1. Introduction
Rheumatoid arthritis (RA) is an autoimmune disease characterized by
synovial inflammation, which mainly affects the peripheral joints with
symmetric distribution1. Cardiovascular diseases
(CVDs) are some of the leading causes of death in patients with
RA2. In fact, the risk of sudden cardiac death was
doubled in patients with RA compared to those without
RA3,4. Pathological findings in cardiovascular
examinations are frequently observed during the course of RA and are
important factors that contribute to mortality2,3.
Several studies have reported that patients with RA have a higher risk
of developing atherosclerosis and cardiac
arrhythmias5,6. RA is not only involved in the
development of CVDs but also accelerates disease progression. Clinical
and pathological evidence suggest that RA may be associated with chronic
inflammation and immune dysregulation during the disease
course7,8.
Electrocardiography (ECG) changes have been reported in patients with RA
and other autoimmune diseases. For example, ST-T abnormalities have been
observed in patients with systemic lupus erythematosus (SLE), and
corrected QT (QTc) prolongation was observed in patients with RA and
SLE9. Although the mechanisms for such changes have
not been elucidated, it is suggested that systemic inflammation may
directly result in electrophysiological changes or indirectly result in
structural changes of the heart; these changes are associated with
arrhythmias and/or worse cardiovascular outcomes in both the general
population and RA patients5.
In this study, we aimed to investigate the ECG characteristics of
patients with RA and the association between QTc interval and disease
activity in these patients using a Japanese population-based RA cohort,
the Kyoto University Rheumatoid Arthritis Management Alliance (KURAMA)
study.