Effects of Asymptomatic Abdominal Aortic Aneurysm on the Soluble Coagulation System, Platelet Count and Platelet Activation

AbstractObjectives: the aim of the study was to determine the effects of infrarenal asymptomatic abdominal aortic aneurysm (AAA) on platelet count and activation. Design: prospective clinical study in a University Department of Vascular Surgery. Patients: one hundred and five patients with AAA. Thirty-two control patients with symptomatic carotid artery stenoses. Methods: platelet count (PC), plasma glycocalicin levels, prothrombin ratio (PTR), activated partial thromboplastin time (APPT), fibrinogen and D-dimer were measured in 23 patients with AAA and 16 control patients with symptomatic carotid artery stenoses. PC alone was measured in a further 84 patients with AAA and 16 with carotid artery stenoses. Results: PC was below the normal range in 8/105 patients and mean PC (215×109/l,S.D. 47.5) was significantly lower than that of a control population (242×109/l, S.D. 16.8) and patients with carotid disease (269×109/l, S.D. 57). Glycocalicin level was above the normal range in 7/23 patients and the median level (28 fg/plt) was significantly higher than that of a normal population (21.6 fg/plt) and patients with carotid disease (12.3 fg/plt). Fibrinogen levels, PTR and APPT were all within the normal range. One patient had a minimally elevated level of D-dimer. Conclusions: the combination of low PC and high glycocalicin levels suggests that there is increased platelet destruction, most likely due to activation within the aneurysm sac