Oral iron fails to improve, transferrin saturation and 6-min walk test in HF with anemia

China: In individuals suffering from heart failure (HF) with iron deficiency (ID) or moderate anemia, oral iron supplementation can raise blood iron levels, but it has little effect on transferrin saturation (Tsat) and 6-min walk test (6MWT), says an article published in European Society of Cardiology Heart Failure.

For individuals with HF and anemia, iron supplementation is a preferable alternative. Recent randomized controlled trials (RCTs) and meta-analyses have demonstrated that intravenous iron delivery increases iron bioavailability, improves exercise tolerance, and lowers the risk of readmission to the hospital.

Zhiping Song and colleagues conducted this review in order to determine if oral iron supplementation in a chronic heart failure population with iron deficiency or moderate anemia is safe and efficacious in accordance with evidence-based medicine.

During the period of 1 January, 1991 to 15 September 2021, 1803 records were obtained from the databases of Embase, PubMed, and the Cochrane Library. The primary goal was the clinical result of oral iron supplementation for ID anemia in individuals with HF. The main effectiveness indicators were transferrin saturation, ferritin levels, and the 6-min walk test, whereas the main safety measures were adverse events and all-cause mortality. The effectiveness metrics were combined using the rate ratio (RR).

The key findings of this study were as follows:

1. Analysis was done on five randomized controlled trials with a total of 590 participants that compared oral iron therapy for patients with a placebo group.

2. There was no discernible difference in all-cause mortality between the oral iron therapy and placebo groups.

3. However, the iron therapy group did not substantially experience more negative occurrences.

4. In addition, after iron complex delivery in HF patients, ferritin levels and Tsat were marginally elevated but not statistically significant.

5. According to the findings of the 6MWT, there was no discernible variation in exercise ability. 

6. Additionally, two non-randomized controlled trials were examined, and the findings of the follow-up studies demonstrated that oral iron supplements raised blood iron levels.

In conclusion, the results of this study demonstrate that safe oral iron supplementation can enhance iron storage capacity. Oral iron supplementation, however, had little effect on Tsat and 6MWT in the HF population with ID or moderate anemia. There are still a relatively small number of clinical trials on the administration of oral iron in HF with ID or anemia. Therefore, there is still a need for further well-designed RCTs including various centers and nationalities.

Reference:

Song, Z., Tang, M., Tang, G., Fu, G., Ou, D., Yao, F., Hou, X., & Zhang, D. (2022). Oral iron supplementation in patients with heart failure: a systematic review and meta‐analysis. In ESC Heart Failure. Wiley. https://doi.org/10.1002/ehf2.14020