Prevalence and the clinical outcome of atrial fibrillation in patients with Autoimmune Rheumatic Disease

Background: Systemic inflammation plays an important role in the pathogenesis of atrial fibrillation (AF). However, little evidence exists whether the risk of AF is increased in autoimmune rheumatic disease (ARD). Methods: In 20,772 consecutive ARD patients (mean age 42 ± 17 years, 13,683 female) in a tertiary hospital from 2005 to 2015, AF prevalence, comorbidities and cardiovascular (CV) outcomes were evaluated. Results: AF was observed in 235 (1.1%) patients. The mean duration to AF diagnoses was 5.9 ± 2.4 years. Compared with patients without AF, AF patients were older, and had a higher CRP level (5.1 ± 0.7 vs. 2.7 ± 0.2 mg/L, p = 0.01), higher incidence of hypertension, heart failure and coronary artery disease. The AF prevalence was higher in inflammatory myositis (3.5%) and systemic sclerosis (2.3%) than that in other ARDs (all p < 0.05). In the multivariate analysis, the independent predictors of AF were an older age (HR 1.05, 95% CI: 1.04-1.06, p = 0.01), hypertension (HR 2.28, 95% CI: 1.70-3.06, p < 0.001), high CRP levels (HR 1.75, 95% CI: 1.07-2.86, p = 0.04), and heart failure (HR 11.96, 95% CI: 8.13-17.60, p = 0.03). During a mean follow-up period of 6.8 ± 4.5 years, ARD patients with AF had a higher all cause death (16.5% vs. 2.1%, p < 0.001) and incidence of strokes (1.9% vs. 0.4%, p = 0.001) than non-AF patients. Conclusions The incidence of AF in ARD was affected by specific disease and an inflammatory status manifested by the CRP level. AF in ARD was related to a higher mortality and strokes mandating meticulous follow-up.