Ntaios G, Pearce LA, Meseguer E, et al. - Researchers conducted this exploratory analysis of NAVIGATE ESUS (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism in Embolic Stroke of Undetermined Source) to concentrate on patients with aortic arch atherosclerosis (AAA) and evaluate their features, stroke recurrence rates, and response to treatment. The study population included 1,382 candidates who had transesophageal echocardiography. The authors discovered that 397 (29%) had AAA and 112 (8%) had complex AAA. According to multivariable analyses, diabetes mellitus, increasing age, aortic valvulopathy, statin use before randomization, chronic infarcts on imaging, and region were independently related to any AAA vs no AAA and also with complex AAA vs no AAA. They observed that complex AAA is common in embolic stroke of undetermined source patients and is related to atherosclerotic burden. Whether complex AAA independently raises the risk of recurrent stroke and whether a non-vitamin-K oral anticoagulant can be effective for decreasing recurrent stroke as compared with aspirin needs further investigation.