High-concentration versus titrated oxygen therapy in ST-elevation myocardial infarction: a pilot randomized controlled trial

Am Heart J. 2012 Feb;163(2):168-75. doi: 10.1016/j.ahj.2011.10.013. Epub 2012 Jan 13.


Background: The optimal approach to oxygen therapy in ST-elevation myocardial infarction (STEMI) is uncertain.

Methods: A randomized controlled trial was undertaken in which 136 patients presenting with their first STEMI uncomplicated by cardiogenic shock or marked hypoxia were randomized to receive high-concentration (6 L/min via medium concentration mask) or titrated oxygen (to achieve oxygen saturation 93%-96%) for 6 hours after presentation. The main outcome variables were 30-day mortality and infarct size assessed by troponin T level at 72 hours. Secondary outcomes included a meta-analysis of mortality data from this study and previous randomized controlled trials, and infarct size was assessed by magnetic resonance imaging at 4 to 6 weeks.

Results: There were 1 of 68 and 2 of 68 deaths in the high-concentration and titrated oxygen groups, respectively; a meta-analysis including these data with those from the 2 previous studies showed an odds ratio for mortality of high-concentration oxygen compared with room air or titrated oxygen of 2.2 (95% CI 0.8-6.0). There was no significant difference between high-concentration versus titrated oxygen in troponin T (ratio of mean levels 0.74, 95% CI 0.50-1.1, P = .14), infarct mass (mean difference -0.8 g, 95% CI -7.6 to 6.1, P = .82), or percent infarct mass (mean difference -0.6%, 95% CI -5.6 to 4.5, P = .83).

Conclusion: This study found no evidence of benefit or harm from high-concentration compared with titrated oxygen in initially uncomplicated STEMI. However, our estimates have wide CIs, and as a result, large randomized controlled trials are required to resolve the clinical uncertainty.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Dose-Response Relationship, Drug
  • Electrocardiography*
  • Female
  • Follow-Up Studies
  • Humans
  • Magnetic Resonance Imaging, Cine
  • Male
  • Middle Aged
  • Myocardial Infarction / diagnosis
  • Myocardial Infarction / epidemiology
  • Myocardial Infarction / therapy*
  • Oxygen / administration & dosage*
  • Oxygen / therapeutic use
  • Oxygen Inhalation Therapy / methods*
  • Pilot Projects
  • Prospective Studies
  • Survival Rate / trends
  • Treatment Outcome


  • Oxygen