Air Versus Oxygen in ST-Segment-Elevation Myocardial Infarction
Dion Stub, Karen Smith, Stephen Bernard, Ziad Nehme, Michael Stephenson, Janet E Bray, Peter Cameron, Bill Barger, Andris H Ellims, Andrew J Taylor, Ian T Meredith, David M Kaye, AVOID Investigators, Stephen Bernard, Karen Smith, Dion Stub, Ziad Nehme, Michael Stephenson, Janet Bray, Bill Barger, Ian Meredith, Peter Cameron, David Kaye, Ian Meredith, Adam Hutchinson, Paul Antonis, Sarah Gutman, Nitesh Nerlekar, Colin Machado, Harendra Wijesekera, Kiran Munnur, Anthony Dart, James Shaw, Stephen Duffy, Andrew Taylor, James Hare, Leah Iles, Andris Ellims, Teressa Lancefield, Prabath Joseph-Francis, Gishel New, Melanie Freeman, Louise Roberts, Robert Whitbourn, Omar Farouque, Louise Brown, Leeanne Grigg, Monique R Watts, Geoff Toogood, Robert Lew, Mark Freilich, Rodney Teperman, Rahul Sharma, Sandeep Prabhu, Greg Szto, Nicholas Cox, Salvatore Rametta, Vanessa Lee, Christopher Reid, Richard Harper, David Garner, Dion Stub, Karen Smith, Stephen Bernard, Ziad Nehme, Michael Stephenson, Janet E Bray, Peter Cameron, Bill Barger, Andris H Ellims, Andrew J Taylor, Ian T Meredith, David M Kaye, AVOID Investigators, Stephen Bernard, Karen Smith, Dion Stub, Ziad Nehme, Michael Stephenson, Janet Bray, Bill Barger, Ian Meredith, Peter Cameron, David Kaye, Ian Meredith, Adam Hutchinson, Paul Antonis, Sarah Gutman, Nitesh Nerlekar, Colin Machado, Harendra Wijesekera, Kiran Munnur, Anthony Dart, James Shaw, Stephen Duffy, Andrew Taylor, James Hare, Leah Iles, Andris Ellims, Teressa Lancefield, Prabath Joseph-Francis, Gishel New, Melanie Freeman, Louise Roberts, Robert Whitbourn, Omar Farouque, Louise Brown, Leeanne Grigg, Monique R Watts, Geoff Toogood, Robert Lew, Mark Freilich, Rodney Teperman, Rahul Sharma, Sandeep Prabhu, Greg Szto, Nicholas Cox, Salvatore Rametta, Vanessa Lee, Christopher Reid, Richard Harper, David Garner
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.
Methods and 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).
Conclusion: 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.
Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01272713.
Keywords: ST-segment elevation myocardial infarction; myocardial infarction; oxygen.
© 2015 American Heart Association, Inc.
Source: PubMed