Clinical and Economic Outcomes Associated with Structured Preoperative Anemia Management in Elective Cardiac Surgery: A Patient Blood Management Cohort Study

Background/Objectives: Preoperative anemia and iron deficiency increase transfusion risk in cardiac surgery. We evaluated outcomes associated with a Patient Blood Management (PBM) pathway and assessed the robustness of these associations to baseline imbalance and secular trends. Methods: This single-center retrospective cohort study compared PBM patients treated in 2019, 2022, and 2023 with historical controls from 2017–2018. Outcomes included red blood cell (RBC) transfusion, length of stay, readmission, mortality, safety events, and costs. Analyses included multivariable regression, propensity-score matching (PSM), inverse probability of treatment weighting (IPTW), and adjacent-period matching. The hospital-perspective cost-consequence analysis used 2024-unit costs, bootstrap confidence intervals (CI), and log-link models. Results: Among 1374 patients (764 PBM; 610 No-PBM controls), any RBC transfusion occurred in 17.3% versus 39.2%, and transfusion of >2 units occurred in 2.6% versus 15.1%. The adjusted odds ratios were 0.30 (95% CI, 0.23–0.39) and 0.14 (95% CI, 0.08–0.24), respectively. PSM yielded 519 pairs, and sensitivity analyses were concordant. The adjusted overall direct-cost ratio was 0.75 (95% CI, 0.68–0.82), with an adjusted marginal mean difference of −EUR 5196 (bootstrap 95% CI, −EUR 6965 to −EUR 3485). Recorded incidences of myocardial infarction, stroke, thromboembolism, and cumulative infection were low and did not differ significantly between cohorts; hypophosphatemia and treatment-specific adverse reactions were not systematically assessed. Adjacent-period matching did not confirm a reduction in 12-month readmission, and mortality was similar between cohorts. Conclusions: PBM was associated with lower transfusion rates, shorter hospitalization, and lower direct costs. Residual temporal confounding limits causal interpretation, and the economic findings do not constitute formal cost-effectiveness results.