Abstract 3510: Hybrid Strategies for Ablation of Permanent AF as an Adjunct to PVI: Implications of Targeting AF NEST in Sinus Rhythm and CFAE in AF
Background: Ablation of permanent atrial fibrillation (PM-AF) remains a clinical challenge. PVI, at its antrum level (PVAI), has decreased recurrence rates to 30%. Real time spectral mapping (SM) in sinus rhythm (SR) identifies sites with disorganized frequencies, namely fibrillar atrial myocardium or AF-Nest (AFN). PVI combined with defragmentation targeting ablation of complex fractionated atrial electrograms (CFAE) may terminate AF by either restoring sinus rhythm (SR) or organizing into an atrial tachyarrhythmia (AT) which seemed to be associated with a higher long-term maintenance of SR.
Purpose: To evaluate the outcome of AFN ablation as an adjunct to PVAI and to assess the mode of PM-AF termination targeting CFAE + PVAI.
Methods and Results: One hundred and seven consecutive pts underwent ablation of PM-AF. The two hybrid ablation strategies and endpoints were: Group 1. PVAI + AFN (N=56) to decrease AF/AT recurrences (F/U 193±46 days); Group 2. CFAE + PVAI (N=51) to assess AF termination during ablation. The modes of AF termination were: Conversion to SR, organization into AT or persistence of AF requiring cardioversion. There were no differences in sex, age, AF duration, LA size and LVEF among the two ablation strategies. SR was rarely restored with ablation. In group 1, AFN ablation sites (32±15 bi-atrial and CS) following PVAI decreased AF/AT recurrences (30% to 21%). Recurrence of AT is significantly higher (p<0.05).In Group 2, bi-atrial and CS CFAE ablation was performed initially but rarely organized AF into AT (1 of 49 pts). PVAI following CFAE ablation often organized AF into AT (cycle length 246.8±36.9 ms).
Conclusions: Ablation of the so called AFN following PVAI favorably decreases recurrence rates following ablation of PM-AF. CFAE ablation had no impact on AF termination whereas adjunctive PVAI succeeded in most pts. Nevertheless, the long-term clinical implications of this hybrid approach remains to be demonstrated.