The S-100B substudy of the GLUTAMICS trial: glutamate infusion not associated with sustained elevation of plasma S-100B after coronary surgery

Clin Nutr. 2010 Jun;29(3):358-64. doi: 10.1016/j.clnu.2009.09.007. Epub 2009 Oct 22.


Background & aims: Concerns have been raised about potential neurological injury related to exogenous glutamate. In cardiac surgery glutamate has been administered as a putative cardioprotective agent by cardioplegia or intravenous infusion. In the GLUTAMICS trial, in addition to surveillance of clinical neurological injuries, a prespecified subgroup was analyzed with regard to postoperative S-100B levels to detect potential subclinical neurological injury related to glutamate infusion.

Methods: Sixty-nine patients operated on for unstable coronary syndrome were randomized to intravenous infusion of glutamate (n=35) or saline (n=34) perioperatively. Plasma levels of S-100B were obtained on the third postoperative day.

Results: S-100B in the glutamate group and the control group were 0.079+/-0.034microg/L and 0.090+/-0.042microg/L respectively (p=0.245). There were no patients with stroke or mortality. Three patients in the control group and two in the glutamate group had postoperative confusion. These patients had significantly elevated S-100B compared with those without confusion (0.132+/-0.047vs 0.081+/-0.036microg/L; p=0.003). Overall, 21 patients had S-100B above reference level (> or =0.10microg/L) and these patients had significantly more calcifications in the ascending aorta on epiaortic scanning.

Conclusions: Intravenous glutamate infusion during surgery for unstable coronary artery disease did not initiate a sustained elevation of plasma S-100B. Thus, no evidence for subclinical neurological injury related to glutamate infusion was found. In contrast, postoperative elevation of plasma S-100B was linked to calcification of the ascending aorta and postoperative confusion.

Trial registration: NCT00489827.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aorta / diagnostic imaging
  • Aortic Diseases / diagnostic imaging
  • Biomarkers / blood
  • Calcinosis / blood
  • Calcinosis / complications
  • Calcinosis / diagnostic imaging
  • Cardiotonic Agents / administration & dosage
  • Cardiotonic Agents / adverse effects*
  • Cardiotonic Agents / therapeutic use
  • Confusion / blood
  • Confusion / etiology
  • Coronary Artery Bypass* / adverse effects
  • Coronary Artery Bypass* / mortality
  • Coronary Artery Disease / blood
  • Coronary Artery Disease / complications
  • Coronary Artery Disease / surgery
  • Female
  • Glutamic Acid / administration & dosage
  • Glutamic Acid / adverse effects*
  • Glutamic Acid / therapeutic use
  • Humans
  • Infusions, Intravenous
  • Male
  • Middle Aged
  • Nerve Growth Factors / blood*
  • Neurotoxicity Syndromes / blood*
  • Neurotoxicity Syndromes / diagnosis
  • Neurotoxicity Syndromes / etiology
  • Postoperative Complications / blood
  • Postoperative Complications / chemically induced
  • Postoperative Period
  • S100 Calcium Binding Protein beta Subunit
  • S100 Proteins / blood*
  • Ultrasonography


  • Biomarkers
  • Cardiotonic Agents
  • Nerve Growth Factors
  • S100 Calcium Binding Protein beta Subunit
  • S100 Proteins
  • Glutamic Acid

Associated data