Gel point and fractal microstructure of incipient blood clots are significant new markers of haemostasis

Introduction

We have investigated the hypothesis that in whole blood the incipient clot formed at the gel point (GP) is characterised by a fractal microstructure [1, 2] and that this could be detected in healthy and anticoagulated blood. We compared the gel time (GT) required to form the incipient clot and the corresponding fractal dimension (d_f) against laboratory markers of haemostasis and thromboelastography (TEG).

Methods

Blood samples were taken from 52 healthy adults and similarly 34 individuals whose blood had been anticoagulated with heparin over the therapeutic range.

Results

The incipient clot in normal blood is established as a sample-spanning network cluster at the GP [2]. The value of d_f in whole healthy human blood is 1.74 (± 0.07), which indicates a high degree of branching in the fibrin network at criticality and is commensurate with that reported to arise in other biological systems. There was a significant reduction in the value of d_f and a corresponding prolongation in the GT in the heparin group as compared with the healthy group (Figure 1).

Figure 1

abstract P26

Conclusion

We describe for the first time that the incipient clot formed at the GP of whole blood is characterised by a fractal microstructure. The values of d_f and GT discriminate between clot structure in healthy and anticoagulated blood. The relationship between these new markers may provide a basis for exploring the relationship between coagulation pathways and clot quality.