# IRONMET-HFpEF: single iron infusion raised peak VO2 by about 10% in HFpEF with iron deficiency

- Published: 2026-11-09 02:41 UTC
- Section: Life & Health › Medicine
- Tags: HFpEF iron deficiency, intravenous iron, ferric derisomaltose, IRONMET-HFpEF trial, peak oxygen uptake, 6-minute walk distance, Mass General Brigham, AHA Scientific Sessions 2026, Circulation
- URL: https://realtech.media/news/rt-338848a460e95f2de34347e6_ironmet_hfpef_single/

**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.**

![IRONMET-HFpEF: single iron infusion raised peak VO2 by about 10% in HFpEF with iron deficiency](https://realtech.media/media/2026/11/6008d5b32923f129.webp)
*ad-hoc-news.de*

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). [1]

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. [1]

## 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. [1]

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). [1]

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). [1]

## 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. [1]

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. [1]

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. [1]

## Sources

1. [ad-hoc-news.de](https://www.ad-hoc-news.de/wissenschaft/hfpef-mit-eisenmangel-infusion-steigert-sauerstoffaufnahme-um-10-prozent/70478476)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-338848a460e95f2de34347e6_ironmet_hfpef_single/