Dangas GD, Mehran R, Nikolsky E et al.; HORIZONS-AMI Trial Investigators. J Am Coll Cardiol 2011;57:2309–16.
In this analysis of HORIZONS-AMI (Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction [MI]) trial data, the authors examined the outcomes of switching from heparin to bivalirudin treatment in patients with ST-segment elevation MI (STEMI) who had received heparin prior to angiography. Consistent with the results of the main trial, the results of this analysis showed that bivalirudin is associated with a lower rate of bleeding events, and also lower rates of short- and long-term cardiac-related mortality. Thus, antithrombin switching appears to be a viable and safe option for STEMI patients who have previously been treated with heparin.
Previous concerns have been raised about antithrombotic agent switching, particularly between unfractionated and low-molecular-weight heparin, resulting in excessive bleeding . For patients with non-ST-segment elevation myocardial infarction (NSTEMI), switching from unfractionated heparin to bivalirudin has been shown to be safe ; however, no data for patients with STEMI are available. The HORIZONS-AMI (Harmonizing Outcomes with Revascularization and Stents in Acute MI) trial was an open-label, randomized, multicenter trial to compare a treatment strategy of unfractionated heparin plus a glycoprotein IIb/IIIa inhibitor (GPI) with bivalirudin monotherapy in patients with acute MI . As treatment with unfractionated heparin is commonly initiated early (prior to angiography), the investigators stratified randomization by pre-enrollment unfractionated heparin use. If the patient was randomized to bivalirudin, bivalirudin treatment was initiated 30 min after the last heparin bolus but prior to percutaneous coronary intervention.