Iron Balance Predicts Acute Heart Failure Survival

A new study shows that a negative iron balance (NIB) can predict survival in patients with acute heart failure (HF) better than standard iron deficiency measures.

Researchers at Wroclaw Medical University (Poland) conducted a prospective, observational study to test a new measure for iron deficiency that measures both depleted iron stores, as measured by circulating hepcidin, and unmet cellular iron needs, measured by levels of soluble transferrin receptor. The concurrent presence of both measures reflects the most severe form of iron deficiency, which the investigators dubbed negative iron balance (NIB). The study included 165 patients hospitalized for acute HF.

The results showed that NIB was found in 37% of patients. Just 29% had only high soluble transferrin receptor, while 9% had only low hepcidin, and 25% had none of these abnormalities. While the overall twelve month mortality was 20% for the whole group, patients with NIB had the highest 12 month mortality (41%) compared to those with only high soluble transferrin receptor (15%), only low hepcidin (7%) and none of these abnormalities (0%). During the hospital stay three patients died, and all of them had NIB. The study was presented at the Heart Failure Congress, held during May 2014 in Athens (Greece).

“Patients with acute heart failure have a major collapse in homeostasis. Iron is a key micronutrient that is required for the maintenance of homeostasis. Iron is needed for cellular metabolism and deficiency leads to severely impaired energy metabolism and mitochondrial dysfunction,” said lead author and study presenter Prof. Ewa Jankowska, MD. “Iron supplementation may reverse NIB and improve survival in acute heart failure patients, but this needs to be tested in a randomized clinical trial. We hope to initiate such trial soon.”

“Levels of hepcidin and soluble transferrin receptor are more clinically relevant in patients with acute heart failure than traditional measures of iron status,” added last author Prof. Piotr Ponikowski, MD. “We propose a new pathophysiological definition of iron deficiency which accurately reflects stored and utilized iron in patients with acute heart failure.”

Iron deficiency has traditionally been measured using serum ferritin to track iron stores and transferrin saturation (TSAT) to assess iron utilization in the cell. However, these measures cannot be reliably interpreted in acute clinical settings because they are influenced by inflammation and oxidative stress. For comparison, the researchers also measured serum ferritin and TSAT, and found that they were less able to predict 12 month mortality than NIB.

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Wroclaw Medical University