Atrial fibrillation (AF) is a common cause of ischemic stroke and is also associated with cognitive impairment in the general population.

The aim of this study was to evaluate the relationship of clinical and imaging cerebral impairment with AF in patients admitted for an ischemic stroke.

Patients with acute ischemic stroke wereprospectively identified from the population-based Dijon Stroke Registry, (France). Patients who had a CT-scan as brain imaging modality were included in the present analysis to assess the presence of pre-existing leukoaraiosis, old vascular brain lesions, and cerebral atrophy.

Among the 916 patients with ischemic stroke recorded in the Dijon Stroke Registry who had brain CT-scan, 288 (31.4%) had AF, of whom 88 (9.6% of total patients with IS) had newly diagnosed AF, and 200 (21.8%) had previous AF. The severity of IS was greater in patients with AF (median NIHSS score [IQR] 7 [2.5–18], vs. 3 [1–8], P<0.001) and patients with AF had more frequent pre-existing mild cognitive impairment (MCI) (17.8% vs. 10.2%) or dementia (22.4% vs. 13.1%) (P=0.001). In multivariate analysis, prestroke cognitive impairment (MCI OR=1.86; 95% CI: 1.05–3.29, P=0.033 and dementia OR=1.93; 95% CI: 1.14–3.28, P=0.015) were independently associated with AF, especially after adjusting for brain imaging characteristics (MCI OR=1.87; 95% CI: 1.20–2.90, P=0.006 and dementia OR=1.76; 95% CI: 1.15–2.69, P=0.009). In contrast, no difference was observed according to AF status regarding brain imaging characteristics after adjustment for confounding factors.

This study confirms that nearly 1 in 3 patients with ischemic stroke suffers from AF. Although AF patients were older and suffered more severe stroke, they also had more frequently pre-existing cognitive impairment, regardless of imaging characteristics. Our results suggest that the cognitive impact of AF is not associated with macroscopic brain alterations.