AtRial Cardiopathy and Antithrombotic Drugs In Prevention After Cryptogenic Stroke

Inclusion Criteria: * Age ≥ 45 years. * Clinical diagnosis of ischemic stroke + brain imaging to rule out hemorrhagic stroke. * Modified Rankin Scale (MRS) score ≤ 4. * Ability to be randomized within 3 to 180 days after stroke onset. * ESUS, defined as all of the following: * Stroke detected by CT or MRI that is not lacunar. Lacunar is defined as a subcortical (this includes pons and midbrain) infarct in the distribution of the small, penetrating cerebral arteries whose largest dimension is ≤1.5 cm on CT or ≤2.0 cm on MRI diffusion images/\<1.5 cm on T2 weighted MR images. The following are not considered lacunes: multiple simultaneous small deep infarcts, lateral medullary infarcts, and cerebellar infarcts. Patients with a clinical lacunar stroke syndrome and no infarct on imaging are excluded. * Absence of extracranial or intracranial atherosclerosis causing ≥50 percent luminal stenosis of the artery supplying the area of ischemia. Patients must undergo vascular imaging of the extracranial and intracranial vessels using either catheter angiography, CT angiogram (CTA), MR angiogram (MRA), or ultrasound, as considered appropriate by the treating physician and local principal investigator. * No major-risk cardioembolic source of embolism, including intracardiac thrombus, mechanical prosthetic cardiac valve, atrial myxoma or other cardiac tumors, moderate or severe mitral stenosis, myocardial infarction within the last 4 weeks, left ventricular ejection fraction \<30 p…