Predictors of a Persistent Status of Pulmonary Vein Electrical Isolation by a Cryoballoon Application for Drug-Refractory Atrial Fibrillation.

Background: Pulmonary vein isolation (PVI) using a cryoballoon (CB) is utilized for treating atrial fibrillation. This study aimed to assess the effect of the procedural characteristics of CB-based PVI (CB-PVI) on late PV reconnections. Methods and Results: A total of 389 consecutive patients underwent the CB-PVI as their index procedure; 45 consecutive patients underwent re-do procedures (184 +/- 87 days after the index CB-PVI). A total of 146 of 178 PVs (82%) remained isolated. The occlusion grade was evaluated in 171 PVs. Complete PV occlusion by the CB (grade 4) was obtained in 122 of 171 PVs (71%) during the index CB-PVI and the PVI status was maintained in 111 PVs (91%). Among the remaining 49 CB-PVIs without complete PV occlusion (grades 1-3), 20 PVs (41%) had late PV reconnections despite successful PVI during the index CB-PVI. A "pull-down maneuver" was performed in 20 PVs because of leakage of blood at the inferior aspect of the PVs, and all those PVs with a successful pull-down maneuver maintained their PVI status. A multivariate analysis demonstrated that the presence of complete PV occlusion was the only independent predictor for persistence of PVI. Conclusions: The occlusion grade was a reliable predictor of the long-term durability of PVI.