Iron deficiency in patients with heart failure with preserved ejection fraction and its association with reduced exercise capacity, muscle strength and quality of life.

BACKGROUND

The prevalence of iron deficiency (ID) in outpatients with heart failure with preserved ejection fraction (HFpEF) and its relation to exercise capacity and quality of life (QoL) is unknown.

METHODS

190 symptomatic outpatients with HFpEF (LVEF 58 ± 7%; age 71 ± 9 years; NYHA 2.4 ± 0.5; BMI 31 ± 6 kg/m) were enrolled as part of SICA-HF in Germany, England and Slovenia. ID was defined as ferritin < 100 or 100-299 µg/L with transferrin saturation (TSAT) < 20%. Anemia was defined as Hb < 13 g/dL in men, < 12 g/dL in women. Low ferritin-ID was defined as ferritin < 100 µg/L. Patients were divided into 3 groups according to E/e' at echocardiography: E/e' ≤ 8; E/e' 9-14; E/e' ≥ 15. All patients underwent echocardiography, cardiopulmonary exercise test (CPX), 6-min walk test (6-MWT), and QoL assessment using the EQ5D questionnaire.

RESULTS

Overall, 111 patients (58.4%) showed ID with 89 having low ferritin-ID (46.84%). 78 (41.1%) patients had isolated ID without anemia and 54 patients showed anemia (28.4%). ID was more prevalent in patients with more severe diastolic dysfunction: E/e' ≤ 8: 44.8% vs. E/e': 9-14: 53.2% vs. E/e' ≥ 15: 86.5% (p = 0.0004). Patients with ID performed worse during the 6MWT (420 ± 137 vs. 344 ± 124 m; p = 0.008) and had worse exercise time in CPX (645 ± 168 vs. 538 ± 178 s, p = 0.03). Patients with low ferritin-ID had lower QoL compared to those without ID (p = 0.03).

CONCLUSION

ID is a frequent co-morbidity in HFpEF and is associated with reduced exercise capacity and QoL. Its prevalence increases with increasing severity of diastolic dysfunction.