Rheumatoid arthritis and the risk of ischemic stroke after diagnosis of atrial fibrillation: a Norwegian nationwide register study.

Abstract

Rheumatoid arthritis (RA) patients have an increased risk for cardiovascular diseases, including atrial fibrillation (AF), but the impact of RA on ischemic stroke risk in the context of AF remains unknown. We explored whether the risk of ischemic stroke after diagnosis of AF is further increased among patients with RA compared with non-RA patients. In the nationwide Norwegian Cardio-Rheuma Register, we evaluated cumulative incidence and hazard rate of ischemic stroke after the first AF diagnosis (2,750 individuals with RA and 158 879 without RA between 2010 and 2017) by using a competing risk model with a 3-month delayed entry. The 5-year unadjusted cumulative incidence of ischemic stroke was 7.3% (95% CI: 5.9%-8.7%) for patients with RA and 5.0% (95% CI 4.9%-5.2%) for patients without RA. Unadjusted univariate analyses indicated that AF patients with RA had a HR of 1.36 (95% CI: 1.13, 1.62) for ischemic stroke compared with those without RA. Sex- and age-adjusted HR for ischemic stroke in RA patients with AF was 1.25 (95% CI: 1.05, 1.50), and the effect size remained unchanged after adjustment for diabetes, hypertension, atherosclerotic cardiovascular disease, and oral anticoagulant (OAC) treatment. RA patients were less likely to receive OAC treatment than non-RA patients (adjusted odds ratio 0.88, 95% CI 0.80, 0.97). RA patients diagnosed with AF are at a further increased risk for stroke compared with non-RA patients with AF, and less likely to receive OAC treatment, emphasizing the need to improve stroke prevention in AF patients with RA.