[Comparison of short-to medium-term ischemia and bleeding risks between unfractionated heparin and bivalirudin in patients with acute coronary syndrome after PCI].

<b>Objective:</b> To compare the short-and medium-term ischemia and bleeding risk between unfractionated heparin and bivalirudin in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). <b>Methods:</b> A total of 742 patients with ACS who underwent emergency PCI in Xinxiang Central Hospital of Henan Province from January 2016 to June 2022 were selected and divided into unfractionated heparin group (385 cases) and bivalirudin group (357 cases) according to the anticoagulant regimen. All patients were followed up for 6 months. The incidence of ischemic and bleeding events at 30 days and 6 months after operation were compared between the two groups. Multivariate Cox proportional regression model was used to analyze the risk factors of ischemic and bleeding events in the two groups. Kaplan Meier method was used to calculate the cumulative survival rate, and log rank method was used to analyze the difference in survival rates. <b>Results:</b> The age of 742 patients was (62.5±14.8) years old, and male accounted for 58.5% (434 cases). The age of unfractionated heparin group was (61.8±14.8) years old, and male accounted for 59.2% (228 cases); The age of bivalirudin group was (63.3±14.8) years old, and male accounted for 57.7% (206 cases). The incidence of bleeding events at 30 days and 6 months in the unfractionated heparin group were 6.8% (26 cases) and 9.9% (38 cases), respectively, which were higher than 3.4% (12 cases) and 4.5% (16 cases) in the bivalirudin group (all <i>P</i>0.05); The incidence of ischemic events at 30 days and 6 months in the unfractionated heparin group were 7.5% (29 cases) and 11.2% (43 cases), respectively, which were not observed to be significantly different with those in the bivalirudin group [6.2% (22 cases) and 9.5% (34 cases)] (all <i>P</i>0.05). Compared with patients using bivalirudin, the <i>HR</i> value (95%<i>CI</i>) of bleeding events after emergency PCI in patients using unfractionated heparin was 1.964 (1.317-3.125) (<i>P</i>0.05), and the <i>HR</i> value (95%<i>CI</i>) of ischemic events was 0.948(0.595-1.510) (<i>P</i>0.05). The cumulative incidence of bleeding events was 9.9% in unfractionated heparin group and 4.5% in bivalirudin group (<i>P</i>=0.005); The cumulative incidence of ischemic events was 11.2% in unfractionated heparin group and 9.5% in bivalirudin group (<i>P</i>=0.459). <b>Conclusions:</b> The incidence of short-term hemorrhage events in ACS patients treated with bivalirudin anticoagulation after emergency PCI is lower than that of unfractonated heparin, which can reduce the risk of short-term hemorrhage.