Heart rhythm monitoring for occult atrial fibrillation is usu- ally recommended if no other cause of stroke is discovered. 7. Extracranial carotid artery disease is an important and treatable cause of stroke. Patients with severe stenosis ipsilateral to a nondisabling stroke or transient ischemic attack who are candidates for intervention should have the stenosis fixed, likely relatively early after their ischemic stroke. The choice between carotid endarterectomy and carotid artery stenting should be driven by specific patient comor- bidities and features of their vascular anatomy. 8. Patients with severe intracranial stenosis in the vascular territory of ischemic stroke or transient ischemic attack should not receive angioplasty and stenting as a first-line therapy for preventing recur- rence. Aggressive medical management of risk factors and short-term dual antiplatelet therapy are preferred. 9. There have been several studies evaluating sec- ondary stroke prevention of patent foramen ovale closure since the previous guideline in 2014. It is now considered reasonable to percutaneously close patent foramen ovale in patients who meet each of the following criteria: age 18 60 years, nonlacunar stroke, no other identified cause, and high risk patent foramen ovale features. 10. Patients with embolic stroke of uncertain source should not be treated empirically with anticoagu- lants or ticagrelor because it was found to be of no benefit. PREAMBLE Since 1990, the American Heart Association (AHA)/ American Stroke Association (ASA)* have translated sci- entific evidence into clinical practice guidelines with rec- ommendations to improve cerebrovascular health. These guidelines, which are based on systematic methods to evaluate and classify evidence, provide a foundation for the delivery of quality cerebrovascular care. The AHA/ ASA sponsor the development and publication of clinical practice guidelines without commercial support, and mem- bers volunteer their time to the writing and review efforts. 