Meta-Analysis and Metaregression of the Treatment Effect of Intravenous Iron in Iron-Deficient Heart Failure

Influence of iron deficiency definition on the efficacy of intravenous iron in heart failure: a meta-analysis of randomized trials

BACKGROUND

Intravenous iron improves symptoms in heart failure (HF) with iron deficiency (ID) but failed to consistently show a benefit in cardiovascular outcomes. The ID definition used may influence the response to intravenous iron. The aim of this meta-analysis is to assess the influence of ID definition on the intravenous iron effect in HF.

METHODS/RESULTS

We performed a random-effects meta-analysis of randomized controlled trials (RCT) on intravenous iron (vs. placebo or standard of care) in patients with HF and ID that provided data on transferrin saturation (TSAT) and ferritin subgroups on the composite outcome of cardiovascular death (CVD) or HF hospitalizations (HFH). The risk ratio (RR) and 95% confidence intervals (95% CI) were extracted on the TSAT (< 20% and ≥ 20%) and ferritin (< 100 ng/mL and ≥ 100 ng/mL) subgroups. Data from four major RCT was collected including a total of more than 5500 patients. In patients with a TSAT < 20%, intravenous iron reduced the composite outcome of CVD or HFH: RR 0.81, 95%CI 0.69-0.94, while in patients with a TSAT ≥ 20% the effect was neutral: RR 0.98, 95%CI 0.79-1.21, interaction, P = 0.05. On the other hand, ferritin levels did not modify the effect of IV iron: ferritin ≥ 100 ng/mL RR 0.84, 95%CI 0.65-1.09, and ferritin < 100 ng/mL RR 0.85, 95%CI 0.74-0.97; interaction, P = 0.96.

CONCLUSIONS

Our meta-analysis suggests that the benefit of intravenous iron may be restricted to patients with TSAT < 20% regardless of ferritin levels and supports the single use of TSAT < 20% to identify patients with ID who may benefit from intravenous iron therapy.

Treating iron deficiency in patients with heart failure: what, why, when, how, where and who

For patients with heart failure and reduced or mildly reduced left ventricular ejection fraction, iron deficiency is common and associated with more severe symptoms, worse quality of life and an increased risk of hospitalisations and death. Iron deficiency can be swiftly, effectively and safely treated by administering intravenous iron, either as ferric carboxymaltose or ferric derisomaltose, which improves patient well-being and reduces the risk of hospitalisations including those for heart failure. However, the current definition of iron deficiency in heart failure has serious flaws. A serum ferritin <100 µg/L does not identify patients more likely to respond to intravenous iron. In contrast, patients with transferrin saturations <20%, most of whom are also anaemic, are more likely to have a beneficial response to intravenous iron. In this review, we summarise the available evidence for use of intravenous iron in heart failure and provide recommendations for targeted future research and practical considerations for the general cardiologist.

The management of heart failure in Sweden-the physician's perspective: a survey

Aims

To assess the barriers to guideline-directed medical therapy (GDMT) use in heart failure (HF), diagnostic workup and general knowledge about HF among physicians in Sweden.

Methods

A survey about the management of HF was sent to 828 Swedish physicians including general practitioners (GPs) and specialists during 2021-2022. Answers were reported as percentages and comparisons were made by specialty (GPs vs. specialists).

Results

One hundred sixty-eight physicians participated in the survey (40% females, median age 43 years; 41% GPs and 59% specialists). Electrocardiography and New York Heart Association class evaluations are mostly performed once a year by GPs (46%) and at every outpatient visit by specialists (40%). Echocardiography is mostly requested if there is clinical deterioration (60%). One-third of participants screen for iron deficiency only if there is anemia. Major obstacles to implementation of different drug classes in HF with reduced ejection fraction are related to side effects, with no significant differences between specialties. Device implantation is deemed appropriate regardless of aetiology (69%) and patient age (86%). Specialists answered correctly to knowledge questions more often than GPs. Eighty-six percent of participants think that GDMT should be implemented as much as possible. Most participants (57%) believe that regular patient assessment in nurse-led HF clinics improve adherence to GDMT.

Conclusion

Obstacles to GDMT implementation according to physicians in Sweden mainly relate to potential side effects, lack of specialist knowledge and organizational aspects. Further efforts should be placed in educational activities and structuring of nurse-led clinics.