[Long-term preventive effect and safety of amiodarone in patients with paroxysmal atrial fibrillation refractory to class I antiarrhythmic agents: analysis based on patient profiles].

OBJECTIVES AND METHODS: The factors controlling the preventive effect of long-term amiodarone therapy were evaluated in patients with paroxysmal atrial fibrillation. The 55 patients (37 men and 18 women, mean age 68 +/- 9 years) with paroxysmal atrial fibrillation refractory to more than two types of Class I antiarrhythmic agents received amiodarone (100-200mg/day) after electrical or pharmacological cardioversion. All patients were observed for 12 months or more (mean follow-up period 48.6 +/- 29.1 months). RESULTS: Actuarial recurrence-free rate at 12 months in patients with ejection fraction < 55% (76.5%, n = 17) was significantly higher than that in patients with ejection fraction > or = 55% (44.7%, n = 38) (p = 0.0411), and tended to be higher in patients with underlying heart disease (65.5%, n = 29) than in patients without underlying heart disease (42.3%, n = 26) (p = 0.0980). Age, sex, diabetes mellitus, alcohol intake, hypertension, hyperlipidemia, and administration of angiotensin converting enzyme inhibitor were not related to the effect of amiodarone. Relative risk reduction of recurrence after amiodarone therapy was 4.01 (95% confidence interval 3.57-4.45) in patients with ejection fraction < 55%, and 2.59 (95% confidence interval 2.07-3.11) in patients with underlying heart disease. None of the above-mentioned factors was related to the development of adverse effects. The incidence of adverse effects requiring discontinuation in all patients was 7.3%. CONCLUSIONS: Amiodarone was more effective for preventing recurrence in patients with poorer left ventricular function and underlying heart disease.

[Relationship between efficacy of antiarrhythmic drug therapy and structural remodeling in patients with paroxysmal atrial fibrillation].

OBJECTIVES: To evaluate whether the response to antiarrhythmic drug therapy in patients with paroxysmal atrial fibrillation affects the development of structural remodeling in the left atrium and ventricle. METHODS: This study included 230 patients (158 men and 72 women, mean age 67 +/- 11 years) in whom antiarrhythmic drug therapy was attempted for > or = 12 months to maintain sinus rhythm (mean follow-up period 45 +/- 27 months). The patients were divided into three groups according to the response to antiarrhythmic drug therapy: group A consisted of 78 patients without recurrence of atrial fibrillation, group B consisted of 87 patients with recurrence of atrial fibrillation and electrical and/or pharmacological cardioversion to restore sinus rhythm, and group C consisted of 65 patients with permanent conversion despite antiarrhythmic drug therapy. RESULTS: In group A, left atrial dimension (LAD), left ventricular end-diastolic dimension (LVDd), and left ventricular ejection fraction (LVEF) did not change after antiarrhythmic drug therapy. In group B, LAD increased significantly after antiarrhythmic drug therapy (from 32.6 +/- 6.4 to 36.0 +/- 6.5 mm, p < 0.01), Whereas either LVDd or LVEF did not change after antiarrhythmic drug therapy. In group C, LAD increased significantly after antiarrhythmic drug therapy (from 37.3 +/- 7.0 to 40.5 +/- 7.9 mm, p < 0.01) and LVEF was significantly reduced after antiarrhythmic drug therapy (from 69.4 +/- 6.2% to 66.5 +/- 8.9%, p < 0.05). LVDd did not change after antiarrhythmic drug therapy. The plasma concentration of human atrial natriuretic peptide during sinus rhythm at the initiation of antiarrhythmic drug therapy in group A (30.5 +/- 26.7 pg/ml) was significantly lower than those in group B (48.0 +/- 49.7 pg/ml) and group C (49.7 +/- 39.5 pg/ml). CONCLUSIONS: The development of structural remodeling in human myocardium can be prevented with antiarrhythmic drug therapy if sinus rhythm is maintained without recurrence of atrial fibrillation in patients with paroxysmal atrial fibrillation.

Long-term prognosis of patients with paroxysmal atrial fibrillation depends on their response to antiarrhythmic therapy.

BACKGROUND: The rhythm control treatment strategy for persistent atrial fibrillation (AF) has been shown not to improve quality of life or prognosis any more than rate control. It is unclear whether the prognosis of the patients with paroxysmal AF (PAF) is influenced by the response to antiarrhythmic drug therapy (AAT). METHODS AND RESULTS: The relationship between the response to AAT and long-term prognosis was evaluated in 290 patients with PAF (mean age, 69 years). During a mean follow-up period of 51 months, 114 patients (39%) had no recurrence of AF (Group 1), 113 (39%) had repeated AF recurrence (Group 2), and the remaining 63 (22%) had permanent AF despite AAT (Group 3). The survival rate without any cardiovascular deaths at 60 months was 99% in Group 1, 95% in Group 2 and 94% in Group 3 (p=NS among 3 groups). Survival rate without symptomatic ischemic stroke was 99% in Group 1, 88% in Group 2 and 76% in Group 3 (p<0.05 Group 1 vs Groups 2 and 3). The annual rate of stroke in the patients with warfarin treatment was similar among the 3 groups, whereas that in the patients without warfarin was higher in Groups 2 and 3 than in Group 1. CONCLUSIONS: Long-term prognosis of patients with PAF varies with the response to AAT: When sinus rhythm is maintained, the prognosis is good even without anticoagulation therapy.

[Relationship between duration of arrhythmia and subsequent preventive effect of disopyramide after cardioversion in patients with symptomatic paroxysmal and persistent atrial fibrillation].

OBJECTIVES: The relationship between the duration of arrhythmia and the subsequent long-term efficacy of disopyramide in preventing atrial fibrillation was investigated in patients with symptomatic paroxysmal and persistent atrial fibrillation. METHODS: A total of 60 patients (39 men, 21 women, mean age 65 +/- 11 years) were given disopyramide (300 mg/day) after electrical and pharmacological cardioversion based on American Heart Association Task Force on Practice Guidelines. The patients were divided into two types based on the duration of atrial fibrillation: conversion within 48 hr (group A, n = 35) and more than 48 hr (group B, n = 25) after the episode. Mean follow-up period was 47.1 +/- 28.7 months. RESULTS: Patient characteristics showed no statistically significant difference between groups A and B. The actuarial rates of maintenance of sinus rhythm at 1, 3, 6, 12, 18 and 24 months were 88.6%, 77.1%, 57.1%, 48.6%, 42.9% and 37.1%, respectively, in group A, and 72.0%, 44.0%, 28.0%, 16.0%, 12.0% and 8.0%, respectively, in group B. There was a significant difference in the rate at 24 months between groups A and B (p < 0.05). The periods for maintenance of sinus rhythm in groups A and B were 20.9 +/- 3.9 and 6.7 +/- 2.1 months, respectively, with a significant difference between groups A and B (p < 0.01). CONCLUSIONS: The efficacy of disopyramide in preventing the recurrence of atrial fibrillation varies with the duration of the previous episode. These results demonstrate that it is important to convert to normal sinus rhythm earlier to prevent the recurrence of atrial fibrillation in the long term.

[Comparison of the efficacies of disopyramide, cibenzoline and aprindine for the termination of paroxysmal and persistent atrial fibrillation in elderly and non-elderly patients].

OBJECTIVES: The relationship between the efficacy of the anticholinergic action of disopyramide, cibenzoline and aprindine and age was examined in patients with paroxysmal and persistent atrial fibrillation. METHODS: This prospective, randomized study included 278 patients (200 men, 78 women, mean age 61 +/- 11 years) divided into two groups; the non-elderly group (age below 60 years) and the elderly group (age over 60 years). Successful termination was defined as conversion of sinus rhythm within 30 min of intravenous administration of 50 mg disopyramide (n = 91), 70 mg cibenzoline (n = 93) or 100 mg aprindine (n = 94) in this prospective and randomized study. RESULTS: No statistically significant difference was found in patient characteristics between the three agents. 1) The rate of conversion to sinus rhythm after disopyramide administration in the non-elderly group(37.8%) was significantly higher than that in the elderly group (17.4%, p = 0.0361). 2) The rate of conversion to sinus rhythm after cibenzoline administration in the non-elderly group (62.2%) tended to be greater than that in the elderly group (43.8%, p = 0.0972). 3) The rate of conversion to sinus rhythm after aprindine administration in the non-elderly group (25.6%) was not significantly higher than that in the elderly group (18.2%, p = 0.4474). CONCLUSIONS: The anticholinergic action of antiarrhythmic agents has an effect on successful termination in non-elderly patients with paroxysmal and persistent atrial fibrillation.

[Relationship between long-term preventive efficacy of cibenzoline and atrial natriuretic peptide in patients with paroxysmal atrial fibrillation].

OBJECTIVES: The relationship between the long-term efficacy of the antiarrhythmic agent cibenzoline in preventing lone paroxysmal atrial fibrillation (PAf) and plasma concentrations of atrial natriuretic peptide (ANP) and catecholamine was investigated during sinus rhythm and PAf. METHODS: Plasma concentrations of ANP, epinephrine, norepinephrine and dopamine during sinus rhythm and PAf were measured in 87 patients (70 men, 17 women, mean age 64 +/- 11 years) with lone-PAf. All patients received cibenzoline (300 mg/day) after cardioversion, and they were divided into the no recurrence group (n = 28) and the recurrence group (n = 59). Mean follow-up period was 41 +/- 29 months. RESULTS: The plasma concentration of ANP was significantly higher during PAf (110.2 +/- 65.0 pg/ml) than during sinus rhythm (39.9 +/- 27.8 pg/ml, p < 0.01) for all patients. The concentrations of epinephrine, norepinephrine and dopamine during PAf were all similar to those during sinus rhythm. Patient characteristics showed no statistically significant difference between the no recurrence and recurrence groups. In the recurrence group, the incidence of thromboembolism was significantly higher (30.5% vs 10.7%) and the period of PAf was significantly longer (26.8 +/- 43.6 vs 12.4 +/- 21.2 months) than in the no recurrence group (both, p < 0.05). The plasma concentrations of ANP during sinus rhythm were similar in the no recurrence group (33.1 +/- 20.1 pg/ml) and the recurrence group (43.5 +/- 30.3 pg/ml), but was significantly higher during PAf in the no recurrence group (142.6 +/- 76.5 pg/ml) than in the recurrence group (95.8 +/- 54.2 pg/ml, p < 0.01). The ratio of ANP level during PAf to that during sinus rhythm in the no recurrence group (5.0 +/- 2.5) was significantly greater than that in the recurrence group (3.2 +/- 2.5, p < 0.01). CONCLUSIONS: Patients without recurrence of PAf under treatment with cibenzoline have preserved capacity of ANP secretion compared with patients with recurrence.