Aspirin is not recommended as a substitute for acute stroke treatment in patients who are otherwise eligible for IV alteplase or mechanical thrombectomy. III: Harm B-R Recommendation revised from 2013 AIS Guidelines. Recommendation was modified to eliminate wording about acute interventions, which are broadly defined, and to specify that aspirin is a less effective substitute for the treatment of AIS in patients who are otherwise eligible for IV alteplase or mechanical thrombectomy. 3.9. Antiplatelet Treatment (Continued) COR LOE New, Revised, or Unchanged 3.10. Anticoagulants COR LOE New, Revised, or Unchanged The usefulness of urgent anticoagulation in patients with severe stenosis of an internal carotid artery ipsilateral to an ischemic stroke is not well established. IIb B-NR Recommendation and COR unchanged from 2013 AIS Guidelines. LOE amended to conform with ACC/AHA 2015 Recommendation Classification System. The safety and usefulness of short-term anticoagulation for nonocclusive, extracranial intraluminal thrombus in the setting of AIS are not well established. IIb C-LD New recommendation. The optimal medical management of patients with AIS and radiologic evidence of nonocclusive, intraluminal thrombus (eg, cervical carotid, vertebrobasilar arteries) remains uncertain. Several small observational studies have suggested the safety of short-term IV heparin or LMWH in this setting,222,223 but further research is required to establish safety and efficacy. See Table XLIX in online Data Supplement 1. At present, the usefulness of argatroban, dabigatran, or other thrombin inhibitors for the treatment of patients with AIS is not well established. IIb B-R Recommendation revised from 2013 AIS Guidelines. Several observational studies have demonstrated the safety and feasibility of treating AIS with thrombin inhibitors as either a single or an adjunct therapy to alteplase. 