State-of-the-Art Review : Evaluation of the Clot Signature Analyzer as a Hemostasis Test in Healthy Volunteers Exposed to Low Doses of Aspirin

Several variables affect bleeding time that make it difficult to obtain consistent measurements. The Clot Signature Analyzer (CSA) has been developed to assess in vitro hemo stasis using well-controlled flow chambers. In this study, the equivalencies in the CSA parameters with the conventional bleeding time or platelet aggregation methods were evaluated in subjects exposed to aspirin. The CSA parameters, platelet hemostasis time (PHT) and collagen-induced thrombus forma tion (CITF), were compared to bleeding time (Surgicutt2®) and collagen-induced platelet aggregation, respectively. Fifty-three healthy volunteers were given two doses of aspirin (81 and 243 mg) in one day. Following the baseline period, the volunteers took 81 mg of aspirin and then took 243 mg 2 hours later. The changes in each value from the baseline to that at either aspirin dose (2 hours after dosing) were evaluated. Platelet hemostasis time and CITF correlated well with bleeding time and aggre gation, respectively, but PHT was not sign...