Early stage effect of ischemic preconditioning for patients undergoing on-pump coronary artery bypass grafts surgery: Systematic review and meta-analysis

Background: during the on-pump coronary artery bypass grafts surgery, ischemia/reperfusion injury would happen. ischemia preconditioning could increase the tolerance against subsequent ischemia and reduce the ischemia/reperfusion injury. however the clinical outcomes of the available trials were different. methods: we searched the cochrane central register of controlled trials on the cochrane library (issue 3, 2013), the medline/pubmed and cnki in march 2013. revman 5.1.6 and gradeprofiler 3.6 were used for statistical analysis and evidence quality assessment. heterogeneity was evaluated with significance set at p ≤ 0.10. results: eighteen randomized controlled trials were included. there were no differences on in- hospital mortality, postoperative myocardial infarction morbidity between ischemia preconditioning and control groups. the heterogeneity of creatine kinase-mb level 24 hours after surgery was obvious. the differences of 72 hours area under the curve of cardiac troponin t (mean differences of -14.50, 95% confidence interval of -21.71 to -7.28) and troponin i (mean differences -181.79, 95% confidence interval of -270.07 to -93.52) after surgery were observed. conclusions: all the 18 trails, the positive and the negative results were equal. the meta-analysis results should be interpreted with caution due to limited effective data. because of high cost-effectiveness, ischemia preconditioning could not be denied completely. large-scale randomized studies are needed, with the operation procedures and included criteria being more specific.