Risk of incident atrial fibrillation in gout: a cohort study

Objective Atrial fibrillation (AF) is the most common arrhythmia associated with cardiovascular disease and mortality. Recent studies suggest an association between inflammation, hyperuricaemia and AF, but little is known whether gout is associated with AF risk. Methods Using data from a US commercial insurance plan (2004-2013), we conducted a cohort study to evaluate the risk of incident AF in patients with gout versus osteoarthritis. Patients with gout or osteoarthritis were identified with >= 2 diagnoses and >= 1 dispensing for gout or osteoarthritis medications. Incident AF was defined as a new AF diagnosis and a new dispensing for anticoagulants or antiarrhythmics. The risk of incident AF in gout was also compared with the non-gout group. Results We identified 70 015 patients with gout and 210 045 with osteoarthritis, matched on age, sex and index date. The mean age was 57 years, and 81% were men. Over the mean 2-year follow-up, the incidence rate of AF per 1000 person-years was 7.19 in gout and 5.87 in osteoarthritis. The age, sex and index date-matched HR of AF was 1.23 (95% CI 1.14 to 1.32) in gout versus osteoarthritis. In a multivariable Cox regression, adjusting for age, sex, comorbidities, medications and healthcare usage, the HR of AF in gout was 1.13 (95% CI 1.04 to 1.23). When compared with non-gout, the multivariable HR of AF in gout was also increased (HR 1.21, 95% CI 1.11 to 1.33). Conclusions In this large population-based cohort study, gout was associated with a modestly increased risk of incident AF compared with osteoarthritis and non-gout after adjusting for other risk factors.