title: Long-term efficacy of amiodarone therapy for the prevention of recurrence of paroxysmal atrial fibrillation. Analysis based on patient characteristics.
abstract: There is little information available on factors affecting the long-term prevention of paroxysmal atrial fibrillation (AF) in the Japanese population. A total of 71 patients (49 men, mean age, 68 ± 8 years) with paroxysmal AF refractory to ≥ 2 class I antiarrhythmic drugs received oral amiodarone (50-200 mg/day). All patients were observed for more than 12 months (mean follow-up period, 47 ± 26 months) and were analyzed on the basis of patient profiles. The percentage of patients with AF recurrence despite amiodarone therapy was 54% in all patients. In multivariate logistic regression analysis adjusted for age and sex, the following factors were associated with preventive efficacy for AF recurrence: left ventricular ejection fraction (LVEF) (relative risk [RR] 0.933, 95% confidence interval [CI] 0.877-0.993, P = 0.029), asymptomatic AF (RR 0.068, CI 0.005-0.870, P = 0.039), and AF occurring irrespective of circadian variation (RR 0.115, CI 0.013-0.988, P = 0.049). The percentage of patients with conversion to permanent AF despite amiodarone therapy was 31% in all patients. In multivariate logistic regression analysis adjusted for age and sex, asymptomatic AF (RR 0.085, CI 0.010-0.732, P = 0.025) was the only factor associated with preventive efficacy for conversion to permanent AF. Amiodarone appears to be effective in maintaining sinus rhythm, especially in patients with impaired left ventricular function. In contrast, amiodarone appears to be refractory in those with asymptomatic AF or AF occurring irrespective of circadian variation.
authors.affiliation: Division of Cardiology, Department of Internal Medicine and Memorial Heart Center, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka, Iwate, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Komatsu
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tachibana
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sato
authors.forename: Mahito
authors.initials: M
authors.lastname: Ozawa
authors.forename: Fusanori
authors.initials: F
authors.lastname: Kunugita
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Nakamura
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000638:Amiodarone / Q000008:administration & dosage*; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage*; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D004305:Dose-Response Relationship, Drug; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D055502:Secondary Prevention; D013318:Stroke Volume / Q000187:drug effects; D013614:Tachycardia, Paroxysmal / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone