Use of hydroxychloroquine and risk of major adverse cardiovascular events in patients with lupus erythematosus: A Danish nationwide cohort study.

Background: Limited data suggest that hydroxychloroquine may affect risk of cardiovascular disease in patients with lupus erythematosus (LE).

Objective: To investigate whether hydroxychloroquine treatment is associated with major adverse cardiovascular events (MACE) (myocardial infarction, ischemic stroke, or cardiovascular-associated death) in patients with cutaneous LE (CLE) or systemic LE (SLE).

Methods: Based on the Danish nationwide registers, an observational cohort study was conducted including patients with first-time diagnosis of CLE or SLE (between 1997 and 2017). Cox regression models calculating the hazard ratio (HR) analyzing the risk of MACE were performed comparing time on and off hydroxychloroquine (including never users). The models were adjusted for age, sex, socioeconomic status, concomitant treatment, and cardiovascular risk factors.

Results: Among 4587 patients with LE, 51% (n = 2343) were treated with hydroxychloroquine during the study period. An inverse association between use of hydroxychloroquine and MACE risk was observed among patients with SLE (adjusted HR, 0.65; 95% confidence interval, 0.46-0.90) and patients with CLE (adjusted HR, 0.71; 95% confidence interval, 0.42-1.19). Consistent results were found in sensitivity analyses including a case-time control design.

Limitations: No information on disease activity/severity was available.

Conclusion: Our findings indicate an opportunity to reduce the risk of cardiovascular events in patients with LE through use of hydroxychloroquine.