Clot Strength as Measured by Thrombelastography Correlates with Platelet Reactivity in Stroke Patients

Abstract

Objective: Platelet reactivity may be important in the management of patients with stroke. However, degree of platelet reactivity has not been correlated with Thrombelastography (TEG(®)) parameters in stroke. We sought to detect a correlation between TEG(®) values and clot platelet reactivity in ex vivo clots of stroke patients.

Methods: We collected venous blood from 40 patients with stroke. TEG(®) measurements were carried out and residual clots were fixed in 10% formalin immediately following completion of TEG(®). The formalin specimens were embedded in paraffin blocks, cut at 4 micrometers, and stained with CD 61 (immunohistochemical stain used to detect platelets) with appropriate controls. Under light microscopy, three pathologists blinded to TEG(®) results independently graded CD61 intensity (how aggregated/intense the CD61 stained) into a low and high group, as a proposed measurement representing the platelet reactivity of the clot. We compared pre-tPA-TEG(®) values among groups with different CD 61 intensities.

Results: After adjusting for confounding factors, we found statistically significant correlation between CD61 staining and several TEG(®) parameters (Delta and CD61 staining intensity (p=0.047); Angle and CD61 staining intensity grade (p=0.04); and G and CD61 staining intensity grade (p=0.04)).

Conclusions: Clot strength on TEG(®) as measured by Delta, Angle, and G correlates with a clot with greater platelet reactivity.