Iron infusion helps heart failure patients exercise longer
A single intravenous dose of ferric derisomaltose produced a nearly 9% improvement in exercise capacity among patients with heart failure and preserved ejection fraction (HFpEF) who also had iron deficiency. Results from the study, presented at the 2026 American Heart Association Scientific Sessions and published in Circulation, showed that peak oxygen uptake, a standard measure of cardiorespiratory fitness, rose by 1.2 mL/kg/min in treated patients after 12 weeks, whereas placebo recipients experienced no change.
Iron deficiency is present in over 50% of HFpEF patients, yet existing therapies rarely target their reduced physical function. The researchers selected intravenous (IV) iron because oral supplements had previously failed in other heart failure trials, likely due to poor gastrointestinal absorption. The study included 65 participants aged between 58 and 76, with 72% of them being women. Participants were randomly assigned to receive either a 1,000 mg IV dose of ferric derisomaltose or a placebo.
The treated group demonstrated improvements beyond peak oxygen uptake. They walked farther in six-minute endurance tests, performed better at lower exercise intensities, and achieved a higher New York Heart Association class, a clinical marker of heart failure severity, compared to those given the placebo. Blood iron levels also increased in the treatment group. However, patient-reported health scores, assessed using the Kansas City Cardiomyopathy Questionnaire, showed no meaningful difference between the two groups. No serious side effects related to the treatment were observed.
The results indicate that restoring iron levels may help reduce physical limitations in HFpEF patients, but the study’s small sample size and predominantly white participant group restrict broader generalizations. Investigators stressed that additional follow-up is necessary to determine whether these short-term benefits lead to lasting clinical advantages.
Even small gains in exercise capacity can significantly affect HFpEF patients, allowing them to manage daily activities instead of enduring constant fatigue. While the findings support broader evidence that iron deficiency harms heart function, the absence of changes in patient-reported outcomes raises questions about whether physical improvements alone enhance overall quality of life. Future research will explore whether IV iron therapy can reduce hospitalizations or other long-term risks for this patient population.
