Long-Term Hydroxychloroquine Therapy and Risk of Coronary Artery Disease in Patients with Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic systemic inflammatory disease associated with a high prevalence of cardiovascular disease (CVD). Hydroxychloroquine (HCQ) is commonly used to control disease activity in patients with SLE. We evaluated its potential additional therapeutic effect for reducing CVD in SLE patients. We conducted a retrospective cohort study, in which one million participants were sampled from 23 million beneficiaries and data were collected from 2000 to 2013. In total, 826 SLE patients receiving HCQ medication were included after exclusion for previous CVD. The total number of SLE patients was 795 after follow-up for more than one year. After adjusting for chronic comorbidity, a significantly decreased hazard ratio (HR) for coronary artery disease (CAD) was found among SLE patients with a high usage of HCQ for at least 318 days (HR = 0.31, 95% confidence interval, CI: 0.12-0.76). A low HR for CAD was observed in SLE patients with a high cumulative dose of at least 100,267 mg HCQ (HR = 0.25, 95% CI: 0.09-0.66). However, there was no significant lowering of the HR for stroke. Long-term HCQ therapy decreases the HR of CVD in SLE patients. The cardiovascular protective effect of HCQ therapy was associated with decrease in CAD, but not stroke.