. Results: There were 121 patients (50.8%) suffering from recurrences after the first ablation procedure during a median follow-up period of 5 years. The CHADS₂ score and left atrial diameter were significant predictors of recurrences in the multivariate analysis. Different patterns of recurrence were observed in different groups of patients categorized on the base of CHADS₂ score. Among patients with a CHADS₂ score of <3 without recurrences at 2 years postablation, 63.6% experienced episodes of arrhythmias during the subsequent follow-up period. In contrast, in patients with a CHADS₂ score of 0 without recurrences at 2 years postablation, the future recurrence rate was only 2.7%. Conclusions: After a successful ablation, recurrences may continue to occur without reaching a plateau during the long-term follow-up, especially in patients with a high CHADS₂ score. The optimal follow-up strategy may differ and should be individualized for patients with different scores.