GORE® Septal Occluder Device for Patent Foramen Ovale (PFO) Closure in Stroke Patients

Inclusion Criteria: * Presence of cryptogenic ischemic stroke or TIA of presumed embolic infarction verified by a neurologist within 180 days prior to randomization * Presence of Patent Foramen Ovale (PFO), as determined initially by positive bubble study utilizing transesophageal echocardiography (TEE), demonstrating spontaneous right-to-left shunting or right-to-left shunting during Valsalva maneuver. * Absence of an identifiable source of thromboembolism in the systemic circulation * No evidence of a hypercoagulable state * Note: Additional Inclusion Criteria may apply Exclusion Criteria: * Other co-morbidities including, but not limited to, mural thrombus, dilated cardiomyopathy, atrial fibrillation/flutter, cardiac prosthetics (valves), mitral valve stenosis, aortic dissection, significant atherosclerosis, vasculitis, pre-existing neurologic disorders, multiple sclerosis, arteriovenous malformations, prior intracranial hemorrhage, severe central nervous system (CNS) disease, severe disability related to prior stroke, and autoimmune disorders that would increase the risk of mortality or morbidity above what is typical for the treatment * Previous Myocardial Infarction * Active infection that cannot be treated successfully prior to randomization * Sensitivity or contraindication to all proposed medical treatments * Pregnancy or intent on becoming pregnant through 24-months after randomization * Indications outside the parameters accepted for placement of the GORE® HELEX® Septal Occluder / GORE® Septal Occluder, including extensive congenital cardiac anomalies and defect diameter estimated to be \> 18mm * Atrial septal anatomy that is expected to necessitate placement of more than one GORE® HELEX® Septal Occluder / GORE® CARDIOFORM Septal Occluder * Need for concomitant procedure(s) that may confound detection of adverse events related to device placement * Note: Additional Exclusion Criteria may apply