title: Significance of troponin elevation after severe traumatic brain injury.
abstract: BACKGROUND
  Elevation of serum troponin (cTnI) after nontraumatic cerebral insult has been associated with an adverse prognosis. This association has not been well documented in traumatic brain injury (TBI).
  
  
  OBJECTIVE
  To evaluate the association and prognostic significance of cTnI elevation in severe TBI. To evaluate the role of beta-blocker (BB) therapy in TBI patients with elevated cTnI.
  
  
  METHODS
  Retrospective review of all blunt trauma patients with severe TBI (head Abbreviated Injury Scale score [AIS] >/=3) admitted to the intensive care unit (ICU) with serial TnI measurements at a Level I trauma center from January 1998 to December 2005. Patients with AIS score >/=3 to other body regions were excluded. Univariate and multivariate logistic regression was performed to determine prognostic significance of TnI elevation.
  
  
  RESULTS
  There were 420 severe blunt TBI patients who had serial cTnI measurements during the study period. One hundred twenty-five (29.8%) had an elevated admission cTnI. TBI patients with an elevated cTnI had a lower admission Glasgow Coma Scale (GCS) score (7.5 vs. 8.7, p < 0.05), higher Injury Severity Score (27.4 vs. 24.8, p < 0.01), and increased hospital mortality (44% vs. 29%, p < 0.05), compared with TBI patients with a normal cTnI. Increasing severity of head injury was associated with an increasing cTnI (TnI level 0.8 mug/L for head AIS score = 3 vs. TnI Level I 0.3 mug/L for head AIS score = 4, 5, p = 0.09). After adjusting for injury severity, elevated cTnI was an independent predictor for mortality (Odds ratio [OR[: 8.5; 95% confidence interval [CI]: 3.46, 22.15, p < 0.0001). BB therapy was associated with a significant survival advantage (OR: 0.38; 95% CI: 0.15, 0.87, p = 0.03) in TBI patients with any elevation of cTnI.
  
  
  CONCLUSIONS
  Elevated TnI is frequently observed after severe TBI. The level of TnI correlates with the severity of head injury and is an independent predictor of adverse outcomes. BB therapy is associated with a survival advantage in TBI patients with elevated cTnI.
authors.affiliation: Division of Trauma and Critical Care, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California, USA. ali.salim@cshs.org
authors.forename: Ali
authors.initials: A
authors.lastname: Salim
authors.forename: Pantelis
authors.initials: P
authors.lastname: Hadjizacharia
authors.forename: Carlos
authors.initials: C
authors.lastname: Brown
authors.forename: Kenji
authors.initials: K
authors.lastname: Inaba
authors.forename: Pedro G R
authors.initials: PG
authors.lastname: Teixeira
authors.forename: Linda
authors.initials: L
authors.lastname: Chan
authors.forename: Peter
authors.initials: P
authors.lastname: Rhee
authors.forename: Demetrios
authors.initials: D
authors.lastname: Demetriades
mesh_terms: D000063:Accidents, Traffic / Q000401:mortality; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000704:Analysis of Variance; D001930:Brain Injuries / Q000097:blood* / Q000145:classification / Q000188:drug therapy / Q000401:mortality; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015599:Trauma Severity Indices; D014336:Troponin / Q000097:blood*; D014949:Wounds, Nonpenetrating / Q000097:blood / Q000145:classification / Q000401:mortality
chemical_list: D000319:Adrenergic beta-Antagonists; D014336:Troponin