Comment on “effectiveness of various interventions for patients with preoperative anemia undergoing cardiac surgery: a bayesian network meta-analysis and systematic review”

To the Editor, Preoperative anemia, common in cardiac surgery patients, is a well-established risk factor associated with increased transfusion needs and higher postoperative morbidity and mortality[1]. The timely identification and management of preoperative anemia is essential to optimizing patient outcomes. A variety of interventions are currently available for the treatment of preoperative anemia, whereas the potential benefits and comparative advantages of individual interventions have not yet been fully elucidated. The Bayesian network meta-analysis conducted by Chen et al constitutes the first effort to date to systematically compare the relative efficacy of various preoperative anemia management strategies in patients undergoing cardiac surgery[2]. They found that erythropoietin (EPO) combined with preoperative autologous blood donation (ABD) is the most effective strategy for reducing perioperative transfusion rates, and combination therapy (EPO + iron + folic acid + vitamin B12) exhibited potential benefits in minimizing intraoperative blood loss. No intervention significantly reduced transfusion volume compared with placebo. The findings of this study offer valuable guidance for optimizing clinical practice; however, the conclusions are limited by its constraints. First, this study is limited by the small number of eligible trials (only 10 randomized controlled trials) and by the fact that several promising strategies (e.g., combination therapy and ABD) were supported by just one trial each, with most included studies having small sample sizes – all of which may have introduced potential bias and resulted in insufficient statistical power. Furthermore, marked heterogeneity existed in treatment regimens (e.g., dosage, initiation timing, and duration), anemia etiology and severity, and surgical procedures. Notably, the lack of subgroup analyses to explore efficacy differences across these heterogeneous factors may preclude definitive conclusions and restrict the generalizability of findings. Consequently, estimated treatment effects are highly context dependent, and this uncertainty undermines the sufficiency of efficacy data alone for guiding clinical decision-making, particularly in Bayesian frameworks where transitivity assumptions may be impacted by unaddressed heterogeneity. Second, safety outcomes were not incorporated in this study, and the risks of intervention-specific adverse events warrant particular attention[3]. Oral iron supplementation exhibits limited tolerability in many patients due to gastrointestinal adverse effects. While, IV iron therapy may be associated with severe anaphylactic reactions, especially high-molecular-weight iron dextran. Short-term use of erythropoiesis-stimulating agents (ESAs) in the perioperative period of cardiac surgery has not been conclusively proven to increase the risk of thromboembolism; however, this potential risk should not be overlooked. Perioperative transfusion-induced iron overload may contribute to the development of acute kidney injury, while ABD presents certain potential concerns, such as sudden symptom worsening and increased infection rate. Third, the high cost constitutes a key barrier to the more widespread treatment of anemia, and economic evaluations comparing different intervention strategies remain limited[4]. Oral iron supplementation is less costly, with significant price variations among IV iron formulations. Newer IV iron formulations are conveniently administered but are characterized by higher costs and incomplete medical insurance coverage. ESAs can be so costly that some healthcare institutions even forgo their use. In conclusion, while the work by Chen et al is an important contribution, its findings must be interpreted with caution, and there is an urgent need for high-quality trials in future. In addition, preoperative anemia treatment rates are low, with inconsistent application of pharmacological interventions. Therefore, greater efforts are required to improve clinician education, secure institutional funding, and implement standardized, evidence-based protocols. We have been assured that the article complies with TITAN Guidelines 2025-governing declaration and use of AI[5].