Treatment of High Risk Patent Foramen Ovale According to Contrast-trans Cranial Doppler Sonography

INTERVENTION: Aspirin 80 mg TID orally and continuing for 1 year until progression or unacceptable toxicity develops. Intervention 1: Aspirin 80 mg TID orally and continuing for 1 year until progression or unacceptable toxicity develops. Intervention 2: Warfarin 5 mg per day orally and adjust it to achieve INR between 2 and 3 and continue it for 1 year until progression or unacceptable toxicity develops. Treatment ‐ Drugs Warfarin 5 mg per day orally and adjust it to achieve INR between 2 and 3 and continue it for 1 year until progression or unacceptable toxicity develops CONDITION: G45‐G46 permanent or transient cerebral or retinal ischemic attack. ; Transient Cerebral Ischaemic attacks and related syndromes‐Vascular syndromes of Brain in Cerebrovascular Diseases Transient Cerebral Ischaemic attacks and related syndromes‐Vascular syndromes of Brain in Cerebrovascular Diseases PRIMARY OUTCOME: Permanent or transient cerebral or retinal ischemic attack or death due to any cause. Timepoint: 3 months, 6 months, 9 months and 12 months after intervention. Method of measurement: by phone for recurrence of stroke. INCLUSION CRITERIA: INCLUSION CRITERIA: permanent or transient cerebral or retinal ischemia, age more than 18 years old, more than 50 bubbles in echocardiography, presence of atrial septal aneurysm, multiple infarctions in brain CT Exclusion criteria: more than 50% stenosis in colour doppler sonography of neck arteries, thrombosis or ulcerated plaques in neck arteries, other cardiac definite source of stroke