Introduction: Pulmonary vein isolation (PVI) has become standard of care for treatment of drug-refractory atrial fibrillation (AF). For this purpose, the use of single shot devices for cryoballoon-guided PVI (CBPVI) is continuously growing. Long-term outcome data for this AF ablation approach are sparse. In this study, we sought to determine the very long-term clinical outcome of patients treated with CBPVI.

Methods: We analyzed data from 715 patients treated with CBPVI in our center between 2005 and 2012. Only patients with a follow-up (FU) of ≥9 years following the index ablation procedure for AF were included in this study. The vast majority of patients underwent CBPVI using the first generation cryoballoon (CB) catheter (size: 28mm) according to a standardized institutional protocol. Reablation procedures using radiofrequency (RF) PVI were performed in 71% of all patients with AF recurrence after initial ablation and the cryoballoon was utilized for repeat ablation in 29% of patients. All patients were followed-up (FU) in our outpatient clinic using 72h-Holter monitoring and by telephone calls. Arrhythmia recurrence was defined as any AF/ atrial tachycardia (AT) episode lasting >30s after a 3 months blanking period.

Results: The entire cohort consisted of 385 patients (71%male). The mean age was 58±10 years and paroxysmal (PAF) was present in 93% of patients. The mean FU time was 124±24 months. Twenty-three patients died during the FU-period. These deaths were not related to the ablation procedure. At the end of the observational period, 73% of all patients were in stable sinus rhythm after a mean of 2±0.8 procedures. In patients with arrhythmia recurrence, persistent AF or AT were found in 41% of patients. Patients with AF/AT recurrence were significantly older (60±8 vs. 57±10 years; p= 0.019), had a higher CHA₂DS₂-Vasc Score (2.47±1.46 vs. 1.98±1.50; p=0.006) and presented with a larger LA-diameter (43±5.6 vs 40± 5.1; p=0.002). The LA-diameter was the only significant predictor for AF/AT recurrence after PVI (p=0.03) from multivariate analysis.

Conclusion: Using the cryoballoon for PVI as index procedure for AF ablation resulted in favorable long-term outcome in patients with paroxysmal AF. Therefore, CBPVI might be recommended as first-line therapy in selected patient cohorts.