Intermittent hypoxia reduces infarct size in rats with acute myocardial infarction: a systematic review and meta-analysis

BACKGROUND: To determine whether intermittent hypoxia (IH) can reduce the infarct size (IS) after acute myocardial infarction (AMI) in rats. METHODS: Articles were identified in PubMed, EMBASE and the Web of Science and were included if they evaluated the effect of IH on the changes in the infarcted area after AMI in rats. RESULTS: A preliminary search identified 3633 articles and 29 data sets from 23 articles (12 in vivo, 16 in vitro). The IS decreased after AMI in IH rats both in vitro (SMD -1.46, 95% CI [− 2.37, − 0.55]; I(2) = 85.6%, P = 0.000) and in vivo (SMD -1.43, 95% CI [− 2.05, − 0.82], I(2) = 73.6%, P = 0.000). Sensitivity analysis indicated that IH had a strong protective effect against myocardial infarction, and the hypoxia concentration was significantly correlated with the change in IS after AMI. CONCLUSION: IH can reduce IS after AMI in rats. This effect of IH may be related to the dose of hypoxia, and the oxygen concentration may be one of the most important influencing factors.