Echocardiographic Screening of Cardiovascular Status in Pediatric Sickle Cell Disease

Guidelines for the management of emergencies and critical illness in pediatric and adult patients with sickle cell disease

Forty-two questions were evaluated concerning management of emergencies and critical illnesses in paediatric and adult patients with sickle cell disease. The assessment covered the following areas: patient referral, vaso-occlusive crisis, acute chest syndrome, transfusion therapy, and priapism. The patient referral category included guidelines for admission to intensive care unit and management at specialized reference centers. The vaso-occlusive crisis topic encompassed pain management, hydration, incentive spirometry, and target oxygen saturation levels. For acute chest syndrome, the focus areas included imaging techniques such as lung ultrasound, computed tomography scans, and echocardiography; treatment with systemic corticosteroids; non-invasive ventilation; prophylactic and therapeutic anticoagulation; and procalcitonin and antibiotic therapy. The section on transfusion therapy addressed indications and methods of transfusion, as well as the diagnosis and prediction of delayed hemolytic transfusion reactions. A total of 45 recommendations were proposed, including 14 specific to adults, 13 specific to pediatrics, and 18 applicable to both adults and children, along with three therapeutic algorithms. The Grade of Recommendation Assessment, Development, and Evaluation (GRADE) methodology was adhered to throughout the process. Sixteen recommendations were based on a low level of evidence (GRADE 2+ or 2-), while 26 were based on evidence that could not be classified under the GRADE system and were therefore considered expert opinions. Finally, for three aspects of sickle cell disease management, the experts concluded that no reliable recommendations could be made based on the current state of knowledge. The recommendations and therapeutic algorithms received strong agreement from the experts.

Global prevalence of elevated estimated pulmonary artery systolic pressure in clinically stable children and adults with sickle cell disease: A systematic review and meta-analysis

BACKGROUND

The current study sought to determine the prevalence of elevated estimated pulmonary artery systolic pressure (ePASP) in clinically stable children and adults with sickle cell disease)SCD(worldwide.

METHODS

The studies included were identified through a search of databases such as PubMed, Scopus, Science Direct, Web of Science, and Embase, as well as Google Scholar engine, adhering to specific inclusion and exclusion criteria. Heterogeneity among the primary study results was assessed using the I-squared index, while publication bias was evaluated through funnel plots, Egger's test, and trim and fill analysis. All statistical analyses were conducted using R software, version 4.3.0.

RESULTS

79 primary studies were included, comprising 6,256 children (<18 years old) and 6,582 adults (≥18 years old) with SCD from 22 countries. The prevalence of elevated ePASP was found to be 21.8% (95% confidence interval [CI]: 18.46 to 25.07) in children and 30.6% (95% CI: 27.1 to 34.1) in adults. The prevalence of elevated ePASP among studies with severe SCD genotypes including HbSS and HbS/β0 was found to be 19.45% (95% CI: 14.95 to 23.95) in children and 29.55% (95% CI: 24.21 to 34.89) in adults. Furthermore, sex-specific prevalence among SCD patients with elevated ePASP indicated the highest prevalence in male children at 60.35% (95% CI: 54.82 to 65.88) and adult female patients at 54.41% (95% CI: 47.3 to 61.5). A comparative analysis of the mean values of clinical and laboratory results revealed significant differences in several characteristics, including age, oxygen saturation, hemoglobin levels, fetal hemoglobin, white blood cell counts, platelet counts, and reticulocyte counts between patients with elevated ePASP and those without, in both children and adult SCD populations.

CONCLUSION

Our findings regarding clinically stable SCD patients highlight a high prevalence of elevated ePASP.

Longitudinal effect of disease-modifying therapy on left ventricular diastolic function in children with sickle cell anemia

Cardiac abnormalities seen in sickle cell anemia (SCA) include diastolic dysfunction, which has been shown to be associated with high morbidity and early mortality. The effect of disease-modifying therapies (DMT) on diastolic dysfunction is poorly understood. We prospectively evaluated the effects of hydroxyurea and monthly erythrocyte transfusions on diastolic function parameters over 2 years. A total of 204 subjects with HbSS or HbSβ0-thalassemia (mean age 11 ± 3.7 years), unselected for disease severity, had diastolic function assessed with surveillance echocardiograms twice, 2 years apart. During this 2-year observation period, 112 participants received DMTs (hydroxyurea, n = 72, monthly erythrocyte transfusions, n = 40), 34 initiated hydroxyurea, and 58 did not receive any DMT. The entire cohort showed an increase in left atrial volume index (LAVi) of 3.40 ± 10.86 mL/m2, p = .001 over 2 years. This increase in LAVi was independently associated with anemia, high baseline E/e' or LV dilation. Individuals not exposed to DMT were younger (mean age 8.8 ± 2.9 years), but at baseline their prevalence of abnormal diastolic parameters was similar to that of the DMT-exposed participants who were older (mean age 12 ± 3.8 years). Participants on DMTs saw no improvement in diastolic function over the study period. In fact, participants on hydroxyurea saw a possible worsening in diastolic parameters (14% increase in LAVi and ~5% decrease in septal e') but also a ~9% decrease in fetal hemoglobin (HbF) levels. Further studies are needed to evaluate if exposure to DMT for a longer duration or achieving higher HbF might be beneficial in alleviating diastolic dysfunction.

The Prevalence of Cardiovascular Manifestations in Pediatric Sickle Cell Anemia Patients in a Large Tertiary Care Hospital in the Western Region of Saudi Arabia

Background Sickle cell disease (SCD) is a common hematological disorder with a high prevalence in Saudi Arabia. Despite that, limited studies are available in our region regarding cardiovascular complications. Objectives The objective of the current study was to estimate the prevalence of cardiovascular complications among children with SCD. Design This was a cross-sectional study. Setting The study took place at a single tertiary-care center in Jeddah, Saudi Arabia. Materials and methods The study reviewed 126 electronic records of pediatric patients up to 16 years old diagnosed with SCD between January 2008 and December 2019 in King Abdulaziz Medical City (KAMC) in Jeddah, Saudi Arabia. Of these, 54 patients had a previous echocardiogram evaluation and were eligible for the study. Main outcomes measures The study identified cardiovascular complications in pediatric sickle cell patients. Sample size The study included a total of 54 pediatric sickle cell patients. Results The mean age was 11.9 (3.48) years, the male-to-female ratio was 2:1, the majority (94.4%) had the HbSS-HbSβ0 genotype, the mean baseline hemoglobin F (fetal hemoglobin) was 20.30 (9.03%), and the clinical severity score was severe in 19 (35.2%) and mild/moderate in 35 (64.8%) patients. Cardiovascular complications occurred in 32 (59.3%) patients. Increased systolic blood pressure was detected in 10 (18.5%) patients. Echocardiography showed left ventricular dilatation in nine (16.7%) patients, tricuspid valve insufficiency in six (11.1%) patients, mitral valve insufficiency in four (7.4%) patients, hyperdynamic left ventricle in one (1.9%) patient, and pulmonary hypertension in one (1.9%) patient. Long QTc interval was noticed in three (5.6%) and cardiomegaly was detected in 18 (33.3%) patients. Conclusion Cardiovascular complications occurred at a high frequency in our pediatric population despite high baseline hemoglobin F levels. Early evaluation and continuous monitoring are important for early intervention.

Heart Failure with Preserved Ejection Fraction in Children

Diastolic dysfunction (DD) refers to abnormalities in the mechanical function of the left ventricle (LV) during diastole. Severe LVDD can cause symptoms and the signs of heart failure (HF) in the setting of normal or near normal LV systolic function and is referred to as diastolic HF or HF with preserved ejection fraction (HFpEF). Pediatric cardiologists have long speculated HFpEF in children with congenital heart disease and cardiomyopathy. However, understanding the risk factors, clinical course, and validated biomarkers predictive of the outcome of HFpEF in children is challenging due to heterogeneous etiologies and overlapping pathophysiological mechanisms. The natural history of HFpEF varies depending upon the patient's age, sex, race, geographic location, nutritional status, biochemical risk factors, underlying heart disease, and genetic-environmental interaction, among other factors. Pediatric onset HFpEF is often not the same disease as in adults. Advances in the noninvasive evaluation of the LV diastolic function by strain, and strain rate analysis with speckle-tracking echocardiography, tissue Doppler imaging, and cardiac magnetic resonance imaging have increased our understanding of the HFpEF in children. This review addresses HFpEF in children and identifies knowledge gaps in the underlying etiologies, pathogenesis, diagnosis, and management, especially compared to adults with HFpEF.

Pulmonary hypertension screening in children with sickle cell disease

BACKGROUND

Screening for pulmonary hypertension (PHT) is recommended in children with sickle cell disease (SCD). However, best approaches are poorly described. We examined the utility of PHT symptoms, echocardiogram (ECHO), N-terminal-pro hormone brain natriuretic peptide (NT-proBNP), and BNP to screen for PHT in the SCD pediatric population.

METHODS

Children (8-18 years old) with SCD-HbSS and HbSthal° were prospectively included and underwent PHT screening. The screening consisted of a comprehensive PHT symptoms evaluation, ECHO measurement, and NT-proBNP and BNP levels.

RESULTS

A total of 73 patients were included (mean age 12 ± 5.7 years; >80% on hydroxyurea), of which 37% had a symptom consistent with PHT, including exertional dyspnea (26.5%), fatigue (17.6%), palpitation (14.7%), and chest pain (10.3%). ECHO was obtained in 53 (72.6%) patients, with only ECHO of 48 patients included in the final analysis. Elevated ECHO peak tricuspid regurgitant jet velocity (TRV) >2.5 m/s or indirect findings to suggest PHT were seen in only two of 48 (4.2%). No significant differences were seen between those with and without PHT symptoms when compared for NT-proBNP, BNP, hemoglobin, pulmonary function testing, fractional exhaled nitric oxide, asthma, oxygen saturation, and sleep apnea.

CONCLUSION

PHT symptoms are not consistent with ECHO, NT-proBNP nor BNP findings in children with SCD. PHT prevalence based on TRV was low in children on hydroxyurea, therefore screening may not be warranted for this group.

Echocardiographic Evaluation in Paediatric Sickle Cell Disease Patients: A Pilot Study

Cardiovascular involvement has a great impact on morbidity and mortality in sickle cell disease (SCD). Currently, few studies are available regarding the paediatric setting and, moreover, current guidelines for the echocardiogram screening program in the asymptomatic paediatric population are controversial. We performed a retrospective observational monocentric study on 64 SCD patients (37 male and 27 female, median age 10) at the Bambino Gesù Childrens' Hospital, who had undergone a routine transthoracic echocardiogram. In total, 46 (72%) patients had at least one cardiac abnormality. Left atrial dilatation (LAD) was present in 41 (65%) patients and left ventricular hypertrophy (LVH) was found in 29 (45%) patients. Patients with LAD showed lower median haemoglobin levels (p = 0.009), and a higher absolute reticulocyte count (p = 0.04). LVH was negatively correlated with the median haemoglobin value (p = 0.006) and positively with the reticulocyte count (p = 0.03). Moreover, we found that patients with cardiac anomalies had higher transfusion needs and a lower frequency of pain crises. In our setting, cardiac involvement has a high prevalence in the paediatric cohort and seems to be associated with specific laboratory findings, and with a specific clinical phenotype characterized by complications related to high haemodynamic load.

Therapeutic Approaches in Heart Failure with Preserved Ejection Fraction (HFpEF) in Children: Present and Future

For a long time, pediatric heart failure (HF) with preserved systolic function (HFpEF) has been noted in patients with cardiomyopathies and congenital heart disease. HFpEF is infrequently reported in children and instead of using the  HFpEF terminology the HF symptoms are attributed to diastolic dysfunction. Identifying HFpEF in children is challenging because of heterogeneous etiologies and unknown pathophysiological mechanisms. Advances in echocardiography and cardiac magnetic resonance imaging techniques have further increased our understanding of HFpEF in children. However, the literature does not describe the incidence, etiology, clinical features, and treatment of HFpEF in children. At present, treatment of HFpEF in children is extrapolated from clinical trials in adults. There are significant differences between pediatric and adult HF with reduced ejection fraction, supported by a lack of adequate response to adult HF therapies. Evidence-based clinical trials in children are still not available because of the difficulty of conducting trials with a limited number of pediatric patients with HF. The treatment of HFpEF in children is based upon the clinician's experience, and the majority of children receive off-level medications. There are significant differences between pediatric and adult HFpEF pharmacotherapies in many areas, including side-effect profiles, underlying pathophysiologies, the β-receptor physiology, and pharmacokinetics and pharmacodynamics. This review describes the present and future treatments for children with HFpEF compared with adults. This review also highlights the need to urgently test new therapies in children with HFpEF to demonstrate the safety and efficacy of drugs and devices with proven benefits in adults.

What is the role of chest X-ray imaging in the acute management of children with sickle cell disease?

Children with sickle cell disease (SCD) frequently present to hospital acutely unwell and are often exposed to diagnostic chest X-rays (CXRs). Little evidence exists to determine when CXRs are clinically useful. Using electronic hospital records, we audited CXR use in children aged 0-18 who presented to hospital over the past 10 years in both an inpatient and emergency department setting. From a total of 915 first CXRs, only 28·2% of CXRs (n = 258) had clinically significant findings that altered management or final diagnosis. Of these abnormalities, consolidation represented 52·3%, effusion 8·9%, cardiomegaly 8·4% and sickle cell-related bone changes 6·3%. Indications for CXR of respiratory distress (OR = 3·74, 95% CI 2·28-6·13), hypoxia (OR = 1·86, 95% CI 1·50-2·31) and cough (OR = 1·64, 95% CI 1·33-2·02), were more likely to have significant CXR findings. Patients who had higher peak fever (38·4°C vs. 37·4°C, P = 0·001), higher peak CRP (156·4 vs. 46·1, P < 0·001) and higher WCC (20·2 vs. 13·6, P < 0·001) were more likely to have clinically significant abnormalities on CXR. We found a decision tool using either hypoxia, cough, respiratory distress, T > 38°C, CRP > 50 or WCC > 15 × 10⁹ /l as indications for CXR, to have a sensitivity of 88% (with 95% CI 0·78-0·95) and specificity of 46% (95% CI 0·43-0·50) for clinically significant findings.

Assessing the atria in pediatric sickle cell disease: Beyond the dilation

BACKGROUND

Diastolic dysfunction (DD) and pulmonary hypertension (PH) are common causes of mortality for sickle cell disease (SCD) patients in developed countries. We hypothesized that left and right atrial strain (LAS-Ɛ, RAS-rƐ) are decreased in SCD adolescents, and that worsening values correlate with laboratory markers of disease severity.

METHODS

Prospective cohort study of patients with HbSS genotype of SCD was compared with healthy controls. LAS and RAS were measured from 4- and 2-chamber views by a blinded reader. Peak strain and strain rate values were obtained for atrial contraction (ac), reservoir (res), and conduit (con) phases. Mitral/tricuspid Doppler velocities, left atrial volume, right atrial area were obtained. Laboratory variables were obtained from the electronic record with the three prior values being averaged. Differences in variables were assessed with Wilcoxon rank sum test, and correlations assessed with Spearman's coefficient.

RESULTS

There were 33 SCD patients compared to 35 healthy controls of similar age, gender, and size. SCD patients had increased left atrial volume and right atrial area. For LAS, Ɛres was significantly lower in SCD patients. For RAS, RƐcon was significantly lower. Neither measurement correlated with clinical markers. The majority of SCD patients had relatively normal atrial strain values. Those with markedly lower values had similar atrial size.

CONCLUSIONS

A sub-set of SCD patients have markedly low Ɛres and rƐcon. No correlation with clinical markers was identified. Larger, longitudinal studies may determine utility of atrial strain as a screening tool in this at-risk population.

Tricuspid regurgitation velocity and other biomarkers of mortality in children, adolescents and young adults with sickle cell disease in the United States: The PUSH study

In the US, mortality in sickle cell disease (SCD) increases after age 18-20 years. Biomarkers of mortality risk can identify patients who need intensive follow-up and early or novel interventions. We prospectively enrolled 510 SCD patients aged 3-20 years into an observational study in 2006-2010 and followed 497 patients for a median of 88 months (range 1-105). We hypothesized that elevated pulmonary artery systolic pressure as reflected in tricuspid regurgitation velocity (TRV) would be associated with mortality. Estimated survival to 18 years was 99% and to 25 years, 94%. Causes of death were known in seven of 10 patients: stroke in four (hemorrhagic two, infarctive one, unspecified one), multiorgan failure one, parvovirus B19 infection one, sudden death one. Baseline TRV ≥2.7 m/second (>2 SD above the mean in age-matched and gender-matched non-SCD controls) was observed in 20.0% of patients who died vs 4.6% of those who survived (P = .012 by the log rank test for equality of survival). The baseline variable most strongly associated with an elevated TRV was a high hemolytic rate. Additional biomarkers associated with mortality were ferritin ≥2000 μg/L (observed in 60% of patients who died vs 7.8% of survivors, P < .001), forced expiratory volume in 1 minute to forced vital capacity ratio (FEV1/FVC) <0.80 (71.4% of patients who died vs 18.8% of survivors, P < .001), and neutrophil count ≥10x10⁹ /L (30.0% of patients who died vs 7.9% of survivors, P = .018). In SCD children, adolescents and young adults, steady-state elevations of TRV, ferritin and neutrophils and a low FEV1/FVC ratio may be biomarkers associated with increased risk of death.