Impact of Iron Deficiency on Response to and Remodeling After Cardiac Resynchronization Therapy

Accepted Manuscript Impact of Iron Deficiency on Response to and Remodeling after Cardiac Resynchronization Therapy Pieter Martens, MD, Frederik Verbrugge, MD, PhD, Petra Nijst, MD, Matthias Dupont, MD, W.H. Wilson Tang, MD, Wilfried Mullens, MD, PhD PII:

S0002-9149(16)31577-6

DOI:

10.1016/j.amjcard.2016.09.017

Reference:

AJC 22159

To appear in:

The American Journal of Cardiology

Received Date: 28 July 2016 Revised Date:

27 August 2016

Accepted Date: 1 September 2016

Please cite this article as: Martens P, Verbrugge F, Nijst P, Dupont M, Tang WHW, Mullens W, Impact of Iron Deficiency on Response to and Remodeling after Cardiac Resynchronization Therapy, The American Journal of Cardiology (2016), doi: 10.1016/j.amjcard.2016.09.017. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT

Impact of Iron Deficiency on Response to and Remodeling after Cardiac Resynchronization Therapy Pieter Martens MD 1,2. Frederik Verbrugge MD, PhD 1. Petra Nijst MD 1,2. Matthias Dupont

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MD 1. W.H. Wilson Tang MD 3. Wilfried Mullens MD, PhD 1,4.

1. Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium

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2. Doctoral School for Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.

3. Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland,

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OH, United States of America.

4. Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.

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Grant Support: Pieter Martens is supported by a doctoral fellowship by the Research Foundation – Flanders (FWO, grant-number: 1127917N). Pieter Martens, Petra Nijst, and Wilfried Mullens are researchers for the Limburg Clinical Research Program (LCRP) UHasselt-ZOL-Jessa, supported by the

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foundation Limburg Sterk Merk (LSM), Hasselt University, Ziekenhuis Oost-Limburg and Jessa Hospital.

Article short title: Impact of Iron Deficiency on Cardiac Resynchronization Therapy

Corresponding author:

Wilfried Mullens, M.D., Ph.D. Department of Cardiology, Ziekenhuis Oost-Limburg Schiepse Bos 6, 3600 Genk, BELGIUM Tel: +32 89 327087 | Fax: +32 89 327918 | E-mail: [email protected]

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ACCEPTED MANUSCRIPT Abstract Iron deficiency is prevalent in heart failure with reduced ejection fraction (HFrEF) and relates to symptomatic status, readmission and all-cause mortality. The relationship between iron status and response to cardiac resynchronization therapy (CRT) remains insufficiently elucidated. This study assesses the impact of iron deficiency on clinical response and reverse cardiac remodeling as well as outcome after

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CRT. Baseline characteristics, change in New York Heart Association (NYHA) functional class, reverse cardiac remodeling on echocardiography, and clinical outcome (i.e. all-cause mortality and heart failure readmissions) were retrospectively evaluated in consecutive CRT patients who had full iron status and

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complete blood count available at implantation, implanted at a single tertiary care center with identical dedicated multi-disciplinary CRT follow-up between October, 2008 and August, 2015. A total of 541

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patients were included with mean follow-up of 38±22 months. Prevalence of iron deficiency was 56% at implantation. Patients with iron deficiency exhibited less symptomatic improvement 6 months after implantation (p-value<0.001). In addition, both the decrease in left ventricular end-diastolic diameter (3.1 mm versus -6.2 mm; p-value=0.011) and improvement in ejection fraction (+11% versus +15%, pvalue=0.001) were significantly lower in patients with iron deficiency. Iron deficiency was significantly

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associated with an increased risk for heart failure admission or all-cause mortality (adjusted HR, 95%CI = 1.718, 1.178-2.506), irrespectively of the presence of anemia (Hemoglobin below 12 g/dl in females and below 13 g/dl in males). In conclusion, Iron deficiency is prevalent and affects both clinical response and

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outcomes in CRT.

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reverse cardiac remodeling after CRT implantation. Moreover, it is a powerful predictor of adverse clinical

Key words: Iron deficiency, Cardiac resynchronization therapy, Reverse remodeling and Outcome.

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ACCEPTED MANUSCRIPT Introduction Anemia is prevalent in patients with chronic heart failure and reduced ejection fraction (HFrEF) 1. Substantial evidence suggests that it should be a target for post-implantation care following cardiac resynchronization therapy (CRT)

2;3

. However, the pathophysiology of anemia is complex with

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hemodilution, occult blood loss, inflammation, renal disease and iron deficiency all playing a role 4. Evidence linking anemia to CRT suggest that a high red cell distribution width and low mean corpuscular hemoglobin concentration relates to poor reverse remodeling, perhaps hinting to presence of iron deficiency 5. Moreover, iron deficiency in HFrEF worsens prognosis and disability, irrespective of the

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presence of anemia 6. Therefore, iron deficiency is increasingly being recognized as an import target in

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HFrEF amenable for intravenous supplementation even when anemia is not present 7;8 . Given the pivotal role of iron in mitochondrial function, cardiac metabolism, oxygen transport, and cardiac remodeling, it seems feasible that iron deficiency might also affect the response and outcome after CRT 9-11. However, there is a paucity of data with regards to iron status and the clinical response as well as potential impact on cardiac reverse remodeling following CRT. The objectives of this study are therefore: (1) to determine

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the prevalence of iron deficiency in CRT candidates; and (2) to assess the impact of iron deficiency at implantation on clinical response, reverse cardiac remodeling as well as outcome after CRT.

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Methods

Consecutive HFrEF patients undergoing CRT implantation in a single tertiary care center

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(Ziekenhuis Oost-Limburg, Genk, Belgium) between October, 2008 and August, 2015, were evaluated. CRT indications were in compliance with the European Society of Cardiology guidelines

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. For the current

analysis, only patients with a full iron status (iron, ferritin and transferrin saturation) and complete blood count available at the time interval of 3 months before or after CRT implantation were included. Patients underwent a similar pre-specified thorough follow-up and dedicated post-implantation CRT optimization protocol, as published previously

2;13

. Briefly, all patients received identical optimization of heart failure

care including up-titration of neurohormonal blockers, as well as echocardiography-guided optimization of their device settings one day after implantation. This was repeated as indicated at each visit in a dedicated multidisciplinary CRT clinic

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. Patients received a first follow-up appointment 6 weeks after

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ACCEPTED MANUSCRIPT implantation and a second follow-up at 6 months. The current study is in compliance with the Declaration of Helsinki. Given the retrospective nature of the study design, the need for written informed consent was waived by the local ethical committee. Iron deficiency was defined according to established criteria

7;14

. Both a ferritin level <100 µg/l

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irrespectively of transferrin saturation (absolute iron deficiency) and a ferritin level 100-300 µg/l with transferrin saturation <20% (functional iron deficiency) were considered as iron deficiency. Anemia was defined as a hemoglobin level <12 g/dl in women and <13g/dl in men according to the World Health Organization criteria. Patients undergoing transfusion or therapy with intravenous iron or oral iron during

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the index hospitalization and first 6 months of follow-up were excluded from the analysis. Comprehensive

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2-dimensional echocardiography exams were performed (Philips Medical Systems, iE33w) at the time of device implantation and after 6 months. All reported measurements were averaged from 3 consecutive cycles (or 5 in case of atrial fibrillation) and assessed as recommended by the American Society of Echocardiography

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. Left ventricular end-diastolic diameter (LVEDD) and end-systolic diameter (LVESD)

were measured from the parasternal long axis view. Left ventricular ejection fraction (LVEF) was obtained

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using the modified Simpson’s biplane method in the apical 2- and 4-chamber view. Analysis of response to CRT was systematically assessed at 6 months after implantation. Symptomatic response was registered as a change in NYHA class between implantation and 6 months.

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Echocardiographic response was measured by the change in LVEF and LVEDD between implantation and 6 months. For the long term outcome analysis, the primary endpoint consisting of a combined endpoint of

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heart failure admission and all-cause mortality. Secondary endpoints consisted of each endpoint (heart failure hospitalization and all-cause mortality) separately. Heart failure admission was defined as an admission lasting > 24 hours necessitating intravenous diuretics and presence of at least one sign and one symptom of congestion.

Normally distributed continuous variables were expressed as mean ± standard deviation. Categorical data were expressed as numbers and % and compared with the Pearson χ²-test. Continuous variables were compared with the Student’s t-test. Linear regression analysis was used to investigate the independent impact of iron deficiency on LVEF change and LVEDD change as a continuous outcome

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ACCEPTED MANUSCRIPT variable after adjusting for differences in baseline characteristics and known-predictors influencing reverse remodeling. The Kaplan-Meier method was used to construct survival curves, with the log-rank test used for comparison among groups. Unadjusted and adjusted hazard ratios were calculated by Cox regression analysis. Statistical significance was always set at a 2-tailed probability level of <0.05. All

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statistics were performed using SPSS version 22 (IBM, Chicago, IL).

Results

From 686 consecutive CRT patients, a total of 547 had full iron status and complete blood count

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available at implantation and were considered for the current analysis. Mean time between baseline iron

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status and CRT-implantation was 3(±56) days. Six patients were excluded from the analysis because they received iron or red blood cell transfusion during the index hospitalization or first six month follow-up, resulting in a final study population of 541 patients. Baseline characteristics are summarized in Table 1. Iron deficiency was present in 301 (56%). Absolute versus functional iron deficiency was present in 162 patients (62%) and 101 patients (38%), respectively. Patients with iron deficiency were more likely to be

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women, diabetic, and more often received loop diuretics and anticoagulation therapy. The use of CRT devices with defibrillator was higher in patients without iron deficiency. When applying WHO-criteria for anemia, iron deficiency was not associated with a higher proportion of anemia, however on numerical

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basis the hemoglobin concentration was significantly lower (12.9 g/dl vs 13.6 g/dl, p =0.001). Symptomatic improvement according to the change in NYHA functional class from implantation

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to 6 months of follow-up is depicted in Figure 1. Patients with iron deficiency had a significantly lower improvement in NYHA functional class (p-value<0.001) despite a similar distribution at baseline. No difference was seen between NYHA class changes between absolute and functional iron deficiency (supplementary table 1).

Reverse cardiac remodeling response according to iron status is presented in Table 2. Echocardiography with high image quality for consecutive measurements was available in 263 patients with iron deficiency (87%) and 222 patients without (92%). The proportion of patients dying in the iron deficient (4.7%) and non-iron deficient (2.5%) group before 6 months was equal (p=0.252). Both groups

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ACCEPTED MANUSCRIPT demonstrated favorable reverse remodeling as indicated by a significant decrease in LVEDD and increase in LVEF (Table 2). However, the change in LVEDD and LVEF was significantly lower in patients with iron deficiency. After correcting for difference in baseline characteristics (table 1) and factors affecting reverse remodeling including female gender, Left bundle branch block, non-ischemic etiology and renal function,

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presence of iron deficiency at baseline remained independently predictive of diminished reverse remodeling (LVEF; β expressed as %, β=-3.1 ±1.1, P=0.004 and LVEDD; β expressed as mm, β=2.6±1.2, P=0.036). Moreover, no differences were observed between patients with absolute versus functional iron deficiency (supplementary table 2).

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Six patients were lost to follow-up, with complete outcome data available for 535 patients (98%

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of the total study population). A total 84 patients died and 53 patients were readmitted for heart failure during mean follow-up of 38 ± 22 months. In the primary endpoint analysis, 96 events (52 deaths and 44 heart failure readmissions) occurred in the iron deficiency group and 42 events (32 deaths and 10 heart failure readmissions) occurred in the group without iron deficiency (Figure 2; p<0.001). Table 3 provides an overview of the unadjusted and adjusted cox regression analysis. Presence of iron deficiency resulted

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in a significant hazard ratio of 1.718 (1.178 – 2.506) on the combined primary endpoint, mainly driven by heart failure hospitalization. Stratifying patients with iron deficiency according to the type of iron deficiency (absolute versus functional), resulted in similar event rate for the primary endpoint with a non-

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Discussion

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significant log-rank test at a p-value of 0.662.

This study provides important novel insights on the impact of iron deficiency on CRT: 1) iron

deficiency is common at the time of CRT implantation; 2) patients with iron deficiency are less likely to improve their functional capacity after CRT; 3) iron deficiency in CRT patients is associated with less favorable reverse remodeling; 4) iron deficiency is associated with worse clinical outcome in CRT patients, irrespectively of the presence of anemia. These data suggest that screening for iron deficiency at the time of CRT implantation may help to identify a subgroup that could potentially benefit from intravenous iron therapy to improve CRT response.

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ACCEPTED MANUSCRIPT Iron deficiency is increasingly being recognized as an important comorbidity in HFrEF . Its reported prevalence ranges from 16% to 57% depending on the criteria used and population being studied 16. Due to guideline-directed selection of CRT candidates, the current study included patients with symptomatic and advanced HFrEF

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. It was therefore not surprising to find a high prevalence of iron

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deficiency in the current analysis. We also confirm previous findings that iron deficiency is often present even in the absence of anemia 6.

In the setting of heart failure patients with a high prevalence of comorbidities, it is important to appreciate that symptomatic response not always neatly tracks echocardiographic response (reverse

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remodeling) or vice versa 17. Results of the current study indicate that iron deficiency in CRT recipients

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influences the clinical response to CRT. From a patient perspective, this is an important observation, because even improvement of the most ingravescent symptoms of functional limitation will be regarded as success by the patient. Several well-conducted double-blind randomized controlled trials have demonstrated improvement in functional status of HFrEF patients with iron deficiency after administration of intravenous iron 7;8. Given the overlap between the inclusion criteria of these trials and

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the current analyzes, an extrapolation of treatment effect is probably safe to make. Moreover, little change was seen in the evolution of NYHA-class in the placebo groups of these trials, indicating that the current difference in NYHA class at 6 months is not due to a secular time effect of iron deficiency 7;8.

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Our data suggests that HFrEF patients with iron deficiency at the time of CRT implantation exhibit a diminished capacity to reverse remodel. These results should be interpreted carefully because any

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meaningful conclusion on causality is hard to defer from a retrospective analysis. On the other hand, it is important to bear in mind that CRT is a clean non-pharmacological treatment for reverse remodeling that allows to assess the impact of a metabolic comorbidity on its reverse remodeling capacity. In that setting iron deficiency independently resulted after adjustment for baseline differences and factors influencing reverse remodeling in -3.1±1.1% less improvement of LVEF and 2.6±1.2mm more dilation of LVEDD. From a pathophysiologic perspective, two explanations might clarify this pivotal finding of reduced reverse remodeling. First, iron deficiency might be a barometer for disease severity, meaning that iron deficiency closely mirrors a more advanced disease state less capable of mounting reverse remodeling. Indeed, an

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ACCEPTED MANUSCRIPT important driver of cardiac remodeling is the pro-inflammatory state of heart failure (cytokine hypothesis), which also partially drives iron deficiency in heart failure. A recent study using circulating microRNA’s illustrated that patients with a diminished level of micro-RNA30d exhibit a reduced ability to offset the detrimental effects of TNF-α leading to less reverse remodeling 18. Thus, implying that higher

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pro-inflammatory states correlate with diminished reverse remodeling. However comparing functional versus absolute iron deficiency showed no difference between diminished reverse remodeling response. This might imply that iron deficiency itself and not the mechanism driving iron deficiency is responsible for the impaired reverse remodeling response. Secondly, we should attain the possibility that iron

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deficiency itself is not a barometer but mediator in the process of reverse remodeling. Rat data indicates that iron deficiency results in left ventricular dilatation, disorganized sarcomeres, mitochondrial swelling

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and increased mitochondrial emission of reactive oxygen species 9-11;19. CRT on the other hand results in numerous beneficial myocardial molecular changes, including sarcomere remodeling, redox-balance improvement, calcium cycling restoration, ion channel remodeling, improved sympatho-vagal balance and mitochondrial proteomic changes 20-27. Given the overlapping themes between iron deficiency and cellular

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remodeling following CRT, it seems feasible that a normal (cardiac) iron balance is a prerequisite for optimal reverse remodeling. Therefore, it might be tempting to speculate whether administration of intravenous iron in iron deficient CRT candidates results in more favorable reverse remodeling. Two small

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randomized controlled trials suggested that intravenous iron results in an improvement of LVEF and LVEDD after 6 months in HFrEF patients (without CRT) 28;29. However larger prospective trials investigating

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intravenous iron in HFrEF have not systematically assessed the effect on reverse remodeling 7;8. The current analysis also demonstrated that patients with baseline iron deficiency exhibit a higher

rate of the primary end-point heart-failure admission or all-cause mortality. However this was mainly driven by the hospitalization for worsening heart failure and not mortality. Importantly, this detrimental effect of iron deficiency remained presence even after adjusting. The finding that patients with functional and absolute iron deficiency have equal readmission and mortality rates corroborates the hypothesis that iron deficiency itself is detrimental (and perhaps not the mechanism driving iron deficiency).

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ACCEPTED MANUSCRIPT Several limitations need to be addressed. First, this study was a retrospective analysis with classic limitations associated with this type of study design. Thereby making the study results mainly hypothesis generating. Nevertheless, all patients were included in a standardized optimization protocol and follow-up clinic, reflected by the low loss to follow-up (2%). Secondly, only NYHA functional class was used as

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surrogate to assess functional improvement and this may be somewhat subjective. Indeed, iron deficiency has been linked to reduced cycloergospirometry or reduced 6-minutes’ walk test

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. These functional

investigations were not available. Third, only 547 patients of a total of 686 had an iron status and complete blood count available at implantation. Importantly, baseline characteristics of the studied

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population and patients excluded because of missing baseline iron measurements were similar

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(supplementary table 3). Fourth, it is important to emphasize that during the entire length of the study period, the scientific evidence for administration of intravenous iron in HFrEF was relatively low, which was reflected by the high prevalence of untreated iron deficiency and the low number of exclusions due to iron therapy in the analysis. Fifth, endpoints such as NYHA-class or reverse remodeling may be biased in a retrospective study, however investigators evaluating these outcome-parameters were blinded to the

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results of the iron or anemia status. Finally, we can only account for a potential impact of blood cell transfusion or iron therapy in the first 6 months, however both reverse remodeling and symptomatic

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improvement were assed in this time-frame.

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and nonanemic patients with symptomatic chronic heart failure and iron deficiency FERRIC-HF: a randomized, controlled, observer-blinded trial. J Am Coll Cardiol 2008;51:103-112.

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ACCEPTED MANUSCRIPT (18) Melman YF, Shah R, Danielson K. Circulating MicroRNA-30d Is Associated With Response to Cardiac Resynchronization Therapy in Heart Failure and Regulates Cardiomyocyte Apoptosis: A Translational Pilot Study. Circulation 2015;131:2202-2216.

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systolic and diastolic heart failure and its therapeutic implications. Eur Heart J 2015;36:2555-2564.

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(21) Lichter JG, Carruth E, Mitchell C. Remodeling of the sarcomeric cytoskeleton in cardiac ventricular myocytes during heart failure and after cardiac resynchronization therapy. J Mol Cell Cardiol 2014;72:186-195.

(22) Kirk JA, Holewinski RJ, Kooij V . Cardiac resynchronization sensitizes the sarcomere to calcium by

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reactivating GSK-3beta. J Clin Invest 2014;124:129-138.

(23) Aiba T, Barth AS, Hesketh GG. Cardiac resynchronization therapy improves altered Na channel gating in canine model of dyssynchronous heart failure. Circ Arrhythm Electrophysiol 2013;6:546-554.

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(24) Chakir K, Depry C, Dimaano VL. Galphas-biased beta2-adrenergic receptor signaling from restoring

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synchronous contraction in the failing heart. Sci Transl Med 2011;3:100ra88.

(25) Wang SB, Foster DB, Rucker J, O'Rourke B, Kass DA, Van Eyk JE. Redox regulation of mitochondrial ATP synthase: implications for cardiac resynchronization therapy. Circ Res 2011;109:750-757.

(26) Agnetti G, Kaludercic N, Kane LA. Modulation of mitochondrial proteome and improved mitochondrial function by biventricular pacing of dyssynchronous failing hearts. Circ Cardiovasc Genet 2010;3:78-87.

(27) Vanderheyden M, Mullens W, Delrue L. Myocardial gene expression in heart failure patients treated with cardiac resynchronization therapy responders versus nonresponders. J Am Coll Cardiol 2008;51:129-136.

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ACCEPTED MANUSCRIPT (28) Usmanov RI, Zueva EB, Silverberg DS, Shaked M. Intravenous iron without erythropoietin for the treatment of iron deficiency anemia in patients with moderate to severe congestive heart failure and chronic kidney insufficiency. J Nephrol 2008;21:236-242.

(29) Toblli JE, Lombrana A, Duarte P, Di GF. Intravenous iron reduces NT-pro-brain natriuretic peptide in

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anemic patients with chronic heart failure and renal insufficiency. J Am Coll Cardiol 2007;50:16571665.

(30) Jankowska EA, Rozentryt P, Witkowska A . Iron deficiency predicts impaired exercise capacity in

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patients with systolic chronic heart failure. J Card Fail 2011;17:899-906.

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ACCEPTED MANUSCRIPT Figure legends

Figure 1. Symptomatic response at 6 month follow-up.

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Figure 2: Long term outcome according to the presence of iron deficiency at implantation

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ACCEPTED MANUSCRIPT Table 1: Baseline characteristics of the study population Variable

Total population (n=541)

Iron deficiency yes (n=301) No (n=240)

P value

Demographics Age (years) Male BMI (Kg/m²)

72.3 ± 10.4 356 (65.8%) 26.9 ± 4.9

71.9 ± 10.6 184 (61.1%) 27.0 ± 4.7

73.0 ± 9.8 172 (71.7%) 26.7 ± 4.7

Cause of heart failure Ischemic Non-ischemic

244 (45.1%) 297 (54.9%)

144 (47.8%) 157 (52.2%)

100 (41.7%) 140 (58.3%)

Comorbidities Atrial fibrillation Obstructive lung disease Hypertension Dyslipidemia Diabetes ¥ Chronic kidney disease

205 (37.9%) 98 (18.1%) 433 (80.0%) 376 (69.5%) 152 (28.1%) 255 (47.1%)

121 (40.2%) 58 (19.3%) 247 (82.1%) 213 (70.8%) 96 (31.9%) 151 (50.2%)

Device type CRT-Pacemaker CRT-Defibrillator

275 (50.8%) 266 (49.2%)

169 (56.1%) 132 (43.9%)

106 (44.2%) 134 (55.8%)

Anemia

176 (32.6%)

105 (34.9%)

71 (29.7%)

0.202

138 ± 8 13.3 ± 1.7 62.2 ± 24

138 ± 10 12.9 ± 1.6 60.2 ± 25

138 ± 9 13.6 ± 1.7 62.4 ± 24

0.822 0.0001 0.325

221 (40.9%) 298 (55.2%) 21 (3.9%)

118 (39.2%) 168 (55.8%) 15 (5.0%)

103 (43.1%) 130 (54.4%) 6 (2.5%)

153 ± 29.4

151 ± 30.6

154 ± 27.9

0.229

404 (75.0%)

216 (72.2%)

188 (78.3%)

0.105

30 ± 9 6.1 ± 0.9 5.5 ± 1.2

30 ± 10 6.0 ± 0.9 5.4 ± 1.1

29 ± 9 6.1 ± 0.9 5.6 ± 1.1

0.082 0.377 0.250

457 (84.6%)

254 (84.7%)

203 (84.6%)

0.979

457 (84.6%) 342 (63.3%) 273 (50.6%) 45 (8.3%) 47 (8.7%) 296 (54.8%) 187 (34.6%)

250 (83.3%) 193 (64.3%) 168 (56.2%) 23 (7.7%) 28 (9.4%) 161 (53.7%) 123 (41.0%)

207 (86.3%) 149 (62.1%) 105 (43.8%) 22 (9.2%) 19 (7.9%) 135 (56.3%) 64 (26.7%)

0.350 0.590 0.004 0.531 0.554 0.549 0.001

QRS duration (ms)

Medication Angiotensin converting enzyme inhibitor or angiotensin receptor blocker Beta-blocker Aldosterone antagonist Loop diuretic Nitrates Hydralazine Antiplatelet agent Anticoagulation therapy

84 (35%) 40 (16.7%) 186 (77.5%) 163 (67.9%) 56 (23.3%) 104 (43.3%)

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Left Bundle Branch Block

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NYHA class II III IV

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0.152

Laboratory analysis Sodium (mmol/l) Hemoglobine (g/dl) GFR (ml/min/1,73m²)

Echocardiography LVEF (%) LVEDD (cm) LVESD (cm)

0.212 0.01 0.519

0.216 0.435 0.187 0.475 0.028 0.114 0.006

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Values are mean ± SD or n (%). ¥ CKD was defined as GFR below 60ml/min, GFR was calculated using MDRD- formula.

ACCEPTED MANUSCRIPT Table 2: Reverse cardiac remodeling after 6 months.

Iron deficiency Variable

P-value No (n=222)

Change in LVEF (%)

+ 10.9% (±12.9)

+ 14.6% (±11.7)

0.001

Change in LVEDD (mm)

- 3.1 mm (±13.2)

- 6.2 mm (±13.6)

0.011

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LVEF= Left Ventricular Ejection Fraction; LVEDD= Left Ventricular End Diastolic Diameter

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Yes (n=263)

ACCEPTED MANUSCRIPT Table 3: Cox regression analysis for heart failure for primary and secondary endpoint.

Unadjusted Hazard ratio

Variable

Adjusted hazard ratio

a

HR

(95% CI)

P-value

HR

(95% CI)

P-value

2.024

1.404 – 2.918

<0.001

1.828

1.262 – 2.647

0.001

Heart failure hospitalization

2.245

1.520 – 3.316

<0.001

1.592

All-cause mortality

1.023

0.654 – 1.599

0.921

1.006

Heart failure hospitalization and all-cause mortality

1.055 – 2.402

0.027

0.630 – 1.608

0.979

SC

Secondary endpoint

RI PT

Primary endpoint

AC C

EP

TE D

M AN U

HR =Hazard Ratio; CI= confidence interval; a= hazard ratios were adjusted for significant differences in baseline characteristics including ICD use, hemoglobin concentration, male sex, loop diuretic use and anticoagulation use and clinically relevant parameters including NYHA-class, glomerular filtration rate, left bundle branch block, ischemic etiology of heart failure, and baseline left ventricular ejection fraction.

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT