The overall purpose of this study is to evaluate how effective Thromboelastography (TEG) is
on identifying ischemic and hemorrhagic stroke patients at increased risk for bleeding after
receiving tissue plasminogen activator (tPA), as well as on differentiating between patients
in whom optimal thrombolysis has been achieved, and those whom it has not.
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
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
- At least 18 years of age or older.
- Symptoms and signs causing measurable neurologic deficit consistent with an acute
- 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.
- 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