Changes in iron metabolism parameters following heart transplantation

Introduction

Iron deficiency is a common comorbidity in patients with heart failure, significantly affecting their quality of life, number of hospitalizations, and functional capacity. Heart transplantation (HTx) causes significant changes in iron metabolism parameters, which are influenced by the degree of inflammation, immunosuppressive therapy, blood loss, and subsequent repeated transfusions in the perioperative period. The aim of this paper is to provide an overview of current knowledge on iron deficiency after HTx, illustrated with our own results.

Patients and methods: The study included 23 patients who underwent HTx in 2023 and 2024 and compared their iron parameters before and after HTx. The parameters analyzed were serum iron, transferrin saturation, ferritin, and hemoglobin, and statistical analysis was performed.

Results

Iron deficiency was present in 70% of patients with advanced heart failure and in 52% after HTx. Before HTx, ferritin levels (median – IQR) were 122.9 (63.6–224.2); after HTx, ferritin was statistically significantly higher, 298.3 (126.9–659.7), p < 0.01, with some patients having extremely elevated ferritin levels. In patients before transplantation, transferrin saturation was 0.15 (0.11–0.19) and after HTx it was also significantly higher, 0.22 (0.15–0.30), p < 0.01. There was no significant difference in serum iron in patients before and after HTx. A higher prevalence of anemia was observed after HTx, with hemoglobin levels of 126.0 (118.0–148.0) before HTx and 119 (106.0–123.5) in patients after transplantation, p < 0.01.

Conclusion

HTx is associated with significant changes in iron metabolism parameters. After HTx, we observe a trend toward improvement in parameters expressing iron utilization; however, significant increases in ferritin levels and persistent anemia likely reflect the impact of repeated blood transfusions and the degree of inflammation. This issue requires further research, as these observations may have clinical implications for the appropriate targeting of supplementation therapy in heart transplant patients.