Dipole Density Guided Catheter Ablation versus Conventional Substrate Modification for Repeat Catheter Ablation of Persistent Atrial Fibrillation

Aims: The optimal ablation strategy for recurrent persistent atrial fibrillation (persAF) after initially successful catheter ablation (CA) remains debatable. Dipole density (DD) guided CA using the AcQMap system has been proven to be feasible and effective in patients with persAF. So far, long-term outcome data for DD-guided CA in patients with recurrence of persAF are sparse. This study sought to assess long-term outcome data in patients undergoing a DD-guided CA for recurrence of persAF after previous CA in comparison to conventional repeat CA. Methods and Results: Patients undergoing DD-guided CA for recurrence of persAF after previous ablation were compared to patients undergoing conventional substrate modification (CSM). A total of 64 patients (32 DD-guided and 32 CSM) were included in this analysis. Procedure duration (DD: 236 +/- 61 min; CSM: 198 +/- 59 min; p = 0.004) and fluoroscopy time (DD: 36 +/- 15 min; CSM: 20 +/- 11 min; p = 0.0001) were significantly longer in the DD group. After a long-term median follow-up (FU) of 27 months (interquartile range 12.8-34.3), DD-guided CA was inferior to CSM regarding overall arrhythmia-free survival (DD: 6 patients (19%), CSM: 11 patients (34%); HR 1.47; p = 0.04). Freedom from AF did not differ between both groups (DD: 16 patients (50%); CSM: 18 patients (56%), HR 0.99, p = 0.47). During FU, more patients underwent repeat CA after DD-guided ablation (DD: 16 patients (50%), CSM: 7 patients (22%), p = 0.04). No major complications occurred overall. Conclusions: Dipole density-guided CA is equally safe but associated with longer procedure duration compared to conventional substrate modification for treatment of recurrent persAF after previous CA. Of note, long-term arrhythmia-free survival is significantly worse after DD-guided ablation, and more patients undergo redo procedures.