Use of the anticlotting drug bivalirudin results in less complications/clinical events in heart attack patients undergoing angioplasty than does use of the conventional treatment of heparin plus a glycoprotein inhibitor (GPI). The findings of the HORIZON-AMI study are reported in an Article Online First and in an upcoming edition of the Lancet, by Dr Roxana Mehran, Columbia University Medical Center, New York, USA. Data from the trial will be presented at the European Society of Cardiology meeting, Barcelona.
The first results from HORIZONS-AMI were reported last year. The study assessed patients with a category of heart attack called ST-segment elevation myocardial infarction (STEMI)—so called because the electrocardiogram of these patients shows a particular pattern. The results reported last year showed that STEMI patients 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 (NACE) compared with patients assigned to heparin plus a GPI. In this study, the authors assessed whether these initial benefits were maintained at 1 year of follow-up.
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 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). There were two primary trial endpoints—the first was major bleeding only; the second was NACE, which consisted of major bleeding or composite major adverse cardiovascular events (MACE-death, reinfarction, target vessel revascularisation for ischaemia, or stroke).
One-year data were available for 1696 patients in the bivalirudin group and 1702 patients in the control group. The main reason for participant dropout was loss to follow-up. The rate of NACE was lower in the bivalirudin group than in the control group (15•6% vs 18•3%—a relative reduction of 17% for the bivalirudin group), as a result of a lower rate of major bleeding in the bivalirudin group (5•8% vs 9•2%, or 39% lower for the bivalirudin group). The rate of MACE was similar between groups (11•9% vs 11•9%). The 1-year rates of cardiac mortality (2•1% vs 3•8%) and all-cause mortality (3•5% vs 4•8%) were substantially lower in the bivalirudin group than in the control group.
The authors conclude: "This 1-year analysis of the HORIZONS-AMI trial shows that in high-risk patients with STEMI undergoing primary PCI, procedural anticoagulation with bivalirudin alone seemed to reduce haemorrhagic complications, late reinfarction, and early and late cardiac and all-cause mortality compared with unfractionated heparin plus the routine use of a GPI... This finding has important clinical implications for the selection of optimum treatment strategies for patients with STEMI."
In an accompanying Comment, Dr Ranil de Silva and Professor Kim Fox, Royal Brompton and Harefield NHS Foundation Trust and National Heart and Lung Institute, Imperial College London, UK say that the HORIZONS-AMI results 'provide the rationale for considering bivalirudin monotherapy in patients with ST elevation acute coronary syndromes receiving primary percutaneous coronary intervention'. They add this strategy should be preferred in patients with the highest bleeding risk.
Dr Roxanna Mehran, Columbia University Medical Center, New York, USA. T) +1 646-331-3921 E) rm2266@columbia.edu
Dr Ranil de Silva, Royal Brompton and Harefield NHS Foundation Trust and National Heart and Lung Institute, Imperial College London, UK. T) +44 (0) 7890 602451 E) r.desilva@imperial.ac.uk
For full Article and Comment, see: http://press.thelancet.com/eschorizons.pdf
Journal
The Lancet