Effect of intravenous repletion of ferric hydroxide sucrose on the functional capacity of pacients with heart failure
A K E Freitas, A C U Costa, E Nakoula, I M Castro, I Azevedo, M Jarek, S B GuttmanAbstract
Abstract
Backgroud: Heart failure (HF) is a prevalent condition with significant clinical impact. Iron deficiency (ID) is common among patients with HF and is associated with reduced functional capacity and impaired quality of life. Oral iron therapy has limited absorption and low tolerability, whereas intravenous iron replacement is more effective. However, most American and European clinical trials have used ferric carboxymaltose, a high-cost intravenous formulation, which limits its use in Brazilian public healthcare settings. In this context, iron hydroxide sucrose emerges as a more affordable alternative, although real-world data on its use are still limited.
Purpose
To evaluate the effect of intravenous iron hydroxide sucrose repletion on functional capacity and iron parameters in patients with HF and ID.
Methods
This prospective descriptive clinical study included clinically stable outpatients with HF who were receiving optimised therapy but remained symptomatic, and who had ID - defined as ferritin <100 ng/mL or ferritin between 100–300 ng/mL with transferrin saturation <20%. Patients received intravenous iron hydroxide sucrose replacement and were evaluated at baseline and 30 days after treatment. Functional capacity was assessed using the six-minute walk test (6MWT) and the New York Heart Association (NYHA) functional class. Serum ferritin levels and transferrin saturation were also measured. Paired statistical analyses were performed according to data distribution, with p < 0.05 considered statistically significant.
Results
Twenty patients were included (mean age 65.8 years; 60% female), predominantly with reduced left ventricular ejection fraction. After treatment, ferritin levels increased significantly (Δ +132.2 ng/mL; 95% CI 70.4–193.9; p < 0.001). NYHA functional class improved significantly (p = 0.011), with a shift towards lower functional classes. The six-minute walk distance increased after the intervention, with no statistically significant difference between etiologies. Among patients with ischemic heart failure (n = 12), the mean variation in the 6MWT was 34.9 meters, while among those with non-ischemic etiology (n = 8), the mean variation was 32.5 meters, demonstrating a similar functional response between groups. A clinically relevant gain (≥30 m) in 6MWT distance was observed in 45% of patients. Baseline ferritin levels were not correlated with functional improvement.
Conclusions
Intravenous iron hydroxide sucrose repletion was associated with significant improvement in iron stores and functional class, with a clinically meaningful gain in functional capacity in nearly half of patients. These findings support intravenous iron as an effective and safe therapeutic strategy in patients with HF and iron deficiency.