Hofmann R, et al.
N Engl J Med. 2017 Sep 28;377(13):1240-1249.
Methodology Score: 4/5 Usefulness Score: 4/5
Question and Methods: This large, registry-based RCT evaluated the effect of oxygen on patient-centered clinical outcomes for normoxic MI patients.
Findings: There were no differences at 365 days or 30 days for all-cause mortality (5.1% v 5.0%, oxygen and ambient air groups; Hazard Ratio, 0.97; 95% CI, 0.79-1.21; P=0.80) nor rehospitalization with MI (3.8% v 3.3%).
Limitations: It is a Swedish-only study which may limit generalizability, and with unexpectedly low mortality it may be underpowered for their primary outcome.
Interpretation: This is convincing evidence that we should stop indiscriminately applying supplemental oxygen to suspected ACS/MI patients unless they are truly hypoxic.
By: Dr. Rajiv Thavanathan
Registries collect uniform/standardized/pre-defined demographic and clinical information on systems of care and patients suffering from a common condition. Registries are particularly helpful to conduct longitudinal observational studies. They can, on occasion, include additional data collected as part of an interventional trial. Examples of such registries include the Canadian Cancer Registry, the Canadian Cystic Fibrosis Registry, and the Canadian Resuscitation Outcomes Consortium (CanROC) Registry.