Introduction

It is well established that hyperglycaemia is common in patients admitted to the hospital with acute coronary syndrome (ACS), and is an an independent risk factor for adverse outcome.1 ,2 A significant proportion of these patients with ACS and hyperglycaemia will not previously have been diagnosed with diabetes mellitus, and not all of them will automatically turn out to be diabetic in the long term.2 It is therefore unsurprising that a number of studies have tried to evaluate the best way to manage hyperglycaemia in ACS.3–6 However, the results have been mixed, contradictory on occasion, and even identified for potential for harm. The waters are muddied further by significant heterogeneity between studies across important factors, such as: the patient populations studied (eg, hyperglycaemic ACS patients,3 versus intensive insulin therapy in unselected ACS patients with or without hyperglycaemia6); and the nature and efficacy of intensive insulin therapy under evaluation (eg, the patients treated with an intensive insulin regimen in DIGAMI-2 did not achieve as good a glycaemic control as intended4). There is a correspondingly wide variation in practice, and it is for this reason that NICE was asked to evaluate the evidence and produce a clinical guideline to guide contemporary practice in this area in England and Wales.7