Glucose

Abstract

Biomarkers are used to establish a diagnosis, provide prognostic information, and guide therapeutic interventions in patients with acute coronary syndromes. In acute myocardial infarction (AMI), white blood cell count, creatine kinase–MB isoenzymes, myoglobin, and troponin are measured for 1 or more of these purposes. Recently, brain natriuretic peptide (a measure of hemodynamic stress), interleukin-6, C-reactive protein, and soluble CD40 ligand (indices of inflammation) have been added. The plasma glucose level at the time of AMI has been a curious but distant cousin to this list. The level of glycemia correlates with short- and long-term prognosis and can also serve as a target for intervention (with insulin). In addition, the glycemic response to the stress of AMI provides important information about the metabolic status of the patient. As a result of the increasing prevalence of insulin-resistant states, hyperglycemia will be encountered more frequently in patients with AMI.1–3 Many cardiologists may be intimidated by the implications of hyperglycemia because glucose metabolism is not part of the core curriculum of cardiology today. In this issue of Circulation , Kosiborod et al4 studied the interactions between levels of glycemia and cardiovascular outcomes during AMI. Article p 1018 It is well known that, in the setting of an AMI, hyperglycemia is associated with adverse outcomes, even after adjustment for numerous “cardiac” variables linked to outcome. Previous studies have shown that an elevated plasma glucose level on admission is a major independent predictor of in-hospital and long-term outcome in patients with AMI.5,6 Moreover, fasting glucose level on the day after admission and failure of an elevated glucose level to fall within 24 hours of admission have been shown to be better predictors of early death in patients with AMI than the glucose level on admission.7,8 At these time points in the course …