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

Late effects of hemopoietic stem cell transplant for sickle cell disease: monitoring and management

INTRODUCTION

Allogeneic hemopoietic stem cell transplantation (HSCT) is a curative therapy for sickle cell disease (SCD). Exposure to both SCD and HSCT conditioning regimens is associated with late health effects.

AREAS COVERED

This review addresses post-HSCT outcomes and late health effects among individuals with SCD exposed to allogeneic HSCT regimens, summarizes recommendations for long-term care, and identifies future survivorship research needs.

EXPERT OPINION

Individuals with SCD exposed to HSCT and gene therapy require multidisciplinary care to monitor late health effects. To optimize care, multi-disciplinary clinics that include experts in late effects of HSCT exposure, SCD, complex chronic pain, mental health, and social work are needed. Research defining the late effects of exposure is needed to inform patient management and build clinical care infrastructure.

Prevalence and associated risk factors of myocardial ischemia in children living with sickle cell anemia in Lagos, Nigeria

Myocardial ischemia (MI) in children living with sickle cell anemia (SCA) is rarely reported. MI among children living with this disease could portend untoward outcomes on their quality of life and survival. This study evaluated the prevalence and associated risk factors of MI in children living with SCA during a vaso-occlusive crisis (VOC) compared with those with SCA who had no symptoms nor an MI in the past (those in "steady state") in Lagos, Nigeria. This comparative cross-sectional study was conducted over 10 months (between March and December 2019) among 250 children living with SCA aged 6 months-18 years (125 in VOC and 125 age and sex-matched controls in steady state). The assessment of MI was determined by measuring cardiac troponin T (cTnT) and electrocardiography (ECG). The prevalence of MI measuring cTnT alone in children with SCA during VOC and steady state was 42.4% and 23.2%, respectively. Comparatively, measuring ECG alone, the prevalence of MI in VOC and steady state was 40.8% and 20.8%, respectively. The prevalence of MI measuring cTnT and ECG in children with SCA in VOC and steady state was 38.4% and 20%, respectively. Older age, severity of pain, longer duration of illness, frequent crises per year, elevated white blood cells, and platelet count were significantly associated with MI in participants with SCA. However, with multivariate analysis, age, severity of pain, and elevated platelet counts remained significantly associated with the occurrence of MI. This study affirms the high prevalence of MI in children with SCA irrespective of the diagnostic criteria. Routine evaluation should be done in this cohort to avert MI-associated sequelae.

PM2.5 exposure and household income are associated with lung function abnormalities in children with sickle cell disease

RATIONALE

Cardiopulmonary dysfunction is a major contributor to mortality among persons with sickle cell disease (pwSCD). Despite this, little is known regarding environmental drivers of lung function decline.

OBJECTIVE

We hypothesized that environmental and socioeconomic variables have a significant effect on lung function in pwSCD that can be detected by spirometry.

METHODS

We retrospectively analyzed all spirometry results from pwSCD followed in the Pediatric Pulmonology clinic at the Children's Hospital of Philadelphia since 1 January 2016.

RESULTS

The study included 349 spirometry tests from 128 patients, primarily "Black or African American" (88%) and male (61%). More frequent exposure to PM2.5 above 25 μg/m3 was associated with higher odds of obstruction. Specifically, when compared to incidence of exposure to PM2.5 above 25 μg/m3 <25th percentile, both pwSCD exposed to 25th-75th percentile and pwSCD >75th percentile had higher odds of obstruction on spirometry (25th-75th: odds ratio [OR]: 9.6, p = .017; >75th: OR: 31.85, p = .002) despite correction for potential confounders. Similarly, median household income below the mean was associated with higher odds of restriction (OR: 4.37; p = .009).

CONCLUSIONS

We report higher odds of obstruction in pwSCD frequently exposed to PM2.5 concentrations above 25 μg/m3 and higher odds of restriction in pwSCD with lower household income. Our findings link spirometry patterns to modifiable risk factors indicating that there may opportunities for early intervention in pwSCD that have been referred to a pulmonology clinic. Further research is needed to assess if these findings can be generalized to the wider population of pwSCD.

Durable engraftment after pharmacological pre-transplant immune suppression followed by reduced-toxicity myeloablative haploidentical stem cell transplantation in highly HLA-immunized adults with sickle cell disease

Allogeneic stem cell transplantation (Allo-SCT) is the only rapidly available curative treatment modality in patients with severe sickle cell disease (SCD). The development of reduced-toxicity myeloablative conditioning (RT-MAC) regimen and the use of partially matched family donors with post-transplantation cyclophosphamide (PT-Cy) have widened the access to Allo-SCT. Antibodies against donor-specific HLA (DSA) increase the risk of engraftment failure in HLA mismatched Allo-SCT. We report the results of five patients with SCD, whereas three with DSA, who underwent an unmanipulated haploidentical stem cell transplantation (Haplo-SCT) after a busulfan-based RT-MAC regimen with PT-Cy. To reduce the risk of engraftment failure, a sequential two courses pharmacological pre-transplant immune suppression (PTIS) phase was added prior to the conditioning regimen. All patients engrafted successfully. The procedure was well tolerated. None of the patients developed acute GVHD, whereas one developed moderate chronic GVHD. After a median follow-up of 5 years (range, 2.2-9), all patients are free of pain with excellent quality of life. Our report shows that Haplo-SCT after a RT-MAC regimen is feasible and safe with stable long-term engraftment and excellent disease control. The risk of graft failure can be abrogated by adding a PTIS phase prior to initiating the conditioning regimen.

Electrocardiographic findings in patients with sickle cell disease: A protocol for systematic review and meta-analysis

Background

Despite advancements in the management of patients with sickle cell disease (SCD), the involvement of the cardiovascular system in these patients remains a significant concern. Cardiovascular manifestations of SCD are well-documented, with electrocardiography (ECG) serving as a valuable diagnostic tool. Studies have reported a high rate of critical ECG findings in patients with SCD that warrants consideration when managing these patients, indicating the need for proactive cardiac screening and management strategies in this patient population. This study aims to systematically review the literature to identify sociodemographic, clinical, and paraclinical factors associated with ECG abnormalities in patients with SCD.

Methods

A comprehensive search strategy will be employed across multiple online databases, including PubMed, Embase, Scopus, Web of Science, and Google Scholar, for published and gray literature. Eligible studies will include original articles reporting associations between sociodemographic, clinical, and paraclinical variables and a spectrum of ECG findings in patients with SCD. Independent reviewers will conduct the screening, quality assessment, and data extraction. Quantitative analyses will be performed under a random-effect model using Comprehensive Meta-Analysis software, with subgroup analyses based on SCD status, sickle hemoglobinopathy form, and age group.

Electrocardiographic Changes and Their Association With Disease Severity in Adults With Sickle Cell Anemia at a Tertiary Care Center: A Cross-Sectional Study

Introduction Sickle cell anemia (SCA), a severe hematological disorder, is characterized by the presence of sickle-shaped erythrocytes that obstruct capillaries and restrict blood flow. This pathophysiology not only promotes systemic complications but may also influence cardiac function. Cardiac complications are a leading cause of mortality in SCA patients, yet the specific electrocardiographic (ECG) changes associated with disease severity are not thoroughly understood. This cross-sectional study aimed to explore ECG abnormalities in adults with SCA and correlate these findings with disease severity. Methods An observational cross-sectional study was conducted over 18 months, from January 2022 to June 2023, among 140 SCA patients at the Sickle Cell OPD of All India Institute of Medical Sciences, Raipur, Raipur, India. Steady-state SCA (HbS >50%) patients screened by high-performance liquid chromatography were enrolled. A history, physical examination, complete blood count, and ECG were done for all cases. The disease severity score was calculated using the Adegoke and Kuti severity scores, and their association with various ECG changes was studied. The chi-square test (Fisher's exact test, wherever applicable) was used for comparing the proportion. The correlation was done using the Pearson correlation coefficient or Spearman's rho. Results Out of 140 patients, the mean age of the study participants was 26 ± 6 years. More than half of the cases (80; 57%) fall under the 18-27 age group, with a male-to-female ratio of 4:3. A total of 99 (70.7%) of the participants had mild disease, and 41 (29.3%) had moderate disease. The QT interval was significantly higher among patients with mild disease compared to those with moderate disease (p-value: <0.01). QTc dispersion and prolonged QTc interval were significantly higher among patients with moderate disease compared to mild disease (p-value <0.01, 0.04, respectively). Sinus tachycardia and right ventricular hypertrophy with p-pulmonale were significantly higher in moderate severity (p < 0.01). A significant positive correlation was observed between QTc dispersion, P-wave dispersion, and severity (r: 0.19, 0.17; p-value: 0.02, 0.04, respectively). Conclusion As the disease severity progressed, the ECG changes studied had a higher distribution and significance. ECG is a readily and widely accessible investigation that can be used to screen all SCA patients for early recognition of various underlying cardiac complications.

Left ventricular global longitudinal strain and acute myocardial injury in patients with sickle cell disease admitted to the intensive care unit for vaso-occlusive crisis

In patients with sickle cell disease (SCD), SCD-related cardiomyopathy may be partly due to repeated ischaemic events related to sickling during vaso-occlusive crises, but few clinical studies support this hypothesis. We evaluated the incidence of acute myocardial ischaemia during vaso-occlusive crises as assessed by the left ventricular global longitudinal strain (LVGLS) and high-sensitive cardiac troponin T (hs-cTnT). We included adult patients with SCD admitted to the intensive care unit (ICU) for vaso-occlusive crisis. We collected hs-cTnT and measured LVGLS with echocardiography at admission (day 1), day 2, day 3 and ICU discharge. Among 55 patients included, considering only the first hospitalization of patients admitted several times, 3 (5%) had elevated hs-cTnT at ≥1 time point of the ICU stay. It was ≤2 times the upper limit of normal in two of these patients. LVGLS was altered at ≥1 time point of the ICU stay in 13 (24%) patients. Both hs-cTnT and LVGLS were abnormal at ≥1 time point of the hospital stay in 2 (4%) patients. Acute myocardial injury as assessed by troponin elevation and LVGLS impairment was a rare event during vaso-occlusive crises.

Cardiovascular complications of sickle cell disease: A primer for the general clinician

Sickle cell disease (SCD) is the most common hereditary hemoglobinopathy and mainly affects individuals of African ancestry. As survival has improved especially in high-income countries, increased rates of cardiopulmonary complications such as pulmonary hypertension, heart failure with diastolic dysfunction, and sudden death are encountered in clinical practice. These complications are the leading causes of morbidity and mortality as these individuals survive into adulthood. Understanding the need for, early identification, timely intervention, and implementation of preventive strategies are critical in reversing this trend and improving quality of life and survival rates. This manuscript aims to provide a comprehensive review of the pathogenesis of cardiovascular complications associated with sickle cell disease and equip the clinician with tools to facilitate the early diagnosis and management of patients with SCD as increasing numbers survive into adulthood.

Rapid MRI Assessment of Long-Axis Strain to Indicate Systolic Dysfunction in Patients With Sickle Cell Disease

BACKGROUND

Patients with sickle cell disease (SCD) have a unique form of cardiomyopathy. However, left ventricular ejection fraction (LVEF) is often preserved. Monoplanar long-axis strain (LAS) can be assessed from MRI four-chamber views and may be better at detecting mild systolic dysfunction in these patients.

PURPOSE

To compare LAS (monoplanar and biplanar) with LVEF as a marker of systolic dysfunction in SCD patients.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 20 patients with genetically proven SCD (35 MRI examinations), 39 healthy controls, and 124 patients with systemic iron overload (for validation purposes).

FIELD STRENGTH/SEQUENCE

1.5 T/3 T. Cine balanced steady-state free-precession.

ASSESSMENT

Rapidly assessed biplanar LAS from four- and two-chamber views was correlated with age and compared to LVEF by two operators. For validation, biplanar LAS was compared to global longitudinal strain (GLS) using MRI feature-tracking in 124 patients with systemic iron overload.

STATISTICAL TESTS

Bland-Altman analysis. Wilcoxon-Mann-Whitney test and Spearman-rank correlation (correlation coefficient, rS ). Receiver-operating-characteristic (ROC) curve analysis (area under the curve, AUC). Bivariate discriminant analysis. Significance level: P < 0.01.

RESULTS

There was strong correlation between biplanar LAS and GLS using feature tracking (rS  = 0.73). Interoperator agreement showed nonsignificant bias for biplanar LAS (-0.02%; ±95%-agreement interval -2.2%/2.2%, P = 0.9). Biplanar LAS increased significantly with age in controls (rS  = 0.70). In SCD patients, biplanar LAS was better correlated with age than monoplanar LAS (r2  = 0.53, standard error of estimate, SEE = 1.4% vs. r2  = 0.37;SEE = 2.0%). ROC analysis of LVEF, biplanar LAS, and age-adjusted Z-scores Z (LAS(age)) showed AUCs of 0.69, 0.75, and 0.86 for differentiation between SCD patients and controls. Bivariate discriminant analysis of biplanar Z (LAS(age)) and LVEF revealed a sensitivity of 63% and a specificity of 95%.

DATA CONCLUSION

Rapidly assessed biplanar LAS demonstrated high diagnostic accuracy and was an indicator of mild systolic dysfunction in patients with SCD. Biplanar LAS provided more precise measurements than monoplanar, and normalization to age increased diagnostic accuracy.

EVIDENCE LEVEL

3.

TECHNICAL EFFICACY

Stage 2.

Evaluation of cardiac fibrosis and subclinical cardiac changes in children with sickle cell disease using magnetic resonance imaging, echocardiography, and serum galectin-3

BACKGROUND

Myocardial fibrosis has recently been proposed as one of the contributing factors to the diverse pathogenicity of cardiomyopathy in sickle cell disease.

OBJECTIVE

In this study, cardiac fibrosis and subclinical cardiac changes in children with sickle cell disease were evaluated using cardiac magnetic resonance imaging (MRI), tissue Doppler echocardiography and serum galectin-3.

MATERIALS AND METHODS

The study included 34 children with sickle cell disease who were compared with a similar number of healthy controls. Cardiac MRI was used to evaluate late gadolinium enhancement, native T1 mapping, extracellular volume, and T2* for estimation of iron load. Cardiac function and myocardial performance index (MPI, evaluated by tissue Doppler echocardiography) and serum galectin-3 were compared to controls.

RESULTS

The mean age of the included patients was 13.3 ± 3.2 years. Myocardial iron load by T2* was normal. The mean level of extracellular volume (35.41 ± 5.02%) was significantly associated with the frequency of vaso-occlusive crises (P = 0.017) and negatively correlated with hemoglobin levels (P = 0.005). Galectin-3 levels were significantly higher among cases than controls (P = 0.00), at a cutoff value on the receiver operating characteristic curve of 6.5 ng/ml, sensitivity of 82.5% and specificity of 72.8%. The extracellular volume was significantly higher in cases, with a MPI > 0.4.

CONCLUSION

Diffuse interstitial myocardial fibrosis can be detected early in children with sickle cell disease using T1 mapping and is associated with a high frequency of vaso-occlusive crisis. MPI of the left ventricle and serum galectin-3 are recommended screening tools for subclinical cardiac abnormalities.

Sickle Cell Disease and the Heart.. [DOI: 10.21203/rs.3.rs-3040535/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Purpose The objective of this study was to explore the relationship between cardiac structure, cardiac index (CI), and diastolic function parameters, and laboratory values in patients with Sickle Cell Disease (SCD), and to characterize the distinct SCD cardiomyopathy phenotype Methods We conducted a retrospective review of 202 adult patients with SCD (mean age 41.02 ± 13.36) at our hospital who underwent outpatient echocardiographic screening from 2019–2022. Results Our study identified cardiac hypertrophy, chamber dilatation with preserved ejection fraction, elevated TRV, increased cardiac output, and diastolic dysfunction as defining echocardiographic features in SCD. There was a negative correlation between CI and lateral e’ (R = -0.182, P = 0.012), and a positive correlation between CI and E/e’ (R = 0.274, P = 0.0001). Conclusions Our study identified a unique cardiomyopathy in patients with SCD characterized by cardiac hypertrophy with preserved systolic function, abnormal mitral inflow patterns, and elevated cardiac output. These features are indicative of restrictive physiology, as evidenced by left atrial enlargement and diastolic dysfunction, superimposed on hyperdynamic physiology. Further research is needed to elucidate the pathophysiological mechanisms underlying these observations and determine their prognostic significance in vulnerable populations with an elevated burden of cardiovascular disease, including the risk of sudden cardiac death.

Positive rate and quality assessment of CT pulmonary angiography in sickle cell disease: a case‒control study

BACKGROUND

Pulmonary complications are common in sickle cell disease (SCD) and can mimic pulmonary embolisms (PEs), leading to potential overuse of computed tomography pulmonary angiography (CTPA). Maximizing the quality of CTPA is essential for its diagnostic accuracy. However, little is known about the positive rate and quality of CTPA in SCD.

METHODS

This retrospective case‒control study aimed to determine the positive rate and quality of CTPA studies performed to rule out PE in SCD (HbSS genotype) patients compared to a control group. Logistic regression analysis was used to identify independent factors associated with suboptimal CTPA studies, defined as a mean enhancement of < 210 HU in the pulmonary artery.

RESULTS

The study included 480 patients, consisting of 240 SCD patients and 240 controls. The positive rate of PE was 4.0%, with a similar rate in both SCD patients and the control group (4.2% vs. 3.8%, p = 0.08). However, SCD patients had significantly lower contrast enhancement of the pulmonary artery than the control group (266.1 ± 90.5 HU vs. 342.2 ± 116.1 HU, p < 0.01). Notably, 25.4% of SCD patients had suboptimal scans. The logistic regression model demonstrated that SCD was significantly associated with suboptimal pulmonary arterial contrast enhancement compared to the control group (OR = 4.4; 95% CI: 2.4-8.3).

CONCLUSIONS

This study revealed a relatively low positive rate of CTPA in both SCD patients and the control group. However, SCD was significantly associated with suboptimal image quality due to inadequate contrast enhancement of the pulmonary artery. Further research is needed to identify measures that can enhance the quality of CTPA studies in SCD patients and to establish a specific imaging protocol for this patient population.

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.

Organ function indications and potential improvements following curative therapy for sickle cell disease

Curative therapies for sickle cell disease include allogeneic hematopoietic stem cell transplantation (HSCT) and gene-modified autologous stem cell transplantation. HSCT has been used for 30 years with success measured by engraftment, symptom control, graft-vs-host disease (GVHD) risk, organ toxicity, and immune reconstitution. While human leukocyte antigen-matched sibling donor (MSD) transplants have excellent outcomes, alternate donor transplants (unrelated/haploidentical) are just beginning to overcome GVHD and engraftment hurdles to match MSD. Gene therapy, a newly developed treatment, is undergoing careful evaluation in many trials with varying approaches. The risk/benefit ratio to the patient in relation to outcomes, toxicities, and mortality risk drives eligibility for curative interventions. Consequently, eligibility criteria for MSD transplants can be less stringent, especially in the young. Posttransplant outcome analysis after the "cure" with respect to organ function recovery is essential. While established damage such as stroke is irreversible, transplant can help stabilize (pulmonary function), prevent further deterioration (stroke), improve (neurocognition), and protect unaffected organs. Tracking organ functions postintervention uniformly between clinical trials and for adequate duration is essential to answer safety and efficacy questions related to curative therapies. Age-appropriate application/outcome analyses of such therapies will be the ultimate goal in overcoming this disease.

Cardiovascular consequences of sickle cell disease

Sickle cell disease (SCD) is an inherited blood disorder caused by a single point mutation within the beta globin gene. As a result of this mutation, hemoglobin polymerizes under low oxygen conditions causing red blood cells to deform, become more adhesive, and increase in rigidity, which affects blood flow dynamics. This process leads to enhanced red blood cell interactions with the endothelium and contributes to vaso-occlusion formation. Although traditionally defined as a red blood cell disorder, individuals with SCD are affected by numerous clinical consequences including stroke, painful crisis episodes, bone infarctions, and several organ-specific complications. Elevated cardiac output, endothelium activation along with the sickling process, and the vaso-occlusion events pose strains on the cardiovascular system. We will present a review of the cardiovascular consequences of sickle cell disease and show connections with the vasculopathy related to SCD. We will also highlight biophysical properties and engineering tools that have been used to characterize the disease. Finally, we will discuss therapies for SCD and potential implications on SCD cardiomyopathy.

Debating the Future of Sickle Cell Disease Curative Therapy: Haploidentical Hematopoietic Stem Cell Transplantation vs. Gene Therapy

Hematopoietic stem cell transplantation (HSCT) is a well-established curative therapy for patients with sickle cell disease (SCD) when using a human leukocyte antigen (HLA)-matched sibling donor. Most patients with SCD do not have a matched sibling donor, thereby significantly limiting the accessibility of this curative option to most patients. HLA-haploidentical HSCT with post-transplant cyclophosphamide expands the donor pool, with current approaches now demonstrating high overall survival, reduced toxicity, and an effective reduction in acute and chronic graft-vs.-host disease (GvHD). Alternatively, autologous genetic therapies appear promising and have the potential to overcome significant barriers associated with allogeneic HSCT, such as donor availability and GvHD. Here the authors each take a viewpoint and discuss what will be the future of curative options for patients with SCD outside of a matched sibling transplantation, specifically haploidentical HSCT vs. gene therapy.

Cardiopulmonary changes in patients with sickle cell anemia: A systematic review

BACKGROUND

Given the high prevalence of cardiovascular and pulmonary abnormalities associated with sickle cell anemia (SCA), the clinical impact caused in addition to compromising the quality of life of patients and the overcharge that it represents to the public health system, this study systematized and evaluated scientific publications on pulmonary complications and cardiovascular diseases in sickle cell patients from 1920 to 2020. This compilation aims to provide knowledge for health professionals and managers in order to draw attention to the importance of chronic diseases in SCA patients and in addition to providing elements that provide improvements in management of useful resources that contribute to improve the quality and increase the life expectancy of these patients.

AIM

To systematically compile information about cardiopulmonary changes in patients with SCA.

METHODS

A systematic literature review was performed based on the PRISMA recom-mendation including scientific articles indexed in the Scientific Electronic Library Online databases of the United States National Library of Medicine and Biblioteca Virtual de Saúde. The search period was delimited between 1990 and 2020 and selected in Portuguese, English and Spanish. Three sets of descriptors were used for each database including research carried out with human beings. After reading the articles, those useful for this review were extracted using a collection instrument designed for this purpose.

RESULTS

The final selection included 27 studies. The year with the highest number of publications was 2016 with 5 studies (18.51%), followed by 2017 with 4 (14.81%). The type of study most carried out in the period was cohort 10 (37.03%) followed by cross-sectional and case-control with 8 studies in each (29.62%). Regarding the language of publication, the distribution was as follows: 25 (92.59%) in English, 1 (3.70%) in Spanish and 1 (3.70%) in Portuguese.

CONCLUSION

The findings of the present study suggest that cardiopulmonary alterations represent a serious clinical repercussion of SCA. Of the analyzed studies, the high occurrence of pulmonary hypertension, ventricular hypertrophy and diastolic dysfunction stands out as the main cardiopulmonary complications. In view of the increased survival in SCA, there is a need for surveillance and the development of strategies aimed at preserving the cardiopulmonary function and consequently improving the quality of life of these patients.

Long-Term Health Effects of Curative Therapies on Heart, Lungs, and Kidneys for Individuals with Sickle Cell Disease Compared to Those with Hematologic Malignancies

The goal of curing children and adults with sickle cell disease (SCD) is to maximize benefits and minimize intermediate and long-term adverse outcomes so that individuals can live an average life span with a high quality of life. While greater than 2000 individuals with SCD have been treated with curative therapy, systematic studies have not been performed to evaluate the long-term health effects of hematopoietic stem cell transplant (HSCT) in this population. Individuals with SCD suffer progressive heart, lung, and kidney disease prior to curative therapy. In adults, these sequalae are associated with earlier death. In comparison, individuals who undergo HSCT for cancer are heavily pretreated with chemotherapy, resulting in potential acute and chronic heart, lung, and kidney disease. The long-term health effects on the heart, lung, and kidney for children and adults undergoing HSCT for cancer have been extensively investigated. These studies provide the best available data to extrapolate the possible late health effects after curative therapy for SCD. Future research is needed to evaluate whether HSCT abates, stabilizes, or exacerbates heart, lung, kidney, and other diseases in children and adults with SCD receiving myeloablative and non-myeloablative conditioning regimens for curative therapy.

Catastrophic Neurological Complications in 2 Patients With Sickle Cell Disease and COVID-19

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection is commonly associated with neurological complications. Patients with sickle cell disease are at increased risk of developing neurologic complications throughout their lifetimes and often have underlying cardiopulmonary comorbidities that may predispose them to poor outcomes during serious infections. In this case series, we describe 2 patients with sickle cell disease who developed devastating neurologic complications following SARS-CoV-2 infection, which ultimately led to brain edema and death. We highlight the unusual manifestations of coronavirus disease 2019 in patients with sickle cell disease and address the risk of these patients to develop catastrophic neurologic injury due to COVID-19, if not recognized promptly.

Early Myeloid Derived Suppressor Cells (eMDSCs) Are Associated With High Donor Myeloid Chimerism Following Haploidentical HSCT for Sickle Cell Disease

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is a widely available curative option for patients with sickle cell disease (SCD). Our original non-myeloablative haplo-HSCT trial employing post-transplant (PT) cyclophosphamide had a low incidence of GVHD but had high rejection rates. Here, we aimed to evaluate immune reconstitution following haplo-HSCT and identify cytokines and cells associated with graft rejection/engraftment. 50 cytokines and 10 immune cell subsets were screened using multiplex-ELISA and flow cytometry, respectively, at baseline and PT-Days 30, 60, 100, and 180. We observed the most significant differences in cytokine levels between the engrafted and rejected groups at PT-Day 60, corresponding with clinical findings of secondary graft rejection. Of the 44 cytokines evaluated, plasma concentrations of 19 cytokines were different between the two groups at PT-Day 60. Factor analysis suggested two independent factors. The first factor (IL-17A, IL-10, IL-7, G-CSF, IL-2, MIP-1a, VEGF, and TGFb1 contributed significantly) was strongly associated with engraftment with OR = 2.7 (95%CI of 1.4 to 5.4), whereas the second factor (GROa and IL-18 contributed significantly) was not significantly associated with engraftment. Sufficient donor myeloid chimerism (DMC) is critical for the success of HSCT; here, we evaluated immune cells among high (H) DMC (DMC≥20%) and low (L) DMC (DMC<20%) groups along with engrafted and rejected groups. We found that early myeloid-derived suppressor cell (eMDSC) frequencies were elevated in engrafted patients and patients with HDMC at PT-Day 30 (P< 0.04 & P< 0.003, respectively). 9 of 20 patients were evaluated for the source of eMDSCs. The HDMC group had high mixed chimeric eMDSCs as compared to the LDMC group (P< 0.00001). We found a positive correlation between the frequencies of eMDSCs and Tregs at PT-Day 100 (r=0.72, P <0.0007); eMDSCs at BSL and Tregs at PT-Day 100 (r=0.63, P <0.004). Of 10 immune regulatory cells and 50 cytokines, we observed mixed chimeric eMDSCs and IL-17A, IL-10, IL-7, G-CSF, IL-2, MIP-1a, VEGF, TGFb1 as potential hits which could serve as prognostic markers in predicting allograft outcome towards engraftment following haploidentical HSCT employing post-transplant cyclophosphamide. The current findings need to be replicated and further explored in a larger cohort.

Left ventricular function and cardiac valvar annular dimensions among children with sickle cell anemia compared to those with hemoglobin AA type in Enugu, Nigeria

Background

Enumerating the relationship between cardiac structures, function and chamber sizes in children with sickle cell anemia would help in delineating some cardiovascular abnormalities which will aid the Pediatric cardiologist and the cardiac surgeons in a number of decision-making situations.

Objectives

The objectives of this study are to assess the dimension of cardiac structures and left ventricular function in children with sickle cell anemia in steady state and controls using echocardiography.

Methods

A cross-sectional prospective study that assessed cardiac structures and left ventricular function among fifty-one children with sickle cell anemia (HBSS) and compared with fifty children with HB AA type serving as controls.

Results

A significant high proportion of children with sickle cell anemia had abnormal Valvar dimension and left ventricular function above two standard deviations (2-SD) from the mean of the standard population compared to the control group, showing a statistically significant difference (χ2 = 10.42, p= 0.001).

All the mean annular valves diameter, left ventricular internal dimension in systole and diastole, inter-sinus distance diameter and sinu-tubular junction diameter are higher in children with sickle cell anemia than controls and this is statistically significant. (p<0.005).

Conclusion

This result shows that children with sickle cell anemia have increased valvar size diameter compared with those with normal hemoglobin type. A significantly higher proportion of respondents in type SS group had abnormal left ventricular systolic and diastolic dysfunction when compared with those in type AA group.

Interleukin-1 receptor inhibition reduces stroke size in a murine model of sickle cell disease

Sickle cell disease (SCD) is associated with chronic hemolytic anemia and a heightened inflammatory state. The causal role of inflammatory pathways in stroke associated with SCD is unclear. Therefore, the hypothesis that deletion of the non-hematopoietic interleukin-1 receptor (IL-1R) pool may be beneficial in SCD was pursued. Since potential deleterious effects of IL-1R signaling in SCD could be mediated via downstream production of interleukin-6 (IL-6), the role of the nonhematopoietic IL-6 pool was also addressed. Bone marrow transplantation (BMT) from SCD to wild-type (WT) recipient mice was used to generate SCD mice (Wt,SCDbmt). In order to generate mice with nonhematopoietic deficiency of IL-1R or IL-6, SCD marrow was transplanted into IL-1R deficient (IL1R-/-,SCDbmt) or IL-6 deficient recipients (IL6-/-, SCDbmt). Blood counts, reticulocytes, soluble E-selectin (sEsel), and IL-6 levels were analyzed 14-15 weeks post-BMT. Ischemic stroke was induced by middle cerebral artery (MCA) photothrombosis at 16 weeks post-BMT. A separate group of Wt,SCDbmt mice was given the IL-1R inhibitor, anakinra, following stroke induction. Seventy-two hours after MCA occlusion, stroke volume was assessed by staining brain sections with 2,3,5-triphenyltetrazolium chloride. Formalin-fixed brain sections were also stained for macrophages with MAC3, for endothelial activation with ICAM-1, and for loss of blood brain barrier integrity with fibrin (ogen) staining. All SCD mice generated by BMT were anemic and the severity of anemia was not different between Wt,SCDbmt, IL1R-/-,SCDbmt, and IL-6-/-,SCDbmt mice. Three days following MCA occlusion, stroke volume was significantly reduced in IL1R-/-,SCDbmt mice compared to Wt,SCDbmt mice and IL6-/-,SCDbmt mice. Plasma levels of sEsel were lower in IL1R-/-,SCDbmt compared to Wt,SCDbmt and IL-6-/-,SCDbmt mice. Post-stroke treatment of Wt,SCDbmt mice with anakinra decreased stroke size, leukocyte infiltration, ICAM-1 expression, and fibrin(ogen) accumulation compared to vehicle-treated mice. Deficiency of non-hematopoietic IL-1R or treatment with an IL-1R antagonist is sufficient to confer protection against the increased stroke size associated with SCD. These effects of IL1R deficiency are associated with reduced endothelial activation, leukocyte infiltration, and blood brain barrier disruption, and are independent of non-hematopoietic IL-6 signaling.

Stable to improved cardiac and pulmonary function in children with high-risk sickle cell disease following haploidentical stem cell transplantation

Children with sickle cell disease (SCD) are at high-risk of progressive, chronic pulmonary and cardiac dysfunction. In this prospective multicenter Phase II trial of myeloimmunoablative conditioning followed by haploidentical stem cell transplantation in children with high-risk SCD, 19 patients, 2.0-21.0 years of age, were enrolled with one or more of the following: history of (1) overt stroke; (2) silent stroke; (3) elevated transcranial Doppler velocity; (4) multiple vaso-occlusive crises; and/or (5) two or more acute chest syndromes and received haploidentical transplants from 18 parental donors. Cardiac and pulmonary centralized cores were established. Pulmonary function results were expressed as percent of the median of healthy reference cohorts, matched for age, sex, height and race. At 2 years, pulmonary functions including forced expiratory volume (FEV), FEV₁/ forced vital capacity (FVC), total lung capacity (TLC), diffusing capacity of lung for carbon monoxide (DLCO) were stable to improved compared to baseline values. Importantly, specific airway conductance was significantly improved at 2 years (p < 0.004). Left ventricular systolic function (fractional shortening) and tricuspid regurgitant velocity were stable at 2 years. These results demonstrate that haploidentical stem cell transplantation can stabilize or improve cardiopulmonary function in patients with SCD.

Obesity and diabetes mellitus in patients with sickle cell disease

Obesity and diabetes mellitus are prevalent among the African-American/Black population. They result in multiple chronic conditions that impact the quality and lifespan of the patients. Their occurrence in patients with sickle cell disease (SCD) will increase the risks for multimorbidity in these patients. We have carried out a chart survey of a cohort of 449 patients with SCD to determine the prevalence rates of obesity and diabetes mellitus in these patients. SCD patients were less likely to develop obesity and diabetes mellitus, compared to their peers of the same race/ethnicity. The lower prevalence rates were observed in those over the age of 6 years, irrespective of the gender of the patients. Their life-time probabilities for obesity and diabetes mellitus were also low. Within this group of SCD patients, obesity was associated with significantly higher prevalence of diabetes mellitus. The underlying reasons for our observed results of low prevalence rate of obesity in SCD remain speculative but may be related to reduced calorie intake, increased calorie use due to hypermetabolism, reduced intestinal absorption, or intestinal dysbiosis.

Sickle cell disease and ventricular myocardial strain: A systematic review

Cardiac disease is the primary cause of death in sickle cell disease (SCD). Cardiac abnormalities begin in childhood and progress throughout life. Right and left ventricular (RV, LV) myocardial strain are early markers of systolic dysfunction but are not well investigated among individuals with SCD. The objectives of this review were to (1) identify all published studies that have evaluated ventricular myocardial strain, (2) summarize their values, and (3) compare findings with those obtained from controls. From search results of four electronic databases-Medline, Embase, Scopus, and Web of Science-42 potential articles were identified, of which 18 articles and 17 studies met eligibility criteria for inclusion. The evaluated studies demonstrate that RV and LV myocardial strain are generally abnormal in individuals with SCD compared with controls, despite having normal ejection/shortening fraction. Myocardial strain has been inconsistently evaluated in this population and should be considered any time an echocardiogram is performed.

Relationship Between Disease Severity and Resting Electrocardiograms of Adults With Sickle Cell Anemia in a Tertiary Institution in Southern Nigeria

Introduction

Sickle cell anemia (SCA) in adults has many clinical manifestations. These manifestations are due to effects of recurrent hemolysis, anemia, and ischemia-reperfusion injury on various organs, including the heart. These factors determine the severity of the disease.

Objectives

The aim of the study was to assess the severity of SCA using a scoring system consisting of clinical and laboratory parameters. In addition, the study aimed to determine the electrocardiographic abnormalities in the adult SCA population.

Study design

This was a cross-sectional, observational study conducted in the medical outpatient clinic of Irrua Specialist Teaching Hospital, Irrua, Nigeria.

Methodology

Sixty SCA patients who were older than 18 years old were recruited for this study between February 2017 and January 2018. Sixty healthy individuals matched for age and sex were recruited to serve as controls. Patients who were pregnant or having an acute crises were excluded from the study. Each participant had an electrocardiogram and a SCA severity score was calculated using their clinical history and complete blood count. Data analysis was carried out using the IBM Statistical Package for Social Sciences Statistics® software, version 21 (IBM SPSS Statistics for Windows, Armonk, NY) and statistical significance assigned to p-values less than 0.05.

Results

Severity scores for SCA ranged between 7 and 24, with a mean score of 14.5 ± 4.04. Out of the 60 patients, 14 (23.3%), 39 (65%), and seven (11.7%) participants met criteria for mild, moderate, and severe disease, respectively. Tachycardia, prolonged QTc, and the presence of ST-segment and T-wave abnormalities were significantly associated with severe SCA (p = 0.024, p = 0.027, and p = 0.018, respectively). There was positive correlation between SCA severity scores and P-wave duration (r = 0.327, p = 0.011), QRS dispersion (r = 0.298, p = 0.021), QTc interval (r = 0.332, p = 0.010), and QTc dispersion (r = 0.320, p = 0.013).

Conclusion

This study demonstrated that moderate and severe forms of SCA are common in our region. Tachycardia, left atrial abnormality, prolonged corrected QT interval, and the presence of ST-segment and T-wave changes are electrocardiographic findings associated with more severe forms of the disease. These abnormalities are significant etiologies of cardiac morbidity and mortality in SCA.

All-Cause Mortality and Incidence of Major Adverse Cardiac Events in Sickle Cell Nephropathy: A Comparative Study

Background

Sickle cell disease (SCD) is an autosomal recessive disease resulting in hemolytic anemia and recurrent vaso-occlusive events. Consequently, it can result in a broad range of functional and structural renal and cardiac alterations. Chronic kidney disease (CKD), in SCD, is associated with proteinuria, microalbuminuria, and hemoglobinuria. Cardiac complications in SCD include pulmonary hypertension, left ventricular diastolic heart disease, dysrhythmia, and sudden death. In patients with advancing age, cardio-renal dysfunction can have substantial effects on morbidity and mortality. Our primary aim was to compare the incidence of major adverse cardiac events (MACE) and all-cause mortality in sickle cell nephropathy (SCN).

Methods

In this retrospective study, we used International Classification of Diseases (ICD)-10 codes to identify admissions in 2019 with a diagnosis of MACE with a prior diagnosis of SCD and/or SCN. Our search of the HCA Healthcare Enterprise Data Warehouse for adult patients >18 years yielded 6,693 patients with SCD, of which 658 patients (9.8%) had SCN. Primary endpoints were incidence of MACE and all-cause mortality. Patients with MACE encompassed those with nonfatal stroke, nonfatal myocardial infarction, and congestive heart failure (CHF) exacerbations. A secondary endpoint was length of stay (LOS). Logistic regression analysis was used for MACE and all-cause mortality. LOS was analyzed using multiple linear regression analysis. Results were considered statistically significant for analyses showing p <0.05. All outcomes were adjusted for demographic variables and comorbidities.

Results

Logistic regression, after adjustment for comorbidities, demonstrated that SCN patients had significantly higher odds of all-cause mortality (odds ratio [OR] 2.343, p = 0.035, 95% confidence interval [CI] 1.063-5.166) compared to patients without SCN. Compared to those without SCN, those with SCN did not have a higher odds of MACE (OR 1.281, p = 0.265, 95% CI 0.828-1.982). Linear regression for LOS did not reveal a significant association with SCN (p = 0.169, 95% CI 0.157-0.899).

Conclusion

Based on the analysis of 6,693 patients with SCD, SCN was associated with significantly higher odds of all-cause mortality. SCN was not associated with significantly higher odds of MACE or prolonged LOS.

Association between pulmonary function and cardiac enzymes in sickle cell disease

BACKGROUND

There is scarcity of data on association between lung function and cardiac markers in patients with sickle cell disease (SCD). Meanwhile, SCD affects multi-organs in any one population. There seem to be an association between reduced pulmonary function with cardiac dysfunction. The current study examined the association between pulomanry function with cardiac markers in patients with SCD.

METHODOLOGY

This was a cross-sectional study with cases and controls. The cases (n=117) were made up of patients with SCD. The control subjects (n=58) were voluntary blood donors without SCD. The cellulose acetate electrophoresis was used to determine the genotypes of the study subjects. Blood samples were collected from all the study subjects for full blood count and measurement of cardiac enzymes. The cardiac enzymes measured were lactate dehydrogenase (LDH) and creatine kinase-myocardial band (CK-MB). Lung function test, using the vitalograph was done on all the study subjects. The Global Lung Initiative criteria were used to categorize lung disease as obstruction, restriction, mixed obstruction/restriction and normal.

RESULTS

The prevalence of elevated CK-MB and LDH among the SCD patients was 76.92% and 9.40% respectively, higher than the non-SCD controls (51.72% and 0% for elevated CK-MB and LDH respectively). Of all the impaired lung function, lung restriction was prevalent in all the study groups (30.77% and 15.52% for SCD patients and non-SCD controls respectively). In the fully adjusted model, reduced FEV1 was associated with nearly 3.5-fold higher odds of elevated CK-MB (odds ratio 3.35, 95% CI 1.26-8.90, p-value 0.015) in individuals with SCD.

CONCLUSION

Reduced FEV₁ which reflects airflow impairments are associated with CK-MB elevations in patients with SCD, suggesting a possible damage to the cardiomyocytes.

IL-18 mediates sickle cell cardiomyopathy and ventricular arrhythmias

Previous reports indicate that IL18 is a novel candidate gene for diastolic dysfunction in sickle cell disease (SCD)-related cardiomyopathy. We hypothesize that interleukin-18 (IL-18) mediates the development of cardiomyopathy and ventricular tachycardia (VT) in SCD. Compared with control mice, a humanized mouse model of SCD exhibited increased cardiac fibrosis, prolonged duration of action potential, higher VT inducibility in vivo, higher cardiac NF-κB phosphorylation, and higher circulating IL-18 levels, as well as reduced voltage-gated potassium channel expression, which translates to reduced transient outward potassium current (Ito) in isolated cardiomyocytes. Administering IL-18 to isolated mouse hearts resulted in VT originating from the right ventricle and further reduced Ito in SCD mouse cardiomyocytes. Sustained IL-18 inhibition via IL-18-binding protein resulted in decreased cardiac fibrosis and NF-κB phosphorylation, improved diastolic function, normalized electrical remodeling, and attenuated IL-18-mediated VT in SCD mice. Patients with SCD and either myocardial fibrosis or increased QTc displayed greater IL18 gene expression in peripheral blood mononuclear cells (PBMCs), and QTc was strongly correlated with plasma IL-18 levels. PBMC-derived IL18 gene expression was increased in patients who did not survive compared with those who did. IL-18 is a mediator of sickle cell cardiomyopathy and VT in mice and a novel therapeutic target in patients at risk for sudden death.

Definity, an affinity for painful crisis: a case series describing vaso-occlusive pain crises in sickle cell patients undergoing echocardiogram with Definity contrast

Background 

Individuals with sickle cell disease (SCD) are at risk for painful crises and long-term cardiopulmonary morbidity. Echocardiogram is recommended if signs or symptoms of cardiopulmonary disease develop in previously asymptomatic patients, or worsen in those with known disease. Second-generation echocardiogram contrast agents (ECAs) improve the diagnostic capacity of echocardiogram; however, these agents have risks in SCD populations that have yet to be investigated.

Case summary 

We report a case series of two patients who experienced vaso-occlusive crises following administration of the ECA, Definity. Both patients were referred for echocardiogram from our institution's sickle cell clinic because of concern for SCD-related cardiopulmonary complications. Both patients were in their usual state of health at the time of their exams. The first patient experienced acute back and hip pain minutes after receiving Definity and was diagnosed with acute vaso-occlusive crisis requiring admission for 6 days for pain management. The second patient developed dyspnoea and chest pain within 90 min of her echocardiogram. She was diagnosed with acute chest syndrome and admitted for further management. Her hospitalization was complicated by hyper-haemolysis and multiple organ failure syndrome. After 13 days, she was discharged home.

Discussion 

The safety profile of ECAs has not been fully evaluated and warrants further study in individuals with SCD. Proposed mechanisms for our observations include the release of pro-inflammatory metabolites from Definity contrast agent's shell and ultrasound-induced haemolysis secondary to ECA administration. Alternative imaging modalities and proper precautions should be considered when evaluating cardiopulmonary function in this patient population.

NT-proBNP levels and cardiopulmonary function in children with sickle cell disease

Patients with sickle cell disease (SCD) are living longer and subsequently more apt to develop cardiopulmonary dysfunction. N-terminal pro-brain natriuretic peptide (NT-proBNP) levels have been used in adults with SCD to assess for pulmonary hypertension and mortality. While the incidence of PH is low in pediatrics, it is reasonable to presume that NT-proBNP levels can be used to assess risk for the development of cardiopulmonary morbidity. We hypothesized that NT-proBNP levels would be increased in patients with SCD compared to age-adjusted healthy children; additionally, these levels would be associated with labs indicative of hemolysis and would demonstrate evidence of obstructive lung disease and cardiac dysfunction. We retrospectively evaluated patients with SCD, 8-18 years old, at a large, tertiary care children's hospital. NT-proBNP levels were assessed in correlation with hemolytic lab work, spirometry, and echocardiographic data. The age group 8-14 years old, 75% of our cohort's population, had a median NT-proBNP of 70 pg/ml, greater than their age-adjusted counterparts (52 pg/ml). NT-proBNP levels were associated with an increased degree of hemolysis when compared with hemoglobin (Hb) (r = -0.43, p < .0001), reticulocyte count (r = .25, p = .01) and lactate dehydrogenase levels (r = .47, p < .0001). An inverse trend was found between NT-proBNP and spirometric data. Finally, a positive correlation was found between NT-proBNP and diastolic left ventricular size (r = .28, p = .047]. The correlations found suggest that NT-proBNP may be used prospectively to identify patients with SCD at increased risk for the development of cardiopulmonary dysfunction.

Tricuspid regurgitant jet velocity and myocardial tissue Doppler parameters predict mortality in a cohort of patients with sickle cell disease spanning from pediatric to adult age groups - revisiting this controversial concept after 16 years of additional evidence

Sickle cell disease (SCD) is a monogenic hemoglobinopathy associated with significant morbidity and mortality. Cardiopulmonary, vascular and sudden death are the reasons for the majority of young adult mortality in SCD. To better understand the clinical importance of multi-level vascular dysfunction, in 2009 we assessed cardiac function including tricuspid regurgitant jet velocity (TRV), tissue velocity in systole(S') and diastole (E'), inflammatory, rheologic and hemolytic biomarkers as predictors of mortality in patients with SCD. With up to 9 years of follow up, we determined survival in 95 children, adolescents and adults with SCD. Thirty-eight patients (40%) were less than 21 years old at initial evaluation. Survival and Cox proportional-hazards analysis were performed. There was 19% mortality in our cohort, with median age at death of 35 years. In the pediatric subset, there was 11% mortality during the follow up period. The causes of death included cardiovascular and pulmonary complications in addition to other end-organ failure. On Cox proportional-hazards analysis, our model predicts that a 0.1 m/s increase in TRV increases risk of mortality 3%, 1 cm/s increase in S' results in a 91% increase, and 1 cm/s decrease in E' results in a 43% increase in mortality. While excluding cardiac parameters, higher plasma free hemoglobin was significantly associated with risk of mortality (p=.049). In conclusion, elevated TRV and altered markers of cardiac systolic and diastolic function predict mortality in a cohort of adolescents and young adult patients with SCD. These predictors should be considered when counseling cardiovascular risk and therapeutic optimization at transition to adult providers.

Sickle cell disease-associated arrhythmias and in-hospital outcomes: Insights from the National Inpatient Sample

BACKGROUND

The frequency and temporal trend in the prevalence of arrhythmias and associated in-hospital outcomes in patients with sickle cell disease (SCD) have never been quantified.

METHODS

Our study cohort of SCD patients and sub-types of arrhythmias were derived from the 2010-2014 National Inpatient Sample using relevant diagnostic codes. The frequency and trends of arrhythmia and odds of inpatient mortality were measured.

RESULTS

A total of 891 450 hospitalized SCD patients were identified, of which, 55 616 (6.2%) patients experienced arrhythmias. The SCD cohort with arrhythmia demonstrated higher all-cause mortality (2.7% vs 0.4%; adjusted OR 2.53, 95% CI 2.15-2.97, P < .001), prolonged hospital stays (6.9 vs 5.0 days) and higher hospital charges ($53 871 vs $30 905) relative to those without arrhythmias (P < .001).The frequency of supraventricular arrhythmia (AFib, SVT, and AF) and ventricular arrhythmia (VFib and VT) were 1893 and 362 per 100 000 SCD-related admissions, respectively. Unspecified arrhythmias (4126) were seen most frequently followed by AFib (1622) per 100 000 SCD-related admissions. From 2010 to 2014, the frequency of any arrhythmias and atrial fibrillation in hospitalized SCD patients relatively increased by 29.6% and 38.5%, respectively. There was nearly a twofold (2.4% in 2010 to 5.0% in 2014) increase in the frequency of arrhythmia among patients aged <18 years. The frequency of arrhythmias in hospitalized male and female SCD patients relatively increased by 28.8% and 31.4%, respectively (P trend < .001).

CONCLUSIONS

The frequency of arrhythmias among SCD patients is on the rise with worse hospitalization outcomes, including higher in-hospital mortality and higher resource utilization as compared to those without arrhythmias.

Ambulatory Hypertension in Pediatric Patients With Sickle Cell Disease and Its Association With End-Organ Damage

Background

Sickle cell disease (SCD), a chronic hemolytic disorder, results in cumulative end-organ damage affecting major organs such as the cardiovascular, renal, and central nervous systems. Effects of modifiable risk factors, such as blood pressure (BP), on the development of end-organ complications in SCD have not been well studied, particularly among the pediatric population. Relative hypertension in patients with SCD increases their risks of stroke, cardiovascular complications, and death. The primary hypothesis of this study was that abnormal BP patterns are common among patients with SCD and they impact end-organ complications.

Methods

Patients with SCD (HbSS, HbSβ0) were enrolled from the Children’s Hospital at Montefiore (N = 100). For each patient, demographic data were collected, biochemical variables in urine and blood samples were analyzed, BP was determined with ambulatory blood pressure monitoring (ABPM), and an echocardiogram was performed. The prevalence of abnormalities in BP parameters was defined, and their relationships with measures of SCD severity and end-organ damage were assessed.

Results

Sufficient ABPM data were available for 67 patients. Enrolled children were 13 ± 4 years (40% were males). Assessment of diurnal variation demonstrated that 81% of patients had abnormal systolic nocturnal dipping and 61% had abnormal diastolic nocturnal dipping. Abnormalities in the diurnal pattern were associated with reticulocytosis and hyperfiltration. Microalbuminuria was present in 19% (n = 13) of patients, of which 77% (n = 10) were females (p = 0.014). Diastolic load and abnormal nocturnal dipping were associated with hyperfiltration but not with microalbuminuria.

Conclusions

BP abnormalities detected with ABPM in SCD patients are prevalent and perhaps are a risk factor for end-organ complications. Further studies are required to identify the mechanisms underlying these relationships and their longitudinal changes.

End points for sickle cell disease clinical trials: renal and cardiopulmonary, cure, and low-resource settings

To address the global burden of sickle cell disease and the need for novel therapies, the American Society of Hematology partnered with the US Food and Drug Administration to engage the work of 7 panels of clinicians, investigators, and patients to develop consensus recommendations for clinical trial end points. The panels conducted their work through literature reviews, assessment of available evidence, and expert judgment focusing on end points related to patient-reported outcome, pain (non-patient-reported outcomes), the brain, end-organ considerations, biomarkers, measurement of cure, and low-resource settings. This article presents the findings and recommendations of the end-organ considerations, measurement of cure, and low-resource settings panels as well as relevant findings and recommendations from the biomarkers panel.

Reversal of a rheologic cardiomyopathy following hematopoietic stem cell transplantation for sickle cell disease

Cardiac complications have been well-described in sickle cell disease; however, it has been rare to see improvements in cardiac abnormalities following any interventions. Previous work has shown no significant structural changes after treatment with hydroxyurea. The cardiac effects of red blood cell exchange transfusion (RBCx) and hematopoietic stem cell transplantation (HSCT) have not been well described. We studied 56 patients undergoing HSCT (41 HLA-matched, 15 haploidentical), of whom 32 had RBCx within 3 months before HSCT. Echocardiograms and laboratory parameters were obtained at baseline, and at 3, 6, and 12 months following HSCT. Although hemolytic parameters and anemia improved following RBCx, there was a small increase in left ventricular volume index. Following successful HSCT, however, there were significant improvements in cardiac size, function, and diastolic filling parameters at 3 months followed by continued smaller improvements up to 1 year. There was a significant improvement in N-terminal pro B-type natriuretic peptide levels and a trend toward improvement in 6-minute walk time 1 year after HSCT. The magnitude of cardiac improvement seen following HSCT was comparable to that observed following correction of a volume overload state as seen in pregnancy or after repair of chronic valvular regurgitation. Further studies in sickle cell disease patients will help delineate which cardiac complications and what level of severity should be considered indications for HSCT.

Curative vs targeted therapy for SCD: does it make more sense to address the root cause than target downstream events?

Sickle cell disease (SCD) places a heavy burden on a global and increasing population predominantly resident in resource-poor and developing countries. Progress continues to be made in preventing childhood mortality, and increasing numbers of chronically ill adults with disease are requiring care for disease sequelae. Curative therapies for SCD are therefore attractive to physicians and investigators focused on SCD. Gene therapies are being developed, and several are now in various stages of early-phase human clinical trials. However, we must also pursue avenues through which we can do the most good for the most people alive today. Such efforts include improving our understanding of disease mechanisms and which disease sequelae most strongly affect survival and interfere with quality of life. The pathways leading to disease sequelae are multiple, complex, and highly interactive. Four drugs have now been approved by the US Food and Drug Administration for SCD; however, each has a distinct mechanism and a measurable but limited effect on the many clinical sequelae of SCD. We therefore need to learn how to approach multi-agent therapy for SCD. The order of addition of each agent to treat a specific patient will need to be guided by response to previous therapy, risk factors identified for specific disease outcomes, and clinical studies to determine more comprehensively how the 4 currently approved drugs might interact and produce (or not) additive effects. Moreover, this will have to be accomplished with defined end points in mind, according to which pose the greatest threats to quality of life as well as survival.

Computer Algorithm-Based Hydroxyurea Dosing Facilitates Titration to Maximum Tolerated Dose in Sickle Cell Anemia

Adults with sickle cell disease (SCD) experience acute and chronic complications and die prematurely. When taken at maximum tolerated dose (MTD), hydroxyurea prolongs survival; however, it has not consistently reversed organ dysfunction. Patients also frequently do not take hydroxyurea, at least in part because of physician discomfort with prescribing hydroxyurea. We sought to develop a computer program that could easily titrate hydroxyurea to MTD. This was a single-arm, open-label pilot study. Fifteen patients with homozygous SCD were enrolled in the protocol, and 10 patients were followed at baseline and then for 1 year after hydroxyurea initiation or dose titration. Fetal hemoglobin significantly increased in all 10 patients from 8.3% to 25.1% (P < .001). Nine patients were titrated to MTD in an average of 7.9 months, and the tenth patient's hydroxyurea dose was increased to 33 mg/kg/day. Computer program dosing recommendations were the same as manual dosing decisions made using the same algorithm for all patients and at all times. We also evaluated markers of cardiopulmonary, liver and renal damage. Although cardiopulmonary function did not significantly improve, direct bilirubin and alanine aminotransferase levels significantly decreased (P < .001 and P < .01, respectively). Last, although kidney function did not improve, degree of proteinuria was significantly reduced (P < .05). We have developed a computer program that reliably titrates hydroxyurea to MTD. A larger study is indicated to test the program either as a computer program or a downloadable application.

Evaluation of Cardiac Function in Patients with Sickle Cell Disease with Left Ventricular Global Longitudinal Strain

Background and Objectives

The importance of myocardial dysfunction in sickle cell disease (SCD) is currently debated. It is difficult to find a reliable index of function in patients with chronic overload as in SCD. Speckle tracking echocardiography, a new mean of evaluating cardiac function, might be a useful tool in SCD. It has been applied in many fields to detect early cardiac function deterioration, and it is less load dependent compared with other function parameters. Studies in patients with SCD are rare, and the results are conflicting. The present study aimed to determine whether left ventricular global longitudinal strain (LV-GLS) was abnormal in a population of adults with SCD and whether it was correlated with clinical or biological parameters.

Methods

We prospectively enrolled 37 patients and 34 age- and sex-matched healthy controls. Echocardiography was performed in patients and controls.

Results

We found that the left ventricular diameter and mass were higher and the ejection fraction and longitudinal strain were lower in patients compared with controls. Diastolic dysfunction was uncommon. LV-GLS was abnormal in 21% of the patients. No correlation was observed between strain and clinical or biological parameters.

Conclusions

We concluded that LV-GLS could be a useful tool for evaluating these patients. However, the clinical impact of reduced LV-GLS remains to be determined.

Left atrial dysfunction in sickle cell anemia is associated with diffuse myocardial fibrosis, increased right ventricular pressure and reduced exercise capacity

Increased extracellular volume (ECV) by CMR is a marker of interstitial myocardial fibrosis and is associated with diastolic dysfunction in sickle cell anemia (SCA). Left atrial (LA) dysfunction and stiffness contribute to the development of diastolic heart failure in other settings. We aimed to evaluate LA function and stiffness associations with ECV, tricuspid regurgitation jet velocity (TRV) and exercise abnormalities in SCA. In a prospective study, individuals with SCA underwent CMR, echocardiography and exercise test. ECV was measured using MOLLI sequence. Atrial strain was studied in the 4- and 2-chamber views. LA stiffness was calculated as the ratio of echocardiographic E/e’-to-LA reservoir strain. Twenty-four participants with SCA were included (median age 20 years). ECV was increased in participant with SCA compared to our lab normal values (mean 0.44 ± 0.08 vs 0.26 ± 0.02, P < 0.0001). Six (25%) had LA LGE. ECV positively correlated with LA stiffness (r = 0.45, p = 0.04). There was a negative correlation between LA stiffness and %predicted VO2 (r = −0.50, p = 0.04). LA stiffness was moderately associated with increased TRV (r = 0.55, p < 0.005). LA stiffness is associated with ECV, exercise impairment and increased TRV. This study sheds insights on the interaction between LA function, RV hypertension, and myocardial fibrosis in SCA.

Intestinal pathophysiological and microbial changes in sickle cell disease: Potential targets for therapeutic intervention

There is a large therapeutic gap in the treatment of sickle cell disease (SCD). Recent studies demonstrated the presence of pathophysiological and microbial changes in the intestine of patients with SCD. The intestinal microbes have also been found to regulate neutrophil ageing and possible basal activation of circulating neutrophils. Both aged and activated neutrophils are pivotal for the pathogenesis of vaso-occlusive crisis in SCD. In this paper, we will provide an overview of the intestinal pathophysiological and microbial changes in SCD. Based on these changes, we will propose therapeutic approaches that could be investigated for treating SCD.

Optimizing Hydroxyurea Treatment for Sickle Cell Disease Patients: The Pharmacokinetic Approach

Background: Hydroxyurea (HU) is a FDA- and EMA-approved drug that earned an important place in the treatment of patients with severe sickle cell anemia (SCA) by showing its efficacy in many studies. This medication is still underused due to fears of physicians and families and must be optimized. Methods: We analyzed our population and identified HU pharmacokinetic (PK) parameters in order to adapt treatment in the future. Working with a pediatric population, we searched for the most indicative sampling time to reduce the number of samples needed. Results: Nine children treated by HU for severe SCA were included for this PK study. HU quantification was made using a validated gas chromatography/mass spectrometry (GC/MS) method. Biological parameters (of effectiveness and compliance) and clinical data were collected. None of the nine children reached the therapeutic target defined by Dong et al. as an area under the curve (AUC) = 115 h.mg/L; four patients were suspected to be non-compliant. Only two patients had an HbF over 20%. The 2 h sample was predictive of the medication exposure (r² = 0.887). Conclusions: It is urgent to be more efficient in the treatment of SCA, and pharmacokinetics can be an important asset in SCA patients.

Allogeneic Hematopoietic Stem Cell Transplantation for Adults with Sickle Cell Disease

Sickle cell disease (SCD) is an inherited red blood cell disorder that leads to substantial morbidity and early mortality. Acute and chronic SCD-related complications increase with older age, and therapies are urgently needed to treat adults. Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapy, but has been used less frequently in adults compared to children. This is, in part, due to (1) greater chronic organ damage, limiting tolerability to myeloablative conditioning regimens, (2) a higher rate of HSCT-related complications in adults versus children with SCD, and (3) limited coverage by public and private health insurance. Newer approaches using nonmyeloablative and reduced-intensity conditioning HSCT regimens have demonstrated better safety and tolerability, with high rates of stable engraftment in SCD adults. This review will focus on the impacts of HSCT, using more contemporary approaches to SCD-related complications in adults.

Identifying Clinical and Research Priorities in Sickle Cell Lung Disease. An Official American Thoracic Society Workshop Report

Background: Pulmonary complications of sickle cell disease (SCD) are diverse and encompass acute and chronic disease. The understanding of the natural history of pulmonary complications of SCD is limited, no specific therapies exist, and these complications are a primary cause of morbidity and mortality.Methods: We gathered a multidisciplinary group of pediatric and adult hematologists, pulmonologists, and emergency medicine physicians with expertise in SCD-related lung disease along with an SCD patient advocate for an American Thoracic Society-sponsored workshop to review the literature and identify key unanswered clinical and research questions. Participants were divided into four subcommittees on the basis of expertise: 1) acute chest syndrome, 2) lower airways disease and pulmonary function, 3) sleep-disordered breathing and hypoxia, and 4) pulmonary vascular complications of SCD. Before the workshop, a comprehensive literature review of each subtopic was conducted. Clinically important questions were developed after literature review and were finalized by group discussion and consensus.Results: Current knowledge is based on small, predominantly observational studies, few multicenter longitudinal studies, and even fewer high-quality interventional trials specifically targeting the pulmonary complications of SCD. Each subcommittee identified the three or four most important unanswered questions in their topic area for researchers to direct the next steps of clinical investigation.Conclusions: Important and clinically relevant questions regarding sickle cell lung disease remain unanswered. High-quality, multicenter, longitudinal studies and randomized clinical trials designed and implemented by teams of multidisciplinary clinician-investigators are needed to improve the care of individuals with SCD.

Robust clinical and laboratory response to hydroxyurea using pharmacokinetically guided dosing for young children with sickle cell anemia

Hydroxyurea is FDA-approved and now increasingly used for children with sickle cell anemia (SCA), but dosing strategies, pharmacokinetic (PK) profiles, and treatment responses for individual patients are highly variable. Typical weight-based dosing with step-wise escalation to maximum tolerated dose (MTD) leads to predictable laboratory and clinical benefits, but often takes 6 to 12 months to achieve. The Therapeutic Response Evaluation and Adherence Trial (TREAT, NCT02286154) was a single-center study designed to prospectively validate a novel personalized PK-guided hydroxyurea dosing strategy with a primary endpoint of time to MTD. Enrolled participants received a single oral 20 mg/kg dose of hydroxyurea, followed by a sparse PK sampling approach with three samples collected over three hours. Analysis of individual PK data into a population PK model generated a starting dose that targets the MTD. The TREAT cohort (n = 50) was young, starting hydroxyurea at a median age of 11 months (IQR 9-26 months), and PK-guided starting doses were high (27.7 ± 4.9 mg/kg/d). Time to MTD was 4.8 months (IQR 3.3-9.3), significantly shorter than comparison studies (p < 0.0001), thus meeting the primary endpoint. More remarkably, the laboratory response for participants starting with a PK-guided dose was quite robust, achieving higher hemoglobin (10.1 ± 1.3 g/dL) and HbF (33.3 ± 9.1%) levels than traditional dosing. Though higher than traditional dosing, PK-guided doses were safe without excess hematologic toxicities. Our data suggest early initiation of hydroxyurea, using a personalized dosing strategy for children with SCA, provides laboratory and clinical response beyond what has been seen historically, with traditional weight-based dosing.

Abnormal submaximal cardiopulmonary exercise parameters predict impaired peak exercise performance in sickle cell anemia patients

PURPOSE

Sickle cell anemia (SCA) patients frequently have many comorbidities, including diastolic dysfunction (DD) and exercise intolerance. SCA patients often cannot reach maximal effort on exercise testing; little is known regarding whether submaximal exercise parameters can predict abnormal maximal exercise results in SCA patients and if there are any possible associations with DD.

METHODS

A prospective longitudinal study was performed in SCA patients. All patients had a resting cardiac MRI (CMR), cardiopulmonary exercise test (CPET) with cycle ergometry using a ramp protocol, and an echocardiogram. Exercise data were compared with age-, gender-, and size-matched normal controls.

RESULTS

Compared with normal controls, the SCA group (n = 19) had lower mean max oxygen consumption (VO₂ ; 1378 ± 412 mL/min vs 2237 ± 580, P < 0.01) and workload (117 ± 37.6 watts vs 175 ± 50.5 watts, P = 0.0003). When evaluating the submaximal exercise parameters, there was lower VO₂ at the anaerobic threshold (AT; 950 ± 311.7 vs 1460 ± 409.9, P < 0.01) and oxygen uptake efficiency slope (OUES) at AT (1512 ± 426.2 vs 2080 ± 339, P < 0.01). The max VO₂ strongly correlated with VO₂ at AT (r = 0.9, P < 0.01) and OUES (r = 0.83, P < 0.01) at AT. The VO₂ at AT correlated with hematocrit (r = 0.77, P < 0.05). The OUES correlated with left ventricular ejection fraction by CMR (r = 0.55, P = 0.01), hematocrit (r = 0.52, P = 0.02), and lateral E/e' (r = -0.54, P = 0.01).

CONCLUSIONS

SCA patients have abnormal submaximal exercise measures compared with controls, which is strongly associated with abnormal maximal exercise results. The degree of submaximal abnormality correlates with DD abnormalities by echocardiography. These data expand the scope of functional cardiovascular abnormalities in SCA.