Risk of arrhythmia following ankylosing spondylitis, 2012-2023: a nationwide cohort study

Ankylosing spondylitis (AS) may increase arrhythmia risk through systemic inflammation, cardiac remodeling, and conduction abnormalities, but population-level evidence is limited. We evaluated this risk using a nationwide matched cohort in South Korea.

We used the Korean National Health Insurance Service cohort (2012-2023) in a retrospective matched study. AS was defined as ICD-10 M45 with copayment registration, and incident arrhythmia was defined as the first recorded diagnosis with ICD-10 codes I47-I49. Each AS case was matched to 10 controls by sex and screening year using a propensity score. We estimated incidence rates, incidence rate ratios, and hazard ratios with Cox models.

We analyzed 3,022 patients with AS and 30,220 controls (mean follow-up 4.3 years). Arrhythmia occurred in 129 patients (4.3%) and 927 controls (3.1%). The crude incidence rate (IR) per 1,000 person-years was 9.90 in AS vs 7.05 in controls, yielding an incidence rate ratio (IRR) of 1.41 (95% CI 1.17-1.69). Risk was highest in women < 60 years (IRR 1.95, 95% CI 1.33-2.87).

AS was associated with elevated arrhythmia risk, particularly in younger women. These findings support structured rhythm-risk awareness in AS care, while interval-specific adjusted analyses remained exploratory. Key Points • Patients with ankylosing spondylitis have a significantly increased risk of arrhythmia compared with matched controls. • The excess risk is most pronounced in younger women, highlighting a vulnerable subgroup. • These findings support structured rhythm-risk awareness and individualized cardiovascular monitoring in ankylosing spondylitis care, with the recognition that interval-specific adjusted estimates remained exploratory.