To evaluate the safety and effectiveness of the SnowyTM PFO closure system in plugging patent foramen ovale

A prospective, multicenter, randomized controlled clinical trial is conducted to evaluate the safety and effectiveness of PFO closure system produced by Hangzhou Dinova EP Technology Co., Ltd.., Ltd. in closing patent foramen ovale (PFO). 242 patients are expected to be selected. They are randomly divided into the PFO closure system treatment group (121 cases) and the Chinese medicine Shengjie Cardi-o-fix PFO occluder treatment group (121 cases) according to 1:1. All patients will be followed up to 7 days after operation or before discharge, 1 month, 3 month, 6 month, 1 year, 2 year, 3 year, 4 year and 5 year.

Inclusion Criteria:

1. Age: 18 to 65 years old, regardless of gender
2. Transthoracic echocardiographic contrast echocardiography (cTTE) confirmed the presence of PFO and at least moderate (see above definition) RLS (in Valsalva active/resting state)
3. Existence of at least one of the following conditions： 1) Unexplained stroke or TIA 2) intractable or chronic migraine
4. The subjects are informed of the nature of the study and agreed to all requirements for participation in the study, signed the informed consent form, and agree to complete the follow-up and follow-up examination

Exclusion Criteria:

1. Patients have definite causes of stroke unrelated to the PFO
2. RLS caused by other causes, such as atrial septal defect or pulmonary arteriovenous shunt
3. Atrial fibrillation or atrial flutter
4. Mitral and aortic stenosis or severe regurgitation
5. Dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy
6. Active endocarditis or other untreated infectious diseases
7. Left ventricular ejection fraction (LVEF) < 40%, or NYHA cardiac function grade III-IV
8. Uncontrollable hypertension
9. Previous intracardiac surgery
10. Myocardial infarction or unstable angina pectoris within 6 months
11. Contraindications to anticoagulants or antiplatelet drugs
12. High risk of bleeding
13. severe liver function impairment（alanine aminotransferase (ALT) or aspartate aminotransferase (AST) greater than 3 times the upper limit of normal value）
14. Serum creatinine greater than 2 times the upper limit of normal or with any history of renal dialysis or renal transplantation
15. Severe pulmonary disease including pulmonary hypertension (clinical diagnosis)
16. Nickel or contrast allergy
17. Active or planned (within 12 months) pregnancy, or lactating female patients
18. Malignant tumors or other serious diseases resulting in a life expectancy of less than 12 months
19. Psychiatric conditions that may interfere with medical compliance and compliance with follow-up
20. Concomitant participation in other clinical trials
21. The investigator determines that the patient is unsuitable because of reasons not listed but thought to interfere with safe trial participation