Effects of on-pump versus off-pump coronary artery bypass grafting on myocardial metabolism

BACKGROUND: On-pump coronary artery bypass grafting (ON-PCABG) and off-pump coronary artery bypass grafting (OF-PCABG) greatly affect myocardial metabolism (MCMB). However, no study has systematically explored and compared the impacts of ON-PCABG and OF-PCABG on MCMB. This study will aim to explore and to compare the effects of ON-PCABG and OF-PCABG on MCMB systematically. METHODS: We will conduct the comprehensive literature search from the following electronic databases from inception to the present: Cochrane Library, EMBASE, MEDILINE, CINAHL, AMED and 4 Chinese databases without language restrictions. This systematic review will only concern randomized controlled trials (RCTs) and case-control studies of ON-PCABG and OF-PCABG on MCMB. The methodological quality of each entered study will be assessed by using Cochrane risk of bias tool. RESULTS: Primary outcomes include myocardial cellular markers, myocardial lactate, oxygen utilization, pyruvate, and intramyocardial concentrations of glucose, urea and lactate. Secondary outcome comprises of glutathione, superoxide dismutase, myeloperoxidase, and oxidative stress and any other complications post surgery. CONCLUSION: This study will provide a high-quality synthesis and will assess and compare the effects of ON-PCABG and OF-PCABG on MCMB based on the current relevant literature evidence. DISSEMINATION AND ETHICS: The results will be submitted to peer-reviewed journals for publication. This study does not require ethic approval, because it only analyzes the data from published literature. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019125381.