Summary: For patients with acute ST-elevation-myocardial infarction (STEMI) who are not hypoxic, avoiding administration of supplemental oxygen may be associated with having a smaller infarct size (as measured by mean peak creatine kinase level and by cardiac MRI 6 months later), a lower rate of recurrent myocardial infarction, and a lower frequency of cardiac dysrhythmia. (In other words, administration of supplemental oxygen to non-hypoxic STEMI patients may lead to a larger infarct size and a higher risk of  dysrhythmia and recurrent infarction)

Strength of Recommendation = B