Association of Anemia with Clinical, Laboratory, and Echocardiographic Characteristics in Patients with Heart Failure with Preserved Ejection Fraction: A Cross-Sectional Study

Objective: To determine the prevalence and severity of anemia among patients with heart failure with preserved ejection fraction (HFpEF) and evaluate its associations with clinical characteristics, laboratory biomarkers, and echocardiographic parameters. Methodology: This hospital-based cross-sectional study included 96 consecutive adult patients diagnosed with HFpEF at Liaquat National Hospital, Karachi, Pakistan, between June and December 2024. HFpEF was diagnosed using clinical criteria, left ventricular ejection fraction (LVEF) ≥50%, N-terminal pro–B-type natriuretic peptide (NT-proBNP) >125 pg/mL, and echocardiographic evidence of structural heart disease and/or diastolic dysfunction. Anemia was defined using World Health Organization sex-specific hemoglobin thresholds and categorized according to severity. Demographic characteristics, comorbidities, laboratory biomarkers, and echocardiographic parameters, including the E/e′ ratio and tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) ratio, were compared according to anemia status and severity. Results: Anemia was present in 66 of 96 patients (68.8%), including 31 (47.0%) with mild, 24 (36.4%) with moderate, and 11 (16.7%) with severe/life-threatening anemia. Median hemoglobin concentration was significantly lower in patients with anemia than in those without anemia [10.2 (9.1–11.4) versus 13.0 (12.0–14.0) g/dL; P=0.001]. Patients with anemia had a significantly lower median TAPSE/PASP ratio [0.305 (0.290–0.330) versus 0.335 (0.310–0.360); P<0.001]. Across anemia severity categories, the median TAPSE/PASP ratio progressively decreased from 0.320 (0.300–0.350) in mild anemia to 0.300 (0.293–0.320) in moderate anemia and 0.280 (0.260–0.290) in severe/life-threatening anemia (P<0.001). In contrast, neither the proportion of patients with E/e′ >14 (P=0.499) nor the median E/e′ ratio (P=0.114) differed significantly across anemia severity groups. Chronic kidney disease differed significantly across severity categories (P=0.033), while NT-proBNP, cardiac troponin I, and most other evaluated parameters showed no statistically significant differences. Conclusion: Anemia was highly prevalent among patients with HFpEF and was associated with lower TAPSE/PASP ratios, suggesting an association with impaired right ventricular–pulmonary arterial coupling. However, anemia severity was not significantly associated with differences in E/e′ or cardiac biomarkers.