Efficacy of beta-blockade after isolated blunt head injury: does race matter?

Several retrospective clinical studies and recent prospective animal models demonstrate improved outcomes with beta-blocker administration after isolated blunt head injury. However, no investigations to date have examined the influence of race on the potential therapeutic effectiveness of these medications. Our hypothesis was that mortality benefits associated with beta-blocker exposure after isolated blunt head injury varies based on ethnicity.

The trauma registry and the surgical intensive care unit (ICU) databases of an academic Level I trauma center were used to identify all patients sustaining blunt head injury requiring ICU admission from July 1998 to December 2009. Patients sustaining major associated extracranial injuries (Abbreviated Injury Scale [AIS] score ≥ 3 in any body region) were excluded. Patient demographics, injury profile, Injury Severity Score, and beta-blocker exposure were abstracted. The primary outcome evaluated was in-hospital mortality stratified by ethnicity.

During the 11-year study period, 3,750 patients were admitted to the Los Angeles County + University of Southern California Medical Center trauma ICU because of blunt trauma. Of these, 65% (n = 2,446) had an "isolated" head injury. When stratified by race, most patients were Hispanics (60%), followed by Whites (21%), Asians (11%), and African Americans (8%). After adjusting for confounding variables with multivariate regression, only those of Asian and Hispanic descent demonstrated significantly improved outcomes associated with beta-blocker administration.

Our results indicate that beta-blockade after traumatic brain injury may not benefit all races equally. Further prospective research is necessary to assess this discrepancy in treatment benefit and explore other possible therapeutic interventions.