RESUMO
Measurements of platelet reactivity and assessment of the efficacy of antiplatelet drugs are widely recognized as pre-requisite for the diagnosis and treatment of stroke patients. A recently established shear-induced platelet reactivity test using non-anticoagulated blood (the Global Thrombosis Test) has facilitated measurements of physiologically relevant platelet function and thrombolytic activity. 195 healthy volunteers, not taking antiplatelet drugs or anticoagulants, and 185 patients with acute cerebrovascular diseases were enrolled. The effect of antiplatelet drugs on platelet function and thrombolytic activity was assessed using the Global Thrombosis Test after 14 days of medication. The occlusion time (OT), an index of platelet reactivity, in healthy controls was 284.9 ± 92.2 s. The lysis time (LT), an index of thrombolytic activity, in healthy controls was 2,231 ± 1,223 s. Both times had no significant difference between males and females. The OT of all stroke patients was 210.3 ± 140.8 s and was shorter than that of the healthy controls (284.9 ± 92.2, p < 0.0001). The LT of all stroke patients was 3,159 ± 1,549 s and was longer than that of the controls (2,231 ± 1,223, p < 0.0001). Medication significantly prolonged the OT from 184.5 ± 150.6 s (before) to 295.3 ± 208.1 s (after) in all patients, indicating a reversal of the hyper-platelet reactivity. In addition, medication shortened the LT from 3,924 ± 1,718 s (before) to 3,107 ± 1,794 s (after) in all patients. A prothrombotic state exists in stroke patients due to enhanced platelet function and suppressed thrombolytic activity. Medication improved these physiological parameters of haemostasis.
