Pulmonary vein orientation is independently associated with outcomes following cryoballoon-based atrial fibrillation ablation

Abstract

Aims: Several studies have investigated the influence of pulmonary vein (PV) anatomy on outcomes of atrial fibrillation (AF) ablation. We aimed to evaluate the relationship between PV orientation and AF-free survival following cryoablation.

Methods: 160 patients scheduled for cryoablation between September 2012-March 2014 were included. Patients underwent a pre-procedural cardiac CT scan with retrospective ECG gating. PV orientation was assessed according to the position of the PV orifice relative to the sagittal plane with reference to coronal and horizontal planes.

Results: 160 patients (57 ± 9 years, 54% male, 33% persistent AF) were included and followed for a median of 17 (12-36) months. Excluding a blanking period of 3 months, freedom from AF after a single ablation procedure was 76%. Ventral-caudal left upper PV (p = 0.044) and ventral-caudal left lower PV orientation (p = 0.001) were more common in patients with AF recurrence. In multivariate Cox regression analysis, only left lower PV orientation [particularly dorsal-caudal (HR: 3.447, 95% CI: 1.180-10.070, p = 0.024) and ventral-caudal (HR: 3.391, 95% CI: 1.088-10.571, p = 0.035) orientations compared to dorsal-cranial orientation] as well as LA diameter (HR: 3.420, 95% CI: 1.809-6.465, p < 0.001) were significantly associated with AF recurrence.

Conclusion: This is the first study to demonstrate the impact of PV orientation on prediction of AF recurrence following cryoablation. Preprocedural assessment of PV orientation may modify operator preferences on treatment strategies in AF.

Keywords: Ablation; Atrial fibrillation; Cryoballoon; Orientation; Pulmonary vein; Recurrence.