Background: Gout is an emerging cardiovascular risk factor. We aimed to assess whether gout is associated with an increased risk of stroke in patients with atrial fibrillation (AF).
Methods: The nationwide registry-linkage FinACAF study (Finnish Anticoagulation in Atrial Fibrillation) included all patients with AF in Finland between 2007 and 2018 from all levels of care. Based on diagnosis codes and pharmacy claims data, the association of gout and urate-lowering therapy with the incidence of ischemic stroke was assessed.
Results: We identified 229 565 patients with new-onset AF (50.0% female; mean age, 72.7 years; mean follow-up, 4.0 years), of whom 6 910 (3.0%) had a history of gout. A total of 16 296 (7.1%) patients experienced an ischemic stroke. Gout was associated with higher stroke rates in both unadjusted and adjusted analyses (incidence rate ratio, 1.35 [95% CI, 1.22-1.49] and incidence rate ratio, 1.12 [95% CI, 1.02-1.24], respectively). Analyses restricted to follow-up without anticoagulation yielded consistent results with slightly higher point estimates (incidence rate ratio, 1.88 [95% CI, 1.63-2.17] unadjusted; incidence rate ratio 1.26 [95% CI, 1.09-1.46] adjusted). In patients with gout and AF, time-dependent exposure to urate-lowering therapy was associated with a 30% lower stroke rate. Nonanticoagulated crude stroke rates were 1.5, 1.0, and 4.8 per 100 patient-years for gout patients with CHA2DS2-VA scores of 0, 1, and ≥2, respectively.
Conclusions: Gout is an important risk factor for ischemic stroke in patients with AF, and considering gout could improve stroke risk stratification. Urate-lowering therapy was associated with reduced stroke risk, suggesting that gout is a modifiable risk factor in patients with AF.
Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04645537.
Keywords: anticoagulant; atrial fibrillation; gout; ischemic stroke; risk factor.