BACKGROUND AND PURPOSE: 

• Oxygen has been a mainstay of treatment for myocardial infarction for decades, whether or not hypoxemia is present 
  • Data is limited as to whether there is any benefit  
• Hofmann et al. (NEJM, 2017) report on the Determination of the Role of Oxygen in Suspected Acute Myocardial Infarction (DETO2X-AMI) trial that looked at the effect of oxygen therapy in the setting of suspected myocardial infarction without hypoxemia 

METHODS: 

• Multicenter, parallel-group, open-label, registry-based, randomized, controlled trial 
• Subjects were categorized into the following groups 
  • Supplemental oxygen: 6 L/min for 6 -12 hours, delivered through face mask 
  • Ambient air 
• Primary outcome  
  • All-cause mortality at 1 year 
• Secondary outcomes were  
  • Death from any cause within 30 days after randomization 
  • Rehospitalization with myocardial infarction 
  • Rehospitalization with heart failure 
  • Cardiovascular death  
  • Composites of the above at 30 days and 365 days 

RESULTS: 

• 6629 patients enrolled with suspected myocardial infarction  
  • 31.6% women in the oxygen arm and 29.4% in the ambient arm
• Hypoxemia developed in 62 (1.9%) in oxygen group and 254 (7.7%) in ambient group 
• The median of highest troponin level during hospitalization was 946.5 ng/L in oxygen group and 983.0 ng/L in ambient-air group 
• Mortality within 1 year occurred in 5.0% of patients in oxygen group and 5.1% in ambient air group 
• Rehospitalization occurred in 126 (3.8%) in oxygen group and 111 (3.3%) in ambient air group 

CONCLUSION: 

• There was no significant difference in mortality rate between groups that received supplemental air and ambient air 
• No significant difference was seen in number of rehospitalizations between study groups 
• Supplemental oxygen does not offer any benefit to patients with acute myocardial infarction without hypoxemia 

Learn More – Primary Sources:  

Oxygen Therapy in Suspected Acute Myocardial Infarction

Is Oxygen Therapy Beneficial in Acute Myocardial Infarction? Simple Question, Complicated Mechanism, Simple Answer

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