Bonus vs No Bonus Cryoballoon Isolation for Paroxysmal Atrial Fibrillation Ablation

To evaluate the benefit of Bonus freeze using second generation cryoballoon after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF).

A bonus freeze is performed after proven pulmonary vein isolation (PVI) for cryoballoon ablation of paroxysmal atrial fibrillation (PAF) as standard. In the current study, no additional freeze (No Bonus) after PVI was compared with additional freeze (Bonus) after PVI using second generation cryoballoon.

A total of 136 patients (mean age 58 ± 13 years, 76 male) were included. No Bonus and Bonus groups had 56 and 80 patients, respectively. Follow-up electrocardiography and Holter monitoring were performed at 1, 3, 6, 12 months, and biannually thereafter. The PVI rate was similar after the initial ablation (82% in No Bonus group, 80% in Bonus group, p>0.05) and, at the end of the procedure (99% in No Bonus group and 99% in Bonus group, p>0.05). The median procedure and fluoroscopy times in No Bonus group were 67 (60-74) minutes and 13 (10-15) minutes, which were significantly shorter than the median durations, 85 (76-90) minutes and 17 (15-21) minutes in Bonus group, respectively (all p<0.001). Phrenic nerve palsy was observed less frequently in No Bonus group compared to Bonus group (1 patient (2%) vs. 5 patients (6%), respectively) without statistically significant difference. During a median follow-up of 13 (11-15) months, the rates of patients free from AF were 82% in No Bonus group and 84% in Bonus group, respectively (p>0.05).

The rate of sinus rhythm at 18 months was similar in patients with PAF who received bonus cryoablation vs patients who did not receive bonus cryoablation.