Increased iron absorption in patients with chronic heart failure and iron deficiency.

BACKGROUND: Iron deficiency (ID) is common in patients with chronic heart failure (CHF), but the underlying causes are not fully understood. We investigated whether ID is associated with decreased iron absorption in patients with CHF. METHODS AND RESULTS: We performed an oral iron-absorption test in 30 patients and 12 controls. The patients had CHF with reduced (n = 15) or preserved (n = 15) ejection fraction and ID, defined as s-ferritin < 100 µg/L, or s-ferritin 100-299 µg/L and transferrin saturation < 20%. The controls had no HF or ID and were of similar age and gender. Blood samples were taken before and 2 hours after ingestion of 100 mg ferroglycin sulphate. The primary endpoint was the delta plasma iron at 2 hours. The delta plasma iron was higher in the group with HF than in the control group (median increase 83.8 [61.5;128.5] µg/dL in HF vs 47.5 [30.7;61.5] µg/dL in controls, P = 0.001), indicating increased iron absorption. There was no significant difference between the groups with preserved or reduced ejection fraction (P = 0.46). CONCLUSION: We found increased iron absorption in patients with CHF and ID compared to controls without ID and HF, indicating that reduced iron absorption is not a primary cause of the high prevalence of ID in patients with CHF. CLINICAL TRIAL REGISTRATION: EudraCT 2017-000158-21.