Comparative Study of Cryoballoon versus Radiofrequency for Pulmonary Vein Isolation when Combined with vein of Marshall Ethanol Infusion for Paroxysmal Atrial Fibrillation.

Introduction: Ethanol infusion (EI) in the vein of Marshall (VOM) has multifactorial effects that could be synergistic to pulmonary vein isolation (PVI) in ablation of atrial fibrillation (AF). The efficacy of radiofrequency (RF) versus cryoablation when combined with a VOM-EI has never been investigated. The aim of this study is to evaluate outcome differences of AF ablation using RF versus cryoablation when combined with a VOM-EI.

Materials and Methods: Consecutive patients (n=132) underwent catheter ablation of paroxysmal AF with either RF or cryoballoon (CB) for PVI combined with VOM-EI. Bi-directional conduction block at the mitral isthmus was attempted. The end-point was the freedom from any atrial arrhythmias documented after a blanking period of 90 days after the procedure.

Results: Kaplan-Meier estimates of the arrhythmia-free survival after 1 year were 63.8 (RF + VOM), and 82.7 % (CB + VOM), respectively. Comparison between CB + VOM versus RF + VOM reached a significance (p=0.0292). The periprocedural complication rate was comparable in both groups (5.0 % RF, 5.8 % CB; p=0.14) with a significant difference in the incidence of phrenic nerve palsy (0 % RF, 2.0 % CB; p<0.05).

Conclusions: PVI with a CB had an increased freedom from AF recurrence compared to RF combined with VOM-EI. The present results suggest a potential additive effect of a VOM-EI to CB application.