Abstract 19559: Risk of Atrial Fibrillation is Increased in Patients with Autoimmune Vasculitis: A Population-Based Cohort Study

Abstract

Introduction Current evidence suggests that abnormal ventriculo-vascular coupling may contribute to the development of atrial fibrillation (AF) by increasing ventricular filling pressures and consequently, left atrial pressure. Recent investigations have also suggested that inflammation might have a role in the pathophysiology of AF. We hypothesize that autoimmune vasculitis plays a significant role in the pathogenetic mechanism of AF. Methods In this longitudinal cohort study, residents of Olmsted County, MN with first- time diagnosed AF during 1980-2000 and a reference age- and sex-matched control group from the same underlying population and time period were identified and followed until death, or 2000. The relationship between autoimmune vasculitis and first documented AF was analyzed. Results Of a total of 8766 patients (mean age 61.1+14.9 years; 56% women), 691 (7.9%) were diagnosed with autoimmune vasculitis during the 20 year period. The prevalence of autoimmune vasculitis in the AF group was 9.9% and 5.9% in the control group; p <0.001, respectively. After adjusting for CAD and LV dysfunction, the odds of autoimmune vasculitis in AF was 1.7 times higher than in controls (OR 1.69, 95%; CI 1.42 - 2.01, p < 0.0001). AF patients with autoimmune vasculitis had a worse survival compared to controls; p=.0114 (log-rank test). Conclusion Autoimmune vasculitis strongly increases the risk of atrial fibrillation and portends shorter survival in the AF population. These observations may represent one mechanism linking increased arterial stiffness and inflammation in the pathogenesis and prognosis of AF as an age-related disorder.