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.