Study on Anti-Thrombotic Regimens for Secondary Prevention in Ischemic Stroke Patients With Possible Benefit From Anticoagulation Therapy

To screen ischemic stroke patients likely to benefit from anticoagulation and compare the effectiveness and safety of anticoagulation versus antiplatelet therapy in preventing recurrent ischemic stroke within 3 months.

Inclusion Criteria: * Age ≥18 years * Ischemic stroke patients with undetermined etiology, within 14 days of onset, with completed etiological assessment * At least one of the following: 1. Cortical or multi-territorial infarct 2. Recurrent stroke or stroke on antiplatelet therapy 3. Left atrial diameter \>40 mm 4. Left ventricular dysfunction (EF 30-40% or regional wall motion abnormality) 5. Atrial premature beats \>1500/24h Exclusion Criteria: * Stenosis ≥50% in the responsible vessel or high-risk plaque * Identified cardioembolic source * PFO with planned closure * Malignancy * Indication for mandatory anticoagulation/antiplatelet therapy * Active bleeding (intracranial, subarachnoid, gastrointestinal, etc.) * History of intracranial hemorrhage * Current or recent gastrointestinal ulcer * Recent brain or spinal injury/surgery * Known or suspected vascular malformations or aneurysms * Severe renal impairment (CrCl \