Impact of Intravenous Iron Repletion On Mechanisms of Exercise InTolerance in HFpEF (IRONMET-HFpEF)

This study is investigating whether giving intravenous (IV) iron to people with heart failure (specifically a type called HFpEF, where the heart pumps normally but is too stiff) improves their ability to exercise. Many heart failure patients are iron-deficient even without anemia, and this trial tests whether correcting that deficiency helps the heart and muscles work better. **You may be eligible if...** - You are 18 or older with stable heart failure (HFpEF — preserved ejection fraction) - Your heart's pumping function is 50% or above - You are iron-deficient (low ferritin or ferritin with low iron saturation) - You have reduced exercise capacity confirmed by a breathing test (peak VO2 ≤75% predicted) - Your hemoglobin is between 9.0 and 15.0 g/dL **You may NOT be eligible if...** - You are currently receiving or planning IV iron therapy - You have a known allergy to the iron product (ferric derisomaltose) - You have had a heart attack, stroke, or TIA in the last 3 months - You have severe kidney problems (eGFR below 20) - You have serious liver disease - You have active internal bleeding - You have another cause of anemia unrelated to iron deficiency or chronic disease - You have severe obesity (BMI over 50) or another condition that prevents safe exercise testing - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.