Intravenous iron supplementation improves energy metabolism of exercising skeletal muscles without effect on either oxidative stress or inflammation in male patients with heart failure with reduced ejection fraction.

BACKGROUND: Skeletal muscle dysfunction is a feature of heart failure (HF). Iron deficiency (ID) is prevalent in patients with HF associated with exercise intolerance and poor quality of life. Intravenous iron in iron deficient patients with HF has attenuated HF symptoms, however the pathomechanisms remain unclear. The aim of study was to assess whether intravenous iron supplementation as compared to placebo improves energy metabolism of skeletal muscles in patients with HF. METHODS: Men with heart failure with reduced ejection fraction (HFrEF) and ID were randomised in 1:1 ratio to either intravenous ferric carboxymaltose (IV FCM) or placebo. In vivo reduction of lactates by exercising skeletal muscles of forearm was analyzed. A change in lactate production between week 0 and 24 was considered as a primary endpoint of the study. RESULTS: There were two study arms: the placebo and the IV FCM (12 and 11 male patients with HFrEF). At baseline, there were no differences between these two study arms. IV FCM therapy as compared to placebo reduced the exertional production of lactates in exercising skeletal muscles. These effects were accompanied by a significant increase in both serum ferritin and transferrin saturation in the IV FCM arm which was not demonstrated in the placebo arm. CONCLUSIONS: Intravenous iron supplementation in iron deficient men with HFrEF improves the functioning of skeletal muscles via an improvement in energy metabolism in exercising skeletal muscles, limiting the contribution of anaerobic reactions generating ATP as reflected by a lower in vivo lactate production in exercising muscles in patients with repleted iron stores.

Pathophysiology and Treatment Opportunities of Iron Deficiency in Heart Failure: Is There a Need for Further Trials?

PURPOSE OF REVIEW: Iron deficiency (ID) complicates heart failure (HF) at different stages of the natural history of the disease; however, this frequent comorbidity is still not comprehensively understood and investigated in terms of pathophysiology. Intravenous iron therapy with ferric carboxymaltose (FCM) should be considered to improve the quality of life, exercise capacity, and symptoms in stable HF with ID, as well as to reduce HF hospitalizations in iron-deficient patients stabilized after an episode of acute HF. The therapy with intravenous iron, however, continues to generate important clinical questions for cardiologists. RECENT FINDINGS: In the current paper, we discuss the class effect concept for intravenous iron formulations beyond FCM, based on the experiences of nephrologists who administer different intravenous iron formulations in advanced chronic kidney disease complicated with ID and anemia. Furthermore, we discuss the neutral effects of oral iron therapy in patients with HF, because there are still some reasons to further explore this route of supplementation. The different definitions of ID applied in HF studies and new doubts regarding possible interactions of intravenous iron with sodium-glucose co-transporter type 2 inhibitors are also emphasized. The experiences of other medical specializations may provide new information on how to optimally replenish iron in patients with HF and ID.

The influence of the sounds of crying baby and the sounds of violence on haemodynamic parameters and autonomic status in young, healthy adults.

INTRODUCTION: There is evidence that various stimuli affect the balance in the autonomic nervous system (ANS) and the functioning of cardiovascular system. OBJECTIVE: The aim of the study was to assess whether the sounds of crying baby and the sounds of violence affected haemodynamic parameters and ANS in young, healthy adults and to measure differences in these reactions between the genders and these 2 stimuli. METHODS: Haemodynamic parameters (measured non-invasively by the NEXFIN device), heart rate and blood pressure variability (HRV and BPV, respectively) and baroreflex sensitivity (BRS) were analyzed in 65 adults (21 women, mean age: 23years) during a 15-minute rest followed by the emission of two 5-minute acoustic stimuli: sounds of crying baby and sounds of violence emitted randomly and separated by a 4-minute pause. RESULTS: Resting systolic blood pressure was lower, whereas indices of HRV (RMSSD, NN50, pNN50, high frequency component of HRV - HRV HF) and BPV (high frequency component - BPV HF) as well as BRS were higher in women as compared to men. During the emission of the sounds of crying baby, a decrease in diastolic blood pressure (DBP), systemic vascular resistance index, HRV HF and BPV LF (low frequency component of BPV) and an increase in stroke volume index were observed in the whole examined group, whereas during the emission of the sounds of violence subjects presented a decrease in DBP, mean blood pressure, HRV HF and BPV LF. The reaction to the sounds of crying baby (expressed as a decrease in HRV HF) was greater in women as compared to men (-0.28±0.49 versus -0.04±0.38ms(2), p=0.04). The comparison of the reaction between 2 stimuli revealed no differences. CONCLUSIONS: The stronger decrease in parasympathetic drive in women exposed to the sounds of crying baby may be related to a particular role of this stimulus, which signals the baby's distress and compels the caregivers to react.