Comparing PFO Outcomes of the Occlutech Flex II PFO Occluder to Standard of Care PFO Occlusion

The objective of this study is to investigate whether percutaneous PFO closure with the Occlutech Flex II PFO Occluder is non-inferior to the AMPLATZER™ PFO Occluder and Gore® Cardioform Septal Occluder in closure of the PFO, prevention of recurrent embolic stroke, and device/procedure related Serious Adverse Events (SAE).

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 \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. * 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.