Prospective Analysis of the Use of TEG in Stroke Patients

Thromboelastography (TEG), a computerized analysis that has been used since the 1940s, is the only stand alone test that can provide integrated information on the balance between the two separate but simultaneously occuring components of coagulation, thrombosis and lysis. It measures the coagulation process from initial clotting cascade to clot strength.

TEG may be used to assess the coagulation status of patients with acute stroke, whether ischemic or hemorrhagic. TEG might also be a useful way to predict and assess the degree of fibrinolysis that is achieved by tissue plasminogen activator (tPA). Currently tPA is given as a standard dose determined by the patient's body weight, thus given the variability in patient outcome after tPA, this dose could sometimes be too small or too large, leading to thrombolysis or bleeding, respectively. One of the purposes of this observational study is to evaluate how effective TEG is on predicting and assessing the degree of thrombolysis following tPA therapy, by producing a range of TEG values correlated with optimal thrombolysis.

The results of the recent FAST trial demonstrated the need to identify patients with spontaneous intracerebral hemorrhage (ICH) who are at increased risk for hematoma enlargement. Such identified patients, could benefit from a therapeutic advantage of activated factor VII or other hemostatic agents may be more clearly studied. Therefore, another purpose of this study is to evaluate how effective TEG is on predicting further bleeding for patients with spontaneous ICH.

The study will consist of 208 ischemic patients and 80 hemorrhagic patients, whom which are approached from all stroke patients admitted to Memorial Hermann Hospital Emergency Department receiving a confirmatory CT or MRI scan. Patients who agree to participate will have blood drawn the day of hospital arrival, will then be followed for 36 +/- 12 hours after the stroke, and 90 +/- 30 days after the stroke, all during which two more blood samples will be obtained.

Normal controls will be age and sex matched to the investigators' research population. A one-time blood draw will be obtained and information collected will be age, sex and TEG values.

Inclusion criteria

• At least 18 years of age or older.
• Symptoms and signs causing measurable neurologic deficit consistent with an acute stroke.
• CT or MRI consistent with stroke (ischemic or hemorrhagic) or with clinical evidence suggesting a stroke.
• For acute ischemic stroke patients, treatment with tPA and TEG blood draw must be done within 4.5 hours of symptom onset.
• For ICH patients, TEG blood draw must be done within 6 hours of symptom onset.

Exclusion criteria

• Contraindication to CT and MRI (ex. inability to lie flat)
• If ICH patient
• Hemorrhage secondary to trauma, arteriovenous malformation (AVM) or crush injury
• Planned surgical evacuation (hemicraniectomy and ventriculostomy allowed).
• Receipt of hemostatic agents (FFP, Cryo, activated factor seven) prior to TEG blood draw.