Pulmonary vein isolation in patients with paroxysmal atrial fibrillation : Long-term clinical outcomes with first- and second-generation cryoballoons.

BACKGROUND: The aim of this study was to evaluate the long-term success rates of pulmonary vein isolation (PVI) using only first-generation cryoballoon (CB-1) and second-generation CB (CB-2) in patients with paroxysmal atrial fibrillation (PAF).

PATIENTS AND METHODS: A total of 114 drug-refractory patients with PAF (mean age: 62 ± 10 years; 62.3 % males) were enrolled. All index ablation procedures were performed using a 28-mm CB. All patients were scheduled for outpatient clinic visits, followed by 24-h or 7‑day Holter electrocardiogram (EGC) evaluation.

RESULTS: All PVs in the CB-1 group and 367 of 368 (99.7 %) PVs in the CB-2 group were completely isolated during the index procedure. The most commonly observed complication was phrenic nerve palsy in four (4.3 %) patients with CB-2. The mean follow-up period for CB-1 and CB-2 was 33.4 ± 14.9 and 27.2 ± 10.6 months, respectively. Freedom from AF was 42.9 % for CB-1 and 74.2 % for CB-2 at the end of the follow-up period. The European Heart Rhythm Association score improved in patients without AF recurrence after the procedure (2.8 ± 0.4 vs. 1.2 ± 0.5, p < 0.001), whereas no significant improvement was observed in the symptomatic status of patients with recurrence (2.8 ± 0.4 vs. 2.2 ± 0.9, p = 0.149).

CONCLUSION: Second-generation CB provided significantly better clinical outcomes than its predecessor and was associated with low peri- and postprocedural complications.