Stroke and dementia risk in patients with and without atrial fibrillation and carotid arterial disease

Background: Patients with carotid arterial disease (CD) with and without atrial fibrillation (AF) are at risk of stroke. Patients with AF are at a higher risk of stroke and dementia.

Objectives: We sought to understand the risks of stroke, transient ischemic attack (TIA), and dementia in patients with and without AF and CD or a combination of both as well as to determine whether therapies for each disease may influence risks.

Methods: A total of 11,572 patients were included in 4 groups, with 2893 patients populating each group (1: no AF or CD; 2: AF, no CD; 3: CD and no AF; 4: AF and CD) and matched for age, sex, and comorbidities. Long-term outcomes of stroke/TIA and dementia were assessed. Subset analyses of these outcomes were performed in patients with CD treated with revascularization and in patients with AF treated with ablation.

Results: CD increased the risk of stroke/TIA (hazard ratio [HR] 2.74; P < .0001) and dementia (HR 1.44; P < .0001). Similarly, AF increased the risk of stroke/TIA (HR 2.08; P < .0001) and dementia (HR 1.30; P = .004). The coexistence of AF and CD further augmented the risk of both end points. CD revascularization was associated with a decreased risk of dementia (HR 0.47; P < .0001) but not stroke. Ablation of AF improved outcomes of stroke/TIA (HR 0.55; P = .002), particularly in those with CD (HR 0.36; P < .0001), and was associated with a reduced risk of dementia (HR 0.51; P = .04).

Conclusion: CD and AF augment risk of stroke/TIA and dementia in the general population, and the coexistence of both diseases is additive in risk. Ablation of AF was associated with lower risk, the magnitude of which was greater in those with CD.