Guidelines on heparin use To summarize the above observations, enoxaparin and UFH appear to be of equal efficacy when patients with UA and NSTEMI are evaluated in the aggregate. However, patients who are managed by a conservative strategy appear to have fewer adverse cardiovascular events when treated with enoxaparin compared to UFH. On the other hand, for patients undergoing an early invasive strategy, UFH may be preferable due to the increased risk of bleeding with enoxaparin seen in the SYNERGY trial. (See "SYNERGY trial of use in PCI" above).
The 2007 American College of Cardiology/American Heart Association (ACC/AHA) guidelines on non-ST elevation ACS reached the following conclusions concerning the role of enoxaparin and UFH in such patients [49] :
* Among patients in whom a conservative strategy is selected, either enoxaparin or UFH was recommended, but it was considered reasonable (a weaker recommendation) to prefer enoxaparin (or fondaparinux). The recommended duration of therapy was enoxaparin for the duration of hospitalization (maximum eight days) or UFH for 48 hours.
* Among patients at increased risk for bleeding, fondaparinux was preferred. .
* Among patients in whom coronary artery bypass graft surgery (CABG) is planned within the next 24 hours. UFH was preferred because its anticoagulant effect can be more rapidly reversed than that of enoxaparin. In patients already being treated with enoxaparin, enoxaparin should be discontinued and the patient should be switched to UFH at a dose consistent with institutional practice.
* Among patients who undergo PCI, it was recommended that anticoagulant therapy be discontinued after the procedure in uncomplicated cases.
* Among patients in whom medical therapy is selected after coronary angiography and a heparin has been given prior to angiography, enoxaparin should be continued for the duration of hospitalization (maximum eight days) and UFH should be continued for at least 48 hours or until discharge.