Abstract:Objective To investigate the association of platelet endothelial aggregation receptor 1 (PEAR1) gene polymorphism with aspirin resistance and prognosis after percutaneous coronary intervention (PCI) in patients with coronary heart disease.? Methods A total of 135 patients with coronary heart disease receiving PCI from June 2015 to March 2017 were selected as the research objects. According to gene polymorphism of PEAR1 at rs1204133 locus, the patients were divided into wild type (GG) group (n=34) , heterozygous mutation type (GA) group (n=72) and homozygous mutation type (GA) group (n=29). The patients in three groups were treated with aspirin after PCI. The platelet aggregation and activation indexes and the levels of serum cyclooxygenase 1 (COX1), cyclooxygenase 2 (COX2), thromboxane A2 (TXA2) and prostaglandins (PGs) before and after treatment were compared in three groups, the clinical efficacy and prognosis of patients in three groups were evaluated after the application of aspirin.? Results PEAR1 gene had single nucleotide polymorphism (SNP) at the rs1204133 locus ( gene mutation of G to A ), so there were three genotypes at the rs1204133 locus:wild type (GG), homozygous mutation type (GA) and homozygous mutation type (AA ), and their genotype frequencies were 25. 19%, 53. 33% and 21. 48%, respectively. Compared with pre-operation, platelet aggregation rate, P selectin and platelet membrane glycoprotein (GP) IIb/ IIIa after PCI in wild type group and heterozygous mutation type group decreased significantly (all P<0.01). After PCI operation, platelet aggregation rate, P selectin and ＧＰⅡｂ／Ⅲａ in wild type group were significantly lower than those in homozygous mutation type group and heterozygous mutation type group (all P<0.05) , and there were significant differences in platelet aggregation rate, P selectin and ＧＰⅡｂ／Ⅲａ between heterozygous mutation type group and homozygous mutation type group (all P<0.01) , while lymphocyte antigen CD62P decrease in wild type group only (P<0.05). Compared with homozygous mutation type group, the platelet aggregation rate and the levels of serum COX1, COX2, TXA2, PGs decreased, and platelet inhibition rate and total effective rate increased, and the total incidence of complications decreased after PCI in wild type group and heterozygous mutation type group. Compared with heterozygous mutation type group, the platelet aggregation rate and the levels of serum COX1, COX2, TXA2, PGs decreased, and platelet inhibition rate and total effective rate increased, and the total incidence of complications decreased after PCI in wild type group (all P<0.01). There were significant differences in the platelet aggregation rate, platelet inhibition rate, the levels of serum COX1, COX2, TXA2, PGs, total effective rate and incidence of complications in three groups (all P<0.01).? Conclusion After PCI for patients with coronary heart disease, the effect of aspirin therapy was closely related to the polymorphism of PEAR1 gene. The wild type has the best response to aspirin, and the heterozygous mutation type has general response to aspirin, and the homozygous mutation type has serious resistance to aspirin which will affect the prognosis.