Risk factors and localization of silent cerebral infarction in patients with atrial fibrillation

Abstract

It is important to identify the risk factors and localization of silent cerebral infarction (SCI), especially in younger patients with atrial fibrillation (AF). The purpose of this study was to examine the characteristics and risk factors for SCI in AF patients, with particular attention to localization of SCI. The study enrolled 286 consecutive neurologically asymptomatic patients who underwent AF ablation from January 2014 to July 2017 (age 61.7 ± 10.2 [SD] years; 208 male and 78 female). All patients underwent magnetic resonance imaging (MRI) before ablation. SCIs were classified independently by 2 radiologists as follows: cardiogenic SCI in 19 (10.6%), lacunar SCI in 13 (8.9%), undetermined causes in 6 (1.6%), and no SCI in 248 (controls, 78.7%). Importantly, no patients with CHA2DS2-VASc score 0 had SCI on MRI. In univariable analysis, significant risk factors for lacunar SCI included age (P = .007), hypertension (P = .037), congestive heart failure (P = .040), left atrial (LA) diameter (P=.013), and cardio-ankle vascular index (P = .004). In multivariable analysis, significant risk factors for cardiogenic SCI were AF duration (odds ratio [OR] 1.01; 95% confidence interval [CI] 1.00-1.02; P = .038), ankle-brachial pressure index (OR 0.002; 95% CI 0-0.68; P = .030), and LA abnormality (OR 8.99; 95% CI 2.78-31.00; P <.001), defined by the presence of spontaneous echo contrast and/or decreased LA appendage emptying velocity. The study results indicate that among AF patients, SCIs localized in the cerebral cortex and cerebellum are frequently noted, for which cardiogenic mechanisms may be mainly involved; CHA2DS2-VASc score could be useful for screening SCI; and LA abnormality is the specific marker for cardiogenic SCI, providing useful information for risk stratification of SCI.