title: Thromboelastography in patients with acute ischemic stroke.
abstract: BACKGROUND
  Thromboelastography measures the dynamics of coagulation. There are limited data about thromboelastography in acute ischemic stroke other than a single study from 1974 suggesting that acute ischemic stroke patients are hypercoagulable. There have been no studies of thromboelastography in the thrombolytic era despite its potential usefulness as a measure of clot lysis. This study was designed to provide initial thromboelastography data in stroke patients before and after tissue plasminogen activator therapy and to provide the necessary preliminary data for further study of thromboelastography's ability to identify clot subtype and predict response to tissue plasminogen activator therapy.
  
  
  METHODS
  All acute ischemic stroke patients presenting between 11/2009 and 2/2011 eligible for tissue plasminogen activator therapy were screened and 56 enrolled. Blood was drawn before (52 patients) and 10 mins after tissue plasminogen activator bolus (30 patients). Demographics, vitals, labs, 24 h National Institutes of Health Stroke Scale, and computed tomography scan results were collected. Patients were compared with normal controls.
  
  
  RESULTS
  Acute ischemic stroke patients had shorter R (4.8 ± 1.5 vs. 6.0 ± 1.7 min, P = 0.0004), greater α Angle (65.0 ± 7.6 vs. 61.5 ± 5.9°, P = 0.01), and shorter K (1.7 ± 0.7 vs. 2.1 ± 0.7 min, P = 0.002) indicating faster clotting. Additionally, a subset formed clots with stronger platelet-fibrin matrices. Treatment with tissue plasminogen activator resulted in reduction in all indices of clot strength (LY30 = 0 (0-0.4) vs. 94.4 (15.2-95.3) P < 0.0001); however, there was considerable variability in response.
  
  
  CONCLUSIONS
  Thromboelastography demonstrates that many acute ischemic stroke patients are hypercoaguable. Thromboelastography values reflect variable clot subtype and response to tissue plasminogen activator. Further study based on these data will determine if thromboelastography is useful for measuring the dynamic aspects of clot formation and monitoring lytic therapy.
authors.affiliation: Department of Neurology, The University of Texas Medical School, Houston, TX, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Elliott
authors.forename: Jeremy
authors.initials: J
authors.lastname: Wetzel
authors.forename: Tiffany
authors.initials: T
authors.lastname: Roper
authors.forename: Evan
authors.initials: E
authors.lastname: Pivalizza
authors.forename: James
authors.initials: J
authors.lastname: McCarthy
authors.forename: Cristina
authors.initials: C
authors.lastname: Wallace
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: Hess
authors.forename: Hui
authors.initials: H
authors.lastname: Peng
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Rahbar
authors.forename: Navdeep
authors.initials: N
authors.lastname: Sangha
authors.forename: James C
authors.initials: JC
authors.lastname: Grotta
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000097:blood* / Q000188:drug therapy; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D020521:Stroke / Q000097:blood* / Q000188:drug therapy; D013916:Thrombelastography; D015912:Thrombolytic Therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator