ROUTINE USE OF SUPPLEMENTAL OXYGEN IN PATIENTS WITH MYOCARDIAL INFARCTION WITHOUT HYPOXIA IS ASSOCIATED WITH HIGHER RATES OF RE-INFARCTION: A META-ANALYSIS

Abstract

SESSION TITLE: Cardiovascular Disease SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/10/2018 01:00 PM - 02:00 PM PURPOSE: Routine use of oxygen in patients with myocardial infarction (MI) used to be the standard of practice until recently. However, recent studies have not shown any benefits in this setting. In addition, recently published AVOID study showed that routine use of oxygen is associated with a larger 6-month myocardial infarct size. At the same time, several studies published recently failed to show any harmful effect of the routine use of oxygen. We did this meta-analysis to further explore this controversial issue. We are aiming to assess whether routine use of oxygen is associated with worsened clinical outcomes. METHODS: We used the PRISMA model for our analysis. We performed a systematic search of PubMed, Scopus, Cochrane library and clinicaltrial.gov since inception till January 2017. We used following terms for the search: “infarction”, “myocardial infarction”, “acute coronary syndrome”, “ACS”, “MI”, “oxygen therapy”, “oxygen effect”, “oxygen supplementation” and “oxygen treatment”. Total of 5 studies was included in our analysis. We used RevMan 5.3 for windows (Cochrane Collaboration, Oxford, United Kingdom) for all the analysis. We used random effect model for analysis of the continuous and dichotomous variables. We used Mental-Haenszel method for the analysis. In addition, we used a confidence interval of 95% as significant and along with p-value of less than 0.5 as significant. Heterogeneity was measured using I2. The heterogeneity of <30 % was considered low, 30%-60 % was considered moderate and >60% was considered substantial. We calculated the mean difference (MD) and odds ratio (OR) for the continuous and dichotomous variables respectively RESULTS: A total of 914 patients were included in our analysis (449 in oxygen group). Infarcted myocardial mass between two groups was not significantly different (MD, 2.76-gram, 95% CI [-1.94, 7.47], a p-value 0.25; I2=67%). Similarly, we did not find a significant difference in percent infarct mass (MD, 1.48 %, CI [-1.34, 4.29], p-value 0.30; I2= 55%). We did not find any significant difference in EF between two groups (MD, -0.71, 95% CI [-3.94, 2.53], a p-value 0.67; I2= 0%). However, we found a significant increase in the incidence of re-infarction in oxygen group(4.92% vs 0.73%) (OR, 5.70, 95%, CI [1.45, 22.35], p-value 0.01; I2= 0%). There was no significant difference between two groups in in-hospital mortality (OR,1.06, 95% CI [0.30, 3.70], p-value 0.93;I2= 49%). CONCLUSIONS: Regular use of supplemental oxygen in MI without hypoxia is associated with adverse clinical outcome secondary to increased rates of re-infarction. CLINICAL IMPLICATIONS: There is uncertainty regarding the use of supplemental oxygen in patients with MI without heart failure or dyspnea in the recent guidelines. In light of our evidence of increased adverse clinical outcome, we think the guidelines should actually now recommend against the regular supplemental use of oxygen. DISCLOSURES: No relevant relationships by Ghassan Bachuwa, source=Web Response No relevant relationships by Sai Pavan Kumar Chintalapati, source=Web Response No relevant relationships by Sunil Upadhaya, source=Web Response No relevant relationships by Ravi Kanth Velagapudi, source=Web Response