Brain lesion and echocardiogenic predictors of newly detected atrial fibrillation in acute ischemic stroke.

Objectives: Atrial fibrillation (AF) is one of the notorious risk factors in acute ischemic stroke (AIS), and the use of anticoagulants has been shown to be effective in preventing ischemic stroke in AF patients. Therefore, identifying AF in AIS patients has become increasingly important. However, the impact of brain imaging and cardiac indices on the development of new AF after stroke remains unclear.

Methods: A consecutive series of AIS patients who were admitted to the Ulsan University Hospital between January 2013 and December 2019 were identified. Patients with relevant ischemic brain lesions on MRI were included, and those without echocardiography data were excluded. We included and classified the AF patients who had the disease prior to or during hospitalization or met the criteria for cryptogenic stroke (CS). Differences in baseline characteristics, stroke risk factors, stroke severity, insular lesion, and echocardiographic data were investigated among each group.

Results: A total of 850 patients were enrolled in the study, comprising 231 patients with AF detected after stroke (AFDAS), 287 patients with known AF (KAF), and 350 patients with CS. Compared with KAF, patients with AFDAS had a lower prevalence of underlying coronary heart disease and stroke history. They had greater right insular cortex lesions and lesser left atrial enlargement in unadjusted analysis. Following adjusted analysis, the involvement of the right insular cortex was found to be associated with the AFDAS patient group (odds ratio, 1.57). When compared to the CS group, AFDAS patients were older, experienced more severe initial strokes, and had similar rates of pre-stroke anticoagulation prescription. Additionally, they demonstrated a higher prevalence of both insular lesions, increased left atrium volume index, reduced ejection fraction, and elevated e/e' ratio. After adjustment, age, initial stroke severity, insular involvement, left atrium volume index, ejection fraction, and e/e' ratio were found to be significant.

Conclusions: These results suggest that the right insular cortex lesion on acute stroke may be a cause of AFDAS.