Giving iron directly into the bloodstream might help heart failure patients who are low on iron (even if they don't have anemia) by fixing the iron deficiency in their heart cells.

Giving iron directly into the bloodstream of mice with heart cell hepcidin deficiency stops their hearts from failing, proving that the heart problems are caused by the heart cells not getting enough iron.

When heart cells don't have enough iron, their energy production systems break down, causing mitochondria to malfunction and forcing the cells to rely more on sugar for energy, which happens before the heart starts failing.