Exercise-induced myocardial perfusion abnormalities in sickle beta-thalassemia: Tc-99m tetrofosmin gated SPECT imaging study

Advanced Echocardiography Techniques: The Future Stethoscope of Systemic Diseases

Cardiovascular disease (CVD) has been showing patterns of extensive rise in prevalence in the contemporary era, affecting the quality of life of millions of people and leading the causes of death worldwide. It has been a provocative challenge for modern medicine to diagnose CVD in its crib, owing to its etiological factors being attributed to a large array of systemic diseases, as well as its non-binary hideous nature that gradually leads to functional disability. Novel echocardiography techniques have enabled the cardiac ultrasound to provide a comprehensive analysis of the heart in an objective, feasible, time- and cost-effective manner. Speckle tracking echocardiography, contrast echocardiography, and 3D echocardiography have shown the highest potential for widespread use. The uses of novel modalities have been elaborately demonstrated in this study as a proof of concept that echocardiography has a place in routine general practice with supportive evidence being as recent as its role in the concurrent COVID-19 pandemic. Despite such evidence, many uses remain off-label and unexploited in practice. Generalization of echocardiography at the point of care can become a much-needed turning point in the clinical approach to case management. To actualize such aspirations, we recommend further prospective and interventional studies to examine the effect of implementing advanced techniques at the point of care on the decision-making process and evaluate their effectiveness in prevention of cardiovascular morbidities and mortalities.

Safety of maximal cardiopulmonary exercise testing in individuals with sickle cell disease: a systematic review

OBJECTIVE

We evaluated the safety of maximal cardiopulmonary exercise testing (CPET) in individuals with sickle cell disease (SCD). Maximal CPET using gas exchange analysis is the gold standard for measuring cardiopulmonary fitness in the laboratory, yet its safety in the SCD population is unclear.

DESIGN

Systematic review.

DATA SOURCES

Systematic search of Medline (PubMed), EMBASE, Cochrane, ClinicalTrials.gov and professional society websites for all published studies and abstracts through December 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Two reviewers independently extracted data of interest from studies that assessed safety outcomes of maximal CPET in children and adults with SCD. A modified version of the Newcastle-Ottawa Scale was used to assess for risk of bias in studies included.

RESULTS

In total, 24 studies met inclusion/exclusion criteria. Adverse events were reported separately or as part of study results in 36 (3.8%) of 939 participants with SCD undergoing maximal CPET in studies included. Most adverse events were related to transient ischaemic changes on ECG monitoring or oxygen desaturation during testing, which did not result in arrhythmias or other complications. Only 4 (0.43%) of 939 participants experienced pain events due to maximal CPET.

CONCLUSION

Maximal CPET appears to be a safe testing modality in children and adults with SCD and can be used to better understand the physiological basis of reduced exercise capacity and guide exercise prescription in this population. Some studies did not focus on reporting adverse events related to exercise testing or failed to mention safety monitoring, which contributed to risk of bias.

Evaluation of myocardial perfusion and function in patients with asymptomatic beta-thalassemia major using myocardial gated single-photon-emission computed tomography

This study was conducted to evaluate the cardiac perfusion and function of patients with beta-thalassemia major (TM) using^99mTc-MIBI cardiac gated single-photon-emission computed tomography (SPECT) and to compare the obtained indices with echocardiographic and hematological parameters. Patients with TM who were referred for regular blood transfusion and periodic checkup were included in this study. A questionnaire containing demographic and medical data was provided for all patients by an expert pediatrician. All of the patients were on Desferal chelation therapy and none of them had clinical signs of heart failure. Myocardial gated perfusion SPECT, echocardiography, and complete blood tests were performed for each patient. In total, 24 patients including 14 men (58.3%) and 10 women (41.7%) aged 15-36 years with a mean age of 24.3 ± 6.5 years' old were enrolled in this study. Myocardial perfusion scan (MPS) was normal in all patients. The mean value of the measured left ventricular ejection fraction (LVEF) was 58.88 ± 13.45%. There was no significant association between measured LVEF on scan and echocardiography (P > 0.05). In terms of hematological results, there was a significant association between the hemoglobin and ferritin level and the amount of blood transfusion (P = 0.02 and P= 0.00, respectively). According to the results of myocardial perfusion imaging (MPI), cardiac perfusion and LVEF were within normal limits in all asymptomatic patients. In the absence of any perfusion abnormality, the use of MPI in patients with asymptomatic beta-TM is not recommended for diagnosing myocardial ischemia.

Speckle tracking evaluation of right ventricular functions in children with sickle cell disease

Background:

Cardiac dysfunction is a risk factor for death in patients with sickle cell disease (SCD).

Aim of the Work:

Aim of the work is to evaluate the right ventricular systolic and diastolic functions by tissue Doppler and speckling tracking imaging in children with SCD.

Subjects and Methods:

Thirty children with SCD and thirty controls were subjected to clinical, laboratory evaluations, and echocardiographic study using GE Vivid 7 (GE Medical System, Horten, Norway with a 3.5-MHz multifrequency transducer) including; Two-dimensional and tissue Doppler echocardiographic study (lateral tricuspid valve annulus peak E’ velocity, lateral tricuspid valve annulus peak A’ velocity, E’/A’ ratio, isovolumetric relaxation time, lateral tricuspid valve annulus S’ and septal S’ waves and peak longitudinal systolic strain [PLSS] and time to PLSS) were done in six right ventricular segments.

Results:

There was a significant decrease in right ventricular systolic and diastolic function in patients group when compared to controls.

Conclusions:

Children with SCD have impaired right ventricular systolic and diastolic functions when compared to healthy children with early evaluation of the systolic dysfunction by speckle tracking imaging technique.

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.

Haematological determinants of cardiac involvement in adults with sickle cell disease

AIMS

Cardiac involvement is common in sickle cell disease (SCD). Studies are needed to establish haematological determinants of this involvement and prognostic markers. The aim of the study was to identify haematological factors associated with cardiac involvement in SCD and their impact on prognosis.

METHODS AND RESULTS

This longitudinal observational study was performed on 1780 SCD patients with SS or S-β(0)-thalassemia referred to our centre. Six hundred fifty-six met our inclusion criteria (availability of a blood-workup and echocardiogram obtained <1 year apart, no heart valve surgery and no current pregnancy). Median age was 31 (interquartile range, 25-40) years, and median haemoglobin (Hb) was 87 (80-95)g/L. Left ventricular (LV) dilation, left atrial dilation, cardiac index (CI) >4 L/min/m(2), LV ejection fraction <55%, and tricuspid regurgitant velocity (TRV) ≥2.5 m/s were found in 35, 78, 23, 8.5, and 17% of patients, respectively. Compared with other patients, those in the fourth quartiles (Q4) of LV end-diastolic dimension index (LVEDDind) and left atrial dimension index (LADind) and those with high CI had significantly lower Hb, % foetal Hb (HbF), and red blood cell (RBC) counts; and significantly higher lactate dehydrogenase, bilirubin, and %dense RBCs. Independent haematologic determinants of Q4 LVEDDind and LADind were low RBC count and %HbF; high %dense RBCs were associated with LADind. Low %HbF and RBC count were associated with high CI. High %dense RBCs or no α-thalassemia gene deletion was associated with greater severity of anaemia and cardiac dilation and with higher CI. During the median follow-up of 48 (32-59) months, 50 (7.6%) patients died. Tricuspid regurgitant velocity ≥ 2.5 m/s was a predictor of mortality. The risk of death increased four-fold when left ventricular ejection fraction <55% was present also (P = 0.0001).

CONCLUSION

Cardiac dilation and CI elevation in patients with SCD are associated with haematologic variables reflecting haemolysis, RBC rigidity, and blood viscosity. Tricuspid regurgitant velocity ≥ 2.5 and LV dysfunction (even mild) predict mortality.

Docetaxel-induced thrombotic thrombocytopenic purpura/hemolytic uremic syndrome-related complex in a patient with metastatic prostate cancer?

A 63-year-old African American man was diagnosed with prostate cancer by biopsy for elevated prostrate-specific antigen. He was initially treated with radiation and then with intermittent androgen ablation because of biochemical relapse. He continued to have rising prostrate-specific antigen and he was thought to have hormone-resistant prostate cancer. So he received chemotherapy with docetaxel. He returned to the hospital within 3 days of the first cycle of treatment with fever, altered mental status, acute renal failure, anemia, and thrombocytopenia. He was started on empiric antibiotics but his cultures from most sites were negative. His platelets dropped from 119,000 to a nadir of 10,000 during hospital stay. Patient had microangiopathic hemolytic anemia suggested by elevated lactate dehydrogenase, decreased haptoglobin, increased indirect bilirubin, and schistocytes in peripheral smear. His coagulation profile was normal. A presumptive diagnosis of chemotherapy-related thrombotic thrombocytopenic purpura (TTP)-hemolytic uremic syndrome was made and patient was started on fresh frozen plasma infusion and hemodialysis for renal failure and steroids. Patient improved symptomatically, platelet count was stable, and lactate dehydrogenase was in a declining trend after 5 days of fresh frozen plasma infusion. The ADAMS TS-13 activity was 37% suggestive of chemotherapy-related TTP. Patient also had sickle cell beta thalassemia disease and glucose 6 phosphate dehydrogenase deficiency. Docetaxel, like some other vascular endothelial growth factor inhibiting chemotherapeutic drugs may cause TTP-hemolytic uremic syndrome.

Gated myocardial perfusion scintigraphy in children with sickle cell anemia: correlation with echocardiography

OBJECTIVES

The heart is one of the organs affected by sickle cell anemia (SCA). This prospective study has aimed to evaluate myocardial perfusion and left ventricle (LV) function in children with SCA by gated myocardial perfusion scintigraphy (G-MPS) and to compare the results with echocardiographic parameters.

METHODS

Forty-three patients with SCA were evaluated by G-MPS and echocardiography. Myocardial perfusion and motion with thickening function were analyzed both visually and quantitatively. End-diastolic (EDV), end-systolic volumes (ESV), ejection fraction (EF), lung-to-heart (L/H) ratio were also calculated.

RESULTS

None of the patients showed stress perfusion impairment in G-MPS. LV dilatation in 15 patients was observed both by G-MPS and echocardiography. EF values were within normal limits. Correlation between EF values calculated by two methods was not statistically significant. However, LV dilatation detected by both methods and EDV-ESV values in G-MPS were correlated to end-diastolic and end-systolic diameters calculated in echocardiography (p<0.05). M-Mode echocardiography revealed higher myocardial performance index (LV-MPI) in patients with LV dilatation. There was also a significant relationship between LV dilatation and frequent blood transfusions (>5/years) and acute chest syndrome (p<0.05).

CONCLUSION

Myocardial perfusion impairment in children with SCA is not frequently observed. Thus, performing the scintigraphy only in patients with cardiac symptoms should be considered. Since EF values of the children with SCA are not deteriorated in early stages, LV-MPI and LV dilatation should be considered as a significant parameter other than EF or perfusion data.

Cardiopulmonary complications leading to premature deaths in adult patients with sickle cell disease

Sickle cell disease (SCD) is associated with early mortality. We sought to determine the incidence, cause, and risk factors for death in an adult population of patients with SCD. All patients aged >/=18 years seen at the Adult Sickle Cell Center at Duke University Medical Center between January 2000 and April 2005 were enrolled. Forty-three patients (21 males and 22 females) died during the study period. The median age of survival was 39 years for females (95% CI: 34-56), 40 years for males (95% CI: 34-48), and 40 years overall (95% CI: 35-48). Cardiac causes of death accounted for 25.6% (11/43 patients); pulmonary, 14.0% (six patients); other SCD related, 32.6% (14 patients); unknown, 14.0% (six patients); and others, 14.0% (six patients). Pulseless electrical activity arrest, pulmonary emboli, multiorgan failure, and stroke were the most frequent causes of death. Among the deceased patients, the most common premorbid conditions were cardiopulmonary: acute chest syndrome/pneumonia (58.1%), Pulmonary hypertension (pHTN; 41.9%), systemic HTN (25.6%), congestive heart failure (25.6%), myocardial infarction (20.9%), and arrhythmias (14.0%). Tricuspid regurgitant jet velocity was significantly higher (3.1 m/sec vs. 2.6 m/sec, P < 0.001) and hemoglobin significantly lower (8.3 g/dL vs. 9.2 g/dL, P < 0.05) in deceased patients when compared with patients who lived, respectively. With improved preventive and therapeutic advances, including hydroxyurea therapy, acute complications such as infection are no longer the leading cause of death; instead, causes of death and premorbid conditions are shifting to chronic cardiopulmonary complications. Further, arrhythmia leading to premature death is under-recognized in SCD and warrants further investigation.

Cardiac involvement in sickle beta-thalassemia

Cardiovascular involvement is a leading cause of mortality and morbidity in patients with inherited hemoglobinopathies, but it has not been adequately assessed in sickle beta-thalassemia. We evaluated 115 sickle beta-thalassemia patients, aged 34 +/- 14 years, along with 50 healthy controls, by resting echocardiography. Patients with systolic left ventricular (LV) dysfunction or severe pulmonary hypertension (PHT) also underwent left and right cardiac catheterization and cardiac magnetic resonance imaging (CMR). Left and right chamber dimensions, LV mass, and cardiac index were significantly higher in patients compared to controls (p < 0.001 in most cases). Three patients (2.9%) had reduced LV ejection fraction (<55%); mean LV ejection fraction was significantly lower in patients (p < 0.001). Left and right ventricular systolic tissue Doppler indices and LV diastolic tissue Doppler indices were also impaired in patients. All three patients with systolic LV dysfunction had normal coronary arteries and mild myocardial iron load (CMR T2* values, 18-25 ms). Systolic pulmonary artery pressure was significantly higher in patients compared to controls (p = 0.002); PHT was present in 28 patients (27%), while severe PHT in three (2.9%). In three patients with severe PHT, only one had impaired LV ejection fraction and increased pulmonary wedge pressure. Overall, three patients (2.9%) had a history of heart failure, two with systolic LV dysfunction, and one with severe PHT. Cardiac involvement in sickle beta-thalassemia concerns biventricular dilatation and dysfunction along with PHT, leading to congestive heart failure.

Endothelial function and arterial stiffness in sickle-thalassemia patients

BACKGROUND

Homozygous sickle-cell anemia and beta-thalassemia are characterized by impaired endothelial function, while data on arterial stiffness have hitherto been conflicting. We sought to investigate aortic elastic properties and endothelial function in sickle-thalassemia, which combines molecular and clinical features of the above conditions.

METHODS AND RESULTS

Forty-seven sickle-thalassemia patients, younger than 45 years, with preserved left ventricular (LV) function and no history of smoking, systemic or pulmonary hypertension, diabetes mellitus, dyslipidemia or thyroid disease, along with 40 healthy controls were studied. Aortic strain, distensibility and stiffness index were calculated by echocardiographically-obtained aortic root diameters. Brachial artery endothelial function was assessed by ultrasonographic evaluation of flow-mediated dilatation (FMD) and nitrate-mediated dilatation (NMD). Left ventricle was assessed by echocardiography. Patients had an impaired FMD (4.2+/-2.9% versus 9.2+/-3.8% in controls, p<0.001) with a preserved NMD (16.9+/-5.6% versus 15.2+/-4.8% in controls, p>0.05). Aortic strain and distensibility were lower and aortic stiffness index was higher in patients compared to controls (8.1+/-4.6 versus 5.8+/-2.9, p<0.01). Indexed LV diameters and mass were higher in patients. Systolic LV function was preserved, while 14.9% of patients had an impaired relaxation transmitral inflow pattern. Patients' LV mass index and diastolic mitral E wave deceleration time were positively correlated with aortic stiffness index (p<0.001).

CONCLUSION

Sickle-thalassemia is characterized by a complex vasculopathy, consisting of endothelial dysfunction and increased arterial stiffness, with a global effect on cardiovascular function.

Systolic and diastolic function in middle aged patients with sickle beta thalassaemia. An echocardiographic study

OBJECTIVE

To evaluate the right and left ventricular systolic and diastolic function in middle aged patients with sickle beta thalassaemia.

METHODS

Forty three patients with sickle beta thalassaemia were recruited for echocardiographic study while 55 controls, matched for age and sex, served as the control group. Parameters measured included: dimensions and wall thickness of left (LV) and right (RV) ventricle and left atrium, LV mass, and cardiac index. LV and RV contractility variables--ejection fraction, circumferential fibre shortening velocity, end systolic stress, end systolic stress/volume index ratio, mitral and tricuspid annulus systolic excursion, and Tei index--were also calculated. The study also evaluated parameters of RV and LV diastolic function including early and late atrioventricular flow velocities (E and A wave respectively), E/A ratio, deceleration time (DT), isovolumic relaxation time (IVRT) as well as pulmonary and hepatic veins systolic to diastolic (S/D) ratio.

RESULTS

Chamber enlargement, greater LV mass index, cardiac index, and RV wall thickness were found in the anaemic group compared with controls. The LV and RV contractility variables of the patients were similar to controls. Conversely the LV and RV Tei index was significantly greater in the patient group. Diastolic dysfunction was present in the anaemic patients resulting from the increased LV and RV A-wave, the longer LVIVRT, RVIVRT, and RVDT, as well as the higher hepatic and pulmonary veins S/D ratio.

CONCLUSIONS

The results show that in middle aged patients with sickle beta thalassaemia the diastolic function is abnormal in both ventricles but still more in RV, whereas the systolic function remains unchanged.