Prevalence of atrial fibrillation and associated factors in a population of long-term hemodialysis patients

Background: Hemodialysis (HD) is associated with cardiovascular structural modifications; moreover, during HD, rapid electrolytic changes occur. Both factors may favor the onset of atrial fibrillation. Methods: To define the prevalence of atrial fibrillation and identify associated factors, 488 patients on long-term HD therapy (age, 66.6 ± 13.4 years; men, 58.0%; duration of HD, 76.5 ± 84.3 months) were studied. Results: Atrial fibrillation was reported in 27.0% of patients; paroxysmal in 3.5%, persistent in 9.6%, and permanent in 13.9%. Clinical and echocardiographic variables were considered: patients with atrial fibrillation were older (71.8 ± 9.3 versus 64.7 ± 14.2 years; P <0.01), and its prevalence increased with age. Patients with arrhythmia had a longer duration of dialysis therapy (93.2 ± 100.5 versus 70.2 ± 76.7 months; P = 0.02). Atrial fibrillation was associated significantly with ischemic heart disease (P <0.01), dilated cardiomyopathy (P <0.01), acute pulmonary edema (P <0.05), valvular disease (P <0.05), cerebrovascular accidents (P <0.05), and predialytic hyperkalemia (P <0.05). Patients with atrial fibrillation more frequently showed left atrial dilatation (59.8% versus 34.5%; P <0.0001), and in these subjects, left ventricular ejection fraction was significantly lower (53.9% versus 57.4%; P = 0.029). No association was found between arrhythmia and hypertension or diabetes. Multivariate analysis confirmed that patient age (P <0.001), duration of HD therapy (P = 0.001), and left atrial dilatation (P <0.001) were associated with atrial fibrillation. Conclusion: Atrial fibrillation is much more frequent in HD patients than in the general population; age, duration of HD history, presence of some heart diseases, and left atrial dilatation are associated with the arrhythmia.