201 Pulmonary vein isolation by cryoballoon ablation in patients with paroxysmal atrial fibrillation: efficacy, safety and predictors of arrhythmia recurrence

Introduction Radiofrequency (RF) catheter ablation has emerged as an effective treatment for patients with drug-refractory atrial fibrillation (AF). The objective of this study is to evaluate the efficacy and safety of pulmonary vein isolation (PVI) with a cryoballoon catheter (Arctic Front, Cryocath, Quebec, Canada). Methods In 44 consecutive patients with symptomatic paroxysmal AF (28 males, age 57 +/− 11 years), circumferential PVI was performed using a cryoballoon catheter. Before discharge, all patients were subjected to 24-hour Holter electrocardiograms, echocardiography, and esophageal endoscopy. Magnetic resonance imaging was performed prior to and 3 months after ablation. At a mean follow up of 4.3 +/− 1.2 months after ablation, patients underwent clinical review and 24-hour Holter electrocardiograms. Clinical and demographic variables were analyzed via logistic regression to assess for predictors of recurrence. Results Thirty-two of the 44 patients (73%) had complete isolation of all PVs. Out of 176 treated veins, 164 were completely isolated (93%). The number of balloon applications per vein was 2.3 ± 0.8. The mean procedure and fluoroscopy times were 163.4 ± 36.2 and 32.0 ± 11.7 min, respectively. Eight patients had evidence of mild pericardial effusions requiring no further treatment. Five patients (11.4%) experienced phrenic nerve palsy, 4 of which resolved immediately and one at 2 weeks. Follow up at 4.3 +/− 1.2 months showed freedom from AF in 28 patients (63.6%) and freedom from AF without antiarrhythmic drug therapy in 19 patients (43.2%). Of all clinical variables analyzed, only early recurrence of AF within 4 days post ablation was associated with long term AF recurrence (p = 0.002; OR = 0.11; CI = [0.018–0.524]). Conclusion PVI can be safely achieved with the cryoballoon catheter with a moderate success rate at 4.3 months follow-up. Early recurrence of AF seems to be a clinical predictor for long term atrial fibrillation recurrence.