Coherex-PFO-Sleep Hypoxia: A multi-center study to determine the response to closure of patent foramen ovale (PFO) with the Coherex FlatStentTM EF PFO Closure System (EF is part of the trade mark name and stands for Enhanced Foam) in patients diagnosed with PFO and significant oxygen desaturation in obstructive sleep apnea (OSA)

Exclusion Criteria1

• Candidates will be excluded from the study if ANY of the following conditions apply: 1. Long-term requirement for anti-platelet therapy, anticoagulation, or coagulopathy. 2. Contraindication and/or allergy to aspirin, clopidogrel, Nitinol, Dacron, polyurethane, nickel, stainless steel or other stent materials. 3. Concurrent enrollment in another clinical study. 4. Body mass index > 40. 5. Botox treatment within the past 90 days. 6. Other known structural heart disease, coronary artery disease, or atrial fibrillation. 7. Chronic liver disease, kidney disease, or organ failure. 8. Auto-immune disease. 9. Psychiatric illness, which in the investigator’s opinion, will interfere with completion of the study. 10. Degenerative neurologic disorders. 11. Any known active bacterial infection. 12. Malignancy or other illness with a life expectancy less than two years. 13. Pregnancy or desire to become pregnant during course of study. 14. Right-to-left shunt besides PFO detected prior to enrollment. 15.Uncontrolled hypertension defined as blood pressure greater than140/90 mmHg. 16. Immunosuppressive therapy. 17.Diabetes requiring insulin or blood glucose greater than 200 mg/deciliter on oral diabetic medications. 18. Concomitant pulmonary disorder (chronic obstructive pulmonary disorder [COPD], asthma, etc.) requiring treatment. 19. Any medical disorder that would interfere with study completion. 20. Known severe pulmonary hypertension (requiring medication). 21.Patients who have had a major stroke within the past two months or a minor stroke within the past two weeks (see National Institutes of Health (NIH) Stroke Scale). 22. Patients who require a transseptal puncture to access the left atrium. 23. Patients with known sustained arrhythmia.