Thromboelastographic Studies in Cerebral Infarction

Abstract

Thromboelastographic Studies in Cerebral Infarction• Blood coagulability in patients following cerebral infarction was studied utilizing the thromboelastograph (TEG). Cerebral infarction patients from two separate institutions were studied within 24 to 48 hours after onset of stroke. Ninety-four stroke patients from one institution and 109 from another yielded a total stroke population of 203 patients for this study. Fifty-nine agematched normals were used as a control group. Frequency distribution curves were determined for a TEG ratio of ma/(r + k). The 59 controls exhibited a normal frequency distribution between the values of 1.6 and 4.0. Both groups of stroke patients revealed an increased number of patients with a ratio exceeding 4.0, suggesting a hypercoagulable state exists following cerebral infarction in approximately 29% to 38% of the patients studied.Additional Key Words clot lysis hypercoagulability platelet function fibrinolysis cerebrovascular disease• Our laboratory has been investigating abnormalities of blood clotting, clot lysis and platelet function in various categories of cerebrovascular disease. One of our objectives has been to identify a simple, reliable and clinically relevant test of blood or plasma which accurately identifies the overall consequences of the separate, yet simultaneously occurring reactions, which collectively result in the balance between clot formation and clot dissolution. A number of "global" tests of coagulation have been described, including the plasma recalcification test, partial thromboplastin time (PTT), the activated partial thromboplastin time, and the whole blood clotting time. All have their limitations with respect to reliability, sensitivity, and lack of correlation with clinically significant clotting or bleeding events. A somewhat different approach to a laboratory measurement of overall coagulation and fibrinolysis, which also is sensitive to platelet dysfunction, has been the development of the thromboelastograph. The thromboelastograph (TEG) provides a continuous recording of the process of blood coagulation and subsequent clot retraction. The instrument is capable of analyzing three blood samples simultaneously ( fig. 1). Stainless steel sample containers maintained at 37°C are set in motion around a vertical axis. A cylindrical dragbar is lowered into the . slowly oscillating metal containers and remains im- This investigation was supported by Research Grant NS03364 from the National Institute of Neurological Diseases and Stroke.Presented at the 46th Scientific Session of the American Heart Association, November 9, 1973, in Atlantic City, New Jersey. mobile as long as the blood or plasma sample is fluid. As the clot forms, the dragbar, suspended by the torsion wire, becomes dynamically coupled to the cup resulting in transmission of the oscillatory rotation of the cup to the cylinder. The cylinder then oscillates with an amplitude governed by the specific mechanical properties of the clot ( fig. 2). A mirror, coupled to the cylinder tors...

Coagulation-fibrinolysis abnormalities in acute and chronic phases of cerebral thrombosis and embolism.

“…A similar tendency persisted in the chronic stage ( Table 2). The fibrinogen concentration exceeded the upper 95% confidence level of controls in 6% (one of 16) of patients with an infarct size smaller than 10 mm 2 , and in 42% (10 of 24) of patients with an infarct size larger than 10 ram. The concentration of plasmin-a 2 plasmin inhibitor complex over the upper 95% confidence level of controls was obtained in 0% (zero of 16) of patients with the smaller infarct size and in 33% (eight of 24) of patients with the larger infarct size.…”

Monitoring heparin therapy with thromboelastography and activated partial thromboplastin time

“…However, it is stated that the incidence of serious bleeding is still 20-25%, regardless of the laboratory measures utilized to monitor the heparin therapy. gery [17], in cerebral infarction [18], and to study the effect of alimentary lipemia on coagulation [10]. The present report represents the first large series of patients whose heparin therapy was monitored clinically using the Thromboelastograph ®.…”

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

“…However, there are limited data about TEG-MA in acute ischemic stroke; Ettinger et al and Elliott et al reported that acute ischemic stroke patients were hypercoagulable compared to normal controls [9,10], and Elliott et al further proved that the treatment with tissue plasminogen activator resulted in reduction of clot strength [10]. We hypothesized that TEG-MA could also predict the ischemic event recurrence after index ischemic stroke.…”