Anemia in Heart Failure: Diagnostic Insights and Management Patterns Across Ejection Fraction Phenotypes

Background: Anemia is a common comorbidity in heart failure (HF) and has been associated with adverse clinical consequences. This retrospective, descriptive cohort study examined phenotype-specific differences in anemia severity, clinical presentation, comorbid burden, and in-hospital management across HF subtypes classified by left ventricular ejection fraction (LVEF). Methods: We retrospectively analyzed 443 adult patients hospitalized with concurrent HF and anemia from January 2022 to December 2024. Patients were stratified by LVEF into HFrEF (<40%), HFmrEF (40-49%), and HFpEF (≥50%). All patients included met WHO criteria for anemia. Demographic, clinical, paraclinical, and therapeutic data were extracted, and descriptive statistical methods were used to evaluate intergroup differences. No formal time-to-event analyses (e.g., Kaplan-Meier curves) were performed; instead, exploratory cumulative readmission analyses using fixed follow-up windows were conducted. In-hospital mortality was recorded and stratified by HF phenotype. Results: The cohort comprised 213 (48.0%) HFrEF, 118 (26.6%) HFmrEF, and 112 (25.3%) HFpEF patients. The distribution of anemia severity, management strategies, and comorbidity profiles varied significantly across phenotypes. Severe anemia predominated in the HFmrEF cohort (54.2%), whereas mild anemia was most common in HFpEF (52.1%) and HFrEF (52.1%). Mean hemoglobin concentrations were 8.39 ± 1.79 g/dL (HFmrEF), 9.07 ± 2.47 g/dL (HFpEF), and 8.62 ± 1.94 g/dL (HFrEF). Rates of atrial fibrillation (48.2% in HFpEF), hypertensive ECG changes (63.4% in HFpEF), and ischemic-lesion patterns (>50% in HFrEF) differed by cohort. Echocardiographically, grade III mitral regurgitation and severe pulmonary hypertension each affected 25.4% of HFmrEF patients, whereas HFpEF patients most often exhibited grade II mitral regurgitation (42.9%) and moderate pulmonary hypertension (42.9%). HFrEF patients had severe pulmonary hypertension. Intravenous (IV) iron was the primary treatment modality, with highest utilization in HFmrEF. IV iron use ranged from 69.9% (HFrEF) to 84.8% (HFmrEF), with transfusion rates of 5.6% (HFrEF)-16.1% (HFpEF). Comorbid burdens differed by phenotype: HFrEF was associated with structural heart disease, HFmrEF with vascular and hepatic pathology, and HFpEF with metabolic and degenerative comorbidities. Discharge pharmacotherapy reflected phenotype-specific treatment patterns. Conclusions: This real-world descriptive analysis highlights substantial variation in anemia burden and management across the HF spectrum. While limited to descriptive findings, our analysis highlights the heterogeneity of anemia in HF and describes observed associations across phenotypes, without implying causality. These findings should be interpreted as hypothesis-generating. These findings are observational, exploratory, and cannot establish a causal relationship between intravenous iron use and survival.