Hydroxychloroquine use is associated with reduced mortality risk in older adults with rheumatoid arthritis

Background: There is little robust data about the cardiovascular safety of hydroxychloroquine in patients with rheumatoid arthritis (RA), who often have cardiovascular comorbidities. We examined the association between use of hydroxychloroquine (HCQ) in patients with RA and major adverse cardiovascular events (MACE). Methods: In a retrospective cohort of Medicare beneficiaries aged ≥ 65 years with RA, we identified patients who initiated HCQ (users) and who did not initiate HCQ (non-users) between January 2015-June 2017. Each HCQ user was matched to 2 non-users of HCQ using propensity score derived from patient baseline characteristics. The primary outcome was the occurrence of MACE, defined as acute admissions for stroke, myocardial infarction, or heart failure. Secondary outcomes included all-cause mortality and the composite of MACE and all-cause mortality. Cox proportional hazards model was used to compare outcomes between HCQ users to non-users. Results: The study included 2380 RA patients with incident HCQ use and matched 4633 HCQ non-users over the study period. The mean follow-up duration was 1.67 and 1.63 years in HCQ non-users and users, respectively. In multivariable models, use of HCQ was not associated with the risk of MACE (hazard ratio 1.1; 95% CI: 0.832–1.33). However, use of HCQ was associated with a lower risk of all-cause mortality (HR: 0.54; 95% CI: 0.45–0.64) and the composite of all-cause mortality and MACE (HR 0.67; 95% CI: 0.58–0.78). Conclusion: HCQ use was independently associated with a lower risk of mortality in older adults with RA but not with incidence of MACE events. Key Points • Using an incident user design (to avoid the biases of a prevalent user design) and a population-based approach, we examined the effect of hydroxychloroquine (HCQ) on the risk of major cardiovascular events (MACE) in older patients with RA.• We did not find an association between HCQ use and incident MACE. We did, however, find a significant association with the composite outcome (MACE and all-cause mortality) driven by a significant reduction in all-cause mortality with HCQ use.