CHICAGO – Another major study appears to back the use of intravenous iron repletion in patients with heart failure (HF) and iron deficiency, strengthening largely consistent evidence, researchers say, that the treatment may improve symptoms and prevent some HF-related hospital admissions.
To be sure, the IRONMAN trial, which compared intravenous iron versus usual care in such patients – most with reduced ejection fraction and not hospitalized – failed to show a benefit for its primary endpoint. The 18% reduction in risk for HF hospitalization or cardiovascular (CV) death seen in the trial, however encouraging, can only be called a trend (P = .07).
But the intervention showed signs of benefit for some secondary endpoints, including quality of life scores, and hinted at such an effect on HF hospitalization. Risk for the latter endpoint dropped 20% (P = .085) over a median follow-up of 2.7 years.
The findings “build upon the other data we have that correcting iron deficiency can help improve well-being, and particularly reduce the risk of hospitalization, in a broad range of [HF] patients,” said Paul Kalra, MD, of the University of Glasgow and Portsmouth (England) Hospitals University NHS Trust.
The tested regimen “was well tolerated with no safety concerns” and offers “reassurance about the long-term safety” of the intravenous iron it used, ferric derisomaltose (MonoFerric), in patients with HF, Dr. Kalra said at a media briefing on the trial.
The remarks preceded his formal presentation of IRONMAN at the American Heart Association scientific sessions. Dr. Kalra is also lead author on the trial’s publication in The Lancet.
IRONMAN strengthens the base of evidence supporting intravenous iron in HF with iron deficiency, especially chronic HF in outpatients, Dr. Kalra and others said. It also supports efficacy for a form of intravenous iron not previously tested in a major HF trial.
Still, “the totality of data are now supporting intravenous iron per se,” regardless of the iron agent used, said Dr. Kalra. But ferric derisomaltose may have dosing advantages, he observed, “and we’ve now got these long-term safety data.”
The strongest prior support for intravenous iron in HF came from hospitalized patients who received it as ferric carboxymaltose (Ferinject) and were followed only 12 months. That was in the AFFIRM-AHF trial, published 2 years ago, which also missed its primary endpoint – the same one used in IRONMAN. Some outcomes in the two trials were similar.
The risk for HF hospitalization or CV death for intravenous iron therapy, compared with usual care, in AFFIRM-AHF fell 21% (P = .059), missing significance but apparently driven by a 26% drop in risk for HF readmissions (P = .013). But neither that trial nor IRONMAN suggested a benefit for CV mortality on its own.
The COVID effect
In IRONMAN, Dr. Kalra said, usual care could include oral iron supplementation, which 17% of patients in the control group received. That could potentially have kept the intravenous iron group from making a better showing for the primary endpoint, he proposed.
And some iron doses and other treatments were missed by a substantial number of patients in both groups who entered the trial after the United Kingdom’s national lockdown in response to the COVID-19 pandemic, he observed. “Patients were not able to come into hospitals for research visits, or in fact when they were able, may not have wanted to.”
So, the group conducted a “prespecified” sensitivity analysis that excluded the 9% of patients enrolled by the end of March 2020, about the time of the first lockdown, and followed the remainder for another 6 months.
In that analysis, risk for HF hospitalization or CV death declined 24% in the intravenous iron group, a marginal but significant result (P = .047) that was dominated by an improvement in HF hospitalizations.