Clinical phenotypes and outcomes of precapillary pulmonary hypertension of sickle cell disease

Haemolytic Anaemia-Related Pulmonary Hypertension

Haemolytic anaemia represents a risk factor for the development of pulmonary hypertension (PH), currently classified as World Health Organization group 5 PH, and data regarding appropriate therapeutic strategy are limited. A total of 28 patients, 85.7% with thalassaemia and 14.3% with sickle cell disease, with a diagnosis of PH confirmed by right heart catheterization were included in the study. The patients were divided into three groups according to the PH haemodynamic definition and overall diagnostic approach: 42.9% had precapillary PH (pulmonary arterial hypertension-PAH group), 25% had post-capillary PH, and 32.1% had chronic thromboembolic PH (CTEPH) (29% of b-thalassemia and 50% of SCD patients). The therapeutic approach in each group and its impact on the outcome and haemodynamics were recorded. PAH-specific drug therapy received 82.1% of patients, and balloon pulmonary angioplasty (BPA) was performed in six patients with CTEPH. There were statistically significant differences in baseline mPAP and PVR values between the CTEPH-haemolytic anaemia group and other groups. PAH-specific drug therapy resulted in haemodynamic improvement for the PAH group. Patients who underwent BPA had improved pulmonary haemodynamics. The median survival time was 162 months, and the survival rate was 1 year-100%; 2, 3, 4, 5, and 6 years-96%; 9 years-90%; and 13 years-78%. In patients with haemolytic anaemia, the wide spectrum of induced PH highlighted the importance of a correct predominant diagnosis. BPA in CTEPH patients and specific-PAH drug therapy for PAH patients represent potential therapeutic strategies; however, the management should be offered in expert PH centres under individualized approaches for patients.

Cardiac diastolic maladaptation is associated with the severity of exercise intolerance in sickle cell anemia patients

This pilot study focusing on Sickle Cell Anemia (SCA) patients offers a comprehensive and integrative evaluation of respiratory, cardiovascular, hemodynamic, and metabolic variables during exercise. Knowing that diastolic dysfunction is frequent in this population, we hypothesize that a lack of cardiac adaptation through exercise might lead to premature increase in blood lactate concentrations in SCA patients, a potential trigger for acute disease complication. SCA patients were prospectively included in PHYSIO-EXDRE study and underwent a comprehensive stress test with a standardized incremental exercise protocol up to 4 mmol L-1 blood lactate concentration (BL4). Gas exchange, capillary lactate concentration and echocardiography were performed at baseline, during stress test (at ∼ 2 mmol L-1) and BL4. The population was divided into two groups and compared according to the median value of percentage of theoretical peak oxygen uptake (%V ˙ O 2 p e a k t h ) at BL4. Twenty-nine patients were included (42 ± 12 years old, 48% of women). Most patients reached BL4 at low-intensity exercise [median value of predicted power output (W) was 37%], which corresponds to daily life activities. The median value of %V ˙ O 2 p e a k t h at BL4 was 39%. Interestingly, diastolic maladaptation using echocardiography during stress test along with hemoglobin concentration were independently associated to early occurrence of BL4. As BL4 occurs for low-intensity exercises, SCA patients may be subject to acidosis-related complications even during their daily life activities. Beyond assessing physical capacities, our study underlines that diastolic maladaptation during exercise is associated with an early increase in blood lactate concentration.

Cardiovascular Consequences of Sickle Cell Disease

Background

Sickle cell disease is an inherited blood disorder which can lead to severe complications, particularly in the cardiovascular and respiratory systems, potentially resulting in arrhythmias, pulmonary hypertension (PH), and cardiomegaly. This study aims to investigate the risk of PH and arrhythmias in adult SCD patients.

Methods

Retrospective analysis of medical records from King Abdulaziz University Hospital (KAUH) for patients with SCD aged 15 and above between 2009 and 2021. The study included 517 patients, with echocardiograms and electrocardiograms assessed according to the European Society of Cardiology/the European Respiratory Society (ESC/ERS) guidelines for categorizing PH risk (low, moderate, high) and detecting arrhythmias. Data analysis employed the Statistical Package for the Social Sciences (SPSS), utilizing quantitative and qualitative data representation. Multivariate logistic regression identified independent risk factors with odds ratios at a 95% confidence interval (CI).

Results

Among participants, 50.3% were male, with a total sample average age of 34.45 ± 9.28 years. Results indicated that 1.4% of patients experienced arrhythmias, 3.7% had a moderate PH risk, and 3.3% were classified as high PH risk. Logistic regression revealed significant independent risk factors for PH and arrhythmia in patients with SCD, with chronic kidney disease (CKD) carrying the highest odds (26.4 times higher odds of PH and 15.36 times higher odds of arrhythmias).

Conclusion

Patients with SCD are at risk for developing PH and various arrhythmias but are often underdiagnosed. Key risk factors for PH included CKD, liver cirrhosis, and pre-existing cardiac conditions. Arrhythmias were significantly associated with CKD and pre-existing cardiac conditions. To mitigate these risks, we recommend involving a multidisciplinary healthcare team in the care of adult patients with SCD. Future prospective studies are advised for early detection of PH and arrhythmias in hemoglobinopathy patients, potentially reducing mortality.

Pulmonary Hypertension in Sickle Cell Disease: Novel Findings of Gene Polymorphisms Related to Pathophysiology

Pulmonary hypertension (PH) is a progressive and potentially fatal complication of sickle cell disease (SCD), affecting 6-10% of adult SCD patients. Various mechanisms and theories have been evaluated to explain the pathophysiology of this disease. However, questions remain, particularly regarding the clinical heterogeneity of the disease in terms of symptoms, complications, and survival. Beyond the classical mechanisms that have been thoroughly investigated and include hemolysis, nitric oxide availability, endothelial disorders, thrombosis, and left heart failure, attention is currently focused on the potential role of genes involved in such processes. Potential candidate genes are investigated through next-generation sequencing, with the transforming growth factor-beta (TGF-β) pathway being the initial target. This field of research may also provide novel targets for pharmacologic agents in the future, as is already the case with idiopathic PH. The collection and processing of data and samples from multiple centers can yield reliable results that will allow a better understanding of SCD-related PH as a part of the disease's clinical spectrum. This review attempts to capture the most recent findings of studies on gene polymorphisms that have been associated with PH in SCD patients.

Diagnosis and management of chronic thromboembolic pulmonary hypertension (CTEPH) in sickle cell disease: A review

Pulmonary hypertension in sickle cell disease (SCD) is a complex phenomenon resulting from multiple overlapping etiologies, including pulmonary vasoconstriction in the setting of chronic hemolytic anemia, diastolic dysfunction, and chronic thromboembolic disease. The presence of pulmonary hypertension of any cause in SCD confers a significant increase in mortality risk. Evidence to guide the management of patients with sickle cell disease and chronic thromboembolic pulmonary hypertension (CTEPH) is scant and largely the realm of case reports and small case series. Centered on a discussion of a complex young patient with hemoglobin hemoglobin SC who ultimately underwent treatment with pulmonary thromboendarterectomy, we review the available literature to guide management and discuss and overview of treatment of CTEPH in SCD, considering the unique considerations and challenges facing patients suffering from this multisystem disease.

Clinical-radiological-pathological correlation in pulmonary hypertension with unclear and/or multifactorial mechanisms

Ever since the second world symposium on pulmonary hypertension (PH) held in Evian, France, in 1998, PH has been classified into five major clinical groups. Group 5 PH includes a variety of distinct conditions with unclear and/or multifactorial underlying pathologies. Management of these patients is challenging as the number of patients within these groups is often small, not all individuals with certain underlying conditions are affected by PH and patients exhibit distinct symptoms due to different underlying diseases. Studies and clinical trials in these groups are largely lacking and mostly restricted to case series and registry reports. Nonetheless, the worldwide burden of group 5 PH is estimated to be significant in terms of the prevalence of some associated diseases. Group 5 PH encompasses six subgroups, including haematological disorders (inherited and acquired chronic haemolytic anaemia and chronic myeloproliferative disorders), systemic disorders (sarcoidosis, pulmonary Langerhans's cell histiocytosis and neurofibromatosis type 1), metabolic disorders (glycogen storage diseases and Gaucher disease), chronic renal failure with or without haemodialysis, pulmonary tumour thrombotic microangiopathy and fibrosing mediastinitis.

Pulmonary hypertension in sickle cell disease

Sickle cell disease (SCD) is a complex genetic disorder that has long challenged both patients and healthcare professionals. One of its chronic and debilitating complications is pulmonary hypertension (PH). SCD-associated PH is often post-capillary, secondary to left heart disease. It can also sometimes be pre-capillary with multiple and often interrelated mechanisms including obstructive remodeling of the pulmonary vascular bed secondary to hemolysis, endothelial dysfunction, thrombosis, hypoxia, or associated risk factors like portal hypertension. Screening symptomatic patients with echocardiographic signs of PH is crucial to determine those who should undergo right heart catheterization, the cornerstone exam to diagnose and categorize patients with PH. The workup following the diagnosis relies on identifying the cause of PH to personalize treatment. Ongoing efforts are made to treat this complex condition, starting with treating the underlying disease with hydroxyurea or chronic blood exchange transfusion. Robust data on the efficacy of PAH-specific therapies are lacking in this specific population. Initiation of such therapies must be made by an expert center after a case-by-case assessment of the benefit-risk ratio according to the phenotype and the mechanisms involved in the development of PH. Efforts are also poured into studying the interventional and medical therapies used on chronic thromboembolic PH for patients presenting with a thrombotic form. The management of those patients requires a multidisciplinary approach, with conjoint efforts from PH and SCD specialists.

Dual-energy computed tomography to detect early pulmonary vascular changes in children with sickle cell disease: a pilot study

Introduction

Pulmonary hypertension (PH) is a rare but fatal complication of sickle cell disease (SCD) that is possibly reversible if treated early. Dual-energy computed tomography (DECT) is a valuable tool for diagnosing PH. We attempted to determine if DECT can detect early signs of PH in children with SCD.

Methods

This prospective observational pilot study was conducted at the Geneva University Hospitals and was approved by the local human ethics committee (CCER 2019-01975). A written informed consent was obtained from the patients and/or their legal guardian. Eight children (consisting of five girls and three boys) with homozygous SCD were included in the study. They underwent full cardiological workup using transthoracic echocardiography (TTE) and cardiopulmonary exercise test (CPET), as well as DECT.

Results

The median age of the children was 11 years old (range 8-12). All patients exhibited a normal biventricular systo-diastolic function using the TTE. The median tricuspid regurgitant jet velocity value was 2.24 m/s (range 1.96-2.98). Four children were found to have signs of vasculopathy detected on DECT. Of them, two had abnormal screening test results. They both had an increased VE/VCO2 slope during CPET and an increased TVR of >2.5 m/s on TTE.

Conclusion

DECT is capable of identifying early signs of pulmonary vascular disease in children with SCD. Further studies are needed to understand the correlation between DECT abnormalities and hemodynamic pulmonary circulation better.

A review of cardio-pulmonary microvascular dysfunction in pulmonary hypertension

Microvascular dysfunction progressing to pulmonary hypertension can be a primary cause of right ventricular failure or a secondary cause because of an underlying systemic illness. Little is known regarding the etiology and epidemiology of coronary microvascular dysfunction in pulmonary hypertension. Despite this limitation, its presence has been described in patients with pulmonary hypertension. This review focuses on the pathogenesis of cardiac and pulmonary microvascular dysfunction in pulmonary hypertension. Additionally, this review provides a contemporary assessment on the diagnosis and treatment of microvascular dysfunction in patients in pulmonary hypertension. This topic is important to raise awareness of microvascular dysfunction in the coronary and pulmonary circulation, so that future studies will investigate its impact on the pulmonary hypertension patient cohort.

Endothelial dysfunction and hypercoagulability in severe sickle-cell acute chest syndrome

Rationale

Acute pulmonary hypertension (PH) may develop during sickle-cell acute chest syndrome (ACS), and is associated with an increased mortality. Its mechanisms remain poorly known. We questioned whether there is endothelial dysfunction and hypercoagulability in severe ACS, with and without acute PH.

Methods

In a prospective monocentre cohort follow-up study, all sickle-cell adult patients with ACS admitted to the intensive care unit underwent transthoracic echocardiography and measurement of biomarkers of coagulation, endothelial activation and platelet and erythrocyte activation. Acute PH was defined as a high echocardiographic probability of PH. The biological profiles of sickle-cell patients were analysed at the time of ACS, contrasting with the existence of acute PH, and compared with steady-state and with non-sickle-cell controls (healthy subjects and community-acquired pneumonia).

Results

Most patients (36 patients with 39 ACS episodes; 23 males; median age 27 years) had thoracic pain, dyspnoea and computed tomography scan lung consolidation. Acute PH was diagnosed in seven (19%) patients. Erythrocyte- and platelet-derived microparticles and the pro-coagulant activity of microparticles were higher in ACS patients with acute PH, compared with their counterparts. Compared with healthy controls, ACS patients had higher levels of tissue factor, fibrin monomers, D-dimer, release of pro-coagulant microparticles and erythrocyte- and platelet-derived microparticles. Compared with community-acquired pneumonia patients, ACS patients had increased levels of fibrin monomers and erythrocyte- and platelet-derived microparticles.

Conclusions

Severe ACS is characterised by endothelial dysfunction and hypercoagulability, with a marked pro-coagulant profile in cases of associated PH.

Severe sickle-cell acute chest syndrome is associated with an activation of the pulmonary vascular endothelium and of coagulation, with higher levels of pro-coagulant microparticles in cases of associated acute pulmonary hypertensionhttps://bit.ly/3sjkaYy

Clinical and physiological characteristics of, medically treated, chronic thromboembolic pulmonary hypertension patients in Saudi Arabia: A single center experience

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is uncommon but well-known sequel of venous thromboembolism (VTE). At present, it is the only potential curable subtype of pulmonary hypertension. The aim of this study is to describe the medically treated-CTEPH patients' characteristics in a single specialized PH center in Saudi Arabia.

METHODS

This study presents demographic, clinical, physiological, and hemodynamic characteristics of medically treated-CTEPH patients in a single PH center, namely Prince Sultan Military Medical City, Riyadh, Saudi Arabia. Both incident and prevalent cases are included.

RESULTS

A total of 20 patients with a confirmed diagnosis of CTEPH were included. Mean age at diagnosis was 43 years with a female preponderance of 75%. Most common presenting symptom was dyspnea (100%) followed by syncope (58%). At diagnosis, a mean of 15 ± 10 months had passed since symptoms onset. About 45% of patients were in WHO functional class IV. At baseline, mean 6-min walk distance was 354.3 meters. Overall, VTE was the most frequent risk factor identified (65% of all patients). Nearly 30% of patients had sickle cell disease. 13 out of 20 patients had radiographic (i.e., computed tomography [CT] pulmonary angiogram) features of chronic thromboembolism. About 75% of patients were found to have distal disease on radiographic imaging. At the time of diagnosis, 7 out of 20 (35%) patients demonstrated right ventricular failure on echocardiography. Mean tricuspid annular plane systolic excursion was 17.7 ± 1.20. Median NT-proBNP levels were found to be 688 pg/ml. Mean diffusing capacity for carbon monoxide was 74.8%.

CONCLUSIONS

Diagnosis of CTEPH was established at a relatively younger age. Majority of patients had advanced but distal disease on radiographic imaging, not amenable to surgery.

Cardiovascular phenotypes predict clinical outcomes in sickle cell disease: An echocardiography-based cluster analysis

This study sought to link cardiac phenotypes in homozygous Sickle Cell Disease (SCD) patients with clinical profiles and outcomes using cluster analysis. We analyzed data of 379 patients included in the French Etendard Cohort. A cluster analyses was performed based on echocardiographic variables, and the association between clusters, clinical profiles and outcomes was assessed. Three clusters were identified. Cluster 1 (n = 123) patients had the lowest cardiac output, mild left cardiac cavities remodeling, mild diastolic dysfunction, and higher tricuspid regurgitation velocity (TRV). They were predominantly female and displayed the most altered functional limitation. Cluster 2 (n = 102) patients had the highest cardiac output and the most remodeled cardiac cavities. Diastolic function and TRV were similar to cluster 1. These patients had a higher blood pressure and a severe hemolytic anemia. Cluster 3 (n = 154) patients had mild left cardiac cavities remodeling, normal diastolic function and lowest TRV values. They were younger with the highest hemoglobin value. Right heart catheterization was performed in 94 patients. Cluster 1 (n = 33) included the majority of pre-capillary PH whilst cluster 2 (n = 34) included post-capillary PH. No PH was found in cluster 3 (n = 27). After a follow-up of 11.4 ± 2 years, death occurred in 41 patients (11%). Cluster 2 patients had the worst prognosis with a 19% mortality rate versus 12% in cluster 1 and 5% in cluster 3 (p log-rank = 0.003). Cluster analysis of echocardiography variables identified three hemodynamic and clinical phenotypes among SCD patients, each predicting a different prognosis.

The different facets of sickle cell disease-related pulmonary hypertension

PURPOSE OF REVIEW

Sickle cell disease (SCD), one of the most common genetic diseases in the world, is characterized by repeated episodes of hemolysis and vaso-occlusion. Hemolytic anemia is a risk factor for the development of pulmonary hypertension, and currently SCD-related pulmonary hypertension is classified as World Health Organization group 5 pulmonary hypertension. Patients with SCD-related pulmonary hypertension have unique hemodynamics, multiple comorbidities, and distinct phenotypes that may contribute to the development of pulmonary hypertension.

RECENT FINDINGS

SCD-related pulmonary hypertension is defined as a mean pulmonary artery pressure >20 mmHg, a pulmonary artery occlusion pressure ≤15 mmHg and relatively low pulmonary vascular resistance (>2 Wood units) rather than the traditional definition of ≥3 Wood units, an important distinction due to a baseline high-cardiac output state in the setting of chronic anemia and low vascular resistance. Diastolic dysfunction is frequently identified in this patient population and right heart catheterization is essential to determine if combined pre- and postcapillary pulmonary hypertension is present. Thromboembolism is common among patients with SCD, and screening for chronic thromboembolic pulmonary hypertension is essential. Data regarding advanced therapies are limited. Primary treatment options include targeting correction of their primary hemoglobinopathy as well as aggressive management of underlying comorbid conditions.

SUMMARY

SCD-related pulmonary hypertension is common among patients with SCD and is associated with increased mortality. A high index of suspicion is warranted during evaluation to identify all potential factors that may be contributing to disease.

Long-term tolerability of phosphodiesterase-5 inhibitors in pulmonary hypertension of sickle cell disease

OBJECTIVES

Sickle cell disease-related pulmonary hypertension (SCD-PH) is a complex disorder with multifactorial contributory mechanisms. Previous trials have evaluated the efficacy of pulmonary arterial hypertension (PAH) therapies in SCD-PH with mixed results. We hypothesized that a subset of patients with right heart catheterization (RHC) confirmed disease may benefit from PAH therapy.

METHODS

We performed a retrospective chart review of patients with SCD-PH diagnosed by RHC who were treated with phosphodiesterase 5 inhibitor (PDE5-I) therapy for ≥4 months between 2008 and 2019 at two institutions.

RESULTS

Thirty-six patients were included in the analysis. The median age (IQR) upon PDE5-I initiation was 47.5 years (35-51.5 years); 58% were female and twenty-nine (81%) had HbSS disease. Of these, 53% of patients had a history of acute chest syndrome, 42% had a history of venous thromboembolism, and 38% had imaging consistent with chronic thromboembolic PH. Patients were treated for a median duration of 25 months (IQR 13-60 months). Use of PDE5-I was associated with a significant improvement in symptoms as assessed by NYHA Class (P = .002).

CONCLUSIONS

In SCD patients with PH defined by RHC, PDE5-I therapy was tolerated long-term and may improve physical activity.

Sickle cell disease related chronic thromboembolic pulmonary hypertension: challenging clinical scenario

Sickle cell disease (SCD), a haemoglobinopathy characterized by chronic haemolysis with acute exacerbations and vascular occlusion episodes, may be complicated by pulmonary hypertension. The latter may be caused by chronic thromboembolic disease of pulmonary artery branches and its management is not well-defined. Herein, we present a case of SCD complicated by chronic thromboembolic pulmonary hypertension of subsegmental pulmonary artery branches successfully treated with endothelin receptor antagonists, orally administered prostacyclin analogs and balloon pulmonary angioplasty. This challenging case highlights the need for clinical awareness of chronic thromboembolic pulmonary hypertension as a specific and potentially curable form of pulmonary hypertension complicating SCD course that may necessitate combined pharmacologic and interventional management.

Epidemiology, Pathogenesis, and Clinical Approach in Group 5 Pulmonary Hypertension

Pulmonary hypertension (PH) is recognized to be associated with a number of comorbid conditions. Based on these associations, PH is classified into 5 groups, considering common pathophysiologic drivers of disease, histopathologic features, clinical manifestations and course, and response to PH therapy. However, in some of these associated conditions, these characteristics are less well-understood. These include, among others, conditions commonly encountered in clinical practice such as sarcoidosis, sickle cell disease, myeloproliferative disorders, and chronic kidney disease/end stage renal disease. PH in these contexts presents a significant challenge to clinicians with respect to disease management. The most recent updated clinical classification schemata from the 6th World Symposium on PH classifies such entities in Group 5, highlighting the often unclear and/or multifactorial nature of PH. An in-depth review of the state of the science of Group 5 PH with respect to epidemiology, pathogenesis, and management is provided. Where applicable, future directions with respect to research needed to enhance understanding of the clinical course of these entities is also discussed.

Hepatocellular carcinoma in adult thalassemia patients: an expert opinion based on current evidence

Beta-thalassemia represents a heterogeneous group of haemoglobin inherited disorders, among the most common genetic diseases in the world, frequent in the Mediterranean basin. As beta-thalassemia patients' survival has increased over time, previously unknown complications are observed with increasing frequency. Among them, an increased risk of hepatocellular carcinoma (HCC) has been registered. Our aim is to reduce inequalities in diagnosis and treatment and to offer patients univocal recommendations in any institution.The members of the panel - gastroenterologists, radiologists, surgeons and oncologists -were selected on the basis of their publication records and expertise. Thirteen clinical questions, derived from clinical needs, and an integration of all the committee members' suggestions, were formulated. Modified Delphi approach involving a detailed literature review and the collective judgement of experts, was applied to this work.Thirteen statements were derived from expert opinions' based on the current literature, on recently developed reviews and on technological advancements. Each statement is discussed in a short paragraph reporting the current key evidence. As this is an emerging issue, the number of papers on HCC in beta-thalassemia patients is limited and based on anecdotal cases rather than on randomized controlled studies. Therefore, the panel has discussed, step by step, the possible differences between beta-thalassemia and non beta-thalassemia patients. Despite the paucity of the literature, practical and concise statements were generated.This paper offers a practical guide organized by statements describing how to manage HCC in patients with beta-thalassemia.