Background: Recent studies suggest a clinical benefit associated with posterior wall isolation as an adjunct to the pulmonary vein (PV) isolation in patients with persistent atrial fibrillation (AF). However, data on the safety and efficacy of this cryoballoon ablation approach are limited. The study aimed to compare the efficacy and safety of catheter treatment of patients with persistent atrial fibrillation using cryoballoon "single shot" technology in two randomized groups.

Materials and methods: Traditional PV cryoballoon isolation was performed in two groups of patients with persistent AF. In the first group of patients (n = 35) underwent only PV cryoballoon isolation. In the second group of patients (n = 33), cryoballoon isolation of the PV and cryoablation of the posterior wall of the left atrium (LA) was performed. Patients after ablation were followed up for 15.6 (2.7–3.5) months for AF recurrence, functional class, and echocardiographic parameters.

Results: The study included 68 patients with persistent AF in the last six months before inclusion, for whom at least two antiarrhythmic drugs of class I-III were ineffective. By random distribution, 35 patients were included in group 1 - (PVI), and they underwent only PV cryoballoon isolation. Group 2 - (PVI+PWA) included 33 patients who underwent PV cryoballoon isolation and additional LA posterior wall cryoablation. The primary efficacy endpoint occurred in 11 patients in group 1 and 6 patients in group 2 (Kaplan-Meier survival, 31.4% and 18.2%, respectively; hazard ratio, 0.96; 95% confidence interval. Undesirable events occurred in 3.8% of each group (p = 1.00). On multivariate analysis, posterior wall ablation and PV isolation using a cryoballoon (PVI+PWA) was an independent predictor of freedom from recurrent atrial fibrillation (odds ratio: 3.57; 95% confidence interval: 1, 39–8.93, p = 0.007).

Conclusions: In patients with persistent AF, posterior wall ablation and PV isolation using a cryoballoon significantly reduce arrhythmia recurrence. Nevertheless, safety is similar compared to patients with only PV isolation.