Comparison of the efficacy and safety of different doses of nifekalant in the instant cardioversion of persistent atrial fibrillation during radiofrequency ablation.

Nifekalant has been used in the treatment of atrial arrhythmia recently. However, there is no consensus on the preferable nifekalant dose to treat atrial fibrillation (AF). The purpose of this study was to explore efficacy and safety of different doses of nifekalant in the cardioversion of persistent AF. The study was a single-centre, randomized controlled trial. All subjects received nifekalant or placebo intravenously, and the nifekalant was given at the dosage of 0.3, 0.4 or 0.5 mg/kg. Primary efficacy end-point: compared with 0.3 mg group, the rate of cardioversion to sinus rhythm from AF in 0.4 and 0.5 mg group was higher. The 0.4 and 0.5 mg/kg doses were associated with a similar magnitude of efficacy (P > .05). Secondary efficacy end-point: termination rates of AF in the group of 0.4 mg and 0.5 mg were higher than 0.3 mg. Primary safety end-point: the rate of Torsades de Pointes or ventricular fibrillation was numerically lower in the 0.4 mg group than 0.5 mg group (P = .02). Secondary safety end-point: The rates of the majority of other common drug-related adverse events in the group of 0.5 and 0.4 mg were higher than the 0.3 mg group. A 0.4 mg/kg dose of intravenous nifekalant may be recommended during the radiofrequency ablation for persistent AF considering the benefit-risk profile.