目的 观察急性冠脉综合征(acute coronary syndromes, ACS)患者血小板聚集性及血小板活化指标P选择素、膜GPⅡb/Ⅲa的变化。探讨活化血小板在ACS急性冠脉综合征发病中的作用。方法　选取健康体检者52名为正常对照组，ACS患者89例，按其病情分为不稳定心绞痛 (unstable angina, UA) 组43例，急性心肌梗死 (acute myocardial infarction, AMI) 组46例。检测两组对象的血小板聚集率及血小板表面表达的P选择素、膜GPⅡb/Ⅲa表达率等活化指标。结果 与正常对照组比较，UA组患者血小板聚集率、血小板P选择素、膜GPⅡb/Ⅲa表达率均明显升高，差异有统计学意义 (P均＜0.001)；ACS患者中，AMI 组与UA组比较，血小板聚集率、血小板P选择素、膜GPⅡb/Ⅲa表达率均明显升高，差异有统计学意义(P均＜0.001)。结论 随着ACS患者病情加重，血小板活化水平明显升高，聚集功能明显增强，血小板功能异常改变与急性冠脉综合征病情轻重有密切关系。

Objective To observe platelet aggregation and changes of platelet activation indexes including P-selection and membrane GP IIb/IIIa in patients with acute coronary syndromes (ACS) and to explore the role of activated platelets in the pathogenesis of ACS. Methods 52 healthy people were selected as the normal control group, while 89 patients with ACS were selected and divided into two observation groups: UA group (unstable angina, n=43) and AMI group (acute myocardial infarction, n=46). The platelet aggregation rate and activation indexes expressed on the surface of platelet such as p-selection and membrane GP IIb/IIIa were detected in patients with ACS. Results Compared to the normal control group, the rate of platelet aggregation in UA group was obviously enhanced (P<0.001); the platelet p-selection and membrane GP IIb/IIIa were also significantly increased with significant differences (P<0.001). For ACS patients, compared to UA group, patients of AMI group had significantly higher platelet aggregation rate (P<0.001); and obviously higher platelet p-selection and membrane GP IIb/IIIa (P<0.001). Conclusion  As the aggregation of disease in patients with ACS, the platelet activation level is increased greatly and the aggregation function is enhanced obviously. The abnormal changes of platelet functions in patients with ACS are closely related to the level of diseases.