Risk of Arrhythmia Among New Users of Hydroxychloroquine in Rheumatoid Arthritis and Systemic Lupus Erythematosus: A Population-Based Study

Hydroxychloroquine and the associated risk of arrhythmias

Hydroxychloroquine (HCQ), which was initially used as an antimalarial drug, is now being used to treat other illnesses, especially rheumatic autoimmune disorders  such as systemic lupus erythematosus, primary Sjögren's syndrome, and rheumatoid arthritis, because it is safe, effective, and cost efficient. This drug has shown high efficacy and has become the first-line treatment for many of these diseases. Although HCQ has many therapeutic effects, it has unfortunately shown some complications, especially with its long-term use. One of these side effects is arrhythmia through prolongation of the QT interval. This narrative literature review focuses on the effects of HCQ on the QT interval in patients with rheumatologic diseases who have been prescribed this drug. In particular, we will focus on the increased risk of arrhythmia when HCQ is administered with other drugs, such as azithromycin and many others, along with drug-drug interactions. In addition, we investigated the safety of this drug in pregnant women.

Antimalarial Adherence and Risk of Cardiovascular Events in Patients With Rheumatoid Arthritis and Systemic Lupus Erythematosus: A Population-Based Study

OBJECTIVE

We aimed to assess the association between antimalarial adherence and cardiovascular events between incident rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) population-based cohorts.

METHODS

All patients with incident RA/SLE and incident antimalarial use in British Columbia, Canada, between January 1997 and March 2015 were identified using provincial administrative databases. The outcomes were incident cardiovascular events, including myocardial infarction (MI), stroke, or venous thromboembolism (VTE). The exposure was antimalarial adherence with levels: discontinuation (proportion of days covered [PDC = 0]), nonadherence (0 < PDC < 0.90), and adherence (PDC ≥ 0.90). We used marginal structural models to estimate the effect of antimalarial adherence on the rate of cardiovascular events, accounting for potential confounders.

RESULTS

We identified 16,538 individuals with incident RA/SLE and incident antimalarial use without any cardiovascular event before the index date. Over nine years mean follow-up, 2,174 incident cardiovascular events (13.2%) were observed. The adjusted hazard ratio (aHR) for incident cardiovascular events for antimalarial adherence relative to discontinuation was 0.72 (95% confidence interval [CI] 0.64-0.81) and 1.01 (95% CI 0.90-1.14) for nonadherence. Additionally, the aHRs for all cardiovascular events, MI, stroke, and VTE for adherence relative to nonadherence was 0.71 (95% CI 0.61-0.82), 0.62 (95% CI 0.51-0.75), 0.45 (95% CI 0.36-0.58), and 0.65 (95% CI 0.46-0.93), respectively. We found older age modified the association between antimalarial adherence and cardiovascular events (P = 0.02).

CONCLUSION

When people newly diagnosed with RA or SLE take their antimalarial regularly as prescribed (PDC ≥ 0.90), they have a 29% lower risk of sustaining a cardiovascular event than patients with a lower degree of adherence (PDC < 0.90) and a 28% lower risk than if they discontinue antimalarials.

New-onset atrial fibrillation in seropositive rheumatoid arthritis: association with disease-modifying anti-rheumatic drugs treatment

OBJECTIVE

Atrial fibrillation (AF) is a potentially lethal complication that leads to increased hospitalization, disability and mortality. Furthermore, the risk of cardiovascular disease is increased in RA. We evaluated whether DMARD treatment is associated with incident AF in patients with seropositive RA (SPRA).

METHODS

The South Korean Health Insurance Review and Assessment Service database was used to identify patients newly diagnosed with SPRA between 2010 and 2020. A nested case-control analysis was performed to match AF-affected patients to unaffected controls for age, sex, follow-up duration, and index year of SPRA diagnosis at a 1:4 ratio. Adjusted conditional logistic regression was used to identify the predictive factors for AF.

RESULTS

Of the 108 085 patients with SPRA, 2,629 (2.4%) developed new-onset AF, and the proportion of females was ∼67%. In the matched population, pre-existing comorbidities of hypertension, chronic kidney disease, and heart failure were associated with increased risk of AF. Meanwhile, the use of methotrexate (MTX) decreased the risk of incident AF [adjusted odds ratio (aOR), 0.89], whereas the use of leflunomide (LEF) increased AF (aOR, 1.21). In a subgroup of patients aged ≥50 years, LEF and adalimumab increased the occurrence of AF, while MTX decreased AF in males and LEF increased this risk in females.

CONCLUSION

Although the number of subjects developing new-onset AF was small, MTX decreased and LEF increased incident AF in patients with RA. Especially, a distinct pattern of AF risk with DMARDs usage was observed according to age and sex.