AVOID
Trial question
What is the role of supplemental oxygen therapy in patients with STEMI?
Study design
Multi-center
Open label
RCT
Population
Characteristics of study participants
21.0% female
79.0% male
N = 441
441 patients (93 female, 348 male)
Inclusion criteria: patients with STEMI diagnosed on paramedic 12-lead ECG
Key exclusion criteria: oxygen saturation < 94% measured on pulse oximeter, bronchospasm requiring nebulized salbutamol therapy with oxygen, oxygen administration before randomization, or altered conscious state
Interventions
N=318 routine supplemental oxygen (via face mask at 8 L/min)
N=320 restricted supplemental oxygen (no oxygen unless oxygen saturation < 94%, in which case oxygen was administered via nasal cannula (4 L/min) or face mask (8 L/min) to achieve an oxygen saturation of 94%)
Primary outcome
Mean peak creatine kinase
1948
1543
1948.0 U/L
1461.0 U/L
974.0 U/L
487.0 U/L
0.0 U/L
Routine supplemental oxygen
Restricted supplemental oxygen
Significant increase ▲
Significant increase in mean peak CK (1948 U/L vs. 1543 U/L; MR 1.27, 95% CI 1.04 to 1.52)
Secondary outcomes
Significant increase in recurrent myocardial infarction (5.5% vs. 0.9%; RR 6.1, 95% CI 1.75 to 10.45)
No significant difference in geometric mean peak cTnI in patients with confirmed STEMI (57.4 µg/L vs. 48 µg/L; RR 1.2, 95% CI 0.92 to 1.56)
Safety outcomes
No significant differences in mortality at hospital discharge (1.8% vs. 4.5%, p=0.11).
Conclusion
In patients with STEMI diagnosed on paramedic 12-lead ECG, routine supplemental oxygen was inferior to restricted supplemental oxygen with respect to mean peak CK.
Reference
Stub D, Smith K, Bernard S et al. Air Versus Oxygen in ST-Segment-Elevation Myocardial Infarction. Circulation. 2015 Jun 16;131(24):2143-50.
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