Iron Deficiency in Heart Failure: Screening, Prevalence, Incidence and Outcome Data from the Swedish Heart Failure Registry and the Stockholm CREAtinine Measurements Collaborative Project

AIMS: Iron deficiency (ID) is common in heart failure (HF) and linked with poor prognosis regardless of anaemia. We assessed temporal trends in ID testing, ID prevalence, ID incidence, iron need, and outcomes associated with ID in HF across the ejection fraction (EF) spectrum. METHODS AND RESULTS: From the Swedish HF registry, we enrolled 15 197 patients from Region Stockholm with available EF and collected laboratory tests from routine practice. Iron screening improved since 2016 but remained <25% as of 2018. In 1486 patients with iron biomarkers at baseline, the prevalence of ID was 55% (HF with reduced EF 54%; mildly reduced EF 51%; preserved EF 61%). Iron need was ≥1500 mg in 72% of patients. ID was independently associated with higher risk for HF rehospitalizations (incidence rate ratio [IRR] 1.62, 95% confidence interval [CI] 1.13-2.31) and with cardiovascular (CV) death or repeated HF hospitalizations (IRR 1.63, 95% CI 1.15-2.30) regardless of EF (p-interaction 0.21 and 0.26, respectively), but not with all-cause death, CV death, or first HF hospitalization. Among 96 patients without ID at baseline and with follow-up iron biomarkers, 21% developed ID within 6 months. CONCLUSIONS: Iron deficiency screening improved over time but is still limitedly implemented, despite being highly prevalent and incident, and independently associated with CV death or HF rehospitalizations regardless of EF. Most patients with ID had an iron need necessitating either repeated administrations of intravenous iron or a preparation permitting >1000 mg doses. These data highlight the need for improved screening for ID in HF.