RecruitingPhase 4Drug trialImpact of Intravenous Iron Repletion On Mechanisms of Exercise InTolerance in HFpEF (IRONMET-HFpEF)The primary objective of this study is to determine if the correction of functional iron deficiency by administering a single dose of intravenous iron (ferric derimaltose or Monoferric®) in participants with heart failure with preserved ejection fraction (HFpEF) will improve exercise capacity as measured by the change in peak oxygen uptake (peak VO2) from baseline to 12 weeks.