Abstract 19595: Anatomic and Clinical Predictors of Need for Repeat Atrial Fibrillation Ablation

Introduction: Although clinical predictors of the need for repeat procedures after catheter ablation of atrial fibrillation (AF) have been evaluated, anatomic predictors have not been well defined. Hypothesis: Anatomic features on cardiac magnetic resonance (CMR) imaging can identify patients most likely to require repeat ablation. Methods: From Jan. 2004 to Feb. 2014, 307 patients underwent CMR prior to initial AF ablation at our institution. Ablation strategies along with the need for and timing of repeat ablation were determined at the discretion of the treating physician. Results: Out of 307 patients, 119 (38.8%) underwent repeat ablation at a mean of 15.0 ± 19.2 months after the initial procedure. Among repeat procedures, 62% were performed primarily for recurrent AF and the remaining for left atrial tachycardias. Across the entire cohort at the initial procedure, mean age was 62.0 ± 10.8 yrs, 75% were male, 23% had persistent AF, 90% had radiofrequency ablation and the remaining had Cryoballoon ablation, without significant differences between those undergoing a single vs. repeat procedures. Other baseline clinical parameters including EF and presence of hypertension, diabetes and sleep apnea were also similar between groups. However, on CMR performed prior to the first ablation, pulmonary vein (PV) ostial diameters were significantly larger in all PVs among those requiring repeat procedures: right superior PV 19.4 ± 4.0 vs. 21.4 ± 4.5 mm (p 2 ) and left (28.0 ± 5.3 vs. 29.2 ± 6.5 cm 2 ) atrial areas were larger among those requiring repeat procedures, the differences were not significant. Conclusions: Among patients undergoing AF ablation, clinical variables were not significantly different between those requiring a single vs. repeat procedures. However, PV dimensions assessed by CMR were significantly larger among those likely to require repeat procedures. Further study is required to determine whether strategies at the initial ablation can be used to mitigate the increased risk of need for repeat procedures among those with larger PVs.