Inclusion Criteria: Subjects with a PFO and cryptogenic stroke:  PFO defined as visualization of microbubbles (during Trans Esophageal Echo (TEE)) in the left atrium within three cardiac cycles of right atrial opacification at rest and/or with Valsalva.  Cryptogenic stroke defined as a stroke of unknown cause.  Stroke defined as an acute focal neurological deficit, presumed to be due to focal ischemia, and either:  Symptoms persisting ≥24 hours, or  Symptoms persisting <24 hours with Magnetic Resonance Imaging (MRI) or Computer Tomography (CT) findings of a new, neuroanatomically relevant, cerebral infarct.  -  Exclusion Criteria: Age <18 years  Myocardial Infarction (MI) or unstable angina within 6 months  Mitral or aortic valve stenosis or severe regurgitation  Left Ventricle Ejection Fraction (LVEF) <35%  Uncontrolled hypertension or diabetes mellitus despite medications  Subjects contraindicated for aspirin or clopidogrel  Subjects not able to discontinue anticoagulation  Qualifying stroke with Modified Rankin score >3  Anatomy in which the device would interfere with intracardiac or vascular structures  Life expectancy < 2 years  Exclusion for patients with known causes of ischemic stroke:  Atrial fibrillation/atrial flutter (chronic or intermittent)  Left Ventricle (LV) aneurysm, intracardiac thrombus, or tumor  Mitral or aortic valve vegetation or prosthesis  Aortic arch plaques protruding >4 mm into the lumen  Atherosclerosis or arteriopathy of intra- or extracranial vessels with >50% diameter stenosis in the artery supplying the infarcted territory  Another cause of right-to-left shunting (e.g., an Atrial Septal Defect (ASD) or a fenestrated atrial septum)  Presence of an arterial hypercoagulable state:  Lupus anticoagulant,  anticardiolipin Abs,  hyperhomocysteinemia,  Cancer-related hypercoagulability.  Lacunar infarct probably due to intrinsic small vessel as the qualifying event, defined as an ischemic stroke in the distribution of a single, small deep penetrating vessel in a patient with any of the following:  A history of hypertension (except in the first week post stroke)  A history of diabetes mellitus  Age ≥50 years  MRI or CT with leukoaraiosis greater than symmetric, well-defined periventricular caps, or bands (European Task Force on Age-Related White Matter Changes rating scale score >0)  Arterial dissection as the qualifying event