Abstract 2005: Effect of Intravenous Iron Sucrose on Exercise Tolerance in Anemic and Non-anemic Patients with Symptomatic Chronic Heart Failure and Iron Deficiency: A Randomised, Controlled, Observer-blinded Trial (FERRIC-HF)
Background: Iron deficiency anemia is common in patients (pts) with chronic heart failure (CHF) and associated with exercise intolerance. Iron deficiency may diminish exercise performance even in the absence of anemia. We tested the hypothesis that intravenous (iv) iron supplementation would safely improve exercise tolerance in anemic and non-anemic iron deficient CHF pts.
Methods: We randomly assigned 35 pts with CHF (age 64±13y, 25 male, peak oxygen consumption [pVO2]/kg 14.0±2.7 mL/min/kg, NYHA class II [n=18] / III [n=17], LVEF 30±7% [all <45%]) and iron deficiency (ferritin <100 ng/mL or ferritin 100–300 ng/mL with transferrin saturations [TSAT] <20%) to 16 weeks of iv iron or no treatment in a 2:1 ratio. Randomization was stratified according to hemoglobin levels (<12.5 g/dL vs 12.5–14.5 g/dL) and centre. Treatment comprised of 200 mg iv iron sucrose weekly until iron repletion (repletion dose = weight (kg) × 2.4 × [15 - hemoglobin (g/dL)] + 500 mg) and 200 mg monthly thereafter. The observer-blinded primary endpoint was the change in absolute pVO2 from baseline to end of study.
Results: The difference (95% confidence interval [CI]) in the mean changes from baseline to end of study between iv iron and control groups was 273 ng/mL (151, 396) for ferritin (P<0.0001), 11 % (5,17) for TSAT (P<0.001), 0.1 g/dL (−0.8, 0.9) for hemoglobin (P=0.9), 96 mL/min (−12, 205) for absolute pVO2 (P=0.08), 2.2 mL/kg/min (0.5, 4.0) for pVO2/kg (P=0.01), 60 sec (−6, 126) for treadmill exercise duration (P=0.08), −0.6 (−0.9, −0.2) for NYHA class (P=0.007), and 1.7 (0.7,2.6) for patient global assessment (P=0.002). In the anemic subgroup, the difference in the mean changes between iv iron (n=12) and control (n=6) groups was 204 mL/min (31, 378) for absolute pVO2 (P=0.02), 4.0 mL/kg/min (1.1, 6.8) for pVO2/kg (P=0.01) and 42 sec (−66, 150) for exercise duration (P=0.4). In the non-anemic subgroup, iv iron improved exercise duration (84 sec [−9, 169], P=0.06) and NYHA class (P=0.06). The incidence of adverse events did not differ between the treatment arms (P=0.6).
Conclusions: Iron repletion with intravenous iron sucrose was safe and associated with improvements in exercise capacity and symptom status in CHF patients with iron deficiency. Benefits were more evident in anemic patients.