title: Thrombelastography detects the anticoagulant effect of rivaroxaban in patients with stroke.
abstract: OBJECTIVE
  Factor Xa inhibitors are prescribed for stroke prevention in atrial fibrillation. Managing such patients is challenging especially if they are eligible for thrombolysis because there is no rapidly available test to detect the effect of such medications. Thrombelastography analyzes the dynamics of coagulation and can be rapidly performed. We sought to determine whether thrombelastography can detect the anticoagulation effect of factor Xa inhibitors in patients with stroke.
  
  
  METHODS
  Blood from 10 patients with stroke was analyzed by thrombelastography at baseline and 2 to 18 hours after rivaroxaban administration.
  
  
  RESULTS
  Increased R, K, and δ were seen at 2, 4, and 6 hours, while G, maximum amplitude, α-angle, and LY30 were decreased. Baseline R was 5.8±0.5 when compared with 11.4±1.0 at 2 hours. R remained prolonged at 18 hours. Other thrombelastography parameters were normal by 18 hours.
  
  
  CONCLUSIONS
  Thrombelastography can detect the anticoagulant effect of factor Xa inhibitors in patients with stroke and might be useful in the emergency management of those eligible for thrombolysis.
authors.affiliation: From the Department of Neurology, The University of Texas Medical School, Houston (R.B., S.F., J.M.A.-L., S.A.P., J.C.G.); and Center for Clinical and Translational Sciences, University of Texas at Houston (C.C., M.H.R.).
authors.forename: Ritvij
authors.initials: R
authors.lastname: Bowry
authors.forename: Stuart
authors.initials: S
authors.lastname: Fraser
authors.forename: Joancy M
authors.initials: JM
authors.lastname: Archeval-Lao
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Parker
authors.forename: Chunyan
authors.initials: C
authors.lastname: Cai
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Rahbar
authors.forename: James C
authors.initials: JC
authors.lastname: Grotta
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D001777:Blood Coagulation / Q000187:drug effects; D005172:Factor XI / Q000037:antagonists & inhibitors; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009025:Morpholines / Q000627:therapeutic use*; D000069552:Rivaroxaban; D020521:Stroke / Q000097:blood* / Q000188:drug therapy; D013876:Thiophenes / Q000627:therapeutic use*; D013916:Thrombelastography / Q000379:methods* / Q000706:statistics & numerical data; D015912:Thrombolytic Therapy / Q000379:methods
chemical_list: D000925:Anticoagulants; D009025:Morpholines; D013876:Thiophenes; D005172:Factor XI; D000069552:Rivaroxaban
keywords: factor Xa; rivaroxaban; stroke; thrombolytic therapy