title: Air Versus Oxygen in ST-Segment-Elevation Myocardial Infarction.
abstract: BACKGROUND
  Oxygen is commonly administered to patients with ST-elevation-myocardial infarction despite previous studies suggesting a possible increase in myocardial injury as a result of coronary vasoconstriction and heightened oxidative stress.
  
  
  RESULTS
  We conducted a multicenter, prospective, randomized, controlled trial comparing oxygen (8 L/min) with no supplemental oxygen in patients with ST-elevation-myocardial infarction diagnosed on paramedic 12-lead ECG. Of 638 patients randomized, 441 patients had confirmed ST-elevation-myocardial infarction and underwent primary end-point analysis. The primary end point was myocardial infarct size as assessed by cardiac enzymes, troponin I, and creatine kinase. Secondary end points included recurrent myocardial infarction, cardiac arrhythmia, and myocardial infarct size assessed by cardiac magnetic resonance imaging at 6 months. Mean peak troponin was similar in the oxygen and no oxygen groups (57.4 versus 48.0 μg/L; ratio, 1.20; 95% confidence interval, 0.92-1.56; P=0.18). There was a significant increase in mean peak creatine kinase in the oxygen group compared with the no oxygen group (1948 versus 1543 U/L; means ratio, 1.27; 95% confidence interval, 1.04-1.52; P=0.01). There was an increase in the rate of recurrent myocardial infarction in the oxygen group compared with the no oxygen group (5.5% versus 0.9%; P=0.006) and an increase in frequency of cardiac arrhythmia (40.4% versus 31.4%; P=0.05). At 6 months, the oxygen group had an increase in myocardial infarct size on cardiac magnetic resonance (n=139; 20.3 versus 13.1 g; P=0.04).
  
  
  CONCLUSIONS
  Supplemental oxygen therapy in patients with ST-elevation-myocardial infarction but without hypoxia may increase early myocardial injury and was associated with larger myocardial infarct size assessed at 6 months.
  
  
  BACKGROUND
  URL: http://www.clinicaltrials.gov. Unique identifier: NCT01272713.
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: Dion
authors.initials: D
authors.lastname: Stub
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.). Karen.smith@ambulance.vic.gov.au.
authors.forename: Karen
authors.initials: K
authors.lastname: Smith
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: Stephen
authors.initials: S
authors.lastname: Bernard
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: Ziad
authors.initials: Z
authors.lastname: Nehme
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: Michael
authors.initials: M
authors.lastname: Stephenson
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: Janet E
authors.initials: JE
authors.lastname: Bray
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: Peter
authors.initials: P
authors.lastname: Cameron
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: Bill
authors.initials: B
authors.lastname: Barger
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: Andris H
authors.initials: AH
authors.lastname: Ellims
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Taylor
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: Ian T
authors.initials: IT
authors.lastname: Meredith
authors.affiliation: From The Alfred Hospital, Melbourne, Australia (D.S., S.B., J.E.B., A.H.E., A.J.T., D.M.K.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (D.S., A.H.E., A.J.T., D.M.K.); Western Health, Melbourne, Australia (D.S.); Ambulance Victoria, Melbourne, Australia (K.S., S.B., Z.N., M.S., B.B.); Monash University, Melbourne, Australia (K.S., S.B., Z.N., M.S., M.E.B., P.C., I.T.M., D.M.K.); University of Western Australia, Western Australia, Australia (K.S.); and Monash Medical Centre, Melbourne, Australia (I.T.M.).
authors.forename: David M
authors.initials: DM
authors.lastname: Kaye
mesh_terms: D000368:Aged; D000388:Air; D000552:Ambulances; D001241:Aspirin / Q000627:therapeutic use; D015415:Biomarkers; D002637:Chest Pain / Q000209:etiology; D003131:Combined Modality Therapy; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects / Q000503:physiopathology; D003402:Creatine Kinase / Q000097:blood; D004562:Electrocardiography; D004630:Emergencies; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D009206:Myocardium / Q000473:pathology; D010100:Oxygen / Q000009:adverse effects* / Q000097:blood / Q000494:pharmacology; D010102:Oxygen Inhalation Therapy / Q000009:adverse effects*; D010313:Partial Pressure; D011446:Prospective Studies; D019210:Troponin I / Q000097:blood; D019564:Unnecessary Procedures; D014655:Vascular Resistance / Q000187:drug effects; D014739:Victoria / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D019210:Troponin I; D003402:Creatine Kinase; D001241:Aspirin; D010100:Oxygen
keywords: ST-segment elevation myocardial infarction; myocardial infarction; oxygen