Risk for cardiovascular disease in Japanese patients with rheumatoid arthritis: a large-scale epidemiological study using a healthcare database

OBJECTIVES To study risk for cardiovascular disease (CVD) in Japanese patients with rheumatoid arthritis (RA). METHODS We used a Medical Data Vision database mainly composed of health insurance claim data and diagnosis-procedure combination data from Japan. Patients with RA diagnosed from April 2011 to March 2014 at 71 hospitals were identified with the International Classification of Diseases 10th revision (ICD-10) and history of anti-RA drug prescription. Hospitalizations for CVD including ischemic heart disease, heart failure, and stroke were identified by a combination of diagnosis (ICD-10) and diagnostic procedures. CVD incidence rate ratio (IRR) for RA versus osteoarthritis was calculated. Risk factors were analyzed using univariate and multivariate Cox proportional hazard models with baseline C-reactive protein (CRP) and traditional risk factors as covariates. RESULTS We identified 8658 patients with RA. The age-sex adjusted IRR for RA versus osteoarthritis was high for total CVD [2.12; 95 % confidence interval (CI) 1.93-2.32], ischemic heart disease (2.16; 95 % CI 1.86-2.50), heart failure (2.34; 95 % CI 2.07-2.65), and stroke (1.68; 95 % CI 1.41-2.00). Risk factor analysis showed a tendency for cardiovascular risk to increase with higher baseline CRP, although the difference was not statistically significant (hazard ratio 1.43; 95 % CI 0.99-2.07). CONCLUSION Our study indicates an increased risk for CVD and an association between systemic inflammation and CVD in Japanese RA patients.