The article “Predictors and Economic Impact of Red Blood Cell Transfusion in Cardiac Surgery: A Simulated Cost Reduction Model for Preoperative Anemia Management” presents a comprehensive clinical and economic analysis of red blood cell (RBC) transfusion in elective cardiac surgery. Conducted at a tertiary hospital in Portugal, this retrospective cohort study evaluated 661 adult patients undergoing cardiac surgery between April 2020 and April 2021. The study integrates transfusion risk prediction with cost modeling, offering clinically actionable and economically relevant insights.
RBC transfusion remains common in cardiac surgery, with reported rates across Europe ranging from 40% to 90%. In this cohort, 41.3% of patients required at least one RBC transfusion during hospitalization. While transfusion can be life-saving, it is associated with adverse outcomes, including infection, acute kidney injury (AKI), prolonged mechanical ventilation, longer intensive care unit (ICU) stays, and increased mortality. Additionally, transfusions impose substantial economic burdens on healthcare systems due to longer hospital stays and higher resource utilization.
The primary objective of the study was to identify independent predictors of RBC transfusion while adjusting for postoperative bleeding—an important variable often omitted from prior models. Multivariable logistic regression revealed five independent predictors:
- Preoperative anemia (OR 3.67) – the strongest modifiable predictor
- Female sex (OR 2.06)
- Higher EuroSCORE II (OR 1.15)
- Longer cardiopulmonary bypass (CPB) time (OR 1.009 per minute)
- Lower intraoperative nadir hemoglobin (OR 0.48)
Notably, the model demonstrated excellent discrimination (AUROC 0.89), indicating strong predictive performance.
Preoperative anemia emerged as the most clinically relevant and modifiable risk factor. With a prevalence of 18–19% in this cohort, anemic patients had nearly a fourfold higher risk of transfusion. This finding reinforces the growing importance of Patient Blood Management (PBM) programs, which emphasize early detection and correction of anemia prior to major surgery.
Female sex also independently predicted transfusion, doubling the odds compared to males. This may reflect lower baseline hemoglobin thresholds, smaller circulating blood volume, or differences in surgical risk profiles. The findings suggest that conventional hemoglobin optimization thresholds may unintentionally disadvantage female patients in cardiac surgery settings.
Beyond identifying predictors, the study evaluated clinical outcomes associated with transfusion. In univariate analysis, RBC transfusion was significantly associated with:
- 30-day mortality (4.4% vs 0% in non-transfused patients)
- Acute kidney injury
- Infection
- Prolonged mechanical ventilation
- Prolonged ICU stay
- Longer total hospital length of stay (LOS)
Transfused patients had a median LOS of 10 days compared to 8 days in non-transfused patients. However, when infection and prolonged ventilation were included in multivariable models, transfusion itself was no longer independently associated with LOS. This suggests that the effect of transfusion on hospital stay may be mediated through postoperative complications, particularly infection and respiratory failure.
The economic analysis adds substantial value to the study. Using hospital financial data, the median hospitalization cost per non-transfused patient was €9057.76, compared to €11 322.22 for transfused patients. This represents a median incremental cost of €2264.44 per transfused patient. Although the effect size (Hedges’ g = 0.272) was small to moderate at the individual level, the cumulative financial burden was considerable due to the high prevalence of transfusion. Total cohort expenditure reached €6.6 million.
To explore potential cost savings, the authors developed a simulation model assuming elimination of preoperative anemia. Applying the transfusion rate observed in non-anemic patients (34%) to the entire cohort yielded:
- 47 fewer transfusions
- 94 fewer hospital days
- Estimated cost savings of €106 429 over 13 months
While simplified and not including the costs of anemia treatment (iron therapy, erythropoietin, diagnostics), the model provides a compelling conceptual framework for evaluating the economic impact of anemia correction strategies.
Importantly, the study acknowledges limitations, including its retrospective single-center design, lack of individualized cost breakdown between ICU and ward care, and absence of anemia treatment cost analysis. The study was also conducted during the COVID-19 pandemic, which may have influenced hospital resource allocation and cost structures.
Despite these limitations, the findings reinforce preoperative anemia management as a cornerstone of patient blood management programs. By identifying high-risk patients and implementing targeted anemia correction strategies, healthcare systems may reduce transfusion rates, postoperative complications, hospital length of stay, and overall costs in cardiac surgery.
In conclusion, this study integrates robust clinical risk modeling with pragmatic economic analysis. Preoperative anemia stands out as the most impactful modifiable risk factor for RBC transfusion. Addressing anemia before cardiac surgery offers both clinical and financial benefits, strengthening the case for structured, multidisciplinary patient blood management protocols.
