To assess whether systematic perioperative correction of anemia and/or iron deficiency (ID) improves hemoglobin (Hb) levels and reduces transfusion requirements in elective cardiac surgery.

Post hoc analysis of a prospective, non-randomized, single-center before-and-after study with intention-to-treat analysis. The control phase was followed by the intervention phase. Adjustments were made using propensity-score overlap weighting and multiple imputation.

A tertiary academic hospital.

Eight hundred thirty-four adults undergoing elective cardiopulmonary bypass surgery: 442 in the control phase and 392 in the subsequent intervention phase.

The intervention group received systematic screening and treatment for anemia (Hb <13 g/dL) and/or ID (ferritin <100 µg/L or <300 µg/L with transferrin saturation <20%) using intravenous iron (1000 mg ferric carboxymaltose) and erythropoietin-α (600 IU/kg weekly, 1-3 doses). Postoperative IV iron (300 mg) was administered on days 0 and 2. The control group received standard care.

Hb significantly increased in anemic patients, with or without ID (+1.8 g/dL, p < 0.001). Patients with isolated ID also showed higher Hb at discharge and 3 months (p = 0.003). RBC transfusion rates were significantly reduced in anemic patients (with ID: 26.1% vs 55.9%, p = 0.003; without ID: 17.4% v 55.3%, p = 0.007). No differences in outcomes or mortality were observed.

Systematic correction of anemia and/or ID significantly improves Hb levels and reduces transfusion needs in elective cardiopulmonary bypass surgery, supporting its role in perioperative patient blood management.