Heart failure in beta-thalassemia syndromes: a decade of progress

Urethral meatus edema with peno-scrotal edema in a patient with transfusion-dependent beta-thalassemia major

Urethral meatus edema is a rare finding and may infer a more severe form of volume overload. Management of patients with thalassemia vary in terms of the severity of the kidney injury due to transfusion, chronicity, and severity of volume overload.

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.

Speckle tracking echocardiography and β-thalassemia major. A systematic review

Heart disease is among the primary causes of morbidity and mortality in β-thalassemia major (β-TM). Conventional echocardiography has failed to identify myocardial dysfunction at an early stage among these patients, thus speckle tracking echocardiography (STE) has been lately used. The objectives of this review were to 1) identify all published studies having evaluated myocardial strain among β-TM patients, 2) gather their results, 3) compare their findings and 4) propose recommendations based on these data. Literature search was conducted in PubMed, SCOPUS and Cohrane Library. Data regarding left ventricular global longitudinal (LV-GLS), circumferential (LV-GCS) and radial strain (LV-GRS), right ventricular longitudinal strain (RV-GLS), left and right atrial strain were extracted. Thirty-five studies (34 original articles and 1 meta-analysis) have met the inclusion criteria. LV-GLS has been reported being worse in patients compared to controls in 13 of 21 studies, LV-GCS in 7 of 11 studies, LV-GRS in 6 of 7 studies, RV-GLS in 2 of 3 studies and left atrial strain in all case-control studies. Myocardial iron overload (MIO) patient subgroups had worse LV-GLS in 6 of 15 studies, LV-GCS in 2 of 7 studies and LV-GRS in none of 7 studies. A small number of studies suggest left atrial strain correlation with electrical atrial ectopy and atrial fibrillation. It is suggested that STE should be applied supplementary to conventional echocardiography for early identification of myocardial dysfunction among β-TM patients. Potential myocardial strain utilities could be screening for myocardial iron overload, left ventricular diastolic dysfunction and atrial fibrillation.

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.

Cardiac Magnetic Resonance at 3.0 T in Patients With C282Y Homozygous Hereditary Hemochromatosis: Superiority of Radial and Circumferential Strain Over Cardiac T2* Measurements at Baseline and at Post Venesection Follow-up

BACKGROUND

Iron-overload cardiomyopathy initially manifests with diastolic dysfunction and can progress to dilated cardiomyopathy if untreated. Previous studies have shown that patients with primary and secondary hemochromatosis can have subclinical left ventricle dysfunction with abnormalities on strain imaging. This study aimed to evaluate the relationship between cardiac T2* values and myocardial-wall strain in patients with hereditary hemochromatosis (HH) at the time of diagnosis and after a course of venesection treatment.

MATERIALS AND METHODS

Baseline cardiac magnetic resonance (CMR) at 3 T was performed in 19 patients with newly diagnosed HH with elevated serum ferritin levels and repeated after a course of treatment with venesection. Quantitative T2* mapping and strain analysis were performed offline using dedicated relaxometry fitting and feature-tracking software.

RESULTS

The majority (84%) of patients had normal baseline myocardial T2* values (mean 19.3 ms, range 8.9 to 31.2 ms), which improved significantly after venesection (mean 24.1 ms, range 11 to 38.1 ms) ( P =0.021). Mean global radial strain significantly improved from 25.0 (range: 15.6 to 32.9) to 28.3 (range: 19.8 to 35.8) ( P =0.001) and mean global circumferential strain improved, decreasing from -15.7 (range: -11.1 to -19.2) to -17.1 (range: -13.0 to -20.1) ( P =0.001).

CONCLUSION

Patients with HH may have normal T2* values in the presence of subclinical left ventricle dysfunction, which can be detected by abnormal radial and circumferential strain. As strain imaging improves following venesection in HH, it may serve as a useful biomarker to guide treatment.

The correlation of cardiac biomarkers and myocardial iron overload based on T2* MRI in major beta-thalassemia

Cardiac hemosiderosis is the primary factor to derive the pathogenesis of cardiac dysfunction in patients with transfusion dependent thalassemia. Biomarkers assessment along with T2 * MRI study could be employed to evaluate the severity of iron deposition-related damage and determination of the diagnostic and prognostic value of these inflammatory factors. The study was conducted on 62 patients (12-44 years old) with major thalassemia. The patients were under regular blood transfusion and they had no signs of cardiac defects, and chronic diseases. The serum levels of inflammatory factors (NT-proBNP, CRP, Copeptin HS) were determined before routine transfusion. Cardiac iron overload was assessed by T2* MRI (within the last three months), and T2* lower than 20 ms was considered as cardiac siderosis. The obtained results were analyzed using statistical methods. 92% of patients showed an increased level of hs-CRP (> 2 µg/dL). All cases showed increased levels of NT-proBNP (> 150 pg/mL). Only 29% of subjects showed high level of Copeptin, 25.8% of patients demonstrated cardiac siderosis based on the T2* MRI (< 20 ms) results. The serum levels of inflammatory factors were not significantly correlated with cardiac siderosis. Given the obtained results, it could be deduced that the serum levels of inflammatory factors could not be exploited for early detection of cardiac siderosis in major beta-thalassemia patients.

Iron Overload in Patients With Heavily Transfused Sickle Cell Disease-Correlation of Serum Ferritin With Cardiac T2* MRI (CMRTools), Liver T2* MRI, and R2-MRI (Ferriscan®)

The treatment of sickle cell disease (SCD) is mainly supportive, except for a minority, who receive bone marrow transplantation (BMT). Serum ferritin (SF) is routinely available but is notoriously unreliable as a tool for iron-overload assessment since it is an acute-phase reactant. Although blood transfusion is one of the most effective ways to deal with specific acute and chronic complications of SCD, this strategy is often associated with alloimmunization, iron overload, and hemolytic reactions. This study, thus, aims to evaluate iron overload in patients with SCD on chronic blood transfusions and specifically, correlate SF with the current standard of care of iron-overload assessment using MRI-based imaging techniques. Amongst a historic cohort of 58 chronically transfused patients with SCD, we were able to evaluate 44 patients who are currently alive and had multiple follow-up testing. Their mean age (±SD) was 35 (9) years and comprised of 68.2% of women. The studied iron-overload parameters included cardiac T2^* MRI, liver iron concentration (LIC) by Liver T2^* MRI, and serial SF levels. Additionally, in a smaller cohort, we also studied LIC by FerriScan^© R2-MRI. Chronic blood transfusions were necessary for severe vaso-occlusive crisis (VOC) (38.6%), severe symptomatic anemia (38.6%), past history of stroke (15.9%), and recurrent acute chest syndrome (6.9%). About 14 (24%) patients among the original cohort died following SCD-related complications. Among the patients currently receiving chelation, 26 (96%) are on Deferasirox (DFX) [Jadenu® (24) or Exjade® (2)], with good compliance and tolerance. However, one patient is still receiving IV deferoxamine (DFO), in view of the significantly high systemic iron burden. In this evaluable cohort of 44 patients, the mean SF (±SD) reduced marginally from 4,311 to 4,230 ng/ml, mean Liver T2^* MRI dropped from 12 to 10.3 mg/gm dry weight, while the mean cardiac T2^*MRI improved from 36.8 to 39.5 ms. There was a mild to moderate correlation between the baseline and final values of SF ng/ml, r = 0.33, p = 0.01; Cardiac T2^* MRI ms, r = 0.3, p = 0.02 and Liver T2^* MRI mg/kg dry weight, r = 0.6, p < 0.001. Overall, there was a positive correlation between SF and Liver T2^* MRI (Pearson's r = 0.78, p < 0.001). Cardiac T2^*MRI increased with the decreasing SF concentration, showing a negative correlation which was statistically significant (Pearson's r = -0.6, p < 0.001). Furthermore, there was an excellent correlation between SF ng/ml and LIC by FerriScan^© R2-MRI mg/g or mmol/kg (Spearmen's rho = -0.723, p < 0.008) in a small subset of patients (n = 14) who underwent the procedure. In conclusion, our study demonstrated a good correlation between serial SF and LIC by either Liver MRI T2^* or by FerriScan^© R2-MRI, even though SF is an acute-phase reactant. It also confirms the cardiac sparing effect in patients with SCD, even with the significant transfusion-related iron burden. About 14 (24%) patients of the original cohort died over the past 15 years, indicative of a negative impact of iron overload on disease morbidity and mortality.

Evaluation of iron overload by cardiac and liver T2* in β-thalassemia: Correlation with serum ferritin, heart function and liver enzymes

Introduction: In this study, we aimed to assess the relationship of cardiac and hepatic T2* magnetic resonance imaging (MRI) values as a gold standard for detecting iron overload with serum ferritin level, heart function, and liver enzymes as alternative diagnostic methods. Methods: A total 58 patients with beta-thalassemia major who were all transfusion dependent were evaluated for the study. T2* MRI of heart and liver, echocardiography, serum ferritin level, and liver enzymes measurement were performed. The relationship between T2* MRI findings and other assessments were examined. Cardiac and hepatic T2* findings were categorized as normal, mild, moderate, and severe iron overload. Results: 22% and 11% of the patients were suffering from severe iron overload in heart and liver, respectively. The echocardiographic findings were not significantly different among different iron load categories in heart or liver. ALT level was significantly higher in patient with severe iron overload than those with normal iron load in heart (P =0.005). Also, AST level was significantly lower in normal iron load group than mild, moderate, and severe iron load groups in liver (P <0.05). The serum ferritin level was significantly inversely correlated with cardiac T2* values (r = -0.34, P =0.035) and hepatic T2* values (r = -0.52, P =0.001). Conclusion: Cardiac and hepatic T2* MRI indicated significant correlation with serum ferritin level.

Discrepancy in patterns of myocardial involvement in beta-thalassaemia vs. sickle cell anaemia

Introduction: Different mechanisms contribute to myocardial dysfunction in sickle cell disease [SCD] and beta thalassaemia major [TM]. TM mainly involves the highly vascular subepicardium by iron load and SCD mainly operates by inducing ischaemia in the relatively ischaemic subendocardium. The aim of this article was to determine if pattern of left ventricular [LV] dysfunction differ among the two groups of patients.Methods: Forty TM and 40 SCD patients and 40 age- and surface area-matched controls were subjected to conventional echocardiography, 2D Speckle tracking myocardial layer strain discriminating echocardiography (MLSD-STE) which is able to discriminate if myocardial dysfunction is predominantly subepicardial or subendocardial and 3D echocardiography for ejection fraction assessment as well as haemoglobin, ferritin, and lactate dehydrogenase levels.Results: TM patients had a deeper subepicardial dysfunction while SCD had prevalent subendocardial dysfunction, epicardial GLS (TM: -10.9 ± 2 vs. SCD: 19.9 ± 1.7; p value < 0.01); endocardial GLS (TM: -19.9 ± 1.7 vs. SCD: -10.6 ± 1.6, p value < 0.01).Conclusion: This study points towards divergent microcirculatory mechanisms in the pathogenesis of myocardial dysfunction in haemoglobinopathies. It shows predominant subendocardial dysfunction with underlying ischaemia of SCD and prevalent subepicardial iron-induced injury in cases of TM.

Cardiorenal syndrome in thalassemia patients

Background

Cardiorenal syndrome (CRS), a serious condition with high morbidity and mortality, is characterized by the coexistence of cardiac abnormality and renal dysfunction. There is limited information about CRS in association thalassemia. This study aimed to investigate the prevalence of CRS in thalassemia patients and also associated risk factors.

Methods

Thalassemia patients who attended the out-patient clinic of a tertiary care university hospital from October 2016 to September 2017 were enrolled onto this cross-sectional study. Clinical and laboratory findings from 2 consecutive visits, 3 months apart, were assessed. The criteria for diagnosis of CRS was based on a system proposed by Ronco and McCullough. Cardiac abnormalities are assessed by clinical presentation, establishment of acute or chronic heart failure using definitions from 2016 ESC guidelines or from structural abnormalities shown in an echocardiogram. Renal dysfunction was defined as chronic kidney disease according to the 2012 KDIGO guidelines.

Results

Out of 90 thalassemia patients, 25 (27.8%) had CRS. The multivariable analysis showed a significant association between CRS and extramedullary hematopoiesis (EMH) (odds ratio (OR) 20.55, p = 0.016); thalassemia type [β⁰/β^E vs β⁰/β⁰ thalassemia (OR 0.005, p = 0.002)]; pulmonary hypertension (OR 178.1, p = 0.001); elevated serum NT-proBNP (OR 1.028, p = 0.022), and elevated 24-h urine magnesium (OR 1.913, p = 0.016). There was no association found between CRS and frequency of blood transfusion, serum ferritin, liver iron concentration, cardiac T2*, type of iron chelating agents, or urine neutrophil gelatinase-associated lipocalin level.

Conclusions

CRS is relatively common in thalassemia patients. Its occurrence is associated with laboratory parameters which are easily measured in clinical practice.

Association between Serum Vitamin D Level and Echocardiographic Abnormalities in Patients with Thalassemia Major

OBJECTIVES

Thalassemia major (TM) is one of the most common blood disorders with a high mortality rate due to cardiovascular disease. Vitamin D deficiency has been suggested to implicate in cardiac abnormalities. In this prospective study, we aimed to investigate the relationship between serum levels of vitamin D and tissue Doppler (TD) echocardiographic indices in thalassemia major patients.

METHODS

A total of 81 TM patients, including 56 females and 25 males, with a mean age of 27.5± 6.8 years, were enrolled consecutively. Serum levels of vitamin D and other biomedical parameters were measured. Then, all patients were subjected to TD echocardiography. Correlations between the serum parameters and systolic and diastolic indices were examined.

RESULTS

The serum level of vitamin D was correlated with systolic and diastolic indices such as the EF (r= 0.33, P= 0.003) and TD Imaging (TDI)-lateral (r= 0.31, P= 0.005). However, no correlations were observed between vitamin D deficiency and the LV septal and posterior wall thickness, TDIseptal, tricuspid regurgitation peak gradient (TRPG), pulmonary artery systolic pressure (PASP), deceleration time (DT), and propagation velocity (PVcm/s) indices. The results revealed also no linear correlations between serum vitamin D and albumin (r= -0.17, P= 0.06), ALP (r= -0.12, P= 0.14), T4 (r= -0.11, P= 0.16), as well as TSH (r= -0.10, P= 0.19).

CONCLUSION

It seems that vitamin D deficiency in patients with TM is associated with systolic but not diastolic dysfunctions, possibly as consequences of related biochemical abnormalities.

Arrhythmias and Sudden Cardiac Death in Beta-Thalassemia Major Patients: Noninvasive Diagnostic Tools and Early Markers

Beta-thalassemias are a group of inherited, autosomal recessive diseases, characterized by reduced or absent synthesis of beta-globin chains of the hemoglobin tetramer, resulting in variable phenotypes, ranging from clinically asymptomatic individuals to severe anemia. Three main forms have been described: heterozygotes, homozygotes β+, and homozygotes β°. Beta-thalassemia major (β-TM), the most serious form, is characterized by an absent synthesis of globin chains that are essential for hemoglobin formation, causing chronic hemolytic anemia. Cardiac complications represent a leading cause of mortality in β-TM patients, although an important and progressive increase of life expectancy has been demonstrated after the introduction of chelating therapies. Iron overload is the primary factor of cardiac damage resulting in thalassemic cardiomyopathy, in which diastolic dysfunction usually happens before systolic impairment and overt heart failure (HF). Although iron-induced cardiomyopathy is slowly progressive and it usually takes several decades for clinical and laboratory features of cardiac dysfunction to manifest, arrhythmias or sudden death may be present without signs of cardiac disease and only if myocardial siderosis is present. Careful analysis of electrocardiograms and other diagnostic tools may help in early identification of high-risk β-TM patients for arrhythmias and sudden cardiac death.

Left and Right Atrial Function and Remodeling in Beta-Thalassaemia Major

This study aimed to assess left (LA) and right atrial (RA) function in patients with beta-thalassaemia major. Thirty-eight patients (19 males) aged 34.5 ± 10.7 years and 43 (18 males) controls aged 30.3 ± 12.6 years (p = 0.12) were studied. The maximum RA and LA areas were measured using two-dimensional planimetry, while atrial and ventricular strain and strain rates were quantified using speckle-tracking echocardiography. Compared with controls, patients had significantly reduced LA and RA peak positive strain and total strain, and LA strain rate during ventricular systole and at atrial contraction (all p < 0.05). The LA and RA strain parameters were significantly associated (all p < 0.05). The maximum LA (10.2 ± 1.6 cm²/m² vs. 8.6 ± 1.3 cm²/m², p < 0.001) and RA (9.2 ± 1.2 cm²/m² vs. 7.5 ± 1.3 cm²/m², p < 0.001) areas were significantly greater in patients than controls. The LV and RV strain and early strain rates were similar between patients and controls (all p > 0.05). Four patients with significant myocardial iron overload had larger LA area (p < 0.001) than those without. Functional and structural remodeling of both the right and left atria occurs in patients with beta-thalassaemia major, even in the absence of ventricular diastolic dysfunction.

Imaging-Specific Cardiomyopathies: A Practical Guide

Heart failure is a clinical syndrome with a broad spectrum of presentations. Cardiovascular imaging techniques such as echocardiography, cardiovascular magnetic resonance, computed tomography, and nuclear imaging play a crucial role in diagnosis, guiding management, and providing prognostic information. Each of these imaging modalities has their own respective strengths and weaknesses. Cardiac imaging can help differentiate between ischemic and nonischemic cardiomyopathies. Additionally, imaging techniques can display disease-specific findings, aiding in diagnosis of nonischemic cardiomyopathies and can provide a means to monitor response to therapy. The choice of imaging modality in the workup of cardiomyopathy should be based on the specific clinical question and the knowledge of the strengths and limitations of each imaging modality.

Elevated levels of platelet- and red cell-derived extracellular vesicles in transfusion-dependent β-thalassemia/HbE patients with pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a serious complication in β-thalassemia. The mechanism of PAH development is believed to be through chronic platelet activation and red cell (RBC) membrane abnormality contributing to a hypercoagulable state and thrombosis, which consequently leads to the development of PAH. Extracellular vesicles (EVs) shed from the plasma membrane of platelets and RBCs are found to be associated with thrombotic risk. This study aimed to investigate the involvement of phosphatidylserine (PS)-bearing cells and EVs in accelerating the progression of the hypercoagulable state in transfusion-dependent thalassemia (TDT) patients. Fresh whole blood samples from splenectomized TDT-β-thalassemia/HbE patients (11 with PAH and 14 without PAH) and 15 normal subjects were analyzed for platelet activation by measuring P-selectin expression using flow cytometry and the number of dense granular using an electron microscope. The amounts of PS-bearing RBCs, large RBC-EVs, platelets, and medium EVs were determined by flow cytometry. Platelet activation in PAH patients was not significantly different from other groups; however, the amounts of PS-bearing large RBC-EVs, platelets, and medium platelet-derived EVs were significantly increased in PAH patients as compared to normal subjects, but they were not different from patients without PAH. This could be affected by antiplatelet therapy that reduced the levels of platelet activation and the amount of PS-bearing cells, including EVs, in PAH patients as well as in patients without PAH.

Left Ventricular Diastolic Dysfunction in β-Thalassemia Major with Heart Failure

We studied the clinical, electrocardiographic, echocardiographic, Doppler and T2* cardiac magnetic resonance (CMR) data of all adult β-thalassemia major (β-TM) patients with heart failure (HF) consecutively observed at our referral center of the Sicilian region between 2008 and 2016. There were 16 patients enrolled in the study. Echocardiographic examination showed that only one patient had HF with systolic dysfunction of the left ventricle (HFrEF), whereas the others had HF with preserved systolic function of the left ventricle (HFpEF). Systolic dysfunction of the right ventricle (RV) was observed in 13 cases. Furthermore, 30.0% of the patients presented T2* CMR values consistent with intermediate risk of systolic dysfunction of the left ventricle (LV) due to iron overload, whereas 70.0% had normal values. Typical electrocardiographic abnormalities (wide T wave inversion and low voltages) were observed in 11 out of 16 patients. In conclusion, in the adult β-TM patients with HF recently observed at our center, the predominant form was that with diastolic dysfunction of the LV, and with systolic dysfunction of the RV. Only 30.0% had low values of T2* CMR. Typical electrocardiographic abnormalities were found in 69.0%.

Carotid Doppler ultrasonography as a screening tool of early atherosclerotic changes in children and young adults with β-thalassemia major

PURPOSE

β-thalassemia major (β-TM) patients had an increased incidence of cardiovascular complications secondary to iron overload. They showed early carotid atherosclerosis as showed by increased carotid intima media thickness (CIMT) that may occur early even when significant iron overload is absent. We aimed to test the diagnostic performance of CIMT measurement by Doppler ultrasonography as a structural indicator for premature atherosclerosis in β-TM patients.

METHODS

Case-control study included 42 β-TM patients (24 males and 18 females) aged from 3 to 30 years and 36 age- and sex-matched healthy controls. Carotid Duplex was used for measurement of CIMT in all subjects.

RESULTS

The frequency of abnormal CIMT among patients was 19%. Mean CIMT of right anterior wall was 0.8 ± 0.16 (range 0.5-1.2) mm, of right posterior wall was 0.80 ± 0.17 (range 0.5-1.2), of right lateral wall was 0.8 ± 0.17 (range 0.5-1.1) mm. CIMT of left anterior wall ranged from 0.5 to 1.2 with mean 0.81 ± 0.17, CIMT of left posterior wall ranged from 0.5 to 1.1 with mean 0.80 ± 0.17 mm. Mean CIMT of left lateral wall was 0.81 ± 0.18 mm (range 0.5-1.2). CIMT of right anterior, right posterior and left anterior walls were thicker in patients compared to controls (P = 0.003, 0.015, < 0.001, respectively). There was no observable difference in CIMT between males and females, splenectomised and non-splenectomised, or well and poorly chelated subgroups (P > 0.05). CIMT of right lateral wall correlated with the disease duration (r = 0.3, P = 0.04).

CONCLUSIONS

Carotid ultrasound was a useful tool to detect subclinical atherosclerosis thorough CIMT evaluation in B-thalassemia major patients. B-thalassemia major children proved to have an increased CIMT regardless the state of iron overload.

Myocardial deformation in iron overload cardiomyopathy: speckle tracking imaging in a beta-thalassemia major population

Traditional echocardiography is unable to detect neither the early stages of iron overload cardiomyopathy nor myocardial iron deposition. The aim of the study is to determine myocardial systolic strain indices in thalassemia major (TM), and assess their relationship with T2*, a cardiac magnetic resonance index of the severity of cardiac iron overload. 55 TM cases with recent cardiac magnetic resonance (CMR-T2*) underwent speckle tracking analysis to assess regional myocardial strains and rotation. The results were compared with a normal control group (n = 20), and were subsequently analyzed on the basis of the CMR-T2* values. Two TM groups were studied: TM with significant cardiac iron overload ("low" T2*, ≤20 ms; n = 21), and TM with normal T2* values ("normal" T2*, >20 ms; n = 34). TM patients show significant, uniform decrease in circumferential and radial strain (P < 0.05), and a remarkable reduction in end-systolic rotation, both global, and for all segments (P < 0.001). No significant differences were found between the low- and the normal T2* group either in regional strains and rotation or in standard echocardiographic and CMR parameters. Spearman's correlation coefficient shows no significant correlation between myocardial strains, rotation and cardiac T2* values. In conclusion, our results are in accordance with recent evidence that myocardial iron overload is not the only mechanism underlying iron cardiomyopathy in TM. Strain imaging can predict subclinical myocardial dysfunction irrespective of CMR-T2* values, although it cannot replace CMR-T2* in assessing cardiac iron overload. Finally, it might be useful to appropriately time cardioactive treatment.

HbE/β-Thalassemia and Oxidative Stress: The Key to Pathophysiological Mechanisms and Novel Therapeutics

SIGNIFICANCE

Oxidative stress and generation of free radicals are fundamental in initiating pathophysiological mechanisms leading to an inflammatory cascade resulting in high rates of morbidity and death from many inherited point mutation-derived hemoglobinopathies. Hemoglobin (Hb)E is the most common point mutation worldwide. The βE-globin gene is found in greatest frequency in Southeast Asia, including Thailand, Malaysia, Indonesia, Vietnam, Cambodia, and Laos. With the wave of worldwide migration, it is entering the gene pool of diverse populations with greater consequences than expected.

CRITICAL ISSUES

While HbE by itself presents as a mild anemia and a single gene for β-thalassemia is not serious, it remains unexplained why HbE/β-thalassemia (HbE/β-thal) is a grave disease with high morbidity and mortality. Patients often exhibit defective physical development, severe chronic anemia, and often die of cardiovascular disease and severe infections. Recent Advances: This article presents an overview of HbE/β-thal disease with an emphasis on new findings pointing to pathophysiological mechanisms derived from and initiated by the dysfunctional property of HbE as a reduced nitrite reductase concomitant with excess α-chains exacerbating unstable HbE, leading to a combination of nitric oxide imbalance, oxidative stress, and proinflammatory events.

FUTURE DIRECTIONS

Additionally, we present new therapeutic strategies that are based on the emerging molecular-level understanding of the pathophysiology of this and other hemoglobinopathies. These strategies are designed to short-circuit the inflammatory cascade leading to devastating chronic morbidity and fatal consequences. Antioxid. Redox Signal. 26, 794-813.

Electrocardiographic Presentation, Cardiac Arrhythmias, and Their Management in β-Thalassemia Major Patients

Beta-thalassemia major (β-TM) is a genetic hemoglobin disorder characterized by an absent synthesis of globin chains that are essential for hemoglobin formation, causing chronic hemolytic anemia. Clinical management of thalassemia major consists in regular long-life red blood cell transfusions and iron chelation therapy to remove iron introduced in excess with transfusions. Iron deposition in combination with inflammatory and immunogenic factors is involved in the pathophysiology of cardiac dysfunction in these patients. Heart failure and arrhythmias, caused by myocardial siderosis, are the most important life-limiting complications of iron overload in beta-thalassemia patients. Cardiac complications are responsible for 71% of global death in the beta-thalassemia major patients. The aim of this review was to describe the most frequent electrocardiographic abnormalities and arrhythmias observed in β-TM patients, analyzing their prognostic impact and current treatment strategies.

Coronary atherosclerosis burden is not advanced in patients with β-thalassemia despite premature extracardiac atherosclerosis: a coronary artery calcium score and carotid intima-media thickness study

Background

Thalassemic patients demonstrate an increased rate of extracardiac vascular complications and increased carotid wall intima-media thickness (cIMT), but very low prevalence of coronary artery disease (CAD). We investigated the atheroma burden by assessing the coronary artery calcium (CAC) and cIMT in these patients.

Methods

We examined 37 patients with β-thalassemia and 150 healthy control volunteers with multi-detector computer tomography (CT) and ultrasonography to determine CAC score and cIMT, respectively.

Results

Propensity score matching (C-statistic: 0.88; 95% CI: 0.83–0.93) resulted in 27 pairs of patients; severe CAC was observed in 2 (7.4%) and 0 of β-thalassemia patients and healthy volunteers respectively (P = 0.5). Median calcium score was 0 (0–0) in β-thalassemia patients and 0 (0–4) in healthy volunteers (P = 0.8). Median intima-media thickness was higher in β-thalassemia patients compared to control group [0.45 (0.06–0.65) vs. 0.062 (0.054–0.086); P = 0.04].

Conclusions

Patients with β–thalassemia in comparison with healthy control subjects exhibit similar CAC score and increased cIMT. Our findings indicate a disparate rate of progression of atherosclerosis between coronary and extracardiac arteries in these patients lending support to the epidemiological evidence.

Endothelial nitric oxide synthase gene intron 4 variable number tandem repeat polymorphism in β-thalassemia major: relation to cardiovascular complications

Endothelial nitric oxide synthase (eNOS), an enzyme that generates nitric oxide, is a major determinant of endothelial function. Several eNOS gene polymorphisms have been reported as 'susceptibility genes' in various human diseases states, including cardiovascular, pulmonary and renal diseases. We studied the 27-base pair tandem repeat polymorphism in intron 4 of eNOS gene in 60 β-thalassemia major (β-TM) patients compared with 60 healthy controls and assessed its role in subclinical atherosclerosis and vascular complications. Patients were evaluated stressing on transfusion history, splenectomy, thrombotic events, echocardiography and carotid intima-media thickness (CIMT). Analysis of eNOS intron 4 gene polymorphism was performed by PCR. No significant difference was found between β-TM patients and controls with regard to the distribution of eNOS4 alleles or genotypes. The frequency of eNOS4a allele (aa and ab genotypes) was significantly higher in β-TM patients with pulmonary hypertension or cardiomyopathy. Logistic regression analysis revealed that eNOS4a allele was an independent risk factor for pulmonary hypertension in β-TM patients [odds ratio (OR) 2.2, 95% confidence interval (95% CI) 1.19-5.6; P < 0.001]. We suggest that eNOS intron 4 gene polymorphism is related to endothelial dysfunction and subclinical atherosclerosis and could be a possible genetic marker for prediction of increased susceptibility to cardiovascular complications.

Optimal method for early detection of cardiac disorders in thalassemia major patients: magnetic resonance imaging or echocardiography?

Background

Heart failure resulting from myocardial iron deposition is the most important cause of death in β-thalassemia major (TM) patients. Cardiac T2*magnetic resonance imaging (MRI), echocardiography, and serum ferritin level serve as diagnostic methods for detecting myocardial iron overload. In this study, we aimed to evaluate the relationship between the above-mentioned methods.

Methods

T2*MRI and echocardiographic measurement of left ventricular (LV) systolic and diastolic function were performed in 63 patients. Serum ferritin level was measured. The relationships between all assessments were evaluated.

Results

There were 40 women and 23 men with a mean age of 23.7±5.1 years (range, 15-35 years). There was no statistically significant correlation between serum ferritin level and LV systolic and diastolic function (P=0.994 and P=0.475, respectively). T2*MRI results had a significant correlation with ferritin level; 63.6% of patients with serum ferritin level >2,000 ng/mL had abnormal cardiac MRI, while none of the patients with ferritin level <1,000 ng/mL had abnormal cardiac MRI (P=0.001). There was no significant correlation between MRI findings and LV systolic function (P=1.00). However, we detected a significant difference between LV diastolic function and cardiac siderosis (P=0.03)

Conclusion

MRI findings are a good predictor of future cardiac dysfunction, even in asymptomatic TM patients; however, diastolic dysfunction may happen prior to cardiac siderosis in some patients, and echocardiography is able to diagnose this diastolic dysfunction while T2*MRI shows normal findings.

Asymmetric dimethylarginine levels in children with β-thalassemia and their correlations to tricuspid regurgitant jet velocity

BACKGROUND

Pulmonary hypertension (PHT) may be the leading cause of death in β-thalassemia patients; however, its pathophysiologic mechanisms are still unclear. Recent studies indicate that asymmetric dimethylarginine (ADMA) plays a role in the initiation and progression of a variety of diseases, especially the cardiovascular system. The aim of this study is to assess the levels of ADMA in children with β-thalassemia and their correlations with tricuspid regurgitant jet velocity.

PROCEDURES

This study was carried out on 30 children with β-thalassemia major and 30 healthy children served as a control group. Both groups underwent the following investigations: Blood sampling for CBC, LDH, serum ferritin, reticulocytic count, serum bilirubin, AST, ALT, in addition to plasma levels of ADMA. Doppler echocardiography was done for thalassemic group. Patients with tricuspid regurgitant jet velocity (TRV ≥ 2.5 m/sec) were considered risky for PHT.

RESULTS

Plasma ADMA levels were significantly higher in patients with β-thalassemia than control group with a mean value 0.91 ± 0.14 and 0.62 ± 0.10 µmol/L respectively (P = 0.001). There was a significant positive correlation between plasma ADMA levels and tricuspid regurgitant jet velocity. The prevalence of elevated tricuspid regurgitant jet velocity (TRV ≥ 2.5 m/sec) in patients with thalassemia was 33.3%, with a significant increase of elevated TVR (≥ 2.5 m/sec) in patients with thalassemia with splenectomy than in patients without splenectomy.

CONCLUSION

High plasma ADMA levels may be implicated in the pathogenesis of PHT in children with β-thalassemia.

The effect of metoprolol succinate on the cardiac function of patients with thalassaemia cardiomyopathy: a double-blind randomised study

BACKGROUND

Heart failure is the most common cause of mortality in β-thalassaemia major. However, the management of this disease, apart from chelation therapy, is largely empirical. Therefore, we decided to evaluate the effect of metoprolol succinate on patients with thalassaemia cardiomyopathy (TCM).

MATERIALS AND METHODS

In this clinical trial, 45 patients with TCM were randomised to receive either metoprolol (n=26) or placebo (n=19). Echocardiography and a 6 min walk test were performed at baseline and repeated after 6 months and the values compared.

RESULTS

In the metoprolol group, left ventricular ejection fraction (LVEF) rose from 38.65% to 42.84% (p<0.001), while it decreased in the placebo group from 37.89% to 35.84% (p=0.01); the difference between the two groups was significant (p<0.001). Left ventricular (LV) mass in the metoprolol group decreased from 154.31 to 144.26 g (p=0.02), while in the placebo group it increased from 174.32 to 200.15 g (p=0.68); the difference between the two groups was significant (p<0.001). End systolic volume (ESV) decreased in the metoprolol group from 42.19 to 36.73 cm(3) (p<0.001) but increased from 47.37 to 57.42 cm(3) in the placebo group (p=0.144); the difference between the groups was significant (p<0.001). No differences in exercise capacity or pulmonary capillary wedge pressure were seen between the two groups (p=0.268 and p=0.535, respectively).

CONCLUSIONS

Metoprolol succinate as a β-blocker may have the potential to significantly improve systolic function in patients with TCM and reverse LV remodelling to the same extent as in other types of cardiomyopathy.

TRIAL REGISTRATION NUMBER

NCT01863173.

Association of Iron Overload with Oxidative Stress, Hepatic Damage and Dyslipidemia in Transfusion-Dependent β-Thalassemia/HbE Patients

Blood transfusion can be a life-saving therapy for β-thalassemia major and β-thalassemia/HbE (β-TM) patients with chronic anemia, major caused severe iron overload particularly in β-TM patients received only blood transfusion therapy. We aim to evaluate the association of iron overload with oxidative stress, liver damage, and elevated very low density lipoprotein cholesterol (VLDL-C) in transfusion-dependent β-TM patients. Serum ferritin, malondialdehyde (MDA), liver profiles, triglycerides levels, and VLDL-C were significantly higher while total cholesterol, low-density lipoprotein cholesterol, high density lipoprotein cholesterol and total antioxidant capacity were lower in β-TM than controls. Serum ferritin was significantly correlated with MDA, liver enzymes and lipid profiles (p < 0.05). Multiple forward stepwise linear regression analyses of the significant variables showed that in these β-TM patients, independent predictors of iron overload were MDA (β = 0.410, r (2) = 0.671, p < 0.001), ALT (β = 0.493, r (2) = 0.578, p < 0.001), and VLDL-C (β = 0.253, r (2) = 0.711, p < 0.001). In conclusion, iron overload associated with increased oxidative stress, lipid peroxidation, liver damage, decreased TC, LDL-C, HDL-C and over production of VLDL-C, is significantly problem in transfusion-dependent β-TM patients. These appeared the major cause of future morbidity and mortality in β-TM patients.

Sildenafil therapy in thalassemia patients with Doppler-defined risk of pulmonary hypertension

Pulmonary hypertension is a common but often overlooked complication associated with thalassemia syndromes. There are limited data on the safety and efficacy of selective pulmonary vasodilators in this at-risk population. We, therefore, designed a 12-week, open-label, phase 1/2, pilot-scale, proof-of-principle trial of sildenafil therapy in 10 patients with β-thalassemia and at increased risk of pulmonary hypertension based on an elevated tricuspid regurgitant jet velocity >2.5 m/s on Doppler-echocardiography. Variables compared at baseline and after 12 weeks of sildenafil treatment included Doppler-echocardiographic parameters, 6-minute walked distance, Borg Dyspnea Score, New York Heart Association functional class, pulmonary function, and laboratory parameters. Treatment with sildenafil resulted in a significant decrease in tricuspid regurgitant jet velocity by 13.3% (3.0±0.7 versus 2.6±0.5 m/s, P=0.04), improved left ventricular end systolic/diastolic volume, and a trend towards a improved New York Heart Association functional class. No significant change in 6-minute walked distance was noted. Sildenafil was well tolerated, although minor expected adverse events were commonly reported. The total dose of sildenafil (mg) was strongly correlated with percent change in nitric oxide metabolite concentration in the plasma (ρ=0.80, P=0.01). There were also significant increases in plasma and erythrocyte arginine concentrations. Our study suggests that sildenafil is safe and may improve pulmonary hemodynamics in patients at risk of pulmonary hypertension; however, it was not demonstrated to improve the distance walked in 6 minutes. Clinical trials are needed to identify the best treatment strategy for pulmonary hypertension in patients with β-thalassemia. (clinicaltrials.gov identifier: NCT00872170).

Serial echocardiographic left ventricular ejection fraction measurements: a tool for detecting thalassemia major patients at risk of cardiac death

Cardiac damage remains a major cause of mortality among patients with thalassemia major. The detection of a lower cardiac magnetic resonance T2* (CMR-T2*) signal has been suggested as a powerful predictor of the subsequent development of heart failure. However, the lack of worldwide availability of CMR-T2* facilities prevents its widespread use for follow-up evaluations of cardiac function in thalassemia major patients, warranting the need to assess the utility of other possible procedures. In this setting, the determination of left ventricular ejection fraction (LVEF) offers an accurate and reproducible method for heart function evaluation. These findings suggest a reduction in LVEF≥7%, over time, determined by 2-D echocardiography, may be considered a strong predictive tool for the detection of thalassemia major patients with increased risk of cardiac death. The reduction of LVEF≥7% had higher (84.76%) predictive value. Finally, Kaplan-Meier survival curves of thalassemia major patients with LVEF≥7% showed a statistically significant decreased probability of survival for heart disease (p=0.0022). However, because of limitations related to the study design, such findings should be confirmed in a large long-term prospective clinical trial.

Beta thalassemia major in a developing country: epidemiological, clinical and evolutionary aspects

Beta-thalassemia major (TM) remains to be one of the major health problems particularly in developing countries. Tunisia is a part of the Mediterranean countries mostly affected by this disease which is highly concentrated in small towns in families with low-income earners. The main objectives of this study are to provide a description of the demographic, clinical features and transfusion-related complications in patients with TM living in Tunisia. A standardized questionnaire was sent to clinicians throughout 33 different medical institutions caring for thalassemic patients. 391 transfusion dependant thalassemic patients with a median age of 10.7 years (range 3 months- 31 years) were included in the study. The majority originated from the north west of the country. A moderate iron overload between 1501 and 2500 ng/ml was found in 61patients, while 81 patients (26.9%) had a ferritin level more than 2500 ng/ml and greater than 5000ng/ml in 21 patients (6.9%). 51 patients died from complications related to their disease. Heart failure was the main cause of death. The incidence of cardiac, endocrine, and infectious complications will be reviewed. Preventive measures such as health education, carrier screening and premarital screening remain the best ways for lowering the incidence of these diseases, which might be reflected in financial saving, social s and health benefits.

Evidence for a novel mechanism independent of myocardial iron in β-thalassemia cardiac pathogenesis

Human β-thalassemia major is one of the most prevalent genetic diseases characterized by decrease/absence of β-globin chain production with reduction of erythrocyte number. The main cause of death of treated β-thalassemia major patients with chronic blood transfusion is early cardiac complications that have been attributed to secondary iron overload despite optimal chelation. Herein, we investigated pathophysiological mechanisms of cardiovascular dysfunction in a severe murine model of β-thalassemia from 6 to 15-months of age in the absence of confounding effects related to transfusion. Our longitudinal echocardiography analysis showed that β-thalassemic mice first display a significant increase of cardiac output in response to limited oxygen-carrying erythrocytes that progressed rapidly to left ventricular hypertrophy and structural remodeling. Following this compensated hypertrophy, β-thalassemic mice developed age-dependent deterioration of left ventricular contractility and dysfunction that led toward decompensated heart failure. Consistently, murine β-thalassemic hearts histopathology revealed cardiac remodeling with increased interstitial fibrosis but virtual absence of myocardial iron deposits. Importantly, development of thalassemic cardiac hypertrophy and dysfunction independently of iron overload has uncoupled these cardiopathogenic processes. Altogether our study on β-thalassemia major hemoglobinopathy points to two successive phases resulting from severe chronic anemia and from secondarily induced mechanisms as pathophysiologic contributors to thalassemic cardiopathy.

Altered vascular function, arterial stiffness, and antioxidant gene responses in pediatric thalassemia patients

Patients with thalassemia major are susceptible to cardiovascular complications by mechanisms not fully understood. Although overt cardiovascular complications usually occur after puberty, their underlying pathogenesis may begin much earlier. This study investigated whether there were early changes in vascular endothelial function and arterial stiffness in young patients with beta-thalassemia and hemoglobin E, and whether these changes were associated with oxidative stress and expression of antioxidant genes. The study recruited 30 pediatric patients and 30 age-matched control subjects. Compared with the control subjects, the patients had increased levels of oxidant biomarkers including malondialdehyde, protein carbonyl, and non-transferrin-bound iron and a decreased glutathione redox ratio. There were clear signs of vascular endothelial dysfunction and increased arterial stiffness, as shown by marked suppression of forearm blood flow after reactive hyperemia and increased pulse-wave velocity in the trunk and legs. The changes in FBF were associated with oxidative stress markers and free iron. An adaptive antioxidant gene response was activated in blood mononuclear cells, as shown by upregulation of GCLC and Bach-1 mRNA but downregulation of heme oxygenase-1 and thioredoxin mRNA. The results highlight the vascular changes seen even in young patients during treatment. These changes were associated with oxidative stress and suggest an adaptive response that serves to protect host cells from further oxidative damage.

Vascular endothelial dysfunction in β-thalassemia occurs despite increased eNOS expression and preserved vascular smooth muscle cell reactivity to NO

Aims

The hereditary β-thalassemia major condition requires regular lifelong blood transfusions. Transfusion-related iron overloading has been associated with the onset of cardiovascular complications, including cardiac dysfunction and vascular anomalies. By using an untransfused murine model of β-thalassemia major, we tested the hypothesis that vascular endothelial dysfunction, alterations of arterial structure and of its mechanical properties would occur despite the absence of treatments.

Methods and Results

Vascular function and structure were evaluated ex vivo. Compared to the controls, endothelium-dependent vasodilation with acetylcholine was blunted in mesenteric resistance arteries of β-thalassemic mice while the endothelium-independent vasodilator (sodium nitroprusside) produced comparable vessel dilation, indicating endothelial cell impairment with preserved smooth muscle cell reactivity to nitric oxide (NO). While these findings suggest a decrease in NO bioavailability, Western blotting showed heightened expression of aortic endothelial NO synthase (eNOS) in β-thalassemia. Vascular remodeling of the common carotid arteries revealed increased medial elastin content. Under isobaric conditions, the carotid arteries of β-thalassemic mice exhibited decreased wall stress and softening due to structural changes of the vessel wall.

Conclusions

A complex vasculopathy was identified in untransfused β-thalassemic mice characterized by altered carotid artery structure and endothelial dysfunction of resistance arterioles, likely attributable to reduced NO bioavailability despite enhanced vascular eNOS expression.

Quantitative analysis of left atrial function in asymptomatic patients with b-thalassemia major using real-time three-dimensional echocardiography

Background

There is strong evidence that left atrial (LA) size is a prognostic marker in a variety of heart diseases. Recently, real-time three-dimensional echocardiography (RT3DE) has been reported as a useful tool for studying the phasic changes of the left atrial volumes. The aim of this study was to investigate the performance of the left atrium in beta-thalassemic patients with preserved left ventricular ejection fraction (EF) and no iron overload, using RT3DE.

Methods

Twenty-eight asymptomatic b-thalassemic patients (32.2 ± 4.3 years old, 17 men) who were on iron chelating therapy, as well as 20 age- and sex-matched healthy controls underwent transthoracic RT3DE. The patient group had normal echocardiographic systolic and diastolic indices, while there was no myocardial iron disposition according to MRI. Apical full volume data sets were obtained and LA volumes were measured at 3 time points of the cardiac cycle: (1) maximum volume (LAmax) at end-systole, just before mitral valve opening; (2) minimum volume (LAmin) at end-diastole, just before mitral valve closure; and (3) volume before atrial active contraction (LApreA) obtained from the last frame before mitral valve reopening or at time of the P wave on the surface electrocardiogram. From the derived values, left atrial active and passive emptying volumes, as well as the respective emptying fractions were calculated.

Results

Left ventricular EF (59.2 ± 2.5% patients vs. 60.1 ± 2.1% controls), E/A, E/E' were similar between the two groups. Differences in the LAmax, LAmin and LApreA between b-thalassemic patients and controls were non-significant, LAmax:(35.5 ± 13.4 vs 31.8 ± 9.8)cm³, LAmin:(16.0 ± 6.0 vs. 13.5 ±4.2)cm³, and LApreA:(25.4 ± 9.8 vs. 24.3 ± 7.2)cm³. However, left atrial active emptying fraction was reduced in the patient group as compared to the healthy population (34.3 ± 16.4% vs. 43.2 ± 11.4%, p < 0.05).

Conclusion

RT3DE may be a novel technique for the evaluation of LA function in asymptomatic patients with b-Thalassemia Major. Among three-dimensional volumes and indices, left atrial active emptying fraction may be an early index of LA dysfunction in the specific patient population.

Risk factors and mortality associated with an elevated tricuspid regurgitant jet velocity measured by Doppler-echocardiography in thalassemia: a Thalassemia Clinical Research Network report

An elevated tricuspid regurgitant jet velocity (TRV) is associated with hemolysis and early mortality in sickle cell disease, yet risk factors, clinical parameters, and mortality associated with this biomarker in thalassemia are poorly defined. This report summarizes the prevalence of an elevated TRV in 325 patients screened by Doppler echocardiography in the Thalassemia Clinical Research Network. A documented TRV was reported in 148 of 325 (46%) of patients. Average age was 25.9 years (range, 5-56 years) and 97% were transfusion-dependent. Mean TRV was 2.3 ± 0.4 m/s (range, 0.2-3.5 m/s). An abnormal TRV ≥ 2.5 m/s was identified in 49 of 148 (33%) of patients with a documented TRV, 5% (8/148), with a TRV ≥ 3.0 m/s, suggesting significant PH risk. Older age was strongly associated with a high TRV; however, 16% of children had a TRV ≥ 2.5 m/s. A history of splenectomy, hepatitis C, smoking, or high white blood cell count was associated with TRV elevation. In summary, an elevated TRV is noted in one-third of transfusion-dependent thalassemia patients with a documented value and develops in both children and adults. Age, splenectomy, hepatitis C, and smoking are significant univariate risk factors, with splenectomy surfacing as the dominant risk factor over time. Mortality was low in this cohort. Prospective longitudinal studies are needed. This study is registered at http://www.clinicaltrials.gov as NCT00661804.

Frequency of pulmonary hypertension in asymptomatic β-thalassemia major patients and the role of physiological parameters in evaluation

In this study, the authors aimed to evaluate the frequency of pulmonary hypertension (PHT) in asymptomatic thalassemia major (TM) patients, and to investigate the impact of pulmonary function test (PFT) and CO diffusion results on the evaluation of pulmonary hypertension. Data from 50 asymptomatic patients with TM over age 10 were evaluated. Pulmonary hypertension was diagnosed in 10 patients (20%). High tricuspid regurgitant jet velocity was found in 14% of adults and in 25% of children. Pulmonary function test including CO diffusion testing results were not different between the TM patients with or without pulmonary hypertension. In conclusion, PHT was frequent among TM patients even they were asymptomatic and although PFT results has shown lack of association, it should be investigated in larger population.