title: Hyperglycemia in acute coronary syndromes: from mechanisms to prognostic implications.
abstract: Hyperglycemia is a frequent condition in patients with acute coronary syndromes (ACS). Hyperglycemia during ACS is caused by an inflammatory and adrenergic response to ischemic stress, when catecholamines are released and glycogenolysis induced. Although the involved pathophysiological mechanisms have not yet been fully elucidated, it is believed that hyperglycemia is associated with an increase in free fat acids (which induce cardiac arrhythmias), insulin resistance, chemical inactivation of nitric oxide and the production of oxygen reactive species (with consequent microvascular and endothelial dysfunction), a prothrombotic state, and vascular inflammation. It is also related to myocardial metabolic disorders, leading to thrombosis, extension of the damaged area, reduced collateral circulation, and ischemic preconditioning. In the last few years, several observational studies demonstrated that hyperglycemia in ACS is a powerful predictor of survival, increasing the risk of immediate and long-term complications in patients both with and without previously known diabetes mellitus. Glucose management strategies in ACS may improve outcomes in patients with hyperglycemia, perhaps by reducing inflammatory and clotting mediators, by improving endothelial function and fibrinolysis and by reducing infarct size. Recent clinical trials of insulin in ACS have resulted in varying levels of benefit, but the clinical benefit of an aggressive treatment with insulin is yet unproved.
authors.affiliation: Division of Cardiology and Cardiovascular Pathophysiology, Hospital S.M. della Misericordia, Perugia, Italy fangeli@cardionet.it.
authors.forename: Fabio
authors.initials: F
authors.lastname: Angeli
authors.affiliation: Department of Internal Medicine, University of Perugia, Perugia, Italy.
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Reboldi
authors.affiliation: Department of Cardiology, University Hospital of Terni, Terni, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Poltronieri
authors.affiliation: Department of Cardiology, University Hospital of Terni, Terni, Italy.
authors.forename: Ludovico
authors.initials: L
authors.lastname: Lazzari
authors.affiliation: Department of Cardiology, University Hospital of Terni, Terni, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Sordi
authors.affiliation: Department of Internal Medicine, Hospital of Assisi, Assisi, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Garofoli
authors.affiliation: Department of Internal Medicine, Hospital of Assisi, Assisi, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Bartolini
authors.affiliation: Department of Internal Medicine, Hospital of Assisi, Assisi, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Verdecchia
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000150:complications* / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D018570:Risk Assessment; D012307:Risk Factors; D013312:Stress, Physiological; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007004:Hypoglycemic Agents
keywords: acute coronary syndrome; glycemic control; hyperglycemia; myocardial infarction; prognosis