Iron Deficiency and Outcomes in Hospitalized Heart Failure Patients

Introduction: Heart failure is highly prevalent and associated with substantial morbidity and mortality, and iron deficiency is an underrecognized comorbidity linked to worse outcomes. We aimed to determine the prevalence and clinical impact of iron deficiency in hospitalized HF patients. Methods: We conducted a single‐center retrospective observational study. 100 patients hospitalized in the cardiac ICU over a year span for HF exacerbation or de novo HF were included in the study. ID was defined according to ESC 2021 criteria (ferritin <100 ng/mL or 100–299 ng/mL with transferrin saturation <20%). The primary outcome was cardiovascular mortality; secondary outcomes included HF readmissions and functional status (NYHA class). Results: ID prevalence was 49% (95% CI 39.2–58.8%), and ID was more frequent in women, older patients, and individuals with diabetes. ID was strongly associated with anemia (RR 2.08, 95% CI 1.21–3.56; p<0.01) and with worse functional status (mean NYHA class 2.43 vs 2.23; p=0.32). ID patients had significantly lower hemoglobin (12.2 vs 13.6 g/dL; p=0.003) and more frequently received aldosterone antagonists (86% vs 67%; p=0.026) and loop diuretics (84% vs 67%; p=0.050), suggesting a more congested clinical phenotype. ID prevalence was highest in HFmrEF and lowest in HFpEF; absolute ID accounted for 37 cases (75%). ID patients had higher mortality (4 (8%) vs 2 (4%)), and among 32 HFrEF patients with ID, 12 (37.5%) received intravenous ferric carboxymaltose and showed significant improvement in functional status at four-week follow-up (mean NYHA 2.00 vs 1.41; p=0.016). Conclusion: Iron deficiency is common among hospitalized HF patients and is associated with anemia, more severe symptoms, and worse outcomes. These findings support systematic screening and consideration of intravenous iron repletion in eligible HF patients.