Increased platelet and coagulatory activity in peripheral atherosclerosis flow mediated platelet function is a sensitive and specific disease indicator.

The importance of flow in both athero- and thrombogenesis is well established. In peripheral arterial disease (PAD) atherosclerosis is disseminated, thrombosis risk high and systemic hemostatic derangement believed contributory. We studied platelet and coagulatory activity in PAD patients, thereby evaluating the clinical efficacy of Stagnation Point Flow Adhesio-Aggregometry (SPAA). SPAA provides real-time quantitative assessment of platelet adhesion and aggregation under convective, low-shear flow conditions. 62 nondiabetic PAD patients and 66 healthy volunteers were examined, whereby SPAA and conventional aggregometry were performed and circulating fibrinogen, fibrin monomer (FM), the fibrin degradation product D-Dimer and thrombin-antithrombin-complex (TAT) assessed. Conventional aggregometry detected no differences between patients and controls. SPAA-measured platelet function (p < 0.001), fibrinogen (p < 0.001), FM (p < 0.001), TAT (p < 0.02) and D-Dimer (p < 0.001) were significantly increased in patients and not effected by aspirin therapy. Respective sensitivity and specificity in detecting PAD was as follows: SPAA (96%/95%), fibrinogen (36%/92%), FM (46%/88%), TAT (40%/73%), D-Dimer (75%/80%). Increased platelet and coagulatory activity was verified in PAD, whereby flow-mediated platelet adhesion and aggregation proved the most sensitive and specific parameter. These findings indicate the usefulness of SPAA for delineating platelet-related disease mechanisms and evaluating therapeutic strategies to prevent platelet activation.