Anemia and Iron Deficiency in Cardiac Surgery Patients: Prevalence, Implications, and Therapeutic Considerations

Abstract

Preoperative anemia and non-anemic iron deficiency are common in cardiac surgery patients. Both are frequently caused by absolute iron deficiency or are associated with chronic diseases and inflammation. Multiple studies have shown an association between preoperative anemia and increased RBC transfusion, prolonged intensive care unit and hospital length of stay, and higher postoperative morbidity and mortality. The impact of preoperative non-anemic iron deficiency on postoperative adverse outcome is less clear, but worsened postoperative outcomes have been suggested. Accordingly, treatment for anemia and iron deficiency is a primary goal in preoperative optimization in cardiac surgery patients. Several guidelines recommend timely supplementation with modern oral iron formulation as first-line intervention, followed by intravenous iron administration in case of patient intolerance or time restriction. In patients with non-pure iron deficiency or in ultra-short treatment strategies, the combined therapy of intravenous iron and erythropoiesis-stimulating agents seems safe and most efficacious to increase red blood mass before surgery. However, the positive effects of preoperative interventions in anemic or iron-deficient patients were mostly limited to reduced transfusion of red blood cells, whereas lower morbidity and mortality were shown in limited studies only. It is also important to note that allogeneic blood products are a limited resource, and preoperative oral iron supplementation showed the best cost-effectiveness.