[Propafenone and sotalol: long-term efficacy and tolerability in the prevention of paroxysmal atrial fibrillation. A placebo-controlled double-blind study].

BACKGROUND: Atrial fibrillation is a relatively frequent atrial arrhythmias activated with increased morbidity and mortality.

METHODS: To assess the propafenone and sotalol efficacy in the prevention of paroxysmal atrial fibrillation (FA) we enrolled, in a double blind placebo controlled study over 1 year, 300 patients (168 males); mean age 52.3 +/- 17.2 years, randomized to receive orally, three times daily, either propafenone (mean daily dose of 13 +/- 1.5 mg/Kg; Group A: 102 patients) or sotalol (mean daily dose of 3 +/- 0.4 mg/Kg; Group B: 106 patients) or placebo (Group C: 92 patients). All subjects experienced in previous 12 months at least 4 FA episodes. During follow-up we considered atrial tachyarrhythmia (TAA) onset: FA recurrences and/or the onset of atrial flutter (FIA). Three patients (3%) of Group A and 5 (5%) of Group B interrupted therapy for side effects; 5 patients (5.5%) of Group C with supraventricular tachycardia interrupted the double blind therapy; 11 were lost to follow-up.

RESULTS: Of the remaining 276 patients, TAA were observed in 43 (44.8%) of 96 patients in Group A, 28 (29.5%) of 95 patients in Group B and 62 (72.9%) of 85 patients in Group C. TAA were significantly less in A and B groups than in Group C (p < 0.005); a significant TAA reduction was also observed in patients treated with sotalol compared with those treated with propafenone (p < 0.05). TAA were: FA-118 (88.7%) and FIA-15 (11.3%). The arrhythmia free time was significantly shorter in Group C.

CONCLUSIONS: Sotalol seems to be more effective than propafenone and therefore represents a valid alternative for FA prevention.