This trial aims to compare the safety and efficacy of apixaban alone versus apixaban combined with clopidogrel in patients with acute ischemic stroke associated with non-valvular atrial fibrillation and concomitant symptomatic intracranial or extracranial atherosclerosis. Participants will be randomly assigned in a 1:1 ratio to receive apixaban monotherapy or dual therapy with clopidogrel for 30 days. The primary outcome is the incidence of symptomatic or asymptomatic recurrent ischemic lesions detected on brain MRI (DWI/FLAIR) at 30 ± 5 days after initiation of study medication.