Jernberg T, et al. - In this pragmatic, registry-based randomized clinical trial, researchers compared prespecified secondary end points of the DETO2X-AMI trial (Determination of the Role of Oxygen in Suspected Acute Myocardial Infarction, wherein supplemental oxygen was compared with ambient air in normoxemic patients presenting with suspected myocardial infarction, with no significant survival benefit at 1 year), including cardiovascular death and the composite of all-cause death and hospitalization for heart failure, through the Swedish population registry (mortality), the Swedish inpatient registry (heart failure), and cause of death registry (cardiovascular death). A total of 6,629 patients with oxygen saturation of ≥90% were randomly assigned to receive either supplemental oxygen at 6 L/min for 6 to 12 hours delivered by open face mask or ambient air. They found that, within 1 year or during long-term follow-up, there was no attenuation in the composite of all-cause mortality and hospitalization for heart failure, or cardiovascular death, with the routine use of supplemental oxygen in normoxemic patients with suspected myocardial infarction.