Prevalence and risk factors of silent brain infarcts in patients with AF detected by 3T-MRI.

Abstract

Silent brain infarcts (SBI), a finding on neuroimaging, are associated with higher risk of future stroke. Atrial Fibrillation (AF) has been previously identified as a cause of SBI. The aim of this study is to determine the prevalence of and risk factors for SBI in patients with AF and low-to-moderate embolic risk according to CHADS2 and CHA2DS2VASc score. Patients with a history of AF based on medical records who scored 0-1 in the CHADS2 score were selected from the Seville urban area using the Andalusian electronic healthcare database (DIRAYA). Demographic and clinical data were collected and a 3T brain MRI was performed on patients older than 50years and with absence of neurological symptoms. 66 of the initial 443 patients (14.9%) and 41 of the 349 patients with low risk according to CHA2DS2VASc score (11.7%) presented at least 1 SBI. After adjusted multivariable analysis, an older age (OR 3.84, 95% CI 1.07-13.76) and left atrial (LA) enlargement (OR 3.13, 95% CI 1.15-8.55) were associated with SBI in the whole cohort, while only LA enlargement was associated with SBI in the low-risk cohort (OR 3.19, 95% CI 1.33-7.63). LA enlargement on echocardiogram was associated with SBI in patients with AF and low or moderate embolic risk according to CHADS2 and in the low-risk population according to CHA2DS2VASc. Although further studies are needed, a neuroimaging screening might be justified in these patients to guide medical therapies to improve stroke prevention.