Whole blood thrombelastographic coagulation profiles using minimal tissue factor activation can display hypercoagulation in thrombosis-prone patients.

OBJECTIVE: Recently, our laboratory devised a dynamic whole blood (WB) thrombelastographic coagulation model employing activation with minute amounts of tissue factor. A series of studies were conducted to validate the feasibility of the model to illustrate hypocoagulation in various bleeding disorders and its usefulness in detecting the haemostatic effect of pro-coagulants by ex vivo titration experiments. In this context, the present study hypothesized that the thrombelastographic model also can reveal hypercoagulation. Hence, the objective of the present study was to record dynamic WB coagulation profiles in a series of patients (n=76) who had previously suffered from a venous (n=34) or arterial (n=42) thrombo-embolic event and to compare the results with those of a group of healthy reference subjects (n=60).
MATERIAL AND METHODS: Patients receiving vitamin K antagonist treatment were not enrolled in the study. Forty-four of the patients had no known thrombophilia risk factor and 32 patients had at least one thrombophilia risk factor.
RESULTS: The most commonly found risk factors were mild hyperhomocysteinaemia and heterozygosity for the factor V Leiden polymorphism. The data showed that, as compared with the healthy controls, patients with a history of venous or arterial thromboembolism had a significantly greater hypercoagulant WB coagulation clot signature as defined by a shortened clotting time together with an accelerated maximum velocity of clot propagation.
CONCLUSIONS: In future studies with ex vivo dose titration assessment of pro-coagulant components mixed with blood from a patient suffering from compromised haemostasis, observation of a significantly shortened clot initiation concomitant with a distinctly accelerated clot propagation is likely to indicate an increased risk of thrombosis.