Procedural findings and clinical outcome of second-generation cryoballoon ablation in patients with variant pulmonary vein anatomy.

INTRODUCTION: The procedural findings and clinical outcome of second-generation cryoballoon (CB2) ablation in patients with variant pulmonary vein (PV) anatomy have not been fully investigated.

METHODS: A total of 424 consecutive patients who underwent PV isolation with CB2 were included. Computed tomographic (CT) scan was performed in all patients before the procedure. The study population was divided into common PV, accessory PV, and nonvariant PV groups according to the CT scan. Procedural findings and clinical outcome between the three groups were compared.

RESULTS: Variant PV anatomy was observed in 118 of 424 (27.8%) patients. PV isolation was successfully achieved in all patients in three groups with low rates of need for touch-up ablation (P = 0.974). Total procedure time was longer in the accessory PV group compared with nonvariant PV group (53.7 ± 12.9 vs 49.5 ± 8.8 minutes; P < 0.001). More number of applications per patient were required in accessory PV group compared with the nonvariant PV and common PV groups (7.5 ± 2.1 vs 6.5 ± 1.6, P < 0.001; 7.5 ± 2.1 vs 6.8 ± 1.4, P = 0.027, respectively). No significant difference in phrenic nerve (PN) injury was observed between the three groups (P = 0.693). During mean follow-up duration of 16.1 ± 3.3 months, there was no significant difference in rates of atrial fibrillation (AF) recurrences in the three groups (13 of 43 common PV group, 21 of 75 accessory PV group, and 80 of 306 nonvariant PV group, P = 0.178).

CONCLUSION: Variant PV patterns are common in patients undergoing ablation for drug-resistant AF. CB2 ablation appears to be a reasonable strategy in the setting of the variant PV anatomy with a small increase in procedure time and the number of cryoapplications.