Aims
Iron deficiency (ID) and anaemia are common in heart failure; less is known about changes over time.
Methods and results
We investigated prevalence, incidence and resolution of ID and anaemia in 906 patients with chronic heart failure (median age 73 (65–79) years, 70% men, 51% with heart failure with reduced ejection fraction) 1 year apart. ID was defined as serum iron ≤13 µmol/L and anaemia as haemoglobin <13.0 g/dL for men or <12.0 g/dL for women. FAIR‐HF criteria for ID were also considered. At baseline, 10% had anaemia without ID, 23% had ID without anaemia, 20% had both, and 47% had neither. Percentages changed little over 1 year, but 157 (30%) patients had new‐onset ID, 104 (16%) new‐onset anaemia, whilst ID resolved in 173 (44%) and anaemia in 63 (23%). Compared to those who remained iron replete (iron >13 µmol/L), mortality was higher in those with persistent or incident ID at 1 year [hazard ratio (HR) 1.81 (1.23–2.67), and HR 1.40 (0.91–2.14), respectively] in multivariable models (P = 0.02). Compared to persistent ID, resolution of ID was associated with a lower mortality [HR 0.61 (0.44–0.86); P = 0.004]. Changes in ID defined by FAIR‐HF criteria were not similarly associated with mortality. Anaemia was associated with a poor outcome even if it resolved.
Conclusions
The prevalence and incidence of ID and anaemia are high in chronic heart failure but so is the rate of resolution. Persistent or incident ID, defined by a serum iron ≤13 µmol/L, is associated with higher mortality and resolution of ID with lower mortality.
Background
The recent AFFIRM-AHF trial assessing the effect of intravenous (IV) iron on outcomes in patients hospitalised with worsening heart failure who had iron deficiency (ID) narrowly missed its primary efficacy endpoint of recurrent hospitalisations for heart failure (HHF) or cardiovascular (CV) death. We conducted a meta-analysis to determine whether these results were consistent with previous trials.
Methods
We searched for randomised trials of patients with heart failure investigating the effect of IV iron vs placebo/control groups that reported HHF and CV mortality from 1st January 2000 to 5th December 2020. Seven trials were identified and included in this analysis. A fixed effect model was applied to assess the effects of IV iron on the composite of first HHF or CV mortality and individual components of these.
Results
Altogether, 2,166 patients were included (n = 1168 assigned to IV iron; n = 998 assigned to control). IV iron reduced the composite of HHF or CV mortality substantially [OR 0.73; (95% confidence interval 0.59–0.90); p = 0.003]. Outcomes were consistent for the pooled trials prior to AFFIRM-AHF. Whereas first HHF were reduced substantially [OR 0.67; (0.54–0.85); p = 0.0007], the effect on CV mortality was uncertain but appeared smaller [OR 0.89; (0.66–1.21); p = 0.47].
Conclusion
Administration of IV iron to patients with heart failure and ID reduces the risk of the composite outcome of first heart failure hospitalisation or cardiovascular mortality, but this outcome may be driven predominantly by an effect on HHF. At least three more substantial trials of intravenous iron are underway.
Graphic abstract
For patients with heart failure (HF) and iron deficiency (ID), randomized trials suggest that intravenous (IV) iron reduces hospitalizations for heart failure (HHF), but uncertainty exists about the effects in subgroups and the impact on mortality. We conducted a meta-analysis of randomized trials investigating the effect of IV iron on clinical outcomes in patients with HF.
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