Aim.To give comparative characteristics of the prevalence of polymorphic alleles in the genes of the hemostatic system PAI-1 (-675 5G/4G) and FGB (-455 G/A) in patients with sudden cardiac death and those with acute coronary syndrome undergoing coronary artery stenting.Material and methods.Genetic typing of biological material (BM) was performed for the prevalence of polymorphic alleles in two genes of the hemostasis system. BM was selected from people with a diagnosis of coronary artery disease, divided into three comparison groups: I-suddenly deceased citizens with a diagnosis of coronary artery disease, II-patients with ACS who underwent urgent coronary artery stenting, and III-patients with a chronic form of coronary artery disease in whom endovascular surgery was performed as planned.Results.The calculated criterion 2of the prevalence of polymorphisms in the FGB (-455 G/A) and PAI-1 (-675 5G/4G) genes turned out to be more than the critical (tabular) value, which indicates an existing relationship between the presence of IHD and the carriage of one of the polymorphic alleles. Based on the same data, the 2criterion was calculated without taking into account data for a group of healthy citizens. For carriers of the polymorphic allele of the FGB gene (-455 G/A), no statistically significant differences were found. For carriers of the PAI-1 gene polymorphic allele (-675 5G/4G), statistically significant differences were found.Conclusions.ACS with a favorable outcome (subject to emergency surgical intervention) occurs at an earlier age than in patients diagnosed with coronary artery disease who die suddenly. The presence of a mutant allele in the PAI-1 gene (-675 5G/4G) requires further studies in order to expertly assess the death rate in patients after surgery with coronary stenting.