Statin therapy reduces dementia risk in atrial fibrillation patients receiving oral anticoagulants

Aims Atrial fibrillation (AF) is linked to an increased risk of dementia, even in stroke-free patients. The impact of statin therapy on dementia risk is unclear in AF patients receiving oral anticoagulant (OAC) (vitamin K antagonist and direct-acting OAC). We sought to investigate the impact of statin therapy on dementia risk in AF patients receiving OAC. Methods and results Using the Korean National Health Insurance Service database, 91 018 non-valvular AF (NVAF) patients from January 2013 to December 2017 were included in the analysis. Of the total, 17 700 patients (19.4%) were in the statin therapy group, and 73 318 patients (80.6%) were in the non-statin therapy group. The primary endpoint was the occurrence of dementia. The median duration of follow-up was 2.1 years. Statin therapy was associated with a significantly lower dementia risk than non-statin therapy for CHA(2)DS(2)-VASc scores & GE;2 (hazard ratio = 0.77, 95% confidence interval 0.64-0.90, P = 0.026) in NVAF patients receiving OAC. The statin therapy group had a significantly lower dementia risk in a dose-dependent relationship compared with the non-statin therapy group (P for trend <0.001). Conclusion In NVAF patients who received OAC, statin therapy lowered the dementia risk compared with no statin therapy. Furthermore, statin therapy is associated with a dose-dependent reduction in dementia risk.