AIM   To explore the risk factors of nifekalant cardioversion failure after catheter ablation of atrial fibrillation.

  METHODS  We performed a retrospective case-control study involving patients with drug-refractory, persistent atrial fibrillation who underwent their first catheter ablation procedure in the Department of Cardiology, the First Affiliated Hospital of Air Force Medical University from November 2020 to January 2022. The patients were assigned to nifekalant group (n=47) and electrical cardioversion group (n=46) based on the results of post-ablation nifekalant cardioversion. Baseline characteristics were described and then univariable and multivariable Logistic regression analyses were sequentially used to find out the independent predictors of nifekalant cardioversion failure.

  RESULTS  Compared with the electrical cardioversion group, nifekalan group had shorter course of AF, lower CHA₂DS₂ VASC score and lower prevalence of diabetes (all P<0.05). There was no statistical difference in other indexes between the two groups, and no adverse drug reactions such as ventricular tachycardia were found. Univariable Logistic regression analysis showed that age ≥65 years old, cha2ds2 VASC score ≥ 2 points, long-standing persistent atrial fibrillation and diabetes were the potential risk factors affecting the efficacy of nifekaran cardioversion. Multivariable Logistic regression analysis excluding mediators showed that age ≥ 65 years old and diabetes mellitus were independent predictors of nifekaran cardioversion failure. Failure of nifekaran cardioversion did not increase the incidence of early recurrence of atrial fibrillation.

  CONCLUSION  This study preliminarily provides evidences that age ≥65 years and diabetes mellitus are the independent predictors of post-ablation nifekalant cardioversion failure. Electrical cardioversion is recommended for these patients directly after catheter ablation.