Atypical atrial flutter ablation: follow-up and predictors of arrhythmia recurrence

Background: Ablation techniques have evolved greatly with advances in high-density 3D mapping systems over the last few years. Some patients develop atypical atrial flutter (AAFL) after pulmonary vein isolation (PVI). The data regarding follow-up after AAFL ablation as well as predictors of arrhythmia recurrence are lacking. This analysis aims to report procedure success rates and establish predictors of long-term success. Methods and Results: This retrospective cohort study included 45 patients (median age: 69 years; 40% female) who qualified for their first AAFL after PVI. The procedures were performed with the use of conventional ablation-index-guided ThermoCool Smarttouch SF and QDOT MICRO catheters. Freedom from arrhythmia recurrence was used as a primary end point. After 52 weeks of follow-up, 60% of patients suffered from arrhythmia recurrence, but over 70% of the studied cohort reported symptom improvement. In multivariate analysis, class I antiarrhythmics prescription (HR = 0.24 [95% CI 0.06-0.94], p = 0.04) was associated with the lack of arrhythmia recurrence during the follow-up, while cardioversion during procedure was associated with increased risk of arrhythmia recurrence (HR = 7.05 [95% CI 2.09-23.72], p = 0.002). Conclusions: Long-term success of AAFL ablation procedures is not satisfactory despite improvement in symptoms. Class I antiarrhythmics prescription at the discharge contributes to higher chances of sinus rhythm maintenance, whereas cardioversion during the procedure is related to increased risk of arrhythmia recurrence.