Relation between NT-proBNP Levels, Iron Overload, and Early Stage of Myocardial Dysfunction in β-Thalassemia Major Patients

Thalassemia and iron overload cardiomyopathy: Pathophysiological insights, clinical implications, and management strategies

Thalassemia is a hereditary blood disorder characterized by reduced hemoglobin production, leading to chronic anemia. A major complication of thalassemia is iron overload, primarily due to regular blood transfusions and increased gastrointestinal iron absorption, which can lead to iron overload cardiomyopathy, a significant cause of morbidity and mortality in thalassemia patients. This review aims to provide an in-depth analysis of the pathophysiological mechanisms underlying iron overload cardiomyopathy in thalassemia, examining how excessive iron accumulation disrupts cardiac function through oxidative stress, cellular damage, and altered calcium homeostasis. Clinical manifestations, including fatigue, arrhythmias, and heart failure, are discussed alongside diagnostic strategies such as echocardiography and cardiac MRI for early detection and monitoring. Management approaches focusing on iron chelation therapy, lifestyle modifications, and advanced interventions like gene therapy are explored. The review also highlights the importance of early diagnosis, regular monitoring, and patient adherence to therapy to prevent the progression of cardiomyopathy. Recent advances in treatment and future research directions, including personalized medicine, and gene editing technologies, are presented. Addressing the challenges in managing iron overload in thalassemia patients is crucial for improving outcomes and enhancing quality of life.

Speckle-tracking echocardiography as screening tool for myocardial fibrosis and Iron overload in transfusion-dependent beta-thalassemia

BACKGROUND

Transfusion-dependent beta thalassemia (TDT) is a genetic disorder characterized by low haemoglobin levels, often leading to myocardial iron overload (MIO) and myocardial fibrosis (MF). Cardiac Magnetic Resonance (CMR) represents the gold standard for MIO and MF assessment, although its limited availability and high costs pose challenges. Left Ventricular Global Longitudinal Strain (LV GLS) measured by Speckle Tracking Echocardiography (STE) could offer a valuable alternative.

METHODS

A monocentric diagnostic accuracy study was conducted to compare the performance of LV GLS with CMR using T2* for evaluating MIO and late gadolinium enhancement (LGE) for detecting MF. Between January 2022 and January 2023, 44 consecutive patients with TDT were enrolled. For each participant was performed LV GLS with STE, including CMR with T2* technique and LGE sequences.

RESULTS

CMR identified MIO in 8 patients (18 %) and MF in 5 (11 %). LV GLS STE was normal in patients without MIO (-20.6 ± 3.1 %) or MF (-20.6 ± 2.8 %), significantly differing from those with MIO (-18.2 ± 2.1 %, p = 0.043) and MF (-16.4 ± 1.7 %, p = 0.002). ROC analysis indicated an optimal LV GLS STE cutoff of -19.8 % for MIO (AUC = 0.76, 95 % CI: 0.59-0.93, p = 0.054) with an overall diagnostic accuracy of 64 % and an optimal cutoff of -18.3 % for MF (AUC = 0.93, 95 % CI: 0.85-1.00, p = 0.009) with an accuracy of 86 %.

CONCLUSIONS

The findings of this pilot study indicate that LV GLS with STE, may be a cost-effective screening tool for the early detection of MIO and MF in TDT patients.

Ferroptosis: The Potential Target in Heart Failure with Preserved Ejection Fraction

Ferroptosis is a recently identified cell death characterized by an excessive accumulation of iron-dependent reactive oxygen species (ROS) and lipid peroxides. Intracellular iron overload can not only cause damage to macrophages, endothelial cells, and cardiomyocytes through responses such as lipid peroxidation, oxidative stress, and inflammation, but can also affect cardiomyocyte Ca²⁺ handling, impair excitation–contraction coupling, and play an important role in the pathological process of heart failure with preserved ejection fraction (HFpEF). However, the mechanisms through which ferroptosis initiates the development and progression of HFpEF have not been established. This review explains the possible correlations between HFpEF and ferroptosis and provides a reliable theoretical basis for future studies on its mechanism.

Predictors of cardiovascular events and all-cause of death in patients with transfusion-dependent myelodysplastic syndrome

Cardiovascular disease (CVD) involves the second cause of death in low-risk myelodysplastic syndrome (MDS) population. Prospective study to characterise the CVD and to identify predictors for the combined event (CE) cardiovascular event and/or all-cause mortality in transfusion dependent low-risk MDS patients. Thirty-one patients underwent a cardiac assessment including biomarkers and cardiac magnetic resonance (cMR) with parametric sequences (T1, T2 and T2* mapping) and myocardial deformation by feature tracking (FT) and were analysed for clonal hematopoiesis of indeterminate potential mutations. Cardiac assessment revealed high prevalence of unknown structural heart disease (51% cMR pathological findings). After 2·2 [0·44] years follow-up, 35·5% of patients suffered the CE: 16% death, 29% cardiovascular event. At multivariate analysis elevated NT-proBNP ≥ 486pg/ml (HR 96·7; 95%-CI 1·135-8243; P = 0·044), reduced native T1 time < 983ms (HR 44·8; 95%-CI 1·235-1623; P = 0·038) and higher left ventricular global longitudinal strain (LV-GLS) (HR 0·4; 95%-CI 0·196-0·973; P = 0·043) showed an independent prognostic value. These variables, together with the myocardial T2* time < 20ms, showed an additive prognostic value (Log Rank: 12·4; P = 0·001). In conclusion, low-risk MDS patients frequently suffer CVD. NT-proBNP value, native T1 relaxation time and longitudinal strain by FT are independent predictors of poor cardiovascular prognosis, thus, their determination would identify high-risk patients who could benefit from a cardiac treatment and follow-up.

Assessment of ventricular dysfunction in Egyptian children with Beta-thalassemia major

OBJECTIVE/BACKGROUND

The purpose of this study was to evaluate serum cardiac troponin I and serum N-terminal (NT) pro-brain natriuretic peptide (pro-BNP) levels and the utility of tissue Doppler imaging in assessing cardiovascular changes following left ventricular (LV) dysfunction in children with beta-thalassemia major (β-TM). In children with β-TM who depend on regular blood transfusion, cardiac iron toxicity is a common serious complication. The most common cause of death among these patients is congestive heart failure.

METHODS

This is a cross-sectional study which included 50 patients with β-TM and 50 healthy controls. Tissue Doppler imaging was performed and levels of serum ferritin, cardiac troponin I, and NT pro-BNP were estimated for all included patients.

RESULTS

Serum NT pro-BNP and cardiac troponin (cTnI) showed a significant increase in patients with β-TM (p < .001). In patients with β-TM, LV dimensions (LV end systolic diameter) and (LV end diastolic diameter) were large (p < .01); LV mass (p < .01), E wave, and E/A ratio (p < .01) were high (p < .05); and deceleration time was short (p < .05). Besides, transmitral ratio (E/E_m) (p < .05) and tricuspid valve velocity were higher (p < .05), and early diastolic velocity (E_m) (p < .05) and systolic wave velocity (S_m) were lower in patients with β-TM (p < .05). A significant positive correlation was detected between the pro-BNP and E wave (r = 0.558, p < .001), E/A ratio (r = 0.403, p < .001), E/E_m ratio (r = 0.576, p < .001), and ferritin (r = 0.545, p < .001).

CONCLUSION

Pulsed wave tissue Doppler imaging and NT pro-BNP had a significant role in the estimation of ventricular dysfunction in children with β-TM.

N-terminal-pro-b-type natriuretic peptide levels and cardiac hemosiderosis in adolescent β-thalassemia major patients

Background:

Iron-induced cardiomyopathy remains the leading cause of mortality in patients with β-thalassemia major. Iron overload cardiomyopathy, which may be reversible through iron chelation, is characterized by early diastolic dysfunction. Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is a sensitive biomarker of diastolic dysfunction.

Aim:

The aim of the study is to evaluate the diagnostic value of NT-proBNP as a surrogate marker of iron overload examined with magnetic resonance imaging T2-star (MRI T2*).

Methods:

Sixty-eight β-thalassemia major patients (10–18 years) with no signs of heart failure underwent NT-proBNP measurement before routine transfusion. All participants prospectively underwent cardiac MRI T2* examination within 3 months (median 19 days). Patients were divided as cardiac hemosiderosis (cardiac MRI T2* <20 ms) and nonhemosiderosis (cardiac MRI T2* >20 ms).

Results:

Of 68 patients, the male-to-female ratio was 1:1.1 and the median age was 14.1 years (range: 10–17.8 years). NT-proBNP levels were not different between hemosiderosis and nonhemosiderosis patients (P = 0.233). Further receiver operating characteristic analysis resulted in no significant correlation of NT-proBNP and MRI T2* (area under the curve 0.393, P = 0.233).

Conclusion:

Measurement of NT-proBNP levels cannot be used for early detection of cardiac iron overload in adolescent with β-thalassemia major.

Management of cardiac hemochromatosis

Iron-overload syndromes may be hereditary or acquired. Patients may be asymptomatic early in the disease. Once heart failure develops, there is rapid deterioration. Cardiac hemochromatosis is characterized by a dilated cardiomyopathy with dilated ventricles, reduced ejection fraction, and reduced fractional shortening. Deposition of iron may occur in the entire cardiac conduction system, especially the atrioventricular node. Cardiac hemochromatosis should be considered in any patient with unexplained heart failure. Screening for systemic iron overload with serum ferritin and transferin saturation should be performed. If these tests are consistent with iron overload, further noninvasive and histologic confirmation is indicated to confirm organ involvement with iron overload. Cardiac magnetic resonance imaging is superior to other diagnostic tests since it can quantitatively assess myocardial iron load. Therapeutic phlebotomy is the therapy of choice in nonanemic patients with cardiac hemochromatosis. Therapeutic phlebotomy should be started in men with serum ferritin levels of 300 μg/l or more and in women with serum ferritin levels of 200 μg/l or more. Therapeutic phlebotomy consists of removing 1 unit of blood (450 to 500 ml) weekly until the serum ferritin level is 10 to 20 μg/l and maintenance of the serum ferritin level at 50 μg/l or lower thereafter by periodic removal of blood. Phlebotomy is not a treatment option in patients with anemia (secondary iron-overload disorders) nor in patients with severe congestive heart failure. In these patients, the treatment of choice is iron chelation therapy.

Heart failure in haemoglobinopathies: pathophysiology, clinical phenotypes, and management

Hereditary haemoglobinopathies, mainly beta-thalassemia and sickle cell disease, constitute the most common monogenic disorders in humans, and although once geographically confined, they are currently globally distributed. They are demanding clinical entities that require multidisciplinary medical management. Despite their genotypic and phenotypic heterogeneity, the haemoglobinopathies share several similarities in pathophysiology, clinical manifestations, therapeutic requirements, and complications, among which heart failure (HF) represents a leading cause of mortality and morbidity. However, haemoglobinopathies have generally been addressed in a rather fragmentary manner. A unifying approach focusing on the underlying similarities of HF attributes in the two main entities might contribute to their better understanding, characterization, and management. In the present review, we attempt such an approach to the pathophysiology, clinical phenotypes, and management of HF in haemoglobinopathies.

Thalassemia Syndromes in Pregnancy

Thalassemia syndromes are becoming more common in the United States as the population becomes more diverse. To provide appropriate care to this patient population, nurses must know that thalassemia syndromes are classified into two main types, α-thalassemia and β-thalassemia. α-Thalassemia is further delineated into four clinical patterns: silent carrier state, mild α-thalassemia, hemoglobin H disease, and hydrops fetalis. Understanding each of these complex anemias and their potential effects on a pregnant woman and her fetus will enable nurses to interpret these women's unique laboratory test results. Intervention when necessary with appropriate treatment may lead to optimal outcomes for women and newborns.

Association between vitamin D levels and left ventricular function and NT-proBNP levels among thalassemia major children with iron overload

BACKGROUND

Heart disease is the major cause of death in thalassemia patients. Repeated blood transfusions and hemolysis cause iron overload and also disrupts the hydroxylation and synthesis of vitamin D, causing vitamin D deficiency. Vitamin D deficiency is associated with cardiac dysfunction.

OBJECTIVE

The purpose of this study was to determine the association between vitamin D levels and left ventricular function and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in thalassemia major children with iron overload.

PATIENTS AND METHODS

A cross-sectional study was conducted in March-April 2015 in the thalassemia clinic, Department of Child Health, Dr. Hasan Sadikin General Hospital, Bandung, Indonesia. Thirty-four children with thalassemia were enrolled consecutively. Serum vitamin D and NT-proBNP levels were measured with electrochemiluminescence (ECLIA) method and echocardiography was performed to assess ventricular function.

RESULTS

Significant correlations were found between vitamin D levels and left ventricular ejection fraction (LVEF) (r = 0.399, P = 0.019) and fractional shortening (FS) (r = 0.394, P = 0.021). There was also significant correlation between vitamin D and NT-proBNP levels (r = -0.444, P = 0.008). Chi-square analysis also showed a relationship between vitamin D and NT-proBNP (P = 0.019) levels. There was a difference in NT-proBNP levels among thalassemia major children with iron overload (P = 0.020). Post hoc analysis showed that there was a significant difference in NT-proBNP levels between those with vitamin D deficiency and those with normal vitamin D levels (P = 0.012).

CONCLUSION

There is an association between vitamin D and left ventricular function and NT-proBNP levels in children with thalassemia major and iron overload. Vitamin D can be considered in patients with thalassemia having vitamin D deficiency.

Comparison of Doppler echocardiographic and tissue Doppler velocity data in beta-thalassaemia major with high and normal NT-proBNP levels of children in the south-east region of Turkey

BACKGROUND

It has been reported that N-terminal pro-brain natriuretic peptide (NT-proBNP) is early biomarker of iron- induced cardiomyopathy in β-thalassemia major (β-TM). In this study, we aimed to assess the Doppler echocardiographic, tissue Doppler velocity datas and clinical characteristics in β-TM patients with high and normal NT-proBNP levels who have normal systolic function.

MATERIAL AND METHOD

Fifty-eight β-TM patients who were on regular transfusion in every 3-4 weeks for more than one year and 20 healthy children were included into the study. According to NT-proBNP levels, β-TM patients are divided in two groups. Group I: the patients with high NT-proBNP levels; Group II: the patients with normal NT-proBNP levels.

RESULTS

The mean serum NT-proBNP levels were significantly increased in patients with β-TM compared to control group (P<0.05). The serum ferritin levels were ranged between 676-9,476 ng/mL (mean: 3,716±2,003 ng/mL) in β-TM. No correlation was found between ferritin and NT-pro BNP in patients with β-TM. The mean age and body surface area (BSA) were significantly low in group with high NT-proBNP compared to group with normal NT-proBNP (P<0.01). The mean heart rate, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were elevated, but not significantly in group with high NT-proBNP. Also, the mean ferritin and hemoglobin levels were decreased in this group compared to group with normal NT-proBNP, but statistically not significant. The left ventricular end diastole (LVED) diameters and left ventricular mass index (LVMI) values were found significantly decreased in group with high NT-proBNP compared to other group respectively (P<0.001, P<0,05). Right ventricular early diastolic tricuspid inflow velocity/early diastolic tissue Doppler indices (TDI) tricuspid annular velocity (RV E/E') were found increased in group with high NT-proBNP levels and difference was statistically significant (P<0.05). In addition, NT-pro BNP was found correlated with RV E/E' (r: 0.320).

CONCLUSIONS

According to our result, elevated NT-proBNP level was correlated with RVE/E', but it was not associated with ferritin level. The serum NT-proBNP level may be increased as a response to increased myocardial workload and decreased hemoglobin level in patients who have an increased need for transfusion.

Blockade of mitochondrial calcium uniporter prevents cardiac mitochondrial dysfunction caused by iron overload

AIM

Iron overload in the heart can lead to iron-overload cardiomyopathy and cardiac arrhythmia. In the past decades, growing evidence has suggested that cardiac mitochondrial dysfunction is associated with the development of cardiac dysfunction and lethal arrhythmias. Despite these facts, the effect of iron overload on cardiac mitochondrial function is still unclear. In this study, we determined the effects of iron overload on the cardiac mitochondrial function and the routes of cardiac mitochondrial iron uptake. We tested the hypothesis that iron overload can lead to cardiac mitochondrial dysfunction and that mitochondrial calcium uniporter (MCU) plays a major role for cardiac mitochondrial iron uptake under iron-overload condition. Cardiac mitochondrial function was assessed via the determination of mitochondrial swelling, mitochondrial reactive oxygen species (ROS) production and mitochondrial membrane potential changes.

METHODS

Isolated cardiac mitochondria from male Wistar rats were used in this study. To determine the routes for cardiac mitochondrial iron uptake, isolated mitochondria were exposed to MCU blocker (Ru360), mitochondrial permeability transition pore (mPTP) blocker (cyclosporin A) and an iron chelator (deferoxamine).

RESULTS

We found that (i) iron overload caused cardiac mitochondrial dysfunction, indicated by increased ROS production, mitochondrial membrane depolarization and mitochondrial swelling; and (ii) only MCU blocker completely protected cardiac mitochondrial dysfunction caused by iron overload.

CONCLUSIONS

These findings strongly suggest that MCU could be the major route for iron uptake into cardiac mitochondria. The inhibition of MCU could be the novel pharmacological intervention for preventing iron-overload cardiomyopathy.