The HORIZONS-AMI trial compared bivalirudin with heparin plus a glycoprotein IIb/IIIa inhibitor in 3602 patients with ST-segment elevation myocardial infarction undergoing primary PCI. Bivalirudin alone reduced 30-day rates of major bleeding (4.9% vs. 8.3%) and net adverse clinical events (9.2% vs. 12.1%) compared to the control group. It also reduced cardiac death (1.8% vs. 2.9%) and all-cause death (2.1% vs. 3.1%). However, bivalirudin was associated with a higher risk of acute stent thrombosis within 24 hours (1.3% vs. 0.3%), though this risk decreased by 30 days. Bivalirudin was associated with lower rates of thrombocytopenia and blood transfusions. The study showed that bivalirudin reduced major bleeding and adverse clinical events without increasing the risk of stent thrombosis over 30 days. The trial was well-designed, with high compliance and low bias. The results suggest that bivalirudin is a safer alternative to heparin plus glycoprotein IIb/IIIa inhibitors in patients with ST-segment elevation myocardial infarction undergoing primary PCI. The study was supported by the Cardiovascular Research Foundation and other organizations. The authors reported potential conflicts of interest. The trial was conducted in multiple countries and involved a large number of patients. The study provides strong evidence that bivalirudin is effective and safe for patients with ST-segment elevation myocardial infarction undergoing primary PCI.The HORIZONS-AMI trial compared bivalirudin with heparin plus a glycoprotein IIb/IIIa inhibitor in 3602 patients with ST-segment elevation myocardial infarction undergoing primary PCI. Bivalirudin alone reduced 30-day rates of major bleeding (4.9% vs. 8.3%) and net adverse clinical events (9.2% vs. 12.1%) compared to the control group. It also reduced cardiac death (1.8% vs. 2.9%) and all-cause death (2.1% vs. 3.1%). However, bivalirudin was associated with a higher risk of acute stent thrombosis within 24 hours (1.3% vs. 0.3%), though this risk decreased by 30 days. Bivalirudin was associated with lower rates of thrombocytopenia and blood transfusions. The study showed that bivalirudin reduced major bleeding and adverse clinical events without increasing the risk of stent thrombosis over 30 days. The trial was well-designed, with high compliance and low bias. The results suggest that bivalirudin is a safer alternative to heparin plus glycoprotein IIb/IIIa inhibitors in patients with ST-segment elevation myocardial infarction undergoing primary PCI. The study was supported by the Cardiovascular Research Foundation and other organizations. The authors reported potential conflicts of interest. The trial was conducted in multiple countries and involved a large number of patients. The study provides strong evidence that bivalirudin is effective and safe for patients with ST-segment elevation myocardial infarction undergoing primary PCI.