Prevalence and clinical impact of iron deficiency and anaemia among outpatients with chronic heart failure: The PrEP Registry

BACKGROUND: Iron deficiency (ID) and anaemia are common in heart failure (HF). The prospective, observational PReP registry (Prävalenz des Eisenmangels bei Patienten mit Herzinsuffizienz) studied prevalence and clinical impact of ID and anaemia in HF outpatients attending cardiology practices in Germany. METHODS AND RESULTS: A total of 42 practices enrolled consecutive patients with chronic HF [left ventricular ejection fraction (LVEF) ≤45%]. ID was defined as serum ferritin <100 µg/l, or serum ferritin ≥100 µg/l/<300 µg/l plus transferrin saturation <20%, and anaemia as haemoglobin <13 g/dl (12 g/dl) in men (women). Exercise capacity was assessed using spiroergometry (69.4%) or 6-min walk test (30.4%). Amongst 1198 PReP-participants [69.0 ± 10.6 years, 25.3% female, New York Heart Association (NYHA) class 2.4 ± 0.5, LVEF 35.3 ± 7.2%], ID was found in 42.5% (previously unknown in all), and anaemia in 18.9% (previously known in 4.8%). ID was associated with female gender, lower body weight and haemoglobin, higher NYHA class and natriuretic peptide (NP) levels (all p < 0.05). ID was also more common in anaemic than non-anaemic patients (p < 0.0001), and 9.8% of PrEP-participants had both, ID and anaemia. On spiroergometry, ID independently predicted maximum exercise capacity even after multivariable adjustment, including anaemia (p = 0.0004). In all PrEP-participants, ID predicted reduced physical performance (adjusted for age, gender, anaemia, serum creatinine, C-reactive protein, LVEF, and NP level). CONCLUSIONS: Despite high prevalence, ID was previously unknown in all PrEP-participants, and anaemia was often unappreciated. Given the clinical relevance, treatability, and independent association with reduced physical performance, ID should be considered more in real-world ambulatory healthcare settings and ID-screening be advocated to cardiologists in such populations.