In the HORIZONS-AMI (Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction) trial, the direct thrombin inhibitor bivalirudin was found to lower 30-day rates of net adverse clinical events and and haemorrhagic complications in AMI when compared to treatment with heparin and a glycoprotein IIb/IIIa inhibitor (GPI).  The trial investigators examined whether these initial benefits could still be seen after one year of follow-up.

3602 patients were assigned to either treatment regime in a 1:1 ratio; the two primary trial endpoints were major bleeding and net adverse clinical events (NACE).  1-year data were available for 1696 patients in the bivalirudin group and 1702 patients in the control group.    The rate of NACE was lower in the bivalirudin group than in the control group (15.6% vs. 18.3%, p=0.022), due to a lower rate of major bleeding in the bivalirudin group.  However when major bleeds were not included, major adverse clinical events (stroke, death, reinfarction, target vessel revascularisation for ischaemia) were similar (11.9% vs. 11.9%; p=0.005).  1-year rates of cardiac mortality, and all-cause mortality, were both lower in the bivalirudin group that the control group, regardless of the stent type the patient was randomised to (see figure – link below).
Conclusions:
In patients undergoing primary PCI, anticoagulation using bivalirudin reduced net adverse clinical events and major bleeding at one year when compared to conventional therapy (heparin plus glycoprotein inhibitor).  Of note, significantly lower rates of recurrent myocardial infarction were noted in the high-risk patient group when treated with bivalirudin.
• Mehran R, Lansky AJ, Witzenbichler B et al.  Bivalirudin in patients undergoing primary angioplasty for acute myocardial infarction (HORIZONS-AMI): 1-year results of a randomised controlled trial