Myocardial Iron Content Research Articles

Early detection of myocardial iron overload in patients with β-thalassemia major using cardiac magnetic resonance T1 mapping

BackgroundThe T2* technique, used for quantifying myocardial iron content (MIC), has limitations in detecting early myocardial iron overload (MIO). The in vivo mapping of the myocardial T1 relaxation time is a promising alternative for the early detection and management of MIO. Methods32 β-thalassemia major (βTM) patients aged 11.5 ± 4 years and 32 healthy controls were recruited and underwent thorough clinical and laboratory assessments. The mid-level septal iron overload was measured through T1 mapping using a modified Look-Locker inversion recovery sequence with a 3 (3 s) 3 (3 s) 5 scheme. Septum was divided at the mentioned level into 3 zones corresponding to segments 8 and 9 in the cardiac segmentation model. Results21.9 % of βTM had clinical cardiac morbidity. The cut-off of T1 mapping of hepatic and myocardium to differentiate between the patients and control groups was ≤466 and ≥ 923 ms respectively. The T1 technique was able to detect 4 patients with high MIC, two of them were not detected by the T2* technique. There was a statistically significant correlation between the average T1 values of the studied zones in patients with βTM and the liver iron content (LIC), the T1 values within segment 8 of the liver, age of patients, the age at first transfusion, age of splenectomy and serum ferritin value. ConclusionThe addition of the T1 mapping sequence to the conventional T2* technique was able to increase the efficacy of the MIC detection protocol by earlier detection of MIO. This would guide chelation therapy to decrease myocardial morbidity.

Assessment of transfusion-induced iron overload with T2*MRI in survivors of childhood acute lymphoblastic leukemia: A case control study

IntroductionChildhood acute lymphoblastic leukemia survivors receiving multiple packed red blood transfusions may be at risk of vital organ iron deposition causing long-term complications. This study was undertaken to assess the prevalence and severity of iron overload in the liver and heart by magnetic resonance imaging. MethodsA case-control study was conducted on 60 acute lymphoblastic leukemia survivors aged from 6 to 18 years and 60 healthy, age- and sex-matched children as a control group. The hematological profile, and serum ferritin was assessed and the iron content of the liver and heart was measured by T2* magnetic resonance imaging. ResultsTwenty-six (43.3 %) and two (3.3 %) patients had elevated liver and myocardial iron concentrations, respectively. The statistics show a significantly positive correlation between liver T2* magnetic resonance and serum ferritin. The total volume of blood transfused and duration of follow up were associated with elevated liver iron concentrations (p-values = 0.036 and 0.028 respectively). Myocardial T2* magnetic resonance lacked correlation with serum ferritin and transfusion therapy ConclusionLiver iron overload was detected in children and adolescents after acute lymphoblastic leukemia therapy. The risk of iron overload was related mainly to the transfusion burden during therapy. These patients need monitoring after therapy to assess their need for future chelation therapy.

Cardiac Disease in Egyptian Thalassemia Major and Sickle Cell Disease Adolescents in relation to Vitamin D Status Using Echocardiogram & Ultrafast Magnetic Resonance Imaging

Abstract Background Cardiovascular complications are well recognized in patients with β-thalassemia major (β-TM) and sickle cell disease (SCD). Vitamin D deficiency is prevalent in patients with transfusion-dependent thalassemia and there is an association between vitamin D deficiency and both left ventricular function and iron overload in thalassemia. However, the relationship between vitamin D and cardiac iron is not well studied in Egypt and the role of vitamin D in cardiac disease in SCD and β-TM needs to be assessed. Aim To assess vitamin D status in children and adolescents with SCD and β-TM in relation to cardiac complications using echocardiography and cardiac magnetic resonance (CMR) T2*. Methods Forty-one patients with SCD and 35 patients with β-TM without symptomatic cardiac disease were studied stressing on history of splenectomy and transfusion history. Markers of hemolysis, serum ferritin and vitamin D levels were measured. Liver iron concentration (LIC) was assessed by magnetic resonance imaging (MRI). Screening for cardiovascular abnormalities was performed by the non-invasive Doppler echocardiography and CMR was used to assess myocardial iron overload. Results Echocardiography showed that cardiac functions were significantly impaired in β-TM patients compared with SCD while the frequency of pulmonary hypertension risk (elevated TRV ≥2.5 m/sec) was consistent between both β-TM and SCD groups. Cardiac T2* (which reflects cardiac iron overload) was significantly lower while myocardial iron concentration (MIC) was significantly higher in β -TM patients compared with SCD group. Vitamin D levels were decreased in both SCD and β-TM patients than control levels; however, SCD patients had significantly lower vitamin D levels. Low vitamin D levels were significantly associated withincreased risk of pulmonary hypertension in the SCD group while In β-TM group, vitamin D levels were significantly lower in patients with cardiac disease and those with serum ferritin levels ≥ 2500 µg/L. A significant evidence of diastolic dysfunction was found in SCD and β-TM patients who had low serum vitamin D level < 20 ng/mL. Vitamin D levels were negatively correlated to serum ferritin and LIC while positively correlated to cardiac T2*. Conclusion Low vitamin D levels were associated with cardiopulmonary dysfunction in adolescents with SCD and β-TM. Vitamin D deficiency in those patients was linked to cardiac iron overload leading to iron induced cardiomyopathy. Proper chelation therapy is mandatory to improve cardiac disease, iron overload and consequently, vitamin D status in β-TM patients.

Intravenous iron therapy results in rapid and sustained rise in myocardial iron content through a novel pathway.

Intravenous iron therapies contain iron-carbohydrate complexes, designed to ensure iron becomes bioavailable via the intermediary of spleen and liver reticuloendothelial macrophages. How other tissues obtain and handle this iron remains unknown. This study addresses this question in the context of the heart. A prospective observational study was conducted in 12 patients receiving ferric carboxymaltose (FCM) for iron deficiency. Myocardial, spleen, and liver magnetic resonance relaxation times and plasma iron markers were collected longitudinally. To examine the handling of iron taken up by the myocardium, intracellular labile iron pool (LIP) was imaged in FCM-treated mice and cells. In patients, myocardial relaxation time T1 dropped maximally 3 h post-FCM, remaining low 42 days later, while splenic T1 dropped maximally at 14 days, recovering by 42 days. In plasma, non-transferrin-bound iron (NTBI) peaked at 3 h, while ferritin peaked at 14 days. Changes in liver T1 diverged among patients. In mice, myocardial LIP rose 1 h and remained elevated 42 days after FCM. In cardiomyocytes, FCM exposure raised LIP rapidly. This was prevented by inhibitors of NTBI transporters T-type and L-type calcium channels and divalent metal transporter 1. Intravenous iron therapy with FCM delivers iron to the myocardium rapidly through NTBI transporters, independently of reticuloendothelial macrophages. This iron remains labile for weeks, reflecting the myocardium's limited iron storage capacity. These findings challenge current notions of how the heart obtains iron from these therapies and highlight the potential for long-term dosing to cause cumulative iron build-up in the heart.

Knockdown of LncRNA Lcn2-204 alleviates sepsis-induced myocardial injury by regulation of iron overload and ferroptosis

Ferroptosis is an iron-dependent programmed cell death form resulting from lipid peroxidation damage, it plays a key role in organ damage and tumor development from various causes. Sepsis leads to severe host response after infection with high mortality. The long non-coding RNAs (LncRNAs) are involved in different pathophysiological mechanisms of multiple diseases. Here, we used cecal ligation and puncture (CLP) operation to mimic sepsis induced myocardial injury (SIMI) in mouse model, and LncRNAs and mRNAs were profiled by Arraystar mouse LncRNA Array V3.0. Based on the microarray results, 552 LncRNAs and 520 mRNAs were differentially expressed in the sham and CLP groups, among them, LncRNA Lcn2–204 was the highest differentially expressed up-regulated LncRNA. Iron metabolism disorder was involved in SIMI by bioinformatics analysis, meanwhile, myocardial iron content and lipocalin-2 (Lcn2) protein expressions were increased. The CNC network comprised 137 positive interactions and 138 negative interactions. Bioinformatics analysis showed several iron-related terms were enriched and six genes (Scara5, Tfrc, Lcn2, Cp, Clic5, Ank1) were closely associated with iron metabolism. Then, we constructed knockdown LncRNA Lcn2–204 targeting myocardium and found that it ameliorated cardiac injury in mouse sepsis model through modulating iron overload and ferroptosis. In addition, we found that LncRNA Lcn2–204 was involved in the regulation of Lcn2 expression in septic myocardial injury. Based on these findings, we conclude that iron overload and ferroptosis are the key mechanisms leading to myocardial injury in sepsis, knockdown of LncRNA Lcn2–204 plays the cardioprotective effect through inhibition of iron overload, ferroptosis and Lcn2 expression. It may provide a novel therapeutic approach to ameliorate sepsis-induced myocardial injury.

Iron Dyshomeostasis and Mitochondrial Function in the Failing Heart: A Review of the Literature.

Cardiac contraction and relaxation require a substantial amount of energy provided by the mitochondria. The failing heart is adenosine triphosphate (ATP)- and creatine-depleted. Studies have found iron is involved in almost every aspect of mitochondrial function, and previous studies have shown myocardial iron deficiency in heart failure (HF). Many clinicians advocated intravenous iron repletion for HF patients meeting the conventional criteria for systemic iron deficiency. While clinical trials showed improved quality of life, iron repletion failed to significantly impact survival or significant cardiovascular adverse events. There is evidence that in HF, labile iron is trapped inside the mitochondria causing oxidative stress and lipid peroxidation. There is also compelling preclinical evidence demonstrating the detrimental effects of both iron overload and depletion on cardiomyocyte function. We reviewed the mechanisms governing myocardial and mitochondrial iron content. Mitochondrial dynamics (i.e., fusion, fission, mitophagy) and the role of iron were also investigated. Ferroptosis, as an important regulated cell death mechanism involved in cardiomyocyte loss, was reviewed along with agents used to manipulate it. The membrane stability and iron content of mitochondria can be altered by many agents. Some studies are showing promising improvement in the cardiomyocyte function after iron chelation by deferiprone; however, whether the in vitro and in vivo findings will be reflected on on clinical grounds is still unclear. Finally, we briefly reviewed the clinical trials on intravenous iron repletion. There is a need for more well-simulated animal studies to shed light on the safety and efficacy of chelation agents and pave the road for clinical studies.

Empagliflozin effects on iron metabolism as a possible mechanism for improved clinical outcomes in non-diabetic patients with systolic heart failure

Sodium-glucose co-transporter-2 (SGLT2) inhibitors improve clinical outcomes in patients with heart failure (HF), but mechanisms of action are incompletely understood. In the EMPA-TROPISM trial, empagliflozin reversed cardiac remodeling and increased physical capacity in stable non-diabetic patients with systolic HF. Here we explore, post hoc, whether treatment effects in this cohort, comprising patients who had a high prevalence of iron deficiency, were related to iron metabolism. Myocardial iron content estimated by cardiac magnetic resonance T2* quantification increased after initiation of empagliflozin but not placebo (treatment effect: P = 0.01). T2* changes significantly correlated with changes in left ventricular volumes, mass and ejection fraction, peak oxygen consumption and 6-minute walking distance; concomitant changes in red blood cell indices were consistent with augmented hematopoiesis. Exploratory causal mediation analysis findings indicated that changes in myocardial iron content after treatment with empagliflozin may be an important mechanism to explain its beneficial clinical effects in patients with HF.ClinicalTrials.gov: NCT03485222.

Cardiac iron overload in pediatric oncology and bone marrow transplant survivors.

e22022 Background: Cardiovascular late effects are a leading cause of mortality and morbidity in childhood cancer and Bone Marrow Transplant (BMT) survivors. In patients receiving chronic red blood cell transfusions, excess iron may be deposited in the liver, heart, and pituitary gland. Iron overload cardiomyopathy is characterized as a restrictive physiology with early diastolic dysfunction ultimately progressing to end-stage dilated cardiomyopathy. Iron loading in the heart can also lead to arrhythmias and increase myocardial ischemia reperfusion injury due to increased formation of reactive oxygen species. It is not yet known whether high transfused packed red blood cell (PRBC) volumes in cancer and BMT patients leads to cardiac iron deposition, and whether iron-induced cardiac injury contributes to the known cardiovascular late effects in these patients. Methods: 83 childhood cancer and BMT survivors with elevated serum ferritin levels and subsequent liver Magnetic Resonance (MR) imaging were identified. 18 patients (21.7%) who had liver iron content of > 12mg/g (mean 16.0 ± 7.36 mg/g) also underwent Cardiac MRI (CMR) to determine cardiac iron content. Results: Median transfused blood volume was 393 ml/kg [95% Confidence Interval (CI) 170-780 ml/kg]. All 18 patients had at least one echocardiogram showing normal ventricular ejection fractions [mean 65.1 ± Standard Deviation (SD) 3.53%] and normal shortening fractions (mean 35.4 ± 3.67%). All patients had myocardial iron content within normal ranges (T2* relaxation time mean 35.1 msec ± 7.1 [normal >20 msec], mean ± SD iron content 0.63± 0.2 mg/g dry weight, range 0.5-1.1). There was no association of cardiac iron content with transfused blood volume, anthracycline dose (mg/m2) or liver iron content (Pearson Correlation Coefficients 0.27, 0.29 and 0.89 respectively). Conclusions: Childhood cancer and BMT patients receive multiple PRBC transfusions to treat symptomatic anemia. It is currently unknown whether excess iron deposition in the heart contributes to the cardiac effects of impaired diastolic function and ultimately systolic dysfunction. In this study, 11 of 18 patients (61.1%) with high levels of liver iron had at least 1 other risk factor for the development of future cardiac dysfunction (either anthracycline exposure, radiation to the chest or total body irradiation or both). Larger studies are needed to determine whether oncology patients with high levels of iron deposition in their liver are also at risk for clinically significant cardiac iron loading, and what risk factors may exist for elevated myocardial iron content.

QiShenYiQi dripping pill alleviates myocardial ischemia-induced ferroptosis via improving mitochondrial dynamical homeostasis and biogenesis.

QiShenYiQi is a Chinese herbal formula composed of Astragalus membranaceus Fisch. ex Bunge, root; Slauia miltiorrhiza Bunge, root and rhizome; Panax notoginseng (Burkill) F.H.Chen, root; and Dalbergia odorifera T.C.Chen, heartwood of trunk and root with a proportion of 10:5:1:0.067. Its dripping pills were approved by the National Medical Products Administration (NMPA) in 2003 and could be used in the clinical treatment of ischemic heart diseases. Ferroptosis is an important pathological mechanism in the process of myocardial ischemia (MI). Whether QSYQ can improve ferroptosis induced by myocardial ischemia is still unclear. In this study, the potential mechanisms of QSYQ against ferroptosis in MI-induced injury were investigated. The main components of QSYQ were analyzed by HPLC-Q-TOF-MS/MS. MI model was established by ligation of the left anterior descending coronary artery and then treated with QSYQ dropping pills for 14 days. The cardiac function of mice was evaluated by echocardiography. Hematoxylin and eosin (H&E) staining and Masson's trichrome staining were used to detect the pathological changes in heart tissue. Serum biochemical indexes were analyzed by biochemical kit. Transmission electron microscope (TEM) was used to observe the mitochondria ultrastructure and mitochondrial ROS was detected by immunofluorescence. Then, photoacoustic imaging was used to observe the redox status of the mice' hearts. Finally, the mitochondrial dynamics and biogenesis related proteins and the proteins of ferroptosis were analyzed by western blotting. RT-PCR was used to detect the mRNA expression changes of ferroptosis. A total of 20 principal components of QSYQ were characterized by HPLC-Q-TOF-MS/MS. QSYQ significantly improved cardiac function and myocardial injury in MI mice. Furthermore, the lipid peroxidation change levels (MDA, 4-HNE, and GSH) in serum were attenuated and myocardial iron content was reduced after QSYQ treatment. On this basis, QSYQ also improved the expression changes of ferroptosis related mRNA and proteins. In addition, QSYQ promoted mitochondrial biogenesis (PGC-1α, Nrf1, and TFAM) and mitochondrial fusion (MFN-2 and OPA1) and inhibited mitochondrial excessive fission (Phosphorylation of Drp1 at ser616) in vitro and in vivo, indicating that the cardioprotection of QSYQ might be related to promoting mitochondrial biogenesis and dynamic homeostasis. In summary, QSYQ could alleviate MI-induced ferroptosis by improving mitochondrial biogenesis and dynamic homeostasis.

MRI for Quantitative Determination of Iron in the Liver and Heart in Patients with Primary and Secondary Hemochromatoses in Association with Serrum Ferritin: Single-Stage Observational Study

Background. An extremely small number of studies have been devoted to the study of differences in LIC (liver iron concentration) and MIC (myocardium iron concentration) indicators, as well as their correlation with each other and with ferritin levels in patients with various nosological forms. Aims to study the relationship of ferritin, LIC and MIC levels in patients with various causes of hemochromatosis (hereditary hemochromatosis (HH), aplastic anemia (AA), primary myelofibrosis (PMF), thalassemia (TL), myelodysplastic syndrome (MDS)). Methods. The design of the study is a singlestage observational one. The study included 91 patients with primary hemochromatosis and secondary transfusion-dependent hemochromatosis receiving regular blood transfusion and iron chelate therapy from 2015 to 2018. The studies were carried out on 1.5 T MR-scanner Magnetom Espree (Siemens, Germany), and myocardial iron concentration (MIC) was calculated using the formula MIC = 45 (T2*) 1.22. Liver iron concentration (LIC) was calculated using the formula LIC = 0.03 R2* + 0.74. The ferritin level was determined by enzyme immunoassay. Statistical processing of the results obtained was carried out using the SPSS software package. Results. Connections between LIC and ferritin (r = 0.867; p 0.001), MIC and ferritin (r = 0.759; p = 0.004) and LIC and MIC (r = 0.737; p = 0.006) were found in patients with primary hemochromatosis, while in patients with secondary hemochromatosis significant correlations were found only between LIC and MIC (r = 0.503; p 0.001), while the relationship was average. Links between LIC and ferritin were found in patients with AA (r = 0.656; p = 0.040), an average relationship, in patients with TL (r = 0.714; p = 0.020), an average relationship. The relationship between MIC and ferritin was revealed in patients with AA (r = 0.703; p = 0.050), an average relationship, in patients with TL (r = 0.757; p = 0.018), an average relationship. At the same time, in patients with MDS and PMF in this study, there was no association between ferritin and LIC, ferritin and MIC. Conclusions. In patients with hereditary hemochromatosis, LIC and MIC are associated with ferritin, and MIC is also associated with LIC (medium bond). In patients with iron overload due to thalassemia, an average correlation between LIC and ferritin, MIC and ferritin was revealed. In patients with iron overload due to aplastic anemia, an average correlation between LIC and ferritin, MIC and ferritin was revealed.

Pulmonary function in patients with transfusion-dependent thalassemia and its associations with iron overload

In patients with transfusion-dependent thalassemia (TDT), pulmonary function impairment has been reported but data are conflicting. Moreover, it remains unclear whether pulmonary dysfunction is associated with iron overload. This study aimed to evaluate the pulmonary function in patients with TDT and to investigate the associations between pulmonary dysfunction and iron overload. It was a retrospective observational study. 101 patients with TDT were recruited for lung function tests. The most recent ferritin levels (pmol/L) and the magnetic resonance imaging (MRI) measurements of the myocardial and liver iron status, as measured by heart and liver T2* relaxation time (millisecond, ms) respectively, were retrieved from the computerized medical records. Only data within 12 months from the lung function measurement were included in the analysis. The serum ferritin, and the cardiac and liver T2* relaxation time were the surrogate indexes of body iron content. The threshold of abnormality in lung function was defined as under 80% of the predicted value. 101 subjects were recruited with a mean age of 25.1 years (standard deviation (SD) 7.9 years). Thirty-eight (38%) and five (5%) demonstrated restrictive and obstructive lung function deficits, respectively. A weak correlation of FVC %Predicted and TLC %Predicted with MRI myocardial T2* relaxation time (rho = 0.32, p = 0.03 and rho = 0.33, p = 0.03 respectively) was observed. By logistic regression, MRI cardiac T2* relaxation time was negatively associated with restrictive lung function deficit (B − 0.06; SE 0.03; Odds ratio 0.94; 95% confidence interval (CI) 0.89–0.99; p = 0.023) after adjusting for age, sex and body mass index. Restrictive pulmonary function deficit was commonly observed in patients with TDT, and the severity potentially correlates with myocardial iron content. Monitoring of lung function in this group of patients, particularly for those with iron overload, is important.

Effect of standard phlebotomy on myocardial and hepatic iron levels in newly diagnosed cardiac asymptomatic hereditary hemochromatosis subjects with C282Y homozygosity.

Effect of standard phlebotomy on myocardial and hepatic iron levels in newly diagnosed cardiac asymptomatic hereditary hemochromatosis subjects with C282Y homozygosity.

No difference in myocardial iron concentration and serum ferritin with deferasirox and deferiprone in pediatric patients with hemoglobinopathies: A systematic review and meta-analysis.

Iron overload is a common complication experienced by transfusion-dependent children with hemoglobin disorders. Chelators such as deferasirox (DFX) and deferiprone (DFP) are effective in overcoming this problem. We conducted this systematic review and meta-analysis to evaluate the effectiveness of DFX compared to DFP in treating iron overload amongst pediatric patients with hemoglobin disorders. PubMed and Cochrane Central were searched from their inception until Dec 21 2021, for randomized clinical trials (RCTs) and observational studies, which assessed the efficacy of DFX compared to DFP in the treatment of inherited hemoglobin disorders. The outcomes of interest included myocardial iron concentration (MRI T2*) at the end of the trial and change in mean serum ferritin (SF) levels at the 6 and 12months mark. Weighted mean differences (WMDs) with their corresponding 95% confidence intervals (CIs) were calculated for continuous outcomes using random effects model. A total of 5 studies comprising 607 children were included. The results of our analysis revealed no significant difference between DFX and DFP in MRI T2* at the end of treatment (WMD: -0.92; 95% CI [-3.35, 1.52]; p=0.46; I2=0). Moreover, there has been no significant difference noted in SF levels at both 6months (WMD: 97.31; 95% CI [-236.16, 430.77]; p=0.57; I2=0) and 12months (WMD: 46.99; 95% CI [-191.42, 285.40]; p=0.70; I2=0) respectively. Our analysis shows no significant difference between the efficacy of DFX and DFP in the management of iron overload in children with inherited blood disorders. Future large-scale clinical trials are required to further validate our results.

Efficacy and safety of calcium channel blockers in preventing cardiac siderosis in thalassemia patients: An updated meta-analysis with trial sequential analysis.

Iron overload in patients with thalassemia represents a serious complication by affecting numerous organ systems. This meta-analysis aims to establish an evidence regarding the effect of amlodipine on cardiac iron overload in thalassemia patients. We searched PubMed, Scopus, Web of Science, Cochrane Central, and EMBASE for all relevant randomized controlled trials (RCTs). The primary outcomes were cardiac T2* and myocardial iron concentration (MIC). Secondary outcomes were liver iron concentration (LIC), risk of Gastrointestinal (G.I.) upset and risk of lower limb edema. We used Hedges' g to pool continuous outcomes, while odds ratio was used for dichotomous outcomes. Seven RCTs were eligible for this systematic review and meta-analysis, comprising of 233 patients included in the analysis. Amlodipine had a statistically significant lower MIC (Hedges' g= -0.82, 95% confidence interval [CI] [-1.40, -0.24], p< .001) and higher cardiac T2* (Hedges' g= 0.36, 95% CI [0.10, 0.62], p= .03). Amlodipine was comparable to standard chelation therapy in terms of the risk of lower limb edema and GI upset. Our meta-analysis found that amlodipine significantly increases cardiac T2* and decreases MIC, hence decreasing the incidence of cardiomyopathy-related iron overload in thalassemia patients.

Deferasirox versus deferoxamine in managing iron overload in patients with Sickle Cell Anaemia: a systematic review and meta-analysis.

To examine the efficacy of deferasirox (DFX) by comparison with deferoxamine (DFO) in managing iron overload in patients with sickle cell anaemia (SCA). Online databases were systematically searched for studies published from January 2007 to July 2022 that had investigated the efficacy of DFX compared with DFO in managing iron overload in patients with SCA. Of the 316 articles identified, three randomized clinical trials met the inclusion criteria. Meta-analysis of liver tissue iron concentration (LIC) showed that iron overload was not significantly higher in the DFX group compared with DFO group (WMD, -1.61 mg Fe/g dw (95% CI -4.42 to 1.21). However, iron overload as measured by serum ferritin was significantly lower in DFO compared with DFX group (WMD, 278.13 µg/l (95% CI 36.69 to 519.57). Although meta-analysis was not performed on myocardial iron concentration due to incomplete data, the original report found no significant difference between DFX and DFO. While limited by the number of studies included in this meta-analysis, overall, the results tend to show that DFX was as effective as DFO in managing iron overload in patients with SCA.

Estimation of iron overload with T2*MRI in children treated for hematological malignancies

Iron overload may contribute to long-term complications in childhood cancer survivors. There are limited reports of assessment of tissue iron overload in childhood leukemia by magnetic resonance imaging (MRI). A cross-sectional, observational study in children treated for hematological malignancy was undertaken. Patients ≥6 months from the end of therapy who had received ≥5 red-cell transfusions were included. Iron overload was estimated by serum ferritin (SF) and T2*MRI. Forty-five survivors were enrolled among 431 treated for hematological malignancies. The median age at diagnosis was 7-years. A median of 8 red-cell units was transfused. The median duration from the end of treatment was 15 months. An elevated SF (>1,000 ng/ml), elevated liver iron concentration (LIC) and myocardial iron concentration (MIC) were observed in 5 (11.1%), 20 (45.4%), and 2 (4.5%) patients, respectively. All survivors with SF >1,000 ng/ml had elevated LIC. The LIC correlated with SF (p < 0.001). MIC lacked correlation with SF or LIC. Factors including the number of red-cell units transfused and duration from the last transfusion were associated with elevated SF (p = 0.001, 0.002) and elevated LIC (p = 0.012, 0.005) in multiple linear regression. SF >595 ng/ml predicted elevated LIC with a sensitivity of 85% and specificity of 91.6% (AUC 91.2%). A cutoff >9 units of red cell transfusions had poor sensitivity and specificity of 70% and 75% (AUC 76.6%) to predict abnormal LIC. SF >600 ng/ml is a robust tool to predict iron overload, and T2*MRI should be considered in childhood cancer survivors with SF exceeding 600 ng/ml.

Improvement of Left Ventricular Graft Function Using an Iron-Chelator-Supplemented Bretschneider Solution in a Canine Model of Orthotopic Heart Transplantation.

Demand for organs is increasing while the number of donors remains constant. Nevertheless, not all organs are utilized due to the limited time window for heart transplantation (HTX). Therefore, we aimed to evaluate whether an iron-chelator-supplemented Bretschneider solution could protect the graft in a clinically relevant canine model of HTX with prolonged ischemic storage. HTX was performed in foxhounds. The ischemic time was standardized to 4 h, 8 h, 12 h or 16 h, depending on the experimental group. Left ventricular (LV) and vascular function were measured. Additionally, the myocardial high energy phosphate and iron content and the in-vitro myocyte force were evaluated. Iron chelator supplementation proved superior at a routine preservation time of 4 h, as well as for prolonged times of 8 h and longer. The supplementation groups recovered quickly compared to their controls. The LV function was preserved and coronary blood flow increased. This was also confirmed by in vitro myocyte force and vasorelaxation experiments. Additionally, the biochemical results showed significantly higher adenosine triphosphate content in the supplementation groups. The iron chelator LK614 played an important role in this mechanism by reducing the chelatable iron content. This study shows that an iron-chelator-supplemented Bretschneider solution effectively prevents myocardial/endothelial damage during short- as well as long-term conservation.

Myocardial Iron Deficiency and Mitochondrial Dysfunction in Advanced Heart Failure in Humans.

BackgroundMyocardial iron deficiency (MID) in heart failure (HF) remains largely unexplored. We aim to establish defining criterion for MID, evaluate its pathophysiological role, and evaluate the applicability of monitoring it non‐invasively in human explanted hearts.Methods and ResultsBiventricular tissue iron levels were measured in both failing (n=138) and non‐failing control (NFC, n=46) explanted human hearts. Clinical phenotyping was complemented with comprehensive assessment of myocardial remodeling and mitochondrial functional profiles, including metabolic and oxidative stress. Myocardial iron status was further investigated by cardiac magnetic resonance imaging. Myocardial iron content in the left ventricle was lower in HF versus NFC (121.4 [88.1–150.3] versus 137.4 [109.2–165.9] μg/g dry weight), which was absent in the right ventricle. With a priori cutoff of 86.1 μg/g d.w. in left ventricle, we identified 23% of HF patients with MID (HF‐MID) associated with higher NYHA class and worsened left ventricle function. Respiratory chain and Krebs cycle enzymatic activities were suppressed and strongly correlated with depleted iron stores in HF‐MID hearts. Defenses against oxidative stress were severely impaired in association with worsened adverse remodeling in iron‐deficient hearts. Mechanistically, iron uptake pathways were impeded in HF‐MID including decreased translocation to the sarcolemma, while transmembrane fraction of ferroportin positively correlated with MID. Cardiac magnetic resonance with T2* effectively captured myocardial iron levels in failing hearts.ConclusionsMID is highly prevalent in advanced human HF and exacerbates pathological remodeling in HF driven primarily by dysfunctional mitochondria and increased oxidative stress in the left ventricle. Cardiac magnetic resonance demonstrates clinical potential to non‐invasively monitor MID.

The role of cardiac T2* magnetic resonance imaging in the assessment of myocardial iron concentration in patients with beta-thalassemia major

Background: Beta-thalassemia is a group of inherited blood disorders that are characterized by reduced levels of functional hemoglobin. These patients require lifelong blood transfusions, leading to iron deposition in various tissues. Prompt detection of myocardial iron helps to assess the extent of myocardial damage and its complications. Aims and Objectives: Our study aims to establish the role of T2* cardiac magnetic resonance imaging (MRI) and its comparison with serum ferritin levels in detecting iron overload in beta-thalassemia major (TM) patients. Materials and Methods: This prospective study included 30 pediatric patients admitted to our institute with beta-TM. The patients underwent T2* cardiac MRI examinations, myocardial iron quantification was assessed, and patients were divided into groups based on the severity of iron overload. Results: In this study, there were 18 males and 12 females. Out of the total studied cases, 15 (50%) showed no evidence of iron overload, 8 (26.67%) showed mild, 4 (13.33%) showed moderate, and 3 (10%) showed severe cardiac siderosis, based on the cardiac T2* values obtained. Conclusion: T2* cardiac MRI is an accurate and invaluable tool that helps to detect iron overload in beta-TM.

Link between Genotype and Multi-Organ Iron and Complications in Children with Transfusion-Dependent Thalassemia.

We evaluated the impact of the genotype on hepatic, pancreatic and myocardial iron content, and on hepatic, cardiac and endocrine complications in children with transfusion-dependent β-thalassemia (β-TDT). We considered 68 β-TDT patients (11.98 ± 3.67 years, 51.5% females) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia network. Iron overload was quantified by T2* technique and biventricular function by cine images. Replacement myocardial fibrosis was evaluated by late gadolinium enhancement technique. Three groups of patients were identified: homozygous β+ (N = 19), compound heterozygous β0β+ (N = 24), and homozygous β0 (N = 25). The homozygous β0 group showed significantly lower global heart and pancreas T2* values than the homozygous β+ group. Compared to patients with homozygous β+ genotype, β0β+ as well as β0β0 patients were more likely to have pancreatic iron overload (odds ratio = 6.53 and 10.08, respectively). No difference was detected in biventricular function parameters and frequency of replacement fibrosis. No patient had cirrhosis/fibrosis, diabetes or heart failure, and the frequency of endocrinopathies was comparable among the groups. In pediatric β-TDT patients, there is an association between genotype and cardiac and pancreatic iron overload. The knowledge of patients’ genotype can be valuable in predicting some patients’ phenotypic features and in helping the clinical management of β-TDT patients.