Long-Term Efficacy of Amiodarone Therapy for the Prevention of Recurrence of Paroxysmal Atrial Fibrillation Analysis Based on Patient Characteristics

Abstract

SummaryThere 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. (Int Heart J 2011; 52: 212-217) Key words: Atrial fibrillation, Amiodarone, Prevention, Ejection fraction, Symptom A ccording to a large-scale epidemiological survey performed in western countries, atrial fibrillation (AF) is an independent risk factor for cardiovascular death, and the risk of such death is 2-3 times higher in patients with AF than in those with sinus rhythm. 1) AF is often encountered in routine medical practice and is an arrhythmia that should be actively treated and controlled, because it not only causes cardiovascular complications, including thromboembolism and heart failure, 2) but also decreases survival in patients with impaired left ventricular function.3) The number of patients with AF in the United States exceeded 5 million in 2000 and is expected to increase two to threefold over the next 50 years. 4) In Japan, the population is aging rapidly and the prevalence of AF among elderly persons aged 70 years or older is already around 3%. This is expected to increase to about 4.5% over the next 20 years. 5)We have previously reported a therapeutic limitation with class I antiarrhythmic drugs (AAD) in preventing recurrence of AF.6) In Japan, amiodarone (a class III antiarrhythmic drug) has been used to maintain sinus rhythm only in patients with paroxysmal and obstructive hypertrophic cardiomyopathy, although two large clinical trials have reported that the efficacy of amiodarone in preventing recurrence of paroxysmal and persistent AF is superior to ...

Obesity Is Associated With the Development of Interstitial Pneumonia Under Long-Term Administration of Amiodarone in Refractory Atrial Fibrillation Patients

“…Oral AMD is effective for refractory atrial fibrillation (AF). [1][2][3][4][5] Although serious lung injury such as interstitial pneumonia (IP) occasionally occurs (10%), the mortality rate is 2%. 2,6) In recent years, the administration of AMD has increased in AF patients, and serious complications such as interstitial pneumonia (IP) occasionally occur.…”

Current strategies of antiarrhythmic drug therapy for paroxysmal atrial fibrillation

“…It is likely that the wide variability in the percentage of patients successfully treated with antiarrhythmic drugs was caused by differences in patient profiles among the studies. It has been suggested that recurrence of AF is associated with aging [19,20], duration of AF episodes [21,21], AF history [23], increased left atrial dimension [21,22,24], the presence of underlying heart disease (e.g., valvular and ischemic heart diseases) [21,25], and circadian variation in AF onset (mixed AF type) [26], among other factors. Moreover, patients in Western countries receive different types of antiarrhythmic drugs at doses 1.5-to 2-fold higher than the standard doses in Japan.…”

Influence of Aerobic and Resistant Load on the Risk of Atrial Fibrillation in Arterial Hypertension and Paroxysmal Atrial Fibrillation

“…Все эти известные в настоящее время нейрогуморальные механизмы снижения АД участвуют также в патогенезе ФП [14]. Большинство исследований влияния физической нагрузки на сердечно-сосудис тую систему проведено использованием АН [8,9], и имеется только несколько исследований с применением РН [10].…”

“…Физическая активность -одна из главных компонентов лечения АГ [8]. В исследованиях, посвященных профилактике и лечению сердечно-сосудистых заболеваний в основном применялся аэробный тип нагрузки (АН) [9,10]; сравнительно недавно началось исследование влияния резистивной нагрузки (РН), т. е. с отягощениями, на профилактику и течение сердечно-сосудистых заболеваний [11].…”