Effects of asymptomatic abdominal aortic aneurysm on the soluble coagulation system, platelet count and platelet activation

Objectives: the aim of the study was to determine the effects of infrarenal asymptomatic abdominal aortic aneurysm (AAA) on platelet count and activat ion. Design: prospective clinical study in a University Department of Vascular S urgery. Patients: one hundred and five patients with AAA. Thirty-two control patien ts with symptomatic carotid artery stenoses. Methods: platelet count (PC), plasma glycocalicin levels, prothrombin ratio (PTR), activated partial thromboplastin time (APPT), fibrinogen and D-dime r were measured in 23 patients with AAA and 16 control patients with sympto matic carotid artery stenoses. PC alone was measured in a further 84 patien ts with AAA and 16 with carotid artery stenoses. Results: PC was below the normal range in 8/105 patients and mean PC (215 x 10(9)/l, S.D. 47.5) was significantly lower than that of a control populat ion (242 x 10(9)/l, S.D. 16.8) and patients with carotid disease (269 x 10( 9)/l, S.D. 57). Glycocalicin level was above the normal range in 7/23 patie nts 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 f g/plt). Fibrinogen levels, PTR and APPT were all within the normal range. O ne patient had a minimally elevated level of D-dimer. Conclusions: the combination of low PC and high glycocalicin levels suggest s that there is increased platelet destruction, most likely due to activati on within the aneurysm sac.