Defining the scope of evidence-based practice for low-molecular-weight heparin therapy in high-risk patients with unstable angina and non-ST-elevation myocardial infarction.

Various therapies have been utilized for the treatment of unstable angina and non-ST-elevation myocardial infarction (NSTEMI). Each therapy has both advantages and disadvantages with regard to clinical outcomes and an increased risk of bleeding. One emerging primary therapy is low-molecular-weight heparin (LMWH). Concerns have emerged, however, over the use of LMWH in patients going to the catheterization laboratory or who receive platelet glycoprotein IIb/IIIa inhibitors. Available trial data point to the safety and efficacy of LMWH in these patients. Eventually, LMWH will probably replace unfractionated heparin (UFH) for the majority of patients with acute coronary syndromes (ACS). At present, however, practitioners need to consider individually how comfortable they are with the available data.