Effectiveness of various interventions for patients with preoperative anemia undergoing cardiac surgery: a bayesian network meta-analysis and systematic review-

Introduction Preoperative anemia, affecting 10-30% of cardiac surgery patients, is a modifiable risk factor associated with increased transfusion needs and adverse outcomes. Current interventions (e.g., iron supplementation, erythropoietin, autologous blood storage) lack consensus due to limited evidence and methodological heterogeneity. This Bayesian network meta-analysis evaluates their relative efficacy, aiming to inform evidence-based strategies for optimizing preoperative anemia management in cardiac surgery. Methods Randomized controlled trials (RCTs) were identified through a PRISMA-compliant systematic review of Medline, EMBASE, Cochrane Library and Web of Science. Inclusion criteria comprised RCTs comparing erythropoietin (EPO) monotherapy, EPO combined with autologous blood donation, combined treatment (iron supplementation, EPO, folic acid, and vitamin B12), preventive transfusion, intravenous iron supplementation, EPO combined with iron supplementation, oral iron supplementation for preoperative anemia patients undergoing cardiac surgery. Bayesian network meta-analysis was conducted using BUGSnet package in R, with outcomes including transfusion rate, transfusion volume and intraoperative blood loss. Results Finally, 10 RCTs qualified for inclusion in this network meta-analysis (NMA). Our analysis revealed statistically significant differences (P<0.05) between EPO combined with autologous blood donation and placebo in reducing transfusion rates (log OR −6.34, 95% CrI [−12.86, − 0.16]). The league table heatmap demonstrates no statistically significant differences between any treatment interventions and placebo regarding transfusion volume reduction. This NMA also revealed that combined treatment demonstrated statistically superior blood loss reduction compared to placebo (MD 126.33 mL, 95% CrI [23.27, 229.49], p<0.05), while preventively RBC transfusion was associated with increased blood loss versus control (MD −225.92 mL, 95% CrI [−446.79, − 4.43], p<0.05). Conclusions This study found that EPO combined with autologous blood donation is the most effective strategy for reducing perioperative transfusion rates and combined treatment has potential benefits in minimizing intraoperative blood loss. However, different interventions showed no significant advantage over placebo in reducing transfusion volume.