Intracoronary supersaturated oxygen therapy after primary percutaneous coronary intervention in ST-segment elevation myocardial infarction: a systematic review and meta-analysis

BACKGROUND: Supersaturated oxygen (SSO2) is a novel adjunctive treatment aims to reduce reperfusion injury after primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI). We conducted this study to evaluate the efficacy and safety of SSO2 therapy in patients with STEMI. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we systematically searched Cochrane Central, Embase, PubMed, Scopus, and Web of Science for studies comparing SSO2 therapy post-PCI with PCI alone in adults with STEMI. Primary efficacy outcomes were infarct size and all-cause death. A random-effects model was used for analysis. RESULTS: Six unique studies that enrolled 1591 patients were included [518 (32.5%) of whom received SSO2]. SSO2 therapy was associated with a reduction in infarct size compared with the control group [mean difference = -4.7% of left ventricular mass, 95% confidence interval (CI): -8.3 to -1.1%; P = 0.01], with the greatest benefit observed in patients reperfused within 6 h of symptom onset (mean difference = -6.0% of left ventricular mass, 95% CI: -8.9 to -3.0%). SSO2 therapy was also associated with reduced left ventricular end-systolic volume (mean difference = -19.9 ml, 95% CI: -33.7 to -6.2). The between-group difference in all-cause mortality was NS (P = 0.58); however, an association between SSO2 use and reduced all-cause death was present in the two studies with long-term (1-year) follow-up (risk ratio = 0.10, 95% CI: 0.01-0.77). No safety concerns were identified. CONCLUSION: SSO2 administration in patients with STEMI after primary PCI was safe and was associated with reduced infarct size, particularly when administered within 6 h of symptom onset. This myocardial salvage was associated with improvement in left ventricular function Further randomized trials are needed to definitively establish the impact of SSO2 on mortality and heart failure.