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

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.