Rivaroxaban Plus ASA in Embolic Stroke of Undetermined Source(AREST-ESUS)

Inclusion Criteria: 1. signing the inform consent 2. recent ischemic stroke ( 7-60) days with criteria of ESUS 3. only one risk factors of potential embolic source including: 1. PTFV1 in standard ECG ≥0.05 mm.s or ≥0.005 mv.s 2. LVH in standard ECG( Sokolow index≥ 35 mm) or on echocardiography 3. Moderate or severe valvular disorder on echocardiography (except MS) 4. PFO without indication of occlusion 5. Left atrium enlargement in echocardiography Exclusion Criteria: 1. History of hypersensitivity to the investigational medicinal product 2. Indication for anticoagulation 3. Indication for dual antiplatelet therapy 4. Contraindication to investigational medications 5. History of intracranial, intraocular, spinal, retroperitoneal or atraumatic intra-articular bleeding 6. Gastrointestinal bleed or major surgery within 3 months 7. Planned or likely revascularization (any angioplasty or vascular surgery) within the next 3 months 8. HAS-BLED score \>3 9. Severe non-cardiovascular comorbidity with life expectancy \< 3 months 10. Severe renal failure, defined as Glomerular Filtration Rate (GFR) \<15ml/min, Dialysis, transplant, Cr \>2.26 mg/dL 11. Severe hepatic insufficiency, Cirrhosis or Bilirubin \>2x Normal or AST/ALT/AP \>3x Normal 12. Modified Rankin Scale of \>=4 at time of randomization or inability to swallow medications. 13. Hemorrhagic transformation of infarction detected by Brain CT or MRI at the time of drug application 14. Radiological or microbiological evidence of COVID-19 infection