Initiating Hydroxychloroquine for RA and SLE Does Not Increase Arrhythmia Risk

Initiation of hydroxychloroquine use does not increase the risk for any type of arrhythmias in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), according to study findings published in Arthritis & Rheumatology.

The aim of the study was to determine the association between hydroxychloroquine use and risk for incident arrhythmia among patients with RA and SLE.

Researchers conducted a retrospective cohort study between January 1996 and December 2014 in British Columbia, Canada. They matched individuals who were initiated on treatment with hydroxychloroquine with those who were not initiated on treatment with hydroxychloroquine. A follow-up was conducted for a mean period of 8 years, comparing the incidence rate of arrhythmias in each group.

The primary study outcome was overall incident arrhythmic events, including atrial fibrillation, prolonged QT syndrome, and conduction disorder.

A total of 11,518 patients (10,655 with RA and 863 with SLE) who were initiated on hydroxychloroquine were propensity-matched with 11,518 patients (10,639 with RA and 879 with SLE) who were not initiated on hydroxychloroquine. During the follow-up period, 1610 (14%) patients receiving hydroxychloroquine and 1646 (14.3%) patients who were not receiving hydroxychloroquine developed incident arrhythmia.

Both the groups demonstrated similar overall risk for arrhythmias (adjusted cause-specific hazard ratio [cHR], 0.96; 95% CI, 0.89-1.03). The incidence rate for developing different types of arrhythmias, such as atrial fibrillation (cHR, 0.93; 95% CI, 0.83-1.04), abnormal electrocardiograms, including prolonged QT syndrome and conduction disorder (cHR, 0.98; 95% CI, 0.87-1.11), and other unspecified cardiac arrhythmias (cHR, 0.95; 95% CI, 0.84-1.07), did not differ between the 2 groups.

Study limitations included the possible misclassification of RA and SLE, which may have affected effect size estimation and missing data regarding important baseline characteristics, such as smoking status, disease activity, and body mass index.

“Hydroxychloroquine is an invaluable medication for RA and SLE patients with known clinical benefits such as reduction of risk of disease flares and organ damage,” the study authors said. “Our study…found no safety issue for [hydroxychloroquine] regarding the risk of arrhythmias.”

Reference

Hoque MR, Lu L, Daftarian N, Esdaile JM, Xie H, Aviña-Zubieta JA. Risk of arrhythmia among new users of hydroxychloroquine in RA and SLE: A population-based study. Arthritis Rheumatol. Published online August 23, 2022. doi:10.1002/art.42337