Background: The present study was conducted to determine the antiarrhythmic efficacy and safety of oral pilsicainide, a class Ic antiarrhythmic drug, in patients with persistent atrial fibrillation (AF).
Methods and results: One hundred and eight patients (mean age, 58.9 years) with AF lasting >or=48 h and <or=6 months were randomized to receive pilsicainide 50 mg t.i.d. (n=58) or placebo (n=50) for 2 weeks in a double-blinded fashion. All patients underwent appropriate anticoagulation therapy with warfarin for >or=3 weeks prior to the study enrolment or after verification of the absence of left atrial thrombi by transesophageal echocardiography. After 2 weeks of treatment, an electrocardiogram was recorded to determine whether sinus rhythm was restored. Sinus rhythm was restored in 22.4% of patients treated with pilsicainide and in 2% treated with placebo (p=0.002). Cardioversion was less likely to occur with oral pilsicainide when the AF duration exceeded 2 months or if the left atrial diameter exceeded 45 mm. There was no significant difference in the adverse cardiovascular event rate between the pilsicainide- and placebo-treated groups. One patient in the pilsicainide group developed an atrial flutter without any hemodynamic deterioration.
Conclusion: A 2-week oral administration of pilsicainide is well tolerated and moderately effective in converting persistent AF into sinus rhythm.