Oxygen Therapy Fails to Prevent Heart Failure in MI Patients

Oxygen therapy does not prevent the development of heart failure (HF) or reduce long-term risk mortality in patients with a suspected heart attack, according to a new study.

Researchers at Karolinska Institutet (KI; Solna, Sweden), Uppsala University (UU; Sweden), Lund University (LU; Sweden), and other institutions conducted a study in 6,629 patients with suspected acute myocardial infarction (MI) treated at 35 Swedish hospitals. Patients with oxygen saturation of 90% or over were randomly assigned to receive either supplemental oxygen at 6 L/min for 6-12 hours delivered by open face mask, or ambient air. The primary outcomes were survival benefit at one year, cardiovascular death, and a composite of all-cause death and hospitalization for HF.

The results revealed that all-cause death or hospitalization for HF within one year occurred in 8% of the patients assigned to oxygen, and in 7.9% of patients assigned to ambient air. During long-term follow-up, the composite end point occurred in 11.2% of patients assigned to oxygen and in 10.8% of patients assigned to ambient air, and cardiovascular death occurred in 5.2% of patients assigned to oxygen and in 4.8% assigned to ambient air. Results were consistent across all predefined subgroups. The study was published on August 26, 2018, in Circulation.

“Our new study has filled a central gap in knowledge regarding how to treat patients suffering a heart attack. Oxygen therapy does not reduce the development of heart failure, the most worrying complication of heart attacks,” said corresponding author consultant cardiologist Robin Hofmann, MD, of the Karolinska Institutet. “On this basis, the routine use of oxygen can now be eliminated, and healthcare personnel can concentrate on more efficient measures and rapid transport to hospital.”

Oxygen has been used to treat patients suffering a heart attack for more than a century, despite the fact that such treatment has not had any scientifically proven effect on patients who have normal oxygen saturation levels in their blood. Since the turn of the millennium, researchers worldwide have started to question whether oxygen therapy for heart attacks is ineffective, or may even be harmful.

Related Links:
Karolinska Institutet
Uppsala University
Lund University