Supplemental Oxygen Is Associated with Excess Risk for Recurrent Myocardial Infarction

Although oxygen has been used for more than a century to treat patients with myocardial infarction (MI), its benefits and risks have come into question recently. For this systematic review and meta-analysis, investigators culled relevant medical literature through 2016 to identify five randomized controlled trials (RCTs) in which the safety and efficacy of oxygen therapy, compared with no oxygen therapy, was evaluated in 921 adults with MI.

Rate of recurrent MI was significantly higher in patients who received oxygen therapy than in those who did not (5.6% vs. 0.7%; number needed to harm, 20). No differences were found between groups in short-term mortality (3.5% vs. 3.4%) or rates of arrhythmia (36% vs. 31%) or chest pain (83% vs. 86%). The…