IRONMET-HFpEF: single iron infusion raised peak VO2 by about 10% in HFpEF with iron deficiency
In a single-center trial at Mass General Brigham, one 1,000 mg ferric derisomaltose infusion raised peak oxygen uptake by about 10% over 12 weeks in HFpEF with iron deficiency.
Researchers at the Mass General Brigham Heart and Vascular Institute and Massachusetts General Hospital in Boston reported that a single intravenous dose of 1,000 mg ferric derisomaltose increased peak oxygen uptake (peak VO2) in patients with heart failure with preserved ejection fraction (HFpEF) and iron deficiency, according to ad-hoc-news.de. The IRONMET-HFpEF trial was presented at the AHA Scientific Sessions 2026 in Chicago and published in Circulation (DOI 10.1161/CIRCULATIONAHA.126.084009). ad-hoc-news.de
ad-hoc-news.dead-hoc-news.deOpen source ↗
HFpEF accounts for about half of all heart failure cases. According to the study authors, more than 50% of these patients also have iron deficiency. The authors chose intravenous administration because oral iron had shown no efficacy in other forms of heart failure, presumably due to insufficient gastrointestinal absorption.
Design and primary endpoint
The median age of the participants was 68 years (range 58 to 76), and 72% were women. At baseline, mean transferrin saturation was 16% and ferritin was 57.8 ng/mL. The primary endpoint was peak VO2 after 12 weeks.
Median baseline peak VO2 was 12.7 and 12.2 mL/kg/min in the two groups. In the intervention group it rose by about 10% (+1.2 mL/kg/min; 95% CI 0.6 to 1.7). In the placebo group it was practically unchanged (+0.1 mL/kg/min; 95% CI -0.7 to 0.9). The difference between the arms was 1.1 mL/kg/min (95% CI 0.2 to 1.9; p=0.02). ad-hoc-news.de
ad-hoc-news.dead-hoc-news.deOpen source ↗
Iron metabolism changed markedly in the treated group: transferrin saturation increased by 9.4 percentage points (95% CI 4.9 to 13.9), and ferritin by 182.6 ng/mL (95% CI 127.7 to 237.5; p<0.001).
Secondary results and limitations
Oxygen uptake at the anaerobic threshold, NYHA class and 6-minute walk distance all improved (each p<0.05). Walking distance increased by 41.1 meters (95% CI 9.5 to 72.8; p=0.01). The KCCQ total score differed by +4.4 points, which was not statistically significant (95% CI -2.4 to 11.2; p=0.20). No severe adverse events or severe infusion-related reactions occurred.
The limitations include a single-center design, a small and predominantly white study population, testing of only one dose, and an observation period of 12 weeks. Further studies in diverse populations and analyses of long-term benefit are considered necessary. ad-hoc-news.de
ad-hoc-news.dead-hoc-news.deOpen source ↗
In an accompanying editorial, the cardiologists Fudim and Ambrosy noted that a single study endpoint does not yet constitute a clinical indication. MonoFerric (ferric derisomaltose) is also not currently approved for improving exercise capacity in HFpEF with iron deficiency.
