Cardiovascular function and treatment in β-thalassemia major: a consensus statement from the American Heart Association

Global longitudinal strain by cardiac magnetic resonance is associated with cardiac iron and complications in beta-thalassemia major patients

BACKGROUND

The aim of this cross-sectional study was to investigate the association of left ventricular (LV) strain parameters with demographics, clinical data, cardiovascular magnetic resonance (CMR) findings, and cardiac complications (heart failure and arrhythmias) in patients with β-thalassemia major (β-TM).

METHOD

We considered 266 β-TM patients (134 females, 37.08 ± 11.60 years) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia (E-MIOT) project and 80 healthy controls (50 females, mean age 39.77 ± 11.29 years). The CMR protocol included cine images for the assessment of global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) using feature tracking (FT) and for the quantification of LV function parameters, the T2* technique for the assessment of myocardial iron overload, and late gadolinium enhancement (LGE) technique.

RESULTS

In comparison to the healthy control group, β-TM patients showed impaired GLS, GCS, and GRS values. Among β-TM patients, sex was identified as the sole independent determinant of all LV strain parameters. All LV strain parameters displayed a significant correlation with LV end-diastolic volume index, end-systolic volume index, mass index, and ejection fraction, and with the number of segments exhibiting LGE. Only GLS exhibited a significant correlation with global heart T2* values and the number of segments with T2* < 20 ms. Patients with cardiac complications exhibited significantly impaired GLS compared to those without cardiac complications.

CONCLUSION

In patients with β-TM, GLS, GCS, and GRS were impaired in comparison with control subjects. Among LV strain parameters, only GLS demonstrated a significant association with cardiac iron levels and complications.

FTO alleviated ferroptosis in septic cardiomyopathy via mediating the m6A modification of BACH1

Sepsis is a global health challenge that results in systemic inflammation, oxidative stress, and multi-organ dysfunction, with the heart being particularly susceptible. This study aimed to elucidate the effect of FTO, a key regulator in m6A methylation in septic cardiomyopathy, and its potential therapeutic implications. Cellular and animal models of septic myocardial injury were established. Moreover, it was revealed that ferroptosis, which is a form of programmed necrosis occurring with iron dependence, was activated within cardiomyocytes during septic conditions. The overexpression of FTO-suppressed ferroptosis alleviated heart inflammation and dysfunction and improved survival rates in vivo. However, the protective effects of FTO were attenuated by the overexpression of BACH1, which is a molecule negatively correlated with FTO. Mechanistically, FTO modulated the m6A modification of BACH1, suggesting a complex interplay in the regulation of cardiomyocyte damage and sepsis. Our findings reveal the potential of targeting the FTO/BACH1 axis and ferroptosis inhibitors as therapeutic strategies for sepsis-induced cardiac injuries.

The predicting formula and scoring system for cardiac iron overload for thalassaemia children: Study from a middle-income country

Magnetic resonance imaging T2* screening is the gold standard for detecting cardiac iron overload in thalassemia, but its implementation in Indonesia is limited by the high costs. A predicting formula and scoring system based on low-cost investigations is needed. This cross-sectional study was conducted among thalassemia aged 6-18 years at Rumah Sakit Anak dan Bunda RSAB Harapan Kita Indonesia, during October 2017 to April 2019. All subjects were scheduled for clinical examination, laboratory tests, ECGs, echocardiography, tissue Doppler imaging, and MRIT2*. Multivariate logistic regression was used to identify the formula, simplifying to a scoring system, and risk classification for myocardial iron overload using odds ratio (OR) and 95% confidence interval (CI). Significance was set as p<0,05. We recruited 80 children, of those, 8 (10%) were classified as cardiac iron overload based on MRI T2* screening. Multivariate logistic regression showed determinant factors for cardiac iron overload were hemoglobin (95% CI:1.92-369.14), reticulocyte (95% CI:1.14-232.33), mitral deceleration time (DT) (95% CI:1.80-810.62,), and tricuspid regurgitation (TR Vmax) (95% CI:1.87-1942.56) with aOR of 26.65, 14.27, 38.22, and 60.27 respectively. The formula for cardiac iron overload was decided as 9.32 + 3.28 (Hb) + 2.9 (reticulocyte) + 3.64 (DT) + 4.1 (TR Vmax). A scoring system was defined by simplifying the formula of Hb ≤ 8.2 g/L, reticulocyte ≤0.33%, DT ≤ 114.5 cm/s, and TR Vmax ≥ 2.37 m/s were given a score of 1, while others were assigned 0. Total scores of 0 or 1, 2 and 3 or 4 were categorized as low, moderate, and high risk for iron cardiac overload. The cardiac iron overload formula was 9.32 + 3.28 (Hb) + 2.9 (reticulocyte) + 3.64 (DT) + 4.1 (TR Vmax). Variables of Hb ≤ 8.2 g/L, reticulocyte ≤0.33%, DT ≤ 114.5 cm/s, and TR Vmax ≥ 2.37 m/s were given a score of 1, while others were assigned 0. Total scores of 0 or 1, 2, and 3 or 4 were categorized as low, moderate, and high risk for iron cardiac overload.

Cardiac Manifestations of Hemochromatosis

Cardiac hemochromatosis, a consequence of primary or secondary iron-overload conditions, poses a threat to patient health, leading to cardiomyopathy and heart failure. This review aims to compile comprehensive information on cardiac hemochromatosis, elucidating its pathophysiology, clinical presentation, diagnosis, and management strategies. Primary and secondary hemochromatosis, genetic and acquired forms, can result in cardiotoxicity by means of iron dysregulation. Diagnostic tools, including biochemical markers, electrocardiography, echocardiography, and magnetic resonance imaging (MRI), are utilized for early detection as well as long-term monitoring post-treatment. For treatment options, phlebotomy is the standard, but for some patients (such as those with anemia), chelation therapy is an alternative option. Other potential therapies include erythrocytapheresis, calcium channel blockers, and hepcidin-targeted approaches, for which more research is needed to understand cardiac function benefits. With the onset of cardiac symptoms, patient health rapidly deteriorates. Thus, timely intervention to mitigate associated morbidity and mortality by means of screening can promote and prolong patient survival.

Magnetic Resonance Evaluation of Tissue Iron Deposition and Cardiac Function in Adult Regularly Transfused Thalassemia Intermedia Compared with Thalassemia Major Patients

Objectives: This multicenter, retrospective, population-based, matched-cohort study compared clinical characteristics and magnetic resonance imaging (MRI) findings, including hepatic, pancreatic, and cardiac iron levels and cardiac function, between 135 adult regularly transfused thalassemia intermedia (TI) patients (44.73 ± 12.16 years, 77 females) and 135 age- and sex-matched thalassemia major (TM) patients (43.35 ± 9.83 years, 77 females), enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network. Methods: The MRI protocol included the quantification of hepatic, pancreatic, and cardiac iron levels (R2* technique), the assessment of biventricular function parameters (cine images), and the detection of replacement myocardial fibrosis (late gadolinium enhancement technique). Results: Age, sex, frequency of splenectomy and chelation, and serum ferritin levels were not significantly different (p > 0.05) between the two groups, but TI patients started regular transfusions significantly later (p < 0.0001) and showed significantly lower pre-transfusion hemoglobin levels (p = 0.005). No difference was found in hepatic iron levels (p = 0.853). TI patients exhibited significantly lower pancreatic R2* values (p < 0.0001), also correcting for the duration of regular transfusions, and significantly lower cardiac R2* values (p < 0.0001). In the receiver operating characteristic analysis, pancreatic iron was the strongest discriminator between the two diseases. Left and right ventricular end-diastolic volume indexes were significantly higher in TI than in TM patients (p = 0.003 and p = 0.046, respectively), but the correction for the duration of regular transfusions removed the disease-specific differences (p > 0.05). Left ventricular (LV) mass index was significantly higher in TI (p = 0.049), while no difference (p > 0.05) was found in biventricular ejection fractions and replacement myocardial fibrosis. Conclusions: TI patients showed lower pancreatic and cardiac iron burden and more pronounced LV hypertrophy. These differences could not be explained by the different duration of the transfusional regimen.

Iron overload: The achilles heel of β-thalassemia

Systematic transfusions coupled with iron chelation therapy have substantially improved the life expectancy of thalassemia patients in developed nations. As the human organism does not have a protective mechanism to remove excess iron, iron overload is a significant concern in thalassemia, leading to organ damage, especially in the heart and liver. Thus, iron chelation therapy is crucial to prevent or reverse organ iron overload. There are three widely used iron chelators, either as monotherapy or in combination. The choice of iron chelator depends on several factors, including local guidelines, drug availability, and the individual clinical scenario. Despite treatment advancements, challenges persist, especially in resource-limited settings, highlighting the need for improved global healthcare access. This review discusses clinical management, current treatments, and future directions for thalassemia, focusing on iron overload and its complications. Furthermore, it underscores the progress in transforming thalassemia into a manageable chronic condition and the potential of novel therapies to further enhance patient outcomes.

Left and right atrioventricular coupling index in patients with beta-thalassemia major

The aim of this cross-sectional study was to investigate the relationship of left atrioventricular coupling index (LACI) and right atrioventricular coupling index (RACI) with demographics, clinical data, cardiovascular magnetic resonance findings, and cardiac complications (heart failure, arrhythmias, and pulmonary hypertension) in a cohort of patients with beta-thalassemia major (β-TM). We evaluated 292 β-TM patients (151 females, 36.72 ± 11.76 years) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia (E-MIOT) project. Moreover, we assessed 32 sex- and age-matched healthy controls (12 females, mean age 40.78 ± 14.35 years). LACI was determined by calculating the ratio of the left atrium end-diastolic volume to the left ventricle end-diastolic volume, while RACI was defined by calculating the ratio of the right atrium end-diastolic volume to the right ventricle end-diastolic volume. Compared to healthy control, β-TM demonstrated increased LACI (22.99 ± 13.58% vs. 16.05 ± 5.28%; p < 0.0001) and RACI (27.84 ± 10.30% vs. 17.06 ± 5.03%; p < 0.0001). Aging, diabetes, splenectomy, and the presence of late gadolinium enhancement (LGE) showed a significant positive association with both LACI and RACI. In stepwise regression analysis, the presence of LGE was found to be an independent predictor of both impaired LACI and RACI (β coefficient = 0.244, p < 0.0001 and β coefficient = 0.218, p = 0.003; respectively). LACI and RACI were not correlated with myocardial iron overload. Patients with cardiac complications had significantly higher LACI and RACI than patients without cardiac complications. In patients with β-TM, LACI and RACI were significantly associated with the presence of LV LGE. In addition, patients with cardiac complications had impaired LACI and RACI.

Beta-Thalassemia Major and Myocardial Iron Overload: A Longitudinal Study with Magnetic Resonance Imaging

Background

Patients with β-thalassemia major depend on lifelong transfusion, resulting in tissue iron overload. This longitudinal retrospective observational study aims to assess myocardial and liver iron overload using magnetic resonance imaging (MRI) and investigate the lag between myocardial and liver iron unloading in β-thalassemia patients undergoing chelation therapy.

Methods

Beta-thalassemia major patients with at least two MRI studies between 2016 and 2020 were enrolled. Myocardial and liver iron overload were defined as T2 ∗ less than 20 and 2.1, respectively. Outcomes included mortality, myocardial and liver T2 ∗ changes, and systolic dysfunction assessed by cardiac MRI.

Results

Fifty-five patients with a mean age of 24.62 ± 7.94 years, a mean follow-up duration of 24.3 ± 12.9 months, and a mean ferritin level of 1475.75 ± 771.12 ng/mL were enrolled. All of the abovementioned patients only took deferoxamine as the iron-chelating medication. Mortality occurred in three patients (5.5%) during follow-up. Liver T2 ∗ significantly increased (p value <0.05), while myocardial T2 ∗ showed a nonsignificant increase. Iron unloading of the myocardium was not significantly different from that of the liver and did not result in a significant lag (56% vs. 44%; p value = 0.419). Baseline myocardial T2 ∗ correlated with extramedullary hematopoiesis, weekly number of deferoxamine injections (p value <0.01), timing between the transfusions, and serum ferritin (p value <0.05).

Conclusion

Liver T2 ∗ reduced during deferoxamine chelation therapy, while myocardial T2 ∗ remained unchanged. No significant lag was observed between myocardial and liver iron unloading. Further studies are required to elucidate these findings.

Multiparametric cardiac magnetic resonance in patients with thalassemia intermedia: new insights from the E-MIOT network

PURPOSE

In a relatively large cohort of thalassemia intermedia (TI) patients, we systematically investigated myocardial iron overload (MIO), function, and replacement fibrosis using cardiac magnetic resonance (CMR), we assessed the clinical determinants of global heart T2* values, and we explored the association between multiparametric CMR findings and cardiac complications.

MATERIALS AND METHODS

We considered 254 beta-TI patients (43.14 ± 13.69 years, 138 females) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia project. MIO was quantified by T2* technique and biventricular function and atrial areas by cine images. Macroscopic myocardial fibrosis was detected by late gadolinium enhancement technique.

RESULTS

Compared to never/sporadically transfused patients, regularly transfused (RT)-TI patients exhibited significantly lower global heart T2* values, biventricular end-diastolic volume indexes, left ventricular mass index, and cardiac index. In RT-TI patients, age and serum ferritin levels were the strongest predictors of global heart T2* values. Independently from the transfusional state, cardiac T2* values were not associated with biventricular function. Of the 103 (40.6%) patients in whom the contrast medium was administrated, 27 (26.2%) had replacement myocardial fibrosis. Age, sex distribution, cardiac iron, and biventricular function parameters were comparable between patients without and without replacement myocardial fibrosis. Twenty-five (9.8%) patients had a history of cardiac complications (heart failure and arrhythmias). Increased age and replacement myocardial fibrosis emerged as significant risk markers for cardiac complications.

CONCLUSIONS

In TI, regular transfusions are associated with less pronounced cardiac remodeling but increase the risk of MIO. Replacement myocardial fibrosis is a frequent finding associated with cardiac complications.

Guideline for the management of conception and pregnancy in thalassaemia syndromes: A British Society for Haematology Guideline

This comprehensive guideline, developed by a representative group of UK-based medical experts specialising in haemoglobinopathies, addresses the management of conception and pregnancy in patients with thalassaemia. A systematic search of PubMed and EMBASE using specific keywords, formed the basis of the literature review. Key terms included "thalassaemia," "pregnancy," "Cooley's anaemia," "Mediterranean anaemia," and others, covering aspects such as fertility, iron burden and ultrasonography. The guideline underwent rigorous review by prominent organisations, including the Endocrine Society, the Royal College of Obstetricians and Gynaecologists (RCOG), the United Kingdom Thalassaemia Society and the British Society of Haematology (BSH) guideline writing group. Additional feedback was solicited from a sounding board of UK haematologists, ensuring a thorough and collaborative approach. The objective of the guideline is to equip healthcare professionals with precise recommendations for managing conception and pregnancy in patients with thalassaemia.

Liver steatosis in patients with transfusion-dependent thalassaemia

We evaluated the prevalence and the clinical associations of liver steatosis (LS) in patients with transfusion-dependent thalassaemia (TDT). We considered 301 TDT patients (177 females, median age = 40.61 years) enrolled in the Extension-Myocardial Iron Overload in Thalassaemia Network, and 25 healthy subjects. Magnetic resonance imaging was used to quantify iron overload and hepatic fat fraction (FF) by T2* technique and cardiac function by cine images. The glucose metabolism was assessed by the oral glucose tolerance test (OGTT). Hepatic FF was significantly higher in TDT patients than in healthy subjects (median value: 1.48% vs. 0.55%; p = 0.013). In TDT, hepatic FF was not associated with age, gender, serum ferritin levels or liver function parameters, but showed a weak inverse correlation with high-density lipoprotein cholesterol. The 36.4% of TDT patients showed LS (FF >3.7%). Active hepatitis C virus (HCV) infection, increased body mass index and hepatic iron were independent determinants of LS. A hepatic FF >3.53% predicted the presence of an abnormal OGTT. Hepatic FF was not correlated with cardiac iron, biventricular volumes or ejection fractions, but was correlated with left ventricular mass index. In TDT, LS is a frequent finding, associated with iron overload, increased weight and HCV, and conveying an increased risk for the alterations of glucose metabolism.

Global, regional, and national burden of thalassemia, 1990-2021: a systematic analysis for the global burden of disease study 2021

Background

Anemia is a significant contributor to the global disease burden, of which thalassemia is the most common hereditary anaemic disease. Previous estimates were based on data that were geographically limited and lacked comprehensive global analysis. This study provides the prevalence, incidence, mortality and disability-adjusted life years (DALYs) of thalassemia in 204 countries and regions of thalassemia between 1990 and 2021, focusing on the age structure and time trends of the disease burden. To provide effective information for health policy, allocation of medical resources and optimization of patient management programs.

Methods

Using the standardised Global Burden of Disease (GBD) methodologies, we aimed to derive a more precise representation of the health burden posed by thalassemia by considering four distinct types of epidemiological data, namely the incidence at birth, prevalence, mortality and DALYs. The presented data were meticulously estimated and displayed both as numerical counts and as age-standardised rates per 100,000 persons of the population, accompanied by uncertainty interval (UI) to highlight potential statistical variability. The temporal trends spanning the years 1990-2021 were subjected to a rigorous examination utilizing Joinpoint regression analysis. This methodological approach facilitated the computation of the annual percentage change (APC) and the average annual percentage change (AAPC), along with their corresponding 95% confidence intervals (CIs).

Findings

Globally, the age-standardized prevalence rates (ASPR), age-standardized incidence rates (ASIR), age-standardized mortality rates (ASMR), and age-standardized DALYs rates for thalassemia in 2021 were 18.28 per 100,000 persons (95% UI 15.29-22.02), 1.93 per 100,000 persons (95% UI 1.51-2.49), 0.15 per 100,000 persons(95% UI 0.11-0.20), and 11.65 per 100,000 persons (95% UI 8.24-14.94), respectively. Compared to 1990, these rates have decreased by 0.18 (95% UI -0.22 to -0.14), 0.25 (95% UI -0.30 to -0.19), 0.48 (95% UI -0.60 to -0.28), and 0.49 (95% UI -0.62 to -0.29) respectively. In 2021, the ASIR of thalassemia was highest in East Asia at 7.35 per 100,000 persons (95% UI 5.37-10.04), and ASMR was highest in Southeast Asia at 0.37 per 100,000 persons (95% UI 0.29-0.45).Gender comparisons showed negligible differences in disease burden, with the highest prevalence noted in children under five, decreasing with age. The global ASPR and ASMR declined from 1990 to 2021 overall, though an increasing trend in prevalence was found among the elderly. Joinpoint analysis revealed that the global ASPR increased between 2018 and 2021 (APC = 9.2%, 95% CI: 4.8%-13.8%, P < 0.001), ASIR decreased (APC = -7.68%, 95% CI: -10.88% to -4.36%, P < 0.001), and there was a significant rise in ASMR from 2019 to 2021 (APC = 4.8%, 95% CI: 0.1%-9.6%, P < 0.05). Trends in ASPR and ASMR varied across regions, with notable changes in South Asia.

Interpretation

The global burden of thalassemia, reflected in its prevalence, incidence, mortality, and DALYs, exhibits significant disparities. Geographic and demographic shifts in disease distribution have been observed from 1990 to 2021, with an overall decrease in burden, yet an increase in cases among the elderly population. Analysis of epidemiological trends over time highlights the influence of health policies and significant public health interventions on thalassemia outcomes. There data are crucial for healthcare professionals, policymakers, and researchers to refine and enhance management strategies, aiming to further mitigate thalassemia's global impact.

Funding

National Natural Science Foundation of China; Guizhou Province Science and Technology Project; Guizhou Province Science and Technology Foundation of Health Commission.

Evaluation of iron overload in visceral organs in thalassemia patients by point shear-wave elastography

INTRODUCTION

The aim of this study was to investigate the value of point shear-wave elastography (pSWE) in the measurement of iron overload in the liver and other visceral organs in patients with beta thalassemia major (BTM).

MATERIALS AND METHODS

The study included 103 patients diagnosed with BTM who were referred to our clinic for cardiac and liver T2* measurement and a control group of 120 age- and gender-matched healthy volunteers. Cardiac and hepatic T2* measurements were performed in the patient group. Hepatic, pancreatic, splenic, and renal pSWE values were measured in both groups. The pSWE values were compared between the two groups. In the patient group, correlations between pSWE values, cardiac-hepatic T2* values and hepatic size, patient age, and serum ferritin levels were analyzed.

RESULTS

Hepatic, pancreatic, splenic, and renal pSWE values were significantly higher in the patient group compared to the control group (p ≤ 0.001, < 0.001, 0.014, 0.026, respectively). In the patient group, hepatic pSWE values established a significant correlation with cardiac T2* values, liver size-T2*, pancreatic pSWE values, serum ferritin levels, and age (p = 0.006, < 0.001, 0.001, 0.042, 0.001, 0.032, respectively). In the ROC analysis, the area under the ROC curve was 0.807 for hepatic pSWE in the discrimination of thalassemia patients and healthy controls, and the cut-off value was 1.42, which gave a sensitivity and specificity of 75.7% and 75%, respectively. CONCLUSıON: Point shear-wave elastography can be a useful technique in the clinical measurement of iron overload in the liver, pancreas, spleen, and kidney.

Emerging regulatory mechanisms in cardiovascular disease: Ferroptosis

Ferroptosis, distinct from apoptosis, necrosis, autophagy, and other types of cell death, is a novel iron-dependent regulated cell death characterized by the accumulation of lipid peroxides and redox imbalance with distinct morphological, biochemical, and genetic features. Dysregulation of iron homeostasis, the disruption of antioxidative stress pathways and lipid peroxidation are crucial in ferroptosis. Ferroptosis is involved in the pathogenesis of several cardiovascular diseases, including atherosclerosis, cardiomyopathy, myocardial infarction, ischemia-reperfusion injury, abdominal aortic aneurysm, aortic dissection, and heart failure. Therefore, a comprehensive understanding of the mechanisms that regulate ferroptosis in cardiovascular diseases will enhance the prevention and treatment of these diseases. This review discusses the latest findings on the molecular mechanisms of ferroptosis and its regulation in cardiovascular diseases, the application of ferroptosis modulators in cardiovascular diseases, and the role of traditional Chinese medicines in ferroptosis regulation to provide a comprehensive understanding of the pathogenesis of cardiovascular diseases and identify new prevention and treatment options.

Multiparametric Cardiac Magnetic Resonance Assessment in Sickle Beta Thalassemia

Cardiac involvement in sickle beta thalassemia (Sβ-thal) patients has been poorly investigated. We aimed to evaluate cardiac function and myocardial iron overload by cardiovascular magnetic resonance (CMR) in patients with Sβ-thal. One-hundred and eleven Sβ-thal patients consecutively enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) network were studied and compared with 46 sickle cell anemia (SCA) patients and with 111 gender- and age- matched healthy volunteers. Cine images were acquired to quantify biventricular function. Myocardial iron overload (MIO) was assessed by the T2* technique, while macroscopic myocardial fibrosis was evaluated by the late gadolinium enhancement (LGE) technique. In Sβ-thal and SCA patients, the morphological and functional CMR parameters were not significantly different, except for the left atrial area and left ventricular (LV) stroke volume, indexed by body surface area (p = 0.023 and p = 0.048, respectively), which were significantly higher in SCA patients. No significant differences between the two groups were found in terms of myocardial iron overload and macroscopic myocardial fibrosis. When compared to healthy subjects, Sβ-thal patients showed significantly higher bi-atrial and biventricular parameters, except for LV ejection fraction, which was significantly lower. The CMR analysis confirmed that Sβ-thal and SCA patients are phenotypically similar. Since Sβ-thal patients showed markedly different morphological and functional indices from healthy subjects, it would be useful to identify Sβ-thal/SCA-specific bi-atrial and biventricular reference values.

The molecular mechanisms and potential drug targets of ferroptosis in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI), caused by the initial interruption and subsequent restoration of coronary artery blood, results in further damage to cardiac function, affecting the prognosis of patients with acute myocardial infarction. Ferroptosis is an iron-dependent, superoxide-driven, non-apoptotic form of regulated cell death that is involved in the pathogenesis of MIRI. Ferroptosis is characterized by the accumulation of lipid peroxides (LOOH) and redox disequilibrium. Free iron ions can induce lipid oxidative stress as a substrate of the Fenton reaction and lipoxygenase (LOX) and participate in the inactivation of a variety of lipid antioxidants including CoQ10 and GPX4, destroying the redox balance and causing cell death. The metabolism of amino acid, iron, and lipids, including associated pathways, is considered as a specific hallmark of ferroptosis. This review systematically summarizes the latest research progress on the mechanisms of ferroptosis and discusses and analyzes the therapeutic approaches targeting ferroptosis to alleviate MIRI.

Ferroptosis and metabolic syndrome and complications: association, mechanism, and translational applications

Metabolic syndrome is a medical condition characterized by several metabolic disorders in the body. Long-term metabolic disorders raise the risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Therefore, it is essential to actively explore the aetiology of metabolic syndrome (MetS) and its comorbidities to provide effective treatment options. Ferroptosis is a new form of cell death that is characterized by iron overload, lipid peroxide accumulation, and decreased glutathione peroxidase 4(GPX4) activity, and it involves the pathological processes of a variety of diseases. Lipid deposition caused by lipid diseases and iron overload is significant in metabolic syndrome, providing the theoretical conditions for developing ferroptosis. Recent studies have found that the major molecules of ferroptosis are linked to common metabolic syndrome consequences, such as T2DM and atherosclerosis. In this review, we first discussed the mechanics of ferroptosis, the regulatory function of inducers and inhibitors of ferroptosis, and the significance of iron loading in MetS. Next, we summarized the role of ferroptosis in the pathogenesis of MetS, such as obesity, type 2 diabetes, and atherosclerosis. Finally, we discussed relevant ferroptosis-targeted therapies and raised some crucial issues of concern to provide directions for future Mets-related treatments and research.

Four‑Dimensional Echocardiographic Evaluation of Cardiac Iron Overload in Patients with Beta-Thalassemia Major

Cardiac magnetic resonance imaging is the gold standard to detect cardiac iron overload in patients with beta-thalassemia. The aim of this study was to evaluate cardiac iron overload using four-dimensional transthoracic echocardiography in thalassemia patients with and without cardiac involvement detected by T2* value and to compare the two techniques. This cross-sectional and observational study was conducted in 44 patients diagnosed with thalassemia major. Left ventricular systolic function was assessed using four-dimensional speckle tracking echocardiography-derived global longitudinal (GLS), circumferential, radial, and area strain indices. Left ventricular ejection fraction, volumes, and mass index were similar between the patients with T2* values less than 20 ms as compared to those with T2* values greater than 20 ms. However, patients with lower T2* values had significantly higher GLS values (- 17.0% vs. - 19.8%, p < 0.001) compared with those with higher T2* values. GLS demonstrated a sensitivity of 91.7% and a specificity of 71.9% at a cut-off value of - 18.5%; however, sensitivity was 75%, and the specificity was 84.4% at a cut-off value of - 17.5%. For - 18.5%, the positive predictive value was 55%, and the negative predictive value was 95.8%; for - 17.5%, these values were 64.2 and 90%, respectively. This novel echocardiographic method, tested for the first time in our study in comparison with cardiac MRI in an adult patient group, has been shown to predict cardiac iron overload in thalassemia patients in the subclinical period without LVEF decline. Four-dimensional GLS is a marker with high sensitivity and negative predictive value.

Ferroptosis Involved in Cardiovascular Diseases: Mechanism Exploration of Ferroptosis' Role in Common Pathological Changes

ABSTRACT

Regulated cell death is a controlled form of cell death that protects cells by adaptive responses in pathophysiological states. Ferroptosis has been identified as a novel method of controlling cell death in recent years. Several cardiovascular diseases (CVDs) are shown to be profoundly influenced by ferroptosis, and ferroptosis is directly linked to the majority of cardiovascular pathological alterations. Despite this, it is still unclear how ferroptosis affects the pathogenic alterations that take place in CVDs. Based on a review of the mechanisms that regulate ferroptosis, this review explores the most recent research on the role of ferroptosis in the major pathological changes associated with CVDs, to provide new perspectives and strategies for cardiovascular research and clinical treatment.

Low Vitamin D Levels Are Associated with Increased Cardiac Iron Uptake in Beta-Thalassemia Major

We evaluated the association of vitamin D and parathormone (PTH) levels with cardiac iron and function in beta-thalassemia major (β-TM) patients. Two-hundred and seventy-eight TM patients (39.04 ± 8.58 years, 56.8% females) underwent magnetic resonance imaging for the assessment of iron overload (T2* technique), biventricular function parameters (cine images), and replacement myocardial fibrosis (late gadolinium enhancement technique). Vitamin D levels were deficient (<20 ng/dL) in 107 (38.5%) patients, insufficient (20-30 ng/dL) in 96 (34.5%) patients, and sufficient (≥30 ng/dL) in 75 (27.0%) patients. Deficient vitamin D patients had a significantly higher frequency of myocardial iron overload (MIO; global heart T2* < 20 ms) than patients with sufficient and insufficient vitamin D levels and a significantly higher left ventricular end-diastolic volume index and mass index than patients with sufficient vitamin D levels. PTH was not associated with cardiac iron, function, or fibrosis. In the multivariate regression analysis, vitamin D, serum ferritin, and pancreatic iron levels were the strongest predictors of global heart T2* values. In receiver operating characteristic curve analysis, a vitamin D level ≤ 17.3 ng/dL predicted MIO with a sensitivity of 81.5% and a specificity of 75.3% (p < 0.0001). In TM, the periodic and regular assessment of vitamin D levels can be beneficial for the prevention of cardiac iron accumulation and subsequent overt dysfunction.

Perturbations in lipid metabolism and gut microbiota composition precede cardiac dysfunction in a mouse model of thalassemia

Cardiomyopathy is a major complication of thalassemia, yet the precise underlying molecular mechanisms remain unclear. We examined whether altered lipid metabolism is an early driving factor in the development of cardiomyopathy using the Th3/+ mouse model of thalassemia. At age 20 weeks, male and female Th3/+ mice manifested anemia and iron overload; however, only males displayed metabolic defects and altered cardiac function. Untargeted lipidomics indicated that the circulating levels of 35 lipid species were significantly altered in Th3/+ mice compared to wild-type controls: triglycerides (TGs) with saturated fatty acids (FAs; TG42:0 and TG44:0) were elevated, while TGs with unsaturated FAs (TG(18:2_20:5_18:2 and TG54:8)) were reduced. Similarly, phosphatidylcholines (PCs) with long chain FAs (palmitic (16:0) or oleic (18:1)) were increased, while PCs with polyunsaturated FAs decreased. Circulating PC(16:0_14:0), GlcCer(d18:1/24:0) correlated significantly with iron overload and cardiac hypertrophy. 16S rRNA gene profiling revealed alterations in the intestinal microbiota of Th3/+ mice. Differentially abundant bacterial genera correlated with PC(39:6), PC(18:1_22:6), GlcCer(d18:1/24:1) and CE(14:0). These results provide new knowledge on perturbations in lipid metabolism and the gut microbiota of Th3/+ mice and identify specific factors which may represent early biomarkers or therapeutic targets to prevent development of cardiomyopathy in β-thalassemia.

Cardiac complications in thalassemia throughout the lifespan: Victories and challenges

Thalassemias are among the most common hereditary diseases in the world because heterozygosity offers protection against malarial infection. Affected individuals have variable expression of alpha or beta chains that lead to their unbalanced utilization during hemoglobin formation, oxidative stress, and apoptosis of red cell precursors prior to maturation. Some individuals produce sufficient hemoglobin to survive but suffer the vascular stress imposed by chronic anemia and ineffective erythropoiesis. In other patients, mature red cell formation is insufficient, and chronic transfusions are required-suppressing anemia and ineffective erythropoiesis but at the expense of iron overload. The cardiovascular consequences of thalassemia have changed dramatically over the previous five decades because of evolving treatment practices. This review summarizes this evolution, focusing on complications and management pertinent to modern patient cohorts.

Ferroptosis in cardiac hypertrophy and heart failure

Heart failure has become a public health problem that we cannot avoid choosing to face in today's context. In the case of heart failure, pathological cardiac hypertrophy plays a major role because of its condition of absolute increase in ventricular mass under various stresses. Ferroptosis, it could be defined as regulatory mechanisms that regulate cell death in the absence of apoptosis in iron-dependent cells. This paper introduces various new research findings on the use of different regulatory mechanisms of cellular ferroptosis for the treatment of heart failure and cardiac hypertrophy, providing new therapeutic targets and research directions for clinical treatment. The role and mechanism of ferroptosis in the field of heart failure has been increasingly demonstrated, and the relationship between cardiac hypertrophy, which is one of the causes of heart failure, is also an area of research that we should focus on. In addition, the latest applications and progress of inducers and inhibitors of ferroptosis are reported in this paper, updating the breakthroughs in their fields.

Therapeutic Approaches Targeting Ferroptosis in Cardiomyopathy

The term cardiomyopathy refers to a group of heart diseases that cause severe heart failure over time. Cardiomyopathies have been proven to be associated with ferroptosis, a non-apoptotic form of cell death. It has been shown that some small molecule drugs and active ingredients of herbal medicine can regulate ferroptosis, thereby alleviating the development of cardiomyopathy. This article reviews recent discoveries about ferroptosis, its role in the pathogenesis of cardiomyopathy, and the therapeutic options for treating ferroptosis-associated cardiomyopathy. The article aims to provide insights into the basic mechanisms of ferroptosis and its treatment to prevent cardiomyopathy and related diseases.

Secondary Hemochromatosis Leading to Acute Coronary Syndrome in a Thalassemic Patient

Thalassemia, a congenital hemoglobinopathy, is characterized by impaired erythropoiesis and peripheral hemolysis, leading to anemia. Thalassemia major, in particular, necessitates regular blood transfusions, resulting in iron accumulation in the body. Iron overload primarily affects the heart and can induce cardiac disorder, including defects in the pump and conduction system, which is one of the leading causes of mortality among thalassemics. The existing literature has revealed limited support for the occurrence of acute coronary syndrome (ACS) due to hemochromatosis. However, it does show that elevated troponin levels can be observed even in cases not associated with ACS. Here, we offer a rare case study of acute coronary syndrome in a patient with thalassemia major who also had elevated ferritin levels and abnormal troponin I values. The difficulty of cardiac problems in thalassemia major is highlighted by this case, as well as the necessity for more clinical attention and study to better comprehend and handle such instances.

Vagus nerve stimulation and acetylcholinesterase inhibitor donepezil provide cardioprotection against trastuzumab-induced cardiotoxicity in rats by attenuating mitochondrial dysfunction

Trastuzumab (Trz) is a targeted anticancer drug for human epidermal growth factor receptor 2 (HER2)-positive tumors, as Trz-induced cardiotoxicity (TIC) is commonly observed in Trz-treated patients. Since cardiac autonomic modulation with electrical vagus nerve stimulation (VNS) and acetylcholinesterase (AChE) inhibitors exerts cardioprotection against various heart diseases, the comparative effects of electrical VNS and an AChE inhibitor (donepezil) on cardiac and mitochondrial functions and programmed cell death pathways in TIC are not known. VNS devices were implanted in thirty-two male Wistar rats and were divided into 4 groups: (i) Control-Sham (CSham), (ii) Trz-Sham (TSham), (iii) Trz-VNS (TVNS), and (iv) Trz-donepezil (TDPZ). Rats in the Trz-treated groups were intraperitoneally injected with Trz (4 mg/kg/day) for 7 days, while CSham rats were injected with NSS. VNS devices were activated in the TVNS rats during the 7-day Trz treatment, but not in the sham rats. Rats in the TDPZ group received donepezil orally (5 mg/kg/day) for 7 days. At the end, left ventricular (LV) function and heart rate variability were evaluated, and heart tissue was collected for biochemical and histological analysis. Trz rats showed LV dysfunction and cardiac sympathovagal imbalance. In addition, mitochondrial function and dynamics were impaired in TIC rats. Trz also increased cardiomyocyte death by inducing apoptosis, pyroptosis, and ferroptosis. Electrical VNS and donepezil had similar efficacy in alleviating cardiac mitochondrial dysfunction, dynamic imbalances, and cardiomyocyte death, leading to improved LV function. These findings suggested that parasympathetic activation via either VNS or an AChE inhibitor could be a promising therapeutic intervention against TIC.

T2* map at cardiac MRI reveals incidental hepatic and cardiac iron overload

PURPOSE

The purpose of this study was to assess the diagnostic capabilities of cardiac magnetic resonance (CMR) T2* mapping in detecting incidental hepatic and cardiac iron overload.

MATERIALS AND METHODS

Patients with various clinical indications for CMR examination were consecutively included at a single center from January 2019 to April 2023. All patients underwent T2* mapping at 1.5 T in a single mid-ventricular short-axis as part of a comprehensive routine CMR protocol. T2* measurements were performed of the heart (using a region-of-interest in the interventricular septum) and the liver, categorized according to the severity of iron overload. The degree of cardiac iron overload was categorized as mild (15 ms < T2* < 20 ms), moderate (10 ms < T2* < 15 ms) and severe (T2* < 10 ms). The degree of hepatic iron overload was categorized as mild (4 ms < T2* < 8 ms), moderate (2 ms < T2* < 4 ms), severe (T2* < 2 ms). Image quality and inter-reader agreement were assessed using intraclass correlation coefficient (ICC).

RESULTS

CMR examinations from 614 patients (374 men, 240 women) with a mean age of 50 ± 18 (standard deviation) years were fully evaluable. A total of 24/614 patients (3.9%) demonstrated incidental hepatic iron overload; of these, 22/614 patients (3.6%) had mild hepatic iron overload, and 2/614 patients (0.3%) had moderate hepatic iron overload. Seven out of 614 patients (1.1%) had incidental cardiac iron overload; of these, 5/614 patients (0.8%) had mild iron overload, 1/614 patients (0.2%) had moderate iron overload, and 1/614 patients (0.2%) had severe iron overload. Good to excellent inter-reader agreement was observed for the assessment of T2* values (ICC, 0.90 for heart [95% confidence interval: 0.88-0.91]; ICC, 0.91 for liver [95% confidence interval: 0.89-0.92]).

CONCLUSION

Analysis of standard CMR T2* maps detects incidental cardiac and hepatic iron overload in 1.1% and 3.9% of patients, respectively, which may have implications for further patient management. Therefore, despite an overall low number of incidental abnormal findings, T2* imaging may be included in a standardized comprehensive CMR protocol.

Phenotypic Clustering of Beta-Thalassemia Intermedia Patients Using Cardiovascular Magnetic Resonance

We employed an unsupervised clustering method that integrated demographic, clinical, and cardiac magnetic resonance (CMR) data to identify distinct phenogroups (PGs) of patients with beta-thalassemia intermedia (β-TI). We considered 138 β-TI patients consecutively enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) Network who underwent MR for the quantification of hepatic and cardiac iron overload (T2* technique), the assessment of biventricular size and function and atrial dimensions (cine images), and the detection of replacement myocardial fibrosis (late gadolinium enhancement technique). Three mutually exclusive phenogroups were identified based on unsupervised hierarchical clustering of principal components: PG1, women; PG2, patients with replacement myocardial fibrosis, increased biventricular volumes and masses, and lower left ventricular ejection fraction; and PG3, men without replacement myocardial fibrosis, but with increased biventricular volumes and masses and lower left ventricular ejection fraction. The hematochemical parameters and the hepatic and cardiac iron levels did not contribute to the PG definition. PG2 exhibited a significantly higher risk of future cardiovascular events (heart failure, arrhythmias, and pulmonary hypertension) than PG1 (hazard ratio-HR = 10.5; p = 0.027) and PG3 (HR = 9.0; p = 0.038). Clustering emerged as a useful tool for risk stratification in TI, enabling the identification of three phenogroups with distinct clinical and prognostic characteristics.

Impact of the COVID-19 Pandemic on Iron Overload Assessment by MRI in Patients with Hemoglobinopathies: The E-MIOT Network Experience

BACKGROUND

The E-MIOT (Extension-Myocardial Iron Overload in Thalassemia) project is an Italian Network assuring high-quality quantification of tissue iron overload by magnetic resonance imaging (MRI). We evaluated the impact of the COVID-19 pandemic on E-MIOT services.

METHODS

The activity of the E-MIOT Network MRI centers in the year 2020 was compared with that of 2019. A survey evaluated whether the availability of MRI slots for patients with hemoglobinopathies was reduced and why.

RESULTS

The total number of MRI scans was 656 in 2019 and 350 in 2020, with an overall decline of 46.4% (first MRI: 71.7%, follow-up MRI: 36.9%), a marked decline (86.9%) in the period March-June 2020, and a reduction in the gap between the two years in the period July-September. A new drop (41.4%) was recorded in the period October-December for two centers, due to the general reduction in the total amount of MRIs/day for sanitization procedures. In some centers, patients refused MRI scans for fear of getting COVID. Drops in the MRI services >80% were found for patients coming from a region without an active MRI site.

CONCLUSIONS

The COVID-19 pandemic had a strong negative impact on MRI multi-organ iron quantification, with a worsening in the management of patients with hemoglobinopathies.

The impact of HCV chronic positivity and clearance on extrahepatic morbidity in thalassemia major patients: an observational study from MIOT Network

BACKGROUND

No study has evaluated the effect of hepatitis C virus (HCV) infection on the wide spectrum of complications affecting patients with thalassemia.

OBJECTIVES

This multicenter study prospectively assessed the relationship of HCV infection with diabetes mellitus and cardiovascular complications in patients with thalassemia major (TM).

METHODS

We considered 1057 TM patients (539 females; 29.79±10.08 years) enrolled in the MIOT Network and categorized into 4 groups: negative patients (group 1a, N=460), patients who spontaneously cleared the virus within 6months (group 1b, N=242), patients who eradicated the virus after the treatment with antiviral therapy (group 2, N=102), and patients with chronic HCV infection (group 3, N=254).

RESULTS

Group 1a and 1b were considered as a unique group (group 1). For both groups 1 and 3, a match 1:1 for age and sex with group 2 was performed. The effective study cohort consisted of 306 patients (three groups of 102 patients). During a mean follow-up of 67.93±39.20months, the group 3 experienced a significantly higher % increase/month in aspartate transaminase levels and left ventricular mass index than both groups 1 and 2. The changes in iron overload indexes were comparable among the three groups. Compared to group 1, the chronic HCV group showed a significantly higher risk of diabetes (hazard ratio-HR=5.33; p=0.043) and of cardiovascular diseases (HR=3.80; p=0.034).

CONCLUSION

Chronic HCV infection is associated with a significant higher risk of diabetes mellitus and cardiovascular complications in TM patients and should be approached as a systemic disease in which extrahepatic complications increase the weight of its pathological burden.

Imaging in Heart Failure with Preserved Ejection Fraction: A Multimodality Imaging Point of View

Heart failure with preserved ejection fraction (HFpEF) is an important global health problem. Despite increased prevalence due to improved diagnostic options, limited improvement has been achieved in cardiac outcomes. HFpEF is an extremely complex syndrome and multimodality imaging is important for diagnosis, identifying its different phenotypes and determining prognosis. Evaluation of left ventricular filling pressures using echocardiographic diastolic function parameters is the first step of imaging in clinical practice. The role of echocardiography is becoming more popular and with the recent developments in deformation imaging, cardiac MRI is extremely important as it can provide tissue characterisation, identify fibrosis and optimal volume measurements of cardiac chambers. Nuclear imaging methods can also be used in the diagnosis of specific diseases, such as cardiac amyloidosis.

Clinical Complications and Their Management

The diversity of disease-related complications among patients with β-thalassemia is complicated by the wide spectrum of genotypes and clinical risk factors. The authors herein present the different complications seen in patients with β-thalassemia, the pathophysiology underlying these complications and their management.

Non-Vitamin K Antagonist Oral Anticoagulants in Patients with β-Thalassemia

Background. Patients with β-thalassemia have a high incidence of atrial fibrillation (AF) and other supraventricular arrhythmias. The use of non-vitamin K antagonist oral anticoagulants (NOACs) for thromboembolic prophylaxis in patients with β-thalassemia has not been systematically evaluated. Methods. We enrolled patients with transfusion-dependent β-thalassemia, who were on treatment with NOACs for thromboembolic prophylaxis of supraventricular arrhythmias. Data on thromboembolic and bleeding events were collected. Results. Eighteen patients were enrolled. The patients had a history of AF (sixteen), typical atrial flutter (five), and atypical atrial flutter (four). The patients were treated with dabigatran (seven), apixaban (five), rivaroxaban (four) or edoxaban (two). The mean follow-up duration was 22 ± 15 months. No thromboembolic events were reported. No major bleedings were observed. Three patients had non-major bleeding events. Two patients reported dyspepsia during treatment with dabigatran and were shifted to a different NOAC. Conclusions. Our study suggests the efficacy and safety of NOACs in patients affected by transfusion-dependent β-thalassemia.

Multi-Parametric Cardiac Magnetic Resonance for Prediction of Heart Failure Death in Thalassemia Major

We assessed the prognostic value of multiparametric cardiovascular magnetic resonance (CMR) in predicting death from heart failure (HF) in thalassemia major (TM). We considered 1398 white TM patients (30.8 ± 8.9 years, 725 women) without a history of HF at baseline CMR, which was performed within the Myocardial Iron Overload in Thalassemia (MIOT) network. Iron overload was quantified by using the T2* technique, and biventricular function was determined with cine images. Late gadolinium enhancement (LGE) images were acquired to detect replacement myocardial fibrosis. During a mean follow-up of 4.83 ± 2.05 years, 49.1% of the patients changed the chelation regimen at least once; these patients were more likely to have significant myocardial iron overload (MIO) than patients who maintained the same regimen. Twelve (1.0%) patients died from HF. Significant MIO, ventricular dysfunction, ventricular dilation, and replacement myocardial fibrosis were identified as significant univariate prognosticators. Based on the presence of the four CMR predictors of HF death, patients were divided into three subgroups. Patients having all four markers had a significantly higher risk of dying for HF than patients without markers (hazard ratio (HR) = 89.93; 95%CI = 5.62-1439.46; p = 0.001) or with one to three CMR markers (HR = 12.69; 95%CI = 1.60-100.36; p = 0.016). Our findings promote the exploitation of the multiparametric potential of CMR, including LGE, for better risk stratification for TM patients.

Prenatal Diagnosis of Fetal Heart Failure

Fetal heart failure (FHF) is a condition of inability of the fetal heart to deliver adequate blood flow for tissue perfusion in various organs, especially the brain, heart, liver and kidneys. FHF is associated with inadequate cardiac output, which is commonly encountered as the final outcome of several disorders and may lead to intrauterine fetal death or severe morbidity. Fetal echocardiography plays an important role in diagnosis of FHF as well as of the underlying causes. The main findings supporting the diagnosis of FHF include various signs of cardiac dysfunction, such as cardiomegaly, poor contractility, low cardiac output, increased central venous pressures, hydropic signs, and the findings of specific underlying disorders. This review will present a summary of the pathophysiology of fetal cardiac failure and practical points in fetal echocardiography for diagnosis of FHF, focusing on essential diagnostic techniques used in daily practice for evaluation of fetal cardiac function, such as myocardial performance index, arterial and systemic venous Doppler waveforms, shortening fraction, and cardiovascular profile score (CVPs), a combination of five echocardiographic markers indicative of fetal cardiovascular health. The common causes of FHF are reviewed and updated in detail, including fetal dysrhythmia, fetal anemia (e.g., alpha-thalassemia, parvovirus B19 infection, and twin anemia-polycythemia sequence), non-anemic volume load (e.g., twin-to-twin transfusion, arteriovenous malformations, and sacrococcygeal teratoma, etc.), increased afterload (intrauterine growth restriction and outflow tract obstruction, such as critical aortic stenosis), intrinsic myocardial disease (cardiomyopathies), congenital heart defects (Ebstein anomaly, hypoplastic heart, pulmonary stenosis with intact interventricular septum, etc.) and external cardiac compression. Understanding the pathophysiology and clinical courses of various etiologies of FHF can help physicians make prenatal diagnoses and serve as a guide for counseling, surveillance and management.

Thalassaemia-A global view

The thalassaemias are a group of genetic disorders of haemoglobin which are endemic in the tropics but are now found worldwide due to migration. Basic standard of care therapy includes regular transfusions to maintain a haemoglobin level of around 10 g/dL, together with iron chelation therapy to prevent iron overload. Novel therapies, bone marrow transplantation, and gene therapy are treatment options that are unavailable in many countries with stressed economies. This Wider Perspectives article presents the strategies for management of an adolescent refugee patient with beta thalassaemia, as it would be performed by expert haematologists in six countries: Italy, Lebanon, Oman, the Sudan, Thailand and the United States. The experienced clinicians in each country have adapted their practice according to the resources available, which vary greatly. Even in the current modern era, providing adequate transfusions and chelation is problematic in many countries. On the other hand, ensuring adherence to therapy, particularly during adolescence, is a similar challenge seen in all countries. The concluding section highlights the disparities in available therapies and puts the role of novel therapies into a societal context.

Targeting ferroptosis: Paving new roads for drug design and discovery

Ferroptosis, first proposed in 2012, is an iron-dependent form of regulated cell death characterized by excessive polyunsaturated fatty acid oxidation. In the past decade, researchers have revealed the formation and mechanisms of ferroptosis. Cancer drug resistance can be reversed by ferroptosis induction, and inhibiting ferroptosis has been shown to block certain disease processes. As a result, several ferroptosis-targeting drugs have been developed. However, the first-generation ferroptosis-targeting agents remain hampered from clinical use, mainly due to poor selectivity and pharmacokinetics. The discoveries of FSP1, GCH1, and other potential ferroptosis-regulating pathways independent of Xc^--GSH-GPX4 provide novel targets for drug design. Recently, protein-targeted degradation and antibody-drug conjugate strategy show promise in future drug design. With novel targets, further optimizations, and new technologies, the next-generation ferroptosis-targeting agents show a promising future with improved selectivity and efficacy. In this review, we summarize mechanisms, target types, drug design, and novel technologies of ferroptosis, aiming to pave the way for future drug design and discovery in the next decade.

Prognostic value of multiparametric cardiac magnetic resonance in sickle cell patients

The aim of this multicenter study was to prospectively assess the predictive value of multiparametric cardiac magnetic resonance (CMR) for cardiovascular complications in sickle cell disease (SCD) patients. Among all patients with hemoglobinopathies consecutively enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) Network, we selected 102 SCD patients (34.38 ± 12.67 years, 49 females). Myocardial iron overload (MIO) was measured by the multislice multiecho T2* technique. Atrial dimensions and biventricular function parameters were quantified by cine images. Late gadolinium enhancement (LGE) images were acquired to detect focal myocardial fibrosis. At baseline CMR, only two patients had significant MIO (global heart T2* < 20 ms). During a mean follow-up of 63.01 ± 24.95 months, 11 cardiovascular events (10.8%) were registered: 3 pulmonary hypertension, 2 supraventricular arrhythmias, 1 heart failure, 1 death for heart failure, 1 pulmonary embolism, 1 peripheral vascular disease, 1 transient ischemic attack, and 1 death after acute chest syndrome. In the multivariate analysis, the independent CMR predictors of cardiovascular events were left ventricular (LV) ejection fraction (hazard ratio-HR = 0.88; p = 0.025) and right ventricular (RV) mass index (HR = 1.09; p = 0.047). According to the receiver-operating characteristic curve analysis for adverse events, an LV ejection fraction < 58.9% and an RV mass index > 31 g/m² were optimal cut-off values. Reduced left ventricular ejection fraction and increased right ventricular mass index showed a significant prognostic value in patients with SCD. Our data seem to suggest that CMR may be added as a screening tool for identifying SCD patients at high risk for cardiopulmonary and vascular diseases.

Increased myocardial extracellular volume is associated with myocardial iron overload and heart failure in thalassemia major

OBJECTIVES

Myocardial extracellular volume (ECV) by cardiovascular magnetic resonance (CMR) is a surrogate marker of diffuse fibrosis. We evaluated the association between ECV and demographics, CMR findings, and cardiac involvement in patients with thalassemia major (TM).

METHODS

A total of 108 β-TM patients (62 females, 40.16 ± 8.83 years), consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network, and 16 healthy subjects (6 females, 37.12 ± 16.13 years) underwent CMR. The protocol included assessment of T2*, native T1, and T2 values in all 16 myocardial segments for myocardial iron overload (MIO) quantification, cine images for left ventricular (LV) function quantification, post-contrast T1 mapping for ECV calculation, and late gadolinium enhancement (LGE) technique for replacement myocardial fibrosis detection.

RESULTS

Global ECV values were significantly higher in females than in males. Global ECV values were significantly higher in patients with significant MIO (global heart T2* < 20 ms) than in patients without significant MIO, and both groups exhibited higher global ECV values than healthy subjects. No association was detected between native T1 and ECV values, while patients with reduced global heart T2 values showed significantly higher global ECV values than patients with normal and increased global heart T2. Global ECV values were not correlated with LV function/size and were comparable between patients with and without LGE. Compared to patients without heart failure, patients with a history of heart failure (N = 10) showed significantly higher global heart ECV values.

CONCLUSION

In TM, increased myocardial ECV, potentially reflecting diffuse interstitial fibrosis, is associated with MIO and heart failure.

KEY POINTS

• CMR-derived myocardial extracellular volume is increased in thalassemia major patients, irrespective of the presence of late gadolinium enhancement. • In thalassemia major, myocardial iron overload contributes to the increase in myocardial ECV, which potentially reflects diffuse interstitial fibrosis and is significantly associated with a history of heart failure.

Global longitudinal strain is superior to ejection fraction for long-term follow-up after allogeneic hematopoietic stem cell transplantation

Global longitudinal strain (GLS), a new cardiac parameter measured by the speckle-tracking method, is reportedly more sensitive than ejection fraction (EF) in detecting slight cardiac dysfunction in heart failure patients. We validated the utility of GLS in allogeneic hematopoietic stem cell transplantation (HSCT) patients during a long-term follow-up. Medical records of patients who underwent allogeneic HSCT between 2013 and 2020 were reviewed retrospectively. We evaluated the last echocardiography performed before transplantation and those performed annually during the 5 years after transplantation. We also investigated newly diagnosed cardiac events, which developed after HSCT. Among 85 patients, 22 used cardioprotective drugs. The median follow-up duration in surviving patients was 54.1 months (range, 2.9-92.6 months). GLS significantly decreased year by year, and patients taking cardioprotective agents tended to have a better GLS at 5 years than at 3 years, while EF did not change. Fifteen patients developed newly diagnosed cardiac events. Multivariate analysis revealed that low GLS and high serum ferritin levels at baseline were independently associated with the development of cardiac events. Therefore, we need a continuous follow-up of cardiac function by GLS and prescription of cardioprotective drugs might be considered for HSCT patients with low GLS. Further research is warranted.

Cardiovascular Complications in β-Thalassemia: Getting to the Heart of It

Beta thalassemia is an inherited disorder resulting in abnormal or decreased production of hemoglobin, leading to hemolysis and chronic anemia. The long-term complications can affect multiple organ systems, namely the liver, heart, and endocrine. Myocardial iron overload is a common finding in β-thalassemia. As a result, different cardiovascular complications in the form of cardiomyopathy, pulmonary hypertension, arrhythmias, and vasculopathies can occur, and in extreme cases, sudden cardiac death. Each of these complications pertains to underlying etiologies and risk factors, which highlights the importance of early diagnosis and prevention. In this review, we will discuss different types of cardiovascular complications that can manifest in patients with β-thalassemia, in addition to the current diagnostic modalities, preventive and treatment modalities for these complications.

Quantitative MRI in cardiometabolic disease: From conventional cardiac and liver tissue mapping techniques to multi-parametric approaches

Cardiometabolic disease refers to the spectrum of chronic conditions that include diabetes, hypertension, atheromatosis, non-alcoholic fatty liver disease, and their long-term impact on cardiovascular health. Histological studies have confirmed several modifications at the tissue level in cardiometabolic disease. Recently, quantitative MR methods have enabled non-invasive myocardial and liver tissue characterization. MR relaxation mapping techniques such as T₁, T_1ρ, T₂ and T₂* provide a pixel-by-pixel representation of the corresponding tissue specific relaxation times, which have been shown to correlate with fibrosis, altered tissue perfusion, oedema and iron levels. Proton density fat fraction mapping approaches allow measurement of lipid tissue in the organ of interest. Several studies have demonstrated their utility as early diagnostic biomarkers and their potential to bear prognostic implications. Conventionally, the quantification of these parameters by MRI relies on the acquisition of sequential scans, encoding and mapping only one parameter per scan. However, this methodology is time inefficient and suffers from the confounding effects of the relaxation parameters in each single map, limiting wider clinical and research applications. To address these limitations, several novel approaches have been proposed that encode multiple tissue parameters simultaneously, providing co-registered multiparametric information of the tissues of interest. This review aims to describe the multi-faceted myocardial and hepatic tissue alterations in cardiometabolic disease and to motivate the application of relaxometry and proton-density cardiac and liver tissue mapping techniques. Current approaches in myocardial and liver tissue characterization as well as latest technical developments in multiparametric quantitative MRI are included. Limitations and challenges of these novel approaches, and recommendations to facilitate clinical validation are also discussed.

Left ventricular global function index is associated with myocardial iron overload and heart failure in thalassemia major patients

PURPOSE

The left ventricular global function index (LVGFI) is a comprehensive marker of cardiac performance, integrating LV morphology with global function. We explored the cross-sectional association of LVGFI with myocardial iron overload (MIO), LV ejection fraction (LVEF), myocardial fibrosis, and heart failure (HF) in β-thalassemia major (TM) patients.

METHODS

We considered 1352 adult TM patients (708 females, 32.79 ± 7.16years) enrolled in the Myocardial Iron Overload in Thalassemia Network and 112 healthy subjects (50 females, 32.09 ± 6.08years). LVGFI and LVEF were assessed by cine images and MIO by multislice multiecho T2* technique. Replacement myocardial fibrosis was detected by late gadolinium enhancement technique.

RESULTS

LVGFI and LVEF were significantly lower in patients with significant MIO (global heart T2*<20ms) than in patients without MIO and in healthy subjects but were comparable between TM patients without MIO and healthy subjects. In TM, LVGFI was significantly associated with LVEF (R = 0.733; p < 0.0001). Global heart T2* values were significantly associated with both LVGFI and LVEF, but the correlation with LVGFI was significantly stronger (p = 0.0001). Male sex, diabetes mellitus, significant MIO, and replacement myocardial fibrosis were the strongest predictors of LVGFI. Eighty-six patients had a history of HF and showed significantly lower global heart T2* values, LVEF, and LVGFI than HF-free patients. A LVGFI ≤ 44.9% predicted the presence of HF. The LVGFI showed a diagnostic performance superior to that of LVEF (area under the curve: 0.67 vs. 0.62; p = 0.039).

CONCLUSION

In TM patients the LVGFI correlates with MIO and provides incremental diagnostic value for HF detection compared with LVEF.

Amlodipine rescues advanced iron overload cardiomyopathy in hemojuvelin knockout murine model: Clinical implications

Background

Iron overload cardiomyopathy (IOC) is a major co-morbidity of genetic hemochromatosis and secondary iron overload with limited therapeutic options. We aim to investigate mechanisms of rescue action of amlodipine in the murine model of iron overload, characterize changes in human cardiac tissue due to IOC, and compare them to the changes in the animal model of IOC.

Methods and results

As an animal model, we used male hemojuvelin knockout (HJVKO) mice, which lacked hemojuvelin (a co-receptor protein for hepcidin expression). The mice were fed a high-iron diet from 4 weeks to 1 year of age. As a rescue, iron-fed mice received the Ca²⁺ channel blocker, amlodipine, from 9 to 12 months. Iron overload resulted in systolic and diastolic dysfunctions and changes in the cardiac tissue similar to the changes in the explanted human heart with IOC. An IOC patient (β-thalassemia) with left-ventricular ejection fraction (LVEF) 25% underwent heart transplantation. The murine model and the explanted heart showed intra-myocyte iron deposition, fibrosis, hypertrophy, oxidative stress, remodeling of Ca²⁺ cycling proteins, and metabolic kinases typical of heart failure. Single-myocyte contractility and Ca²⁺ release were diminished in the murine model. The amlodipine-treated group exhibited normalization of cellular function and reversed fibrosis, hypertrophy, oxidative stress, and metabolic remodeling. We also report a clinical case of primary hemochromatosis successfully treated with amlodipine.

Conclusions

The aged HJVKO murine model on the iron-rich diet reproduced many features of the human case of IOC. The use of amlodipine in the murine model and clinical case reversed IOC remodeling, demonstrating that amlodipine is effective adjuvant therapy for IOC.

Electrophysiological properties and heart rate variability of patients with thalassemia major in Jakarta, Indonesia

Beta thalassemia major (TM) is a common hereditary disease in Indonesia. Iron overload due to regular transfusion may induce myocardial iron deposition leading to electrophysiological dysfunction and functional disorders of the heart. Ventricular arrhythmia is one of the most common causes of sudden cardiac death in thalassemia patients. This cross-sectional study of 62 TM patients aged 10-32 years in Cipto Mangunkusumo General Hospital was done to assess their electrophysiological properties and heart rate variability, including 24- hour Holter monitoring, signal averaged electrocardiogram (SAECG) for detection of ventricular late potential (VLP), and determination of heart rate variability (HRV). We also assessed their 12-lead ECG parameters, such as P wave, QRS complex, QT/ QTc interval, QRS dispersion, and QT/ QTc dispersion. Iron overload was defined by T2-star magnetic resonance (MR-T2*) values of less than 20 ms or ferritin level greater than 2500 ng/mL. Subjects were grouped accordingly. There were significant differences of QTc dispersion (p = 0.026) and deceleration capacity (p = 0.007) between MR-T2* groups. Multivariate analysis showed an inverse correlation between QTc dispersion and MR-T2* values. There was a proportional correlation between heart rate deceleration capacity in the low MR-T2* group (p = 0.058) and the high ferritin group (p = 0.007). No VLPs were detectable in any patients. In conclusion, prolonged QTc dispersion and decreased heart rate deceleration capacity were significantly correlated with greater odds of iron overload among patients with Thalassemia major.

Role of Mitochondrial Iron Overload in Mediating Cell Death in H9c2 Cells

Iron overload (IO) is associated with cardiovascular diseases, including heart failure. Our study's aim was to examine the mechanism by which IO triggers cell death in H9c2 cells. IO caused accumulation of intracellular and mitochondrial iron as shown by the use of iron-binding fluorescent reporters, FerroOrange and MitoFerroFluor. Expression of cytosolic and mitochondrial isoforms of Ferritin was also induced by IO. IO-induced iron accumulation and cellular ROS was rapid and temporally linked. ROS accumulation was detected in the cytosol and mitochondrial compartments with CellROX, DCF-DA and MitoSOX fluorescent dyes and partly reversed by the general antioxidant N-acetyl cysteine or the mitochondrial antioxidant SkQ1. Antioxidants also reduced the downstream activation of apoptosis and lytic cell death quantified by Caspase 3 cleavage/activation, mitochondrial Cytochrome c release, Annexin V/Propidium iodide staining and LDH release of IO-treated cells. Finally, overexpression of MitoNEET, an outer mitochondrial membrane protein involved in the transfer of Fe-S clusters between mitochondrial and cytosol, was observed to lower iron and ROS accumulation in the mitochondria. These alterations were correlated with reduced IO-induced cell death by apoptosis in MitoNEET-overexpressing cells. In conclusion, IO mediates H9c2 cell death by causing mitochondrial iron accumulation and subsequent general and mitochondrial ROS upregulation.

Nutritional Heart Disease and Cardiomyopathies: JACC Focus Seminar 4/4

This JACC Focus Seminar provides an overview of and highlights recently published research on cardiomyopathies and nutritional heart disease that have a higher prevalence in tropical regions. The development of tropical cardiomyopathies and nutritional cardiovascular disease (CVD) is complicated by high rates of poverty, fragmented health care systems, and suboptimal access to health care because of socioeconomic inequalities, leading to the fact that children, adolescents, and young adults are disproportionally affected. Such tropical cardiomyopathies and nutritional CVD that have not been prevalent in high-income countries in the past decades are now reemerging. When treating migrants or refugees, it is important for attending physicians to consider the burden of endemic diseases in the countries of origin and the likelihood that such patients might be affected. In this review, the authors propose an approach for adequate diagnostic work-up leading to appropriate care for those with suspected or confirmed tropical cardiomyopathies and nutritional CVD.

Genetic support of a causal relationship between iron status and atrial fibrillation: a Mendelian randomization study

Background

Atrial fibrillation is the most common arrhythmia disease. Animal and observational studies have found a link between iron status and atrial fibrillation. However, the causal relationship between iron status and AF remains unclear. The purpose of this investigation was to use Mendelian randomization (MR) analysis, which has been widely applied to estimate the causal effect, to reveal whether systemic iron status was causally related to atrial fibrillation.

Methods

Single nucleotide polymorphisms (SNPs) strongly associated (P < 5 × 10−8) with four biomarkers of systemic iron status were obtained from a genome-wide association study involving 48,972 subjects conducted by the Genetics of Iron Status consortium. Summary-level data for the genetic associations with atrial fibrillation were acquired from the AFGen (Atrial Fibrillation Genetics) consortium study (including 65,446 atrial fibrillation cases and 522,744 controls). We used a two-sample MR analysis to obtain a causal estimate and further verified credibility through sensitivity analysis.

Results

Genetically instrumented serum iron [OR 1.09; 95% confidence interval (CI) 1.02–1.16; p = 0.01], ferritin [OR 1.16; 95% CI 1.02–1.33; p = 0.02], and transferrin saturation [OR 1.05; 95% CI 1.01–1.11; p = 0.01] had positive effects on atrial fibrillation. Genetically instrumented transferrin levels [OR 0.90; 95% CI 0.86–0.97; p = 0.006] were inversely correlated with atrial fibrillation.

Conclusion

In conclusion, our results strongly elucidated a causal link between genetically determined higher iron status and increased risk of atrial fibrillation. This provided new ideas for the clinical prevention and treatment of atrial fibrillation.