Bivalirudin in patients undergoing primary angioplasty for acute myocardial infarction (HORIZONS-AMI): 1-year results of a randomised controlled trial

Abstract

Background: In the HORIZONS-AMI trial, patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) who were treated with the thrombin inhibitor bivalirudin had substantially lower 30-day rates of major haemorrhagic complications and net adverse clinical events than did patients assigned to heparin plus a glycoprotein IIb/IIIa inhibitor (GPI). Here, we assess whether these initial benefits were maintained at 1 year of follow-up.

Methods: Patients aged 18 years or older were eligible for enrolment in this multicentre, open-label, randomised controlled trial if they had STEMI, presented within 12 h after the onset of symptoms, and were undergoing primary PCI. 3602 eligible patients were randomly assigned by interactive voice response system in a 1:1 ratio to receive bivalirudin (0.75 mg/kg intravenous bolus followed by 1.75 mg/kg per h infusion; n=1800) or heparin plus a GPI (control; 60 IU/kg intravenous bolus followed by boluses with target activated clotting time 200-250 s; n=1802). The two primary trial endpoints were major bleeding and net adverse clinical events (NACE; consisting of major bleeding or composite major adverse cardiovascular events [MACE; death, reinfarction, target vessel revascularisation for ischaemia, or stroke]). This prespecified analysis reports data for the 1-year follow-up. Analysis was by intention to treat. Patients with missing data were censored at the time of withdrawal from the study or at last follow-up. This trial is registered with ClinicalTrials.gov, number NCT00433966.

Findings: 1-year data were available for 1696 patients in the bivalirudin group and 1702 patients in the control group. Reasons for participant dropout were loss to follow-up and withdrawal of consent. The rate of NACE was lower in the bivalirudin group than in the control group (15.6%vs 18.3%, hazard ratio [HR] 0.83, 95% CI 0.71-0.97, p=0.022), as a result of a lower rate of major bleeding in the bivalirudin group (5.8%vs 9.2%, HR 0.61, 0.48-0.78, p<0.0001). The rate of MACE was similar between groups (11.9%vs 11.9%, HR 1.00, 0.82-1.21, p=0.98). The 1-year rates of cardiac mortality (2.1%vs 3.8%, HR 0.57, 0.38-0.84, p=0.005) and all-cause mortality (3.5%vs 4.8%, HR 0.71, 0.51-0.98, p=0.037) were lower in the bivalirudin group than in the control group.

Interpretation: In patients with STEMI undergoing primary PCI, anticoagulation with bivalirudin reduced the rates of net adverse clinical events and major bleeding at 1 year compared with treatment with heparin plus a GPI. This finding has important clinical implications for the selection of optimum treatment strategies for patients with STEMI.

Funding: Cardiovascular Research Foundation, with unrestricted grant support from Boston Scientific Corporation and The Medicines Company.