Background: Atrial fibrillation is the most prevalent cardiac arrhythmia with significant healthcare impact with regards to treatment costs, morbidity, and mortality. Many of the focal electrical activities that initiate and sustain atrial fibrillation have been found to reside within or near the pulmonary veins. Consequently, pulmonary vein isolation by catheter ablation has emerged as an effective method to eliminate the focal triggers associated with atrial fibrillation.
Methods: In this single-center study, 205 patients were ablated for atrial fibrillation using a cryoballoon catheter and followed-up long-term by retrospective chart examination to evaluate their post-procedural freedom from atrial fibrillation.
Results: Patients were followed for up to 6 years with a cohort median of 3 years of post-ablation evaluation. Overall, at 12, 24, and 36 months post-ablation, 71, 49, and 31% of evaluated patients were free of atrial fibrillation, respectively. We found the type of atrial fibrillation (paroxysmal vs. persistent) as an independent predictor for arrhythmia recurrence (HR 1.97; 95% CI: 1.24-3.13, P = 0.006). The cohort median atrial fibrillation-free survival time was 24 months (27 months for paroxysmal atrial fibrillation patients and 14 months for persistent atrial fibrillation patients). There were a total of 37 (18%) complications, 8 (3.9%) were categorized as major complications, all without permanent sequels. The most common complication was phrenic nerve palsy which occurred in 14 (6.8%) patients.
Conclusion: Long-term outcomes in this study suggest that the pulmonary vein isolation using the cryoballoon technique is relatively an effective method especially in the treatment of paroxysmal atrial fibrillation.
Keywords: Atrial fibrillation; Catheter ablation; Complications; Cryoballoon; Efficacy.