[A comparison between flecainide and sotalol in the prevention of recurrences of paroxysmal atrial fibrillation]

Abstract

Objectives: Aim of the present study was to assess the efficacy and safety of flecainide (F) and sotalol (S) for the prevention of recurrences of paroxysmal atrial fibrillation (PAF).

Methods: Sixty-six patients with PAF (> or = 3 episodes of atrial fibrillation in the last year) in sinus rhythm, were randomized to pharmacological oral treatment with F (20 patients-Group A), with S (20 patients-Group B) and placebo (P) (26 patients-Group C). During the follow-up (one year duration) were evaluated on I, III, VI and XII months the number and tolerance of the atrial fibrillation recurrences, cardiac and/or noncardiac side effects. The patients with more than two recurrences in the same follow-up interval withdrew from the study. In each patient 14 clinical and laboratory variables were evaluated.

Results: After 12 months were arrhythmia-free respectively 70% of Group A patients, 60% of Group B patients, 27% of Group C patients. Univariate analysis showed that treatment with F was related to decrease of atrial fibrillation recurrences (one recurrence 67%, two recurrences 81%, three recurrences 81%), treatment with S was related to decrease of recurrences (two recurrences 59%); the variable most significantly related to the risk of arrhythmia recurrence is the higher value of basal cardiac rate (one recurrence t = 2.15, two t = 2.22, three t = 2.96, four t = 2.06). There was not statistically significant difference in maintenance of sinus rhythm at the end of the follow-up between the groups of patients on F and S (p = 0.163); treatment efficacy was significantly higher than P (p = 0.002). Multivariate analysis showed that treatment with F and S decreases the risk of arrhythmia recurrence respectively of 85% and 76% versus placebo at the end of the follow-up. The incidence of cardiac and/or noncardiac side effects was not clinically significant.

Conclusion: F and S are both effective and safe for prevention of PAF, with 70% and 60% respectively of patients arrhythmia-free after 12 months of treatment. Side effects were common, but clinically significant adverse events were uncommon. A higher value of basal cardiac rate was predictive of atrial fibrillation recurrences in the patients during treatment.