Background: Cryoballoon ablation is a common strategy for pulmonary vein isolation (PVI) in atrial fibrillation. The potential anatomic determinants of success are unclear.
Objective: To elucidate the effects of non-conventional anatomy (deviation from 4 pulmonary veins) as well as pulmonary vein (PV) size on AF recurrence rates after cryoballoon PVI.
Methods: A registry from a single hospital system of patients with AF who underwent index cryoballoon PVI from 2013-2017 was analyzed. AF recurrence was assessed after a 3 months blanking period and computed tomography scans were reviewed to determine presence of non-conventional vein anatomy and PV diameters. Kaplan-Meier (KM) survival analysis was used to estimate arrhythmia-free survival. Multivariate Cox regression analysis was used to control for various baseline characteristics.
Results: 709 patients underwent first time cryoballoon PVI, of which 140 were excluded due to absent radiographic data. Of the 569 remaining patients, 393 (69%) had conventional anatomy, and 176 (31%) had non-conventional anatomy. Cox regression analysis of AF free survival revealed no difference between conventional vs non-conventional anatomy (HR = 1.11, p=0.44). Of those with conventional anatomy, patients with recurrence at 3 years revealed larger PV perimeters (123 mm vs 118 mm, p = 0.006) as well as larger calculated PV cross-sectional areas (1170 mm2 vs 1090 mm2, p =0.005). Patients with persistent AF also had larger PV perimeters than those with paroxysmal AF (126 mm vs 118 mm, p <0.001).
Conclusion: Cryoballoon PVI is equally effective in patients with non-conventional anatomy and PV size is increased in patients with AF recurrence.