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.