Abstract 20055: Etiology of Atrial Fibrillation Recurrence After Previous Successful Pulmonary Vein Isolation With Cryoablation; A Two-center Review of Redo AF Ablation Data

Background: Cryoballoon ablation has been effective in treating atrial fibrillation (AF) with high rate of pulmonary vein isolation (PVI). Repeat ablation for failed prior cryoballoon PVI may reveal atypical etiologies of AF. However, limited data are available to characterize the pulmonary and extra-pulmonary vein sites for recurrence AF. Methods: We retrospectively examined 688 consecutive patients who had undergone prior AF ablation using second-generation cryoballoon in 2 high volume centers (219 paroxysmal, 335 persistent, and 114 long-standing persistent). Repeat ablation for recurrent AF was performed and reconnection data was assessed in 97 of 688 (15%). Procedures characteristics and the status of pulmonary and extra-pulmonary areas at the time of repeat ablations were analyzed. Results: 97 patients underwent a total of 98 redo-ablation (one of patients had 2 redo-ablation). Time to repeat ablation was from 1 month to 34 months (average 7.5 months). 369/392 PV’s were isolated at repeat procedure (94%). Of the 24 PVs with re-conduction, 11 RIPV, 6 LIPV, 3 RSPV, 3 LSPV and 1 left common PV. All PVs with time-to-isolation 2 minute repeat ablation were isolated at redo. No stroke, PV stenosis, phrenic nerve injury, or atrial-esophageal fistula observed in this series. Most frequently observed extra-pulmonary triggers included left atrial flutter (33/97), ectopic atrial tachycardia (22/97) and typical flutter in 9/97 patients. Extra PV ablation for unmappeable AF at repeat procedure (100% RF) was performed at LA roof (85/97), Posterior wall (33/97), atrial septum (22/97), RA lateral wall (13/97), RA posterior wall (12/97) and SVC (3/97). Conclusions: Second generation cryoballoon has durable long-term PVI in a majority of patients including persistent and long-standing persistent AF. Less than 90 seconds time-to-isolation is a good predictor of long-term PVI. For recurrent AF after previous cryoablation, RIPV is the most common pulmonary reconnection site meanwhile a variable extra PV sites were observed at repeat procedure. LA roof is the most common extra-pulmonary site in these patients.