The guidelines

The new joint guidelines from the American Heart Association (AHA) and the American College of Cardiology (ACC) for non-ST-elevation acute coronary syndromes (NSTE-ACS) represent the culmination of a massive undertaking to synthesise a large body of evidence, and the guideline writing committee is to be applauded for their efforts in preparing these guidelines.1 ,2 As is the current standard, the online version of these guidelines was published ahead of print, and review of the electronic publication ahead of print revealed that the handling of enoxaparin was problematic.1 The problem concerned the discussion of giving an initial 30 mg intravenous loading dose of enoxaparin prior to administering 1 mg/kg of enoxaparin subcutaneously every 12 h (q12h) when enoxaparin is selected as the anticoagulant. The electronic version published ahead of the print version simply stated “An initial intravenous loading dose is 30 mg.” (ref. 1, p.42). This or similar phrasing appeared on page 43 in the text and in table 7 as well. These statements are accompanied by a grade of A for level of evidence.

However, although the final guideline now says the initial 30 mg intravenous loading dose “has been used in selected patients” (ref. 2, pp.164–5), and thus does seem to make it clear that the loading dose is not mandatory, the guideline still does not adequately convey the details of the literature with respect to use of enoxaparin in NSTE-ACS.2 Guideline documents are plagued by space limitations in the setting of endeavours to summarise a large body of evidence, and this certainly may have contributed to the limited discussion of the data pertaining to the use of enoxaparin, but the details in this instance are important for clinicians to bear in mind when selecting enoxaparin as the anticoagulant when managing NSTE-ACS.

Pursuing the evidence

The only randomised controlled trial (RCT) that …