In patients with stroke at high risk of hemor- rhagic conversion in the setting of AF, it is reasonable to delay initiation of oral antico- agulation beyond 14 days to reduce the risk In patients with TIA in the setting of nonvalvu- lar AF, it is reasonable to initiate anticoagu- lation immediately after the index event to reduce the risk of recurrent stroke. In patients with stroke or TIA in the setting of nonvalvular AF who have contraindications for lifelong anticoagulation but can tolerate at least 45 days, it may be reasonable to consider percutaneous closure of the left atrial appendage with the Watchman device to reduce the chance of recurrent stroke and In patients with stroke at low risk for hemor- rhagic conversion in the setting of AF, it may be reasonable to initiate anticoagulation 2 to 14 days after the index event to reduce the risk of recurrent stroke.428,429,437 In patients with AF and stroke or TIA who have end-stage renal disease or are on dialysis, it may be reasonable to use warfarin or apixaban (dose adjusted if indicated) for anticoagulation to reduce the chance of Synopsis AF is an important cause of cardioembolic stroke, and the initial clinical presentation of AF is often stroke or TIA. In patients with ischemic stroke or TIA, a diagnosis of AF allows the reduction of recurrent events by treat- ment with long-term oral anticoagulation. The left atrial appendage is thought to be the main source of cardio- embolism in AF. In a series of patients with stroke and AF evaluated by echocardiography, 90% of identified thrombus was seen in the left atrial appendage.432 Anti- coagulation decreases thrombus formation systemically, including the left atrium, and reduces the risk of stroke or systemic embolism in AF, but at the cost of increased bleeding. 