ObjectiveTo evaluate the effect of levosimendan on acute kidney injury (AKI) in patients with left ventricular dysfunction (preoperative left ventricular ejection fraction≤40.0%) undergoing cardiac surgery.MethodsA systematic review and meta-analysis was conducted based on a comprehensive search of the randomized controlled trial (RCT) from PubMed, EMbase and The Cochrane Library (up to Jan 2018). The clinical endpoints included the incidence of AKI and need for renal replacement therapy (RRT), mortality, mechanic ventilation (MV) duration and intensive care unit (ICU) stay. Random-effect model was used for the potential clinical inconsistency. All analyses were performed by RevMan 5.3 and Stata 12.0.ResultsThirteen trials with a total of 2 046 patients were selected. Compared with controls, levosimendan significantly reduced the incidence of postoperative AKI (OR=0.44, P=0.000 1, I2=0%), the risk of RRT (OR=0.63, P=0.02, I2=0%) and the mortality (OR=0.49, P<0.000 1, I2=0%). Levosimendan also shortened the postoperative MV duration (WMD=–5.62, P=0.07, I2=93%) and ICU stay (WMD=–1.50, P=0.005, I2=98%).ConclusionThe present meta-analysis suggests that perioperative levosimendan for patients with left ventricular ejection fraction≤40.0% undergoing cardiac surgery reduces the incidence of AKI, RRT and death, as well as shortens MV duration and ICU stay.