Comparison of radiofrequency ablation versus cryoballoon ablation for paroxysmal atrial fibrillation: A nonrandomized controlled study (English version)

Background: In recent years, catheter ablation has been widely used in the treatment of paroxysmal atrial fibrillation (AF). Radiofrequency ablation has long been standard of care, whereas cryoballoon ablation has emerged as a new alternative for the treatment of paroxysmal AF. The present study aims to investigate the efficacy and safety of radiofrequency ablation and cryoballoon ablation for paroxysmal AF. Subjects and Methods: This retrospective nonrandomized controlled study consecutively enrolled 582 patients with paroxysmal AF who underwent radiofrequency ablation or cryoballoon ablation for the first time in Nanjing Drum Tower Hospital from September 2014 to October 2018. The enrolled patients were divided into four groups according to the ablation energy source used and instruments: normal saline irrigation catheter group (Group A), contact force-sensing catheter group (Group B), first-generation cryoballoon group (Group C), and second-generation cryoballoon group (Group D). The procedure time, X-ray exposure time, procedural complications, and 1-year recurrence rate were observed. This study was approved by the Medical Ethics Committee of Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, China (approval No. 2014-190-01) on August 6, 2014. Results: There were no significant differences in baseline patient characteristics among the four groups. There were significant differences in the procedure times among Groups A, B, C, and D (163.6 ± 49.3, 142.4 ± 40.5, 136.6 ± 30.4, and 114.6 ± 24.2 min, respectively; P < 0.01). Moreover, the significant difference also existed in the X-ray exposure times among Groups A, B, C, and D (22.2 ± 8.4, 13.6 ± 8.7, 31.5 ± 7.3, and 26.5 ± 8.5 min, respectively; P < 0.01). In terms of procedural complications, the incidence of phrenic nerve palsy in patients who underwent cryoballoon ablation in Groups C and D was significantly higher than that under radiofrequency ablation in Groups A and B (P < 0.05), and there were no significant differences in the incidence of other procedural complications. The 1-year recurrence rates of AF/atrial flutter/atrial tachycardia in Groups A, B, C, and D were 23.8%, 15.4%, 15.1%, and 11.6%, respectively. Among them, the recurrence rates in Groups B and D were significantly lower than that in Group A (P < 0.05). Conclusions: The efficacy of a contact force-sensing catheter or second-generation cryoballoon in the treatment of paroxysmal AF is better than that of normal saline irrigation catheter. Both radiofrequency ablation and cryoballoon ablation are safe, and phrenic nerve palsy is a complication that requires special attention for cryoballoon ablation.