Impact of iron deficiency on exercise capacity and outcome in heart failure with reduced, mid-range and preserved ejection fraction

<b>Background:</b> Little information is available about the prevalence and impact on exercise capacity and outcome of iron deficiency in heart failure with mid-range (HFmrEF) and preserved (HFpEF) ejection fraction in comparison to heart failure with reduced ejection-fraction (HFrEF). Furthermore, no data is available about the progression of ID in patients without baseline anaemia. <b>Methods:</b> We evaluated baseline iron and haemoglobin-status in a single-centre, prospective heart failure database. Baseline functional status, VO_2max, echocardiography and clinical-outcome (all-cause mortality and heart failure admissions) were evaluated. ID, anaemia, HFrEF, HFmrEF and HFpEF were defined according to established criteria. <b>Results:</b> A total of 1197 patients (71% male) were evaluated (HFrEF, <i>n</i> = 897; HFmrEF, <i>n</i> = 229; HFpEF, <i>n</i> = 72). The overall prevalence of ID was 53% (50% in HFrEF; 61% in HFmrEF; 64% in HFpEF) and 36% for anaemia. ID was associated with a lower VO_2max in patients with HFrEF, HFmrEF and HFpEF (<i>p</i> 2max than anaemia status (<i>p</i> p = .046) than patients without progression. <b>Conclusions:</b> Iron deficiency is common in patients with HFrEF, HFmrEF and HFpEF, and negatively affects VO_2max and clinical-outcome. Progression of iron deficiency parallels an increased risk for worsening of heart failure.