Use of the anti-clotting drug bivalirudin (Angiomax, The Medcines Company) 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) at one year of follow up, according to findings of the HORIZON-AMI randomized, controlled trial presented Sunday at the European Society of Cardiology (ESC) Congress in Barcelona, Spain.
The first results from HORIZONS-AMI were reported last year. The study, which assessed STEMI patients undergoing PCI who were treated with the thrombin inhibitor bivalirudin, showed that they had substantially lower 30-day rates of major hemorrhagic complications and net adverse clinical events (NACE) compared with patients assigned to heparin plus a GPI. In this follow-up study, simultaneously published in the Lancet, the authors assessed whether these initial benefits were maintained at one year.
Study presenter and lead author Roxana Mehran, MD, from Columbia University Medical Center in New York City, reported that patients aged 18 years or older were eligible for enrollment in this multicenter, open-label trial if they had STEMI, presented within 12 hours after the onset of symptoms, and were undergoing primary PCI. A total of 3,602 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; 1,800 patients) or heparin plus a GPI (control; 60 IU/kg intravenous bolus followed by boluses with target activated clotting time 200-250 s; 1,802 patients).
There were two primary trial endpoints—the first was major bleeding only; the second was net adverse coronary events (NACE), which consisted of major bleeding or composite major adverse cardiovascular events (MACE).
One-year data were available for 1,696 patients in the bivalirudin group and 1,702 patients in the control group, according to the authors. The main reason for participant dropout was loss to follow-up.
Mehran reported that rate of NACE was lower in the bivalirudin group than in the control group (15.6 vs. 18.3 percent—a relative reduction of 17 percent for the bivalirudin group), as a result of a lower rate of major bleeding in the bivalirudin group (5.8 vs. 9.2 percent, or 39 percent lower for the bivalirudin group).
However, the researchers also noted that the rate of MACE was similar between groups (11.9 vs. 11.9 percent). The one-year rates of cardiac mortality (2.1 vs. 3.8 percent) and all-cause mortality (3.5 vs. 4.8 percent) were substantially lower in the bivalirudin group than in the control group.
"This one-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 hemorrhagic complications, late reinfarction, and early and late cardiac and all-cause mortality compared with unfractionated heparin plus the routine use of a GPI,” the authors said. “This finding has important clinical implications for the selection of optimum treatment strategies for patients with STEMI."
In an accompanying Lancet commentary, Ranil de Silva, MD, and Kim Fox, PhD, from the Royal Brompton and Harefield NHS Foundation Trust and National Heart and Lung Institute, Imperial College London, wrote that the HORIZONS-AMI results “provide the rationale for considering bivalirudin monotherapy in patients with ST elevation acute coronary syndromes receiving primary PCI.” They added that this strategy should be preferred in patients with the highest bleeding risk.