Characterising the Role of Perioperative Erythropoietin for Preventing Acute Kidney Injury after Cardiac Surgery: Systematic Review and Meta-Analysis

Background The role of perioperative erythropoietin (EPO) for preventing cardiac surgery associated acute kidney injury (CSA-AKI) remains uncertain with published trials producing conflicting results. Perspective into the factors at work is needed, due to ongoing uncertainty. Methods We undertook the systematic review and meta-analysis of randomised-controlled trials (RCTs) using random-effects modelling. The primary outcome was safety and efficacy of perioperative EPO to prevent CSA-AKI and the secondary outcomes were change in serum creatinine, urinary neutrophil gelatinase-associated lipocalin, time in ICU, rates of postoperative transfusions, haemodialysis, and mortality. Subgroup analysis explored the effect of the timing of the EPO dose in relation to surgery, the dose response, and the impact of the preoperative risk for CSA-AKI for the patient group. Results Six RCTs were included, which totalled 473 participants. Erythropoietin administration did not reduce the incidence of CSA-AKI compared with controls (OR: 0.69, 95% CI: 0.35 to 1.36, P=0.28; I²=64%, P=0.001), however, subgroup analysis suggested administrating EPO before anaesthesia was correlated with a reduction in CSA-AKI (OR: 0.27, 95% CI: 0.13 to 0.54, P=0.0002; I²=0%, P=0.98). Additionally, in low risk populations, perioperative EPO administration correlated with significant reduction in CSA-AKI when compared to controls (OR: 0.25, 95% CI: 0.11 to 0.56, P=0.0008; I²=0%, P=0.86). Conclusion Our findings suggest that administering EPO before anaesthesia is emerging as an important factor for efficacy. Erythropoietin may have a role in preventing CSA-AKI, however, additional high-quality prospective studies are warranted, particularly aimed at describing the methodological components, such as the timing and size of the dose, which potentiate the cytoprotective effect of EPO in the clinical setting.