The role of insulin therapy and glucose normalisation in patients with acute coronary syndrome

Patients with acute myocardial infarction (AMI) and diabetes mellitus, as well as patients admitted with elevated blood glucose without known diabetes, have impaired outcome. Therefore intensive glucose-lowering therapy with insulin (IGL) has been proposed in diabetic or hyperglycaemic patients and has been shown to improve survival and reduce incidence of adverse events. The current manuscript provides an overview of randomised controlled trials investigating the effect of IGL. Furthermore, systematic glucose–insulin–potassium infusion (GIK) has been studied to improve outcome after AMI. In spite of positive findings in some early studies, GIK did not show any beneficial effects in recent clinical trials and thus this concept has been abandoned. While IGL targeted to achieve normoglycaemia improves outcome in patients with AMI, achievement of glucose regulation is difficult and carries the risk of hypoglycaemia. More research is needed to determine the optimal glucose target levels in AMI and to investigate whether computerised glucose protocols and continuous glucose sensors can improve safety and efficacy of IGL

Glucose-Insulin Therapy, Plasma Substrate Levels and Cardiac Recovery After Cardiac Ischemic Events

INTRODUCTION: The potential usefulness of glucose-insulin therapy relies to a large extent on the premise that it prevents hyperglycemia and hyperlipidemia following cardiac ischemic events. METHODS: In this review we evaluate the literature concerning plasma glucose and free fatty acids levels during and following cardiac ischemic events. RESULTS: The data indicate that hyperlipidemia and hyperglycemia most likely occur during acute coronary ischemic syndromes in the conscious state (e.g. acute myocardial infarction) and less so during reperfusion following CABG reperfusion. This is in accordance with observations that glucose-insulin therapy during early reperfusion post CABG may actually cause hypolipidemia, because substantial hyperlipidemia does not appear to occur during that stage of cardiac surgery. DISCUSSION: Considering recent data indicating that hypolipidemia may be detrimental for cardiac function, we propose that free fatty acid levels during reperfusion post CABG with the adjunct glucose-insulin therapy need to be closely monitored. CONCLUSION: From a clinical point of view, a strategy directed at monitoring and thereafter maintaining plasma substrate levels in the normal range for both glucose (4-6 mM) and FFA (0.2-0.6 mM) as well as stimulation of glucose oxidation, promises to be the most optimal metabolic reperfusion treatment following cardiac ischemic episodes. Future (preclinical and subsequently clinical) investigations are required to investigate whether the combination of glucose-insulin therapy with concomitant lipid administration may be beneficial in the setting of reperfusion post CAB