Antimalarials and electrocardiographic alterations: New data bring confidence

Previous findings on the link between hydroxychloroquine and risk of arrhythmia have been contradictory, with low-level evidence-based results. To address this, Md Rashedul Hoque and colleagues in Arthritis Research Canada and Simon Fraser University ran a large cohort study. The group identified 11,518 hydroxychloroquine initiators with newly diagnosed with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE), and assessed the risk of incident arrhythmia. The results were presented at the 2022 EULAR Congress in Copenhagen.

Over mean follow-up of 8 years, there were 1,610 and 1,646 incident arrhythmias in the initiator and non-initiator groups, respectively – giving crude incidence rates of 17.5 and 18.1 per 1,000 person-years. This suggests no increased risk of any type of arrhythmia among new users of hydroxychloroquine.

Dr Carmen Riesco Bárcena also presented findings on the possible relationship between antimalarial drugs and electrocardiographic alterations in people with SLE. In this cross-sectional study of 91 patients, 4.69% of those on current antimalarials had a prolonged QTc, compared to 3.7% of those without current treatment.

Further investigation showed a statistically significant association between taking antimalarial drugs and the elongated QTc interval. However, multivariate analysis suggested there was no significant relationship between electrocardiographic alterations and treatment with antimalarials.