A review of evidence failed to show the benefit of the treatment, which has been in use for over 100 years.
The only trial of routine oxygen therapy in MI, which was in 1976, showed that patients who received routine oxygen therapy within 24 hours of MI had more heart damage than those who breathed room air.
Patients given 100 per cent oxygen were nearly three times more likely to die. It is suspected that high oxygen levels lead to a reduction in coronary artery blood flow in stable patients with heart disease.
‘Oxygen therapy should only be given if the oxygen level is significantly reduced, which is uncommon in the situation of a heart attack,’ said lead researcher Professor Richard Beasley from the New Zealand Medical Research Institute.