Efficacy of pulmonary vein isolation by cryoballoon ablation in patients with paroxysmal atrial fibrillation.

BACKGROUND: Radiofrequency ablation of pulmonary veins (PVs) has emerged as an effective treatment for patients with paroxysmal atrial fibrillation (AF). However, serious complications raise concern about an even wider application. In terms of safety, cryoenergy has advantages compared with radiofrequency. A new cryoenergy balloon catheter has been recently developed to make AF ablation shorter and safer.

OBJECTIVE: The purpose of this study was to test the 6-month efficacy of this new device for ablation of paroxysmal AF.

METHODS: Twenty-one patients with highly symptomatic paroxysmal AF, normal left atrial size, and frequent episodes of AF were included. All PVs were targeted during cryoballoon ablation. Patients received 24-hour Holter electrocardiograms (ECGs) and event recorder during follow-up after 1, 3, and 6 months.

RESULTS: A total of 81 (95%) of 85 PVs could be completely isolated with a single-balloon technique. Procedure time was 165 +/- 35 minutes, and fluoroscopy time was 39 +/- 9 minutes. After 6 months, 86% of the patients were free of symptomatic AF. In two of three patients with recurrence of AF, complete PV isolation has not been achieved initially. After a second procedure (1.04 procedures per patient), 90% of the patients were free of symptomatic AF. Three phrenic nerve palsies occurred during ablation of the right superior PV; two completely resolved after 6 and 9 months, and one is still persisting after 2 months.

CONCLUSION: This is the first study that reports the results of the new cryoballoon AF ablation approach showing 86% freedom from AF recurrence after 6 months. Cryoballoon PV ablation promises to be effective for patients with paroxysmal AF and normally sized left atria.