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

A double-blind, prospective, randomized, placebo-controlled study to assess change in exercise capacity after iron repletion with a single dose of ferric derisomaltose (Monoferric®) IV compared to placebo in heart failure with preserved ejection fraction and with functional iron deficiency.

Sixty-six HFpEF participants who have functional iron deficiency will be recruited from the Cardiopulmonary Exercise Testing (CPET) Laboratory and will have a recent or scheduled clinical care CPET with exercise hemodynamic assessment. These measurements will serve as baseline measures. After undergoing other baseline measurements such as echocardiogram, actigraphy, research biomarkers, and the Kansas City Cardiomyopathy Questionnaire (KCCQ) participants will be randomized (2:1) to either a single dose of ferric derisomaltose (Monoferric®)1000 mg/100 ml (n=44) or placebo (n=22).

Given that the iron drug formulation is of brown color and the placebo is clear, unblinded staff members will be assigned to order, pick up and administer drug to the subject. The subject is blinded; therefore, the drug will be infused using a tented covering over the arm in which the IV has been placed. The tented covering will allow adequate viewing of the IV site, but outside of the view of the subject. All blinded staff will not be present during study drug infusion. Prior to infusion the subject will undergo vital signs; blood pressure, heart rate, and temperature. A peripheral intravenous catheter will be placed followed by an infusion of Monoferric 1000 mg (for subjects less than 50 kg, 20 mg/kg) as per current FDA-approved dosing or placebo over 20 minutes. Vital signs will be performed immediately after dosing and after 30 minutes. Subjects will remain in the clinic for observation for 30 minutes following infusion.

Randomization will be stratified by sex and will be performed in permutated blocks of 4 to assure balanced group sizes. In order to allocate without bias, and in a manner blinded to both participants and investigators, we will use random number generation at the time of randomization.

Participants will return for a CPET, echocardiogram, actigraphy, KCCQ, ECG, complete metabolic panel, and blood draw for research biomarkers, cardiovascular exam, and assessment of adverse experiences. A subset of subjects (n=33) will undergo a CPET with exercise hemodynamic assessment. The remaining subjects will undergo an noninvasive CPET (N=33)