to assess relation ofhigh functional activity ofplatelets to prognosis ofunfavorable cardiovascular events in patients with Acute Coronary Syndrome (ACS).The study was based on the data of a single center ACS registry conducted in the Central Clinical Hospital of the Presidential Affairs Department of Russian Federation. Of 529 included patients in 425 without contraindications to double antiplatelet therapy we carried out analysis of dependence of 30 days level of unfavorable events on parameters of functional activity of platelets.High on-treatment platelet reactivity (HTPR) was found to be associated with 3.5 increase of mortality in the group of patients with high cardiovascular risk. Logistic model of prognosis of unfavorable events based on multifactorial analysis of data from patients with measured platelet aggregation included chronic kidney disease, type of myocardial infarction, and degree ofplatelet aggregation >45%. C -statistic was equal to 0.77. We also present in this paper discussion of problems related to studying approaches to individualization of anti-aggregation therapy in real clinical practice and problems of organization ofsimilar studies.The study showed that patients with ACS increased platelet aggregation, as well as chronic kidney disease and type 2 MI are associated with a 30 day prognosis of adverse events.