LAUSR

BACKGROUND Adaptability of cryoballoons to anatomic pulmonary vein (PV) variations is limited due to the fixed geometrical shape, and use for left common PVs (LCPVs) is controversial. We compared the procedural and clinical outcomes in patients with LCPVs after cryoballoon and radiofrequency ablation, and explored the morphological parameters associated with procedural difficulty in LCPV isolations using cryoballoons. METHODS AND RESULTS Eighty-nine consecutive atrial fibrillation patients with LCPVs undergoing PV isolation using either 28-mm second-generation cryoballoons (n=30) or irrigated-tip catheters (n=59) were included. The patient characteristics except for the left atrial diameter (p=0.05) or morphological parameters obtained from cardiac computed tomography were similar between the two groups. The number needed to disconnect the LCPVs (NND) in the cryoballoon-group was ≦3 applications in 22 patients, but ≧4 in the remaining 8, including 1 requiring touch-up ablation. The PV isolation procedure time was significantly shorter in the cryoballoon-group than radiofrequency-group (43.0±19.5min vs. 68.2±31.4min, p<0.001), whereas the single procedure 1-year atrial fibrillation freedom was similar between the groups (74% vs. 67%, p=0.73). A multivariate logistic regression analysis revealed that the ovality index in the cryoballoon-group (odds ratio=1.474; 95%confidence interval=1.020-2.128; p=0.039) and orientation difference between the LCPV and lower branch in the frontal plane (odds ratio=1.071; 95%confidence interval=1.008-1.137; p=0.026) were independent predictors of an NND≧4. The incidence of LCPV reconnections was similar between the cryoballoon- and radiofrequency-groups during the second procedure (50.0% vs. 58.3%, p=0.73). CONCLUSIONS Cryoballoon ablation was similarly as effective as radiofrequency ablation in patients with LCPVs, and morphological evaluations aided in predicting procedural difficulty in LCPV isolations.