Selected clotting factors in blood of patients with abdominal aortic aneurysms

Tissue factor (TF), tissue factor pathway inhibitor (TFPI) and vascular endothelial growth factor A (VEGF-A) present in vascular structures take part in blood coagulation and in organ revascularisation. The concentration of thrombin-antithrombin complexes (TAT) in blood of patients with abdominal aortic aneurysms (AAA) reflects thrombin-generation.

To determine the concentration of TF, TFPI, VEGF-A and TAT complexes in blood of patients with AAA and to consider if these factors after clot formation can play a role in the pathogenesis of abdominal aortic aneurysms.

Forty eight patients (43 men and 5 women) in the age of 59-80 (mean 72) years with AAA were examined. The blood was drawn in the morning to 3.2% natrium citrate in proportion 9:1. The concentration of TF, TFPI, VEGF-A and TAT complexes were measured in plasma with commercial kits using enzyme immunoassay.

In plasma of patients with AAA the mean concentration of TF was elevated almost twice and TAT complexes were three times higher compared with controls. But the mean levels of TFPI and VEGF-A were similar as in control group.

Increased concentrations of TF and TAT complexes indicate on high thrombin-generation, hypercoagulability and formation in abdominal aortic aneurysm of intraluminal thrombus, which can induce proteolytic processes in aortic wall.