Thrombelastography Maximal Clot Strength Could Predict One-Year Functional Outcome in Patients with Ischemic Stroke

BACKGROUND: Elevated maximal clot strength, measured by thrombelastography (TEG) maximum amplitude (MA) has been associated with a higher risk for ischemic events in patients with coronary artery diseases. However, it has not been investigated in patients with cerebrovascular diseases. In the current study, we aimed to evaluate the predictive ability of TEG-MA in assessing the risk for ischemic event recurrence and the functional outcome after index ischemic stroke. METHODS: This was a prospective observational study. Consecutive eligible patients with acute ischemic stroke were included and followed up for one year. Patients were stratified into tertile groups based on MA levels. TEG-hypercoagulability was defined as an MA of ≥ 69 mm. Ischemic events were defined as a composite of ischemic stroke, myocardial infarction, or vascular death (excluding hemorrhagic death). The functional outcome was evaluated by modified Rankin Scale (mRS). Unfavorable functional outcome was defined as mRS ≥ 2. RESULTS: Two hundred and eleven patients were enrolled with 27 lost to follow-up at one year contact. At baseline, 38 (18.0%) patients were TEG-hypercoagulopathy after the treatment of antiplatelets. Patients with higher tertile of MA were more likely to be females, and had lower hemoglobin levels, higher platelet counts, higher fibrinogen levels, higher white blood cell counts, as well as higher ESR and hsCRP levels. Patients in the third tertile group were more likely to have intracranial artery stenosis and large-vessel subtype stroke than those in the other two groups. Higher tertile of MA was also related to stroke severity in acute phase (higher NIHSS scores on admission and longer in-hospital stay). At one year of follow-up, a higher percentage of unfavorable functional outcome and a non-significant trend of higher ischemic event rate were observed in higher MA tertile groups. Multivariate logistic analysis revealed that higher MA level (OR = 1.192, p = 0.022) was an independent predictor for unfavorable one-year functional outcome. Other independent predictors included old age (OR = 1.119, p = 0.001), diabetes mellitus (DM) (OR = 4.280, p = 0.014), previous ischemic stroke/TIA history (OR = 4.953, p = 0.008), and higher NIHSS scores on admission (OR = 1.437, p = 0.001). CONCLUSIONS: We found that higher TEG-MA levels could predict an unfavorable functional outcome after index ischemic stroke. Further, large-scale studies are required to investigate the relationship between MA levels and risk of recurrent ischemic events in ischemic stroke patients.