A new study has identified reticulocyte hemoglobin equivalent (Ret-He) as a useful parameter and easily applicable marker for detecting iron deficiency in patients with acute decompensated heart failure (ADHF).¹

The study found that the cutoff value of Ret-He for iron deficiency screening is the same for each definition of iron deficiency, based on transfer saturation (TSAT) <20% and serum ferritin <100 μg/L in ADHF patients. It was revealed. .

“Taken together, Ret-He levels may be a useful parameter for detecting iron deficiency in patients with acute decompensated heart failure,” said the study, led by Yoshiro Naito of the Department of Cardiology and Nephrology, School of Medicine, Hyogo School of Medicine. the team writes.

Iron deficiency is associated with poor prognosis in ADHF patients, so it is important to prioritize an appropriate treatment plan.² However, controversy over the definition of iron deficiency in these heart failure analyzes can lead to different conclusions. The 2023 update of the 2021 European Society of Cardiology (ESC) guidelines defined iron deficiency based on either TSAT <20% or serum ferritin <100 μg/L.³

Ret-He, a marker of iron deficiency, may be useful as a measure in patients with heart failure, but definitions of iron deficiency vary and data regarding its use in heart failure are limited. For this analysis, Naito et al sought to evaluate Ret-He according to the 2023 update of the 2021 ESC guidelines to determine its applicability for iron deficiency in ADHF patients.¹

This analysis included 360 consecutive patients admitted for ADHF based on the Framingham criteria at the investigator’s institution between December 2017 and August 2019. Exclusions were made for patients with renal failure or undergoing hemodialysis, patients with hematological disorders, or patients with active malignancy.

Ultimately, 225 participants met inclusion criteria. Baseline characteristics and laboratory and echocardiographic data were obtained at admission. Ret-He levels were calculated using an automated hematology analyzer.

Among the study population, the mean age of the 225 patients with ADHF was 79 years, and 56% were male. Median left ventricular ejection fraction, hemoglobin, and serum iron levels were 37%, 10.6 g/dL, and 7.1 μmol/L, respectively. Overall, ADHF patients with iron deficiency had lower median Ret-He levels than those without deficiency.

Based on the definition of TSAT <20%, the cutoff value for Ret-He for iron deficiency screening was 32.4 pg by receiver operating characteristic analysis. According to the definition of serum ferritin <100 μg/L, the cutoff value was also 32.4 pg. The area under the curve values ​​corresponding to the TSAT and serum ferritin definitions were 0.776 and 0.754, respectively.

Based on the World Health Organization anemia criteria, the cutoff values ​​for Ret-He for iron deficiency anemia screening were 32.4 pg and 31.0 pg for TSAT <20% and serum ferritin <100 μg/L, respectively. Because Ret-He is correlated with iron parameters, the research team suggested that these findings may reflect iron levels.

Naito et al. suggested that measuring Ret-He levels could help detect iron deficiency in ADHF patients, citing its ultimate utility and value in screening.

“Measurement of Ret-He is inexpensive and cost-effective,” Naito et al. write.

References

1. _{Kazuya Okuno, Yuya Naito, Jun Ohno et al. Reticulocyte hemoglobin equivalent is an easily applied marker to detect iron deficiency in patients with acute decompensated heart failure. Amhart J Plus. 2023;35:100332. Published October 6, 2023. doi:10.1016/j.ahjo.2023.100332}
2. _{Masini G, Graham FJ, Pericoli P, Criteria for iron deficiency in patients with other heart failure. J Am Coll Cardiol, 2022;79(4):341-351. doi:10.1016/j.jacc.2021.11.039}
3. _{Authors/Task Force Members: McDonagh TA, Metra M, et al. His 2023 Focused Update of the 2021 ESC Guidelines on the Diagnosis and Treatment of Acute and Chronic Heart Failure: Developed by the Task Force on the Diagnosis and Treatment of Acute and Chronic Heart Failure of the European Society of Cardiology (ESC). ESC Heart Failure Association (HFA). Eur J Heart Fail. 2024;26(1):5-17. doi:10.1002/ejhf.3024}