Down patients with Eisenmenger syndrome: Is bosentan treatment an option?

Recent Advances in Pediatric Pulmonary Hypertension: Implications for Diagnosis and Treatment

PURPOSE

Pediatric pulmonary hypertension (PH) is a condition characterized by elevated pulmonary arterial pressure, which has the potential to be life-limiting. The etiology of pediatric PH varies. When compared with adult cohorts, the etiology is often multifactorial, with contributions from prenatal, genetic, and developmental factors. This review aims to provide an up-to-date overview of the causes and classification of pediatric PH, describe current therapeutics in pediatric PH, and discuss upcoming and necessary research in pediatric PH.

METHODS

PubMed was searched for articles relating to pediatric pulmonary hypertension, with a particular focus on articles published within the past 10 years. Literature was reviewed for pertinent areas related to this topic.

FINDINGS

The evaluation and approach to pediatric PH are unique when compared with that of adults, in large part because of the different, often multifactorial, causes of the disease in children. Collaborative registry studies have found that the most common disease causes include developmental lung disease and subsets of pulmonary arterial hypertension, which includes genetic variants and PH associated with congenital heart disease. Treatment with PH-targeted therapies in pediatrics is often guided by extrapolation of adult data, small clinical studies in pediatrics, and/or expert consensus opinion. We review diagnostic considerations and treatment in some of the more common pediatric subpopulations of patients with PH, including developmental lung diseases, congenital heart disease, and trisomy 21.

IMPLICATIONS

The care of pediatric patients with PH requires consideration of unique pediatric-specific factors. With significant variability in disease etiology, ongoing efforts are needed to optimize treatment strategies based on disease phenotype and guide evidence-based practices.

Hemodynamic Characteristics After Fontan Procedure in Patients with Down's Syndrome

Patients with Down's syndrome (DS) are generally regarded as not being good candidates for the Fontan procedure. However, detailed hemodynamic changes over time are not fully clarified. A retrospective chart review of all patients with DS who underwent the Fontan procedure and 5 times that number of Fontan patients without DS performed in Fukuoka Children's Hospital and Kyushu University Hospital. Seven Fontan patients with DS were identified, and 35 Fontan patients without DS were recruited. During the mean observational periods of 14.7 years and 15.0 years (DS and non-DS, respectively) after the Fontan procedure, only one DS patient died. Central venous pressure (CVP) and transpulmonary pressure gradient significantly increased, and arterial oxygen saturation significantly decreased over time in DS patients after the Fontan procedure compared with those without DS. CVP in DS patients after the Fontan procedure increased over time compared with non-DS patients. Better management including the efficacy of Pulmonary arterial hypertension-specific therapy should be clarified in further studies.

Pulmonary Hypertension in the Population with Down Syndrome

Persons with Down syndrome (DS) have an increased reported incidence of pulmonary hypertension (PH). A majority of those with PH have associations with congenital heart disease (CHD) or persistent pulmonary hypertension of the newborn (PPHN); however, there are likely multifactorial contributions that include respiratory comorbidities. PH appears to be most commonly identified early in life, although respiratory challenges may contribute to a later diagnosis or even a recurrence of previously resolved PH in this population. Currently there are few large-scale, prospective, lifetime cohort studies detailing the impact PH has on the population with DS. This review will attempt to summarize the epidemiology and characteristics of PH in this population. This article will additionally review current known and probable risk factors for developing PH, review pathophysiologic mechanisms of disease in the population with DS, and evaluate current screening and management recommendations while suggesting areas for additional or ongoing clinical, translational, and basic science research.

Palliative care in pulmonary hypertension associated with congenital heart disease: systematic review and expert opinion

AIMS

Pulmonary arterial hypertension (PAH) is common amongst patients with congenital heart disease (CHD). It is a severe and complex condition that adversely affects quality of life and prognosis. While quality of life questionnaires are routinely used in clinical pulmonary hypertension practice, little is known on how to interpret their results and manage PAH-CHD patients with evidence of impaired health-related quality of life, especially those with advanced disease and palliative care needs.

METHODS AND RESULTS

We performed a systematic review of studies concerning palliative care for people with PAH-CHD, also reviewing the health-related quality of life literature pertaining to these patients. Of 330 papers identified through initial screening, 17 were selected for inclusion. Underutilization of advance care planning and palliative care resources was common. Where palliative care input was sought, this was frequently late in the course of the disease. No studies provided evidence-based clinical criteria for triggering referral to palliative care, a framework for providing tailored care in this patient group, or how to manage the risk of sudden cardiac death and implantable cardioverter defibrillators in advanced PAH-CHD. We synthesize this information into eight important areas, including the impact of PAH-CHD on quality of life, barriers to and benefits of palliative care involvement, advance care planning discussions, and end-of-life care issues in this complex patient group, and provide expert consensus on best practice in this field.

CONCLUSIONS

This paper presents the results of a systematic review and expert statements on the preferred palliative care strategy for patients with PAH-CHD.

Preventing disease progression in Eisenmenger syndrome

Introduction: Eisenmenger syndrome describes a condition in which a congenital heart defect has caused severe pulmonary vascular disease, resulting in reversed (right-left) or bidirectional shunting and chronic cyanosis.Areas covered: In this paper, the progression of congenital heart defects to Eisenmenger syndrome, including early screening, diagnosis and operability are covered. The mechanisms of disease progression in Eisenmenger syndrome and management strategies to combat this, including the role of pulmonary arterial hypertension therapies, are also discussed.Expert opinion/commentary: Patients with congenital heart disease (CHD) are at increased risk of developing pulmonary arterial hypertension with Eisenmenger syndrome being its extreme manifestation. All CHD patients should be regularly assessed for pulmonary hypertension. Once Eisenmenger syndrome develops, shunt closure should be avoided. The clinical manifestations of Eisenmenger syndrome are driven by the systemic effects of the pulmonary hypertension, congenital defect and long-standing cyanosis. Expert care is essential for avoiding pitfalls and preventing disease progression in this severe chronic condition, which is associated with significant morbidity and mortality. Pulmonary arterial hypertension therapies have been used alongside supportive care to improve the quality of life, exercise tolerance and the outcome of these patients, although the optimal timing for their introduction and escalation remains uncertain.

Pulmonary hypertension in children with Down syndrome

Individuals with Down syndrome (DS) have an increased risk of developing pulmonary hypertension (PH). In this review, we explore the epidemiology and clinical characteristics of PH in the population with DS and examine genetic, molecular and clinical contributions to the condition. The presence of an additional copy of chromosome 21 (trisomy 21) increases the risk of developing PH in children with DS through many mechanisms, including increased hemodynamic stress in those with congenital heart disease, hypoxemia through impaired ventilation to perfusion matching secondary to developmental lung abnormalities, pulmonary hypoplasia from pulmonary vascular endothelial dysfunction, and an increase in pulmonary vascular resistance often related to pulmonary comorbidities. We review recent studies looking at novel biomarkers that may help diagnose, predict or monitor PH in the population with DS and examine current cardiopulmonary guidelines for monitoring children with DS. Finally, we review therapeutic interventions specific to PH in individuals with DS. Contemporary work has identified exciting mechanistic pathways including the upregulation of antiangiogenic factors and interferon activity, which may lead to additional biomarkers or therapeutic opportunities. Throughout the manuscript, we identify gaps in our knowledge of the condition as it relates to the population with DS and offer suggestions for future clinical, translational, and basic science research.

Advanced therapies in pulmonary arterial hypertension and congenital heart disease in people with Down syndrome

Background

Management of patients with pulmonary arterial hypertension associated with congenital heart disease and trisomy 21 is complex due to uncertainty over the best first-line agent to use for treatment, and the outcome measures for assessing response to therapy. There are also ethical issues around therapeutic decisions which may require ‘best interests’ meetings of carers and health care professionals.

Case presentation

We present a case of a 35-year-old man with Down syndrome, with un-operated atrioventricular septal defect, right ventricular hypertrophy and moderate left atrioventricular valve regurgitation. In the clinic he was visibly cyanosed with peripheral oxygen saturations of 78% at rest. He had very limited walk distance and was in WHO class III.

Conclusions

We discuss the decisions made around the best therapy for his Eisenmenger syndrome taking into account patient and family views on therapy and considering the psychosocial burden of treatment.

Drug Treatment of Pulmonary Hypertension in Children

Pulmonary arterial hypertension (PAH) is a rare disease in infants and children that is associated with significant morbidity and mortality. The disease is characterized by progressive pulmonary vascular functional and structural changes resulting in increased pulmonary vascular resistance and eventual right heart failure and death. In many pediatric patients, PAH is idiopathic or associated with congenital heart disease and rarely is associated with other conditions such as connective tissue or thromboembolic disease. PAH associated with developmental lung diseases such as bronchopulmonary dysplasia or congenital diaphragmatic hernia is increasingly more recognized in infants and children. Although treatment of the underlying disease and reversal of advanced structural changes have not yet been achieved with current therapy, quality of life and survival have improved significantly. Targeted pulmonary vasodilator therapies, including endothelin receptor antagonists, prostacyclin analogs, and phosphodiesterase type 5 inhibitors have resulted in hemodynamic and functional improvement in children. The management of pediatric PAH remains challenging as treatment decisions depend largely on results from evidence-based adult studies and the clinical experience of pediatric experts. This article reviews the current drug therapies and their use in the management of PAH in children.

Cardiovascular disease in Down syndrome

PURPOSE OF REVIEW

In the last 40 years, with a better understanding of cardiac defects, and with the improved results of cardiac surgery, the life expectancy of persons with Down syndrome has significantly increased. This review article reports on advances in knowledge of cardiac defects and cardiovascular system of persons with trisomy 21.

RECENT FINDINGS

New insights into the genetics of this syndrome have improved our understanding of the pathogenetic mechanisms of cardiac defects. Recent changes in neonatal prevalence of Down syndrome suggest a growing number of children with cardiac malformations, in particular with simple types of defects. Ethnic and sex differences of the prevalence of specific types of congenital heart disease (CHD) have also been underlined. A recent study confirmed that subclinical morphologic anomalies are present in children with trisomy 21, also in the absence of cardiac defects, representing an internal stigma of Down syndrome. The results of cardiac surgery are significantly improved in terms of immediate and long-term outcomes, but specific treatments are indicated in relation to pulmonary hypertension. Particular aspects of the cardiovascular system have been described, clarifying a reduced sympathetic response to stress but also a 'protection' from atherosclerosis and arterial hypertension in these patients.

SUMMARY

Continuing dedication to clinical and basic research studies is essential to further improve survival and the quality of life from childhood to adulthood of patients with trisomy 21.

The Effect of Endothelin Receptor Antagonists in Patients with Eisenmenger Syndrome: A Systematic Review

INTRODUCTION

The efficacy of endothelin receptor antagonists (ERAs) in the management of Eisenmenger syndrome (ES) remains controversial. The aim of this study is to systemically review the safety and effects of ERAs in improving the quality of life and basic cardiac functions of these patients.

METHODS

Twelve databases were searched, including PubMed, Web of Science, Scopus, Virtual Health Library, World Health Organization (WHO) Global Health Library, Google Scholar, POPLINE, Systems for Information of Grey Literature in Europe, New York Academy of Medicine, ClinicalTrials.gov, metaRegister of Controlled Trials and the WHO International Clinical Trials Registry Platform, through August 2016. We included randomized clinical trials addressing the effect of ERAs on cardiac functions in patients with ES. The quality of studies was assessed using the Cochrane Collaboration tool.

RESULTS

We included two trials represented by four papers, of which three papers reported the efficacy of bosentan against placebo and one paper reported the results of a combination of bosentan and sildenafil versus placebo and bosentan. One trial showed a significant effect of bosentan treatment over placebo on indexed pulmonary vascular resistance and mean pulmonary artery pressure, but a non-significant increase in 6-min walk distance and a non-significant effect on systemic pulse oximetry. The other trial reported the safe but non-significant effect of combination therapy of bosentan and sildenafil compared with bosentan and placebo.

CONCLUSIONS

This study demonstrated safety and improved hemodynamic effects of bosentan in ES, with a controversial effect on exercise capacity. Further randomized controlled trials with longer follow-up duration are needed to confirm these results.

Efficacy and safety of oral sildenafil in children with Down syndrome and pulmonary hypertension

BACKGROUND

Despite the increased risk for pulmonary hypertension in children with Down syndrome, the response to treatment with targeted therapies for pulmonary hypertension in these patients is not well characterized. The Sildenafil in Treatment-naive children, Aged 1-17 years, with pulmonary arterial hypertension (STARTS-1) trial was a dose-ranging study of the short-term efficacy and safety of oral sildenafil in children with pulmonary arterial hypertension. We assessed the safety and efficacy of oral sildenafil in children with Down syndrome and pulmonary arterial hypertension.

METHODS

This was a post-hoc analysis of children with Down syndrome and pulmonary arterial hypertension enrolled in the STARTS-1 trial. Mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance index (PVRI), and cardiac index (CI) were assessed at baseline and following 16 weeks of treatment with sildenafil.

RESULTS

Of 234 patients randomized and treated in the STARTS-1 trial, 48 (20.5%) had Down syndrome. Although sildenafil produced dose-related reductions in PVRI and mPAP, compared with placebo, in non-Down syndrome patients and children developmentally able to exercise, this was not satisfactorily marked in patients with Down syndrome. The dose-related reductions in PVRI, compared with placebo, occurred in all subgroups, with the exception of the Down syndrome subgroup. Sildenafil appeared to be well tolerated in the Down syndrome subpopulation and the most frequently reported AEs were similar to those reported for the entire STARTS-1 population.

CONCLUSION

Sildenafil treatment for 16 weeks had no effect on PVRI or mPAP in children with Down syndrome and pulmonary arterial hypertension. The results suggest that children with Down syndrome may be less responsive to sildenafil for pulmonary arterial hypertension, but the incomplete work-up for the etiology of pulmonary arterial hypertension may have introduced a potential bias.

TRIAL REGISTRATION

Study received, September 8, 2005 (retrospectively registered); Study start, August 2003; ClinicalTrials.gov identifier, NCT00159913 .

Advanced Therapy in Eisenmenger Syndrome: A Systematic Review

Treatment options for patients with the Eisenmenger syndrome have until recently been scarce, but new knowledge in the field of pulmonary arterial hypertension has expanded the therapeutic possibilities for these patients. Advanced therapy with pulmonary vasodilators has become part of the standard treatment, offering long-term benefits on exercise capacity, clinical symptoms, and possibly survival. However, there are currently only few studies to guide the use of advanced therapies in this population, and important questions such as indications for initiation or escalation of advanced therapy and valid effect parameters and treatment goals remain unanswered. This review covers the pharmacology, therapeutic options, risk stratification, and treatment strategy of pulmonary arterial hypertension-specific drugs in patients with Eisenmenger syndrome.

The Changing Landscape of Pulmonary Arterial Hypertension in the Adult with Congenital Heart Disease

Pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) is a common type of pulmonary arterial hypertension (PAH) and a frequent complication of congenital heart disease (CHD). PAH-CHD represents a heterogeneous patient population and it is important to distinguish between the underlying cardiac defects considering the prognostic and therapeutic implications. Improved interventional techniques have enabled repair or palliation of most cardiac defects, though a substantial number of patients remain at high risk for PAH after closure. Traditionally, the treatment and management of PAH-CHD patients has been limited to palliative and supportive care, and based on expert opinion rather than clinical trials. Recently, however, the availability of advanced PAH-specific treatment has opened up a new field for the clinical management of this condition. Nevertheless, there is limited evidence on the optimal therapeutic approach for PAH-CHD. Herein, we discuss the current and novel therapeutic options for PAH-CHD as well as highlight several challenges in the clinical management at present.

What people with Down Syndrome can teach us about cardiopulmonary disease

Down syndrome is the most common chromosomal abnormality among live-born infants. Through full or partial trisomy of chromosome 21, Down syndrome is associated with cognitive impairment, congenital malformations (particularly cardiovascular) and dysmorphic features. Immune disturbances in Down syndrome account for an enormous disease burden ranging from quality-of-life issues (autoimmune alopecia) to more serious health issues (autoimmune thyroiditis) and life-threatening issues (leukaemia, respiratory tract infections and pulmonary hypertension). Cardiovascular and pulmonary diseases account for ∼75% of the mortality seen in persons with Down syndrome. This review summarises the cardiovascular, respiratory and immune challenges faced by individuals with Down syndrome, and the genetic underpinnings of their pathobiology. We strongly advocate increased comparative studies of cardiopulmonary disease in persons with and without Down syndrome, as we believe these will lead to new strategies to prevent and treat diseases affecting millions of people worldwide.

Decrease in quality of life predicts mortality in adult patients with pulmonary arterial hypertension due to congenital heart disease

Background

Decrease in quality of life (QoL) in left-sided heart failure precedes poor survival, which can be reversed with exercise training. We investigated whether QoL is associated with mortality in pulmonary arterial hypertension due to congenital heart disease (PAH-CHD) patients.

Methods

In this observational study, PAH-CHD adults referred for PAH-specific therapy were included. QoL surveys (SF36) were recorded during 2 years of therapy. Based on shift in SF36 scores during this period, patients had either decreased or non-decreased QoL. Subsequently, the patients were followed for mortality.

Results

Thirty-nine PAH-CHD patients (mean age 42, 44 % male, 49 % Down’s syndrome) were analysed. Following PAH-specific therapy, SF36 physical component summary (PCS) decreased in 13 (35–31 points, p = 0.001) and showed no decrease in 26 patients (34–43 points, mean values, p < 0.001). Post-initiation phase, median follow-up was 4.5 years, during which 12 deaths occurred (31 %), 10 (56 %) in the decreased and 2 (10 %) in the non-decreased group (p = 0.002). Cox regression showed a decrease in SF36 PCS predicted mortality (HR 3.4, 95 % CI 1.03–11, p = 0.045).

Conclusions

In PAH-CHD patients, decrease in SF36 PCS following initiation of PAH-specific therapy is a determinant of mortality.

Electronic supplementary material

The online version of this article (doi:10.1007/s12471-015-0666-9) contains supplementary material, which is available to authorized users.

Clinical characteristics of pulmonary arterial hypertension associated with Down syndrome

The genetic abnormalities associated with Down syndrome (DS) are still being identified. Few studies have examined the roles of CRELD1 and GATA4 in cardiac abnormalities or their association with pulmonary artery histopathology. Children with DS have an elevated risk of pulmonary arterial hypertension (PAH). This increased risk is likely mainly due to genetic background, the structural characteristics of the pulmonary vascular wall, and certain heart diseases and partly due to pulmonary hypoplasia, upper and lower airway obstructive diseases, chronic infection, and neuromuscular underdevelopment. Exposure to increased left-to-right shunt flow increases sheer stress on endothelium and may induce endothelial dysfunction followed by irreversible remodeling of pulmonary arteries. Pathologic changes include endothelial cell proliferation and thickening of the pulmonary arterial wall due to mechanical responses to the thinner medial smooth muscle cell layer, which includes underdevelopment of alveoli. Production of prostacyclin and nitric oxide is diminished in DS, but endothelin-1 and thromboxane are elevated. Perioperatively, patients with DS may experience pulmonary hypertensive crisis after intracardiac repair and prolonged PAH, and have a poorer response to nitric oxide inhalation. To better manage DS, it is crucial to systematically evaluate the systemic complications of DS. Cardiac catheterization data, particularly those regarding pulmonary arterial resistance, are essential in assessing severity and response to vasodilating agents, preventing postoperative crisis, and evaluating the possibility of intracardiac repair. Advanced therapy with pulmonary vasodilating agents appears effective. Operative risk is similar for individuals with and without DS, except among patients with a complete atrioventricular canal defect.

Pulmonary hypertension in adults with congenital heart disease and Eisenmenger syndrome: current advanced management strategies

The presence of pulmonary arterial hypertension (PAH) increases morbidity and reduces survival in patients with congenital heart disease (CHD). PAH-CHD is a heterogeneous condition, depending on the type of the underlying defect and previous repair strategies. There is growing evidence of the benefits of PAH-specific therapy in the PAH-CHD population, but despite recent advances mortality rates remain relatively high. In the last years, an increasing focus has been placed on patients with PAH-CHD and net left-to-right shunt. Currently, there are limited data to guide the management of these patients and uncertainty on the cut-off values for eventual defect closure. Pregnancy conveys significant risks in PAH-CHD patients: appropriate counselling and care, including psychological support and a multidisciplinary team, should be part of the routine management of women with PAH-CHD of reproductive age. Some subgroups, such as patients with Down's syndrome, Fontan circulation and 'segmental' pulmonary hypertension, present particular challenges in terms of management and therapy. The current review focuses on contemporary treatment strategies in PAH-CHD patients with particular emphasis on challenging patient groups and conditions.

Drug treatment of pulmonary hypertension in children

Pulmonary arterial hypertension (PAH) is a rare disease in infants and children that is associated with significant morbidity and mortality. The disease is characterized by progressive pulmonary vascular functional and structural changes resulting in increased pulmonary vascular resistance and eventual right heart failure and death. In the majority of pediatric patients, PAH is idiopathic or associated with congenital heart disease and rarely is associated with other conditions such as connective tissue or thromboembolic disease. Although treatment of the underlying disease and reversal of advanced structural changes has not yet been achieved with current therapy, quality of life and survival have been improved significantly. Targeted pulmonary vasodilator therapies, including endothelin receptor antagonists, prostacyclin analogs, and phosphodiesterase type 5 inhibitors, have demonstrated hemodynamic and functional improvement in children. The management of pediatric PAH remains challenging, as treatment decisions continue to depend largely on results from evidence-based adult studies and the clinical experience of pediatric experts. This article reviews the current drug therapies and their use in the management of PAH in children.

Long-term results of treatment with bosentan in adult Eisenmenger's syndrome patients with Down's syndrome related to congenital heart disease

Background

Patients with Down’s syndrome and shunt lesions are at high risk of developing pulmonary arterial hypertension (PAH) earlier than patients without Down’s syndrome. However, data on the efficacy of PAH-specific therapy in patients with Down’s syndrome are limited. The aim of this retrospective analysis was to determine the long-term efficacy of the dual endothelin receptor antagonist, bosentan, in Eisenmenger's syndrome (ES) patients with Down’s syndrome.

Methods

In this observational study adults with Down’s syndrome with a confirmed diagnosis of ES (World Health Organization functional class III) and receiving bosentan therapy and were followed up long term. Clinical evaluation at baseline and follow-up visits included resting transcutaneous arterial oxygen saturation and laboratory assessments. Exercise capacity was evaluated using a 6-minute walk test where transcutaneous arterial oxygen saturation at peak exercise (SpO₂), 6-minute walk distance (6MWD) and Borg dyspnoea index were assessed. A full echocardiographic assessment was conducted at baseline and follow-up visits.

Results

Overall, seven adults (mean age 29.6 ± 11.2 years; 57% male) received bosentan at a starting dose of 62.5 mg twice daily. This was increased to the target dose of 125 mg twice daily 4 weeks later. All patients remained on bosentan until the end of the study. After a mean (± standard deviation) duration of 52.2 ± 3.9 months (range: 46.0–55.5 months), 6MWD had increased from 199.6 ± 69.1 metres to 303.7 ± 99.9 metres (P < 0.05) and SpO₂ at the end of the 6-minute walk test had increased from 61.6 ± 7.6% to 74.7 ± 6.2% (P < 0.05). Echocardiography demonstrated a significant change in acceleration time from 62.9 ± 11.6 m/s to 83.0 ± 9.6 m/s (P = 0.0156), and acceleration time/ejection time ratio from the pulmonary flow from 0.24 ± 0.04 at baseline to 0.30 ± 0.02 (P = 0.0156) at final follow-up.

Conclusions

Long-term treatment with bosentan significantly improved exercise capacity and oxygen saturation following exercise in adult ES patients with Down’s syndrome. These data confirm that the presence of Down’s syndrome does not affect the response to oral bosentan therapy.

Current challenges in pediatric pulmonary hypertension

Pulmonary arterial hypertension (PAH) in the pediatric population is associated with a variety of underlying diseases and causes, significantly morbidity and mortality. In the majority of patients, PAH in children is idiopathic or associated with congenital heart disease (CHD), with pulmonary hypertension (PH) associated with connective tissue disease, a rare cause in children. Classification of pediatric PH has generally followed the WHO classification, but recognition of the importance of fetal origins of PH and developmental abnormalities have led to the formation of a new pediatric-specific classification. Incidence data from the Netherlands has revealed an annual incidence and point prevalence of 0.7 and 4.4 for idiopathic PAH and 2.2 and 15.6 for associated pulmonary arterial hypertension-CHD cases per million children. Although the treatment with new selective pulmonary vasodilators offers hemodynamic and functional improvement in pediatric populations, the treatments in children largely depend on results from evidence-based adult studies and experience of clinicians treating children. A recent randomized clinical trial of sildenafil and its long-term extension has led to disparate recommendations in the United States and Europe.

Effect of bosentan on exercise capacity and clinical worsening in patients with dual down and eisenmenger syndrome

This single-center, retrospective analysis evaluated long-term bosentan treatment in adult patients (n = 7) with both Down and Eisenmenger syndromes (DS-ES). Laboratory tests, 6-minute walk distance (6MWD), functional class, and Doppler echocardiography were assessed at baseline and during 2 years' follow-up. Improvements or maintenance of 6MWD were observed (68 m improvement from baseline at month 12) after bosentan initiation. 6MWD was maintained up to year 2. Overall, 6 patients experienced a significant improvement in functional class during 2 years' therapy (P = 0.01). There were no significant changes in parameters measured by Doppler echocardiography. None of the patients required either hospitalization or additional pulmonary arterial hypertension (PAH) therapy because of PAH progression. Bosentan treatment was generally well tolerated; no liver function abnormalities or serious adverse drug reactions were noted. In this DS-ES cohort, bosentan seemed to be well tolerated and clinically effective.

Adults with Down syndrome have reduced cardiac response after light exercise testing

Objective

Physical fitness is reduced in adults with Down syndrome (DS). The present study was conducted to elucidate the exercise response in adults with DS.

Design

Case controlled before-after trial.

Setting

Residential centre for people with intellectual disabilities.

Participants

96 Adults with DS, 25 non-DS adults with an intellectual disability, 33 controls.

Interventions

Echocardiography to exclude heart defects and to measure cardiac index (CI) in the supine position, supine position with raised legs, and following ten knee bends.

Main outcome measure

Exercise testing

Results

At rest, mean CI was not significantly different between persons with DS and controls (2.3 vs. 2.4 l/min/m², p = 0.3). However, mean CI after exercise was significantly lower in DS (2.9 vs. 3.7 l/min/m², p < 0.001) and mean CI increase from rest to exercise was more than 50% lower in DS. On the contrary, CI after exercise was similar among controls and non-DS adults with an intellectual disability. Significantly lower stroke volumes in DS were found with insufficient heart rate response.

Conclusions

CI at rest was similar in adults with DS and controls; however persons with DS have a diminished cardiac response to exercise. Stroke volumes were significantly lower in DS during exercise and a compensated heightened heart rate was absent.

Prolonged beneficial effect of bosentan treatment and 4-year survival rates in adult patients with pulmonary arterial hypertension associated with congenital heart disease

Pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD) due to systemic to pulmonary shunting is associated with a high risk of morbidity and mortality. In this study we evaluated 4 years treatment effect of bosentan on exercise capacity and quality of life and survival rates in 64 adult patients with PAH associated with CHD, including patients with Down syndrome (DS). All patients were evaluated at baseline and during follow-up with laboratory tests, 6-minute walk test, quality of life questionnaires, and Doppler echocardiography. In total, 13 patients (20%) died during 4-years of follow-up; 4 patients with DS and 9 patients without DS. Mean follow-up of all patients treated with bosentan was 3.5 ± 1.2 year. We analyzed treatment efficacy separately within patients without DS (n=34) and patients with DS (n=30). Mean 6-minute walking distance (6 MWD) in patients without DS significantly increased at 6 months from 417 ± 108 to 458 ± 104 m (+41 m; p=0.002) and significant improvement continued to exist during at least 2.5 years of follow-up (p=0.003). Moreover, stroke volume increased significantly (p=0.02). In the patients with DS, 6-MWD, stroke volume and quality of life remained stable during treatment. In this study we demonstrate a prolonged beneficial effect of bosentan treatment on exercise capacity, stroke volume and quality of life in patients without DS. However the mortality rate of 20% of patients after 4 years of follow-up remains high.

Adult patients with pulmonary arterial hypertension due to congenital heart disease: a review on advanced medical treatment with bosentan

Pulmonary arterial hypertension (PAH) is a progressive disease with poor survival outcome. PAH is classified by the 2009 updated clinical classification of pulmonary hypertension and a major subgroup is PAH due to congenital heart disease (CHD) with systemic-to-pulmonary shunt. CHD-PAH is a result of systemic-to-pulmonary shunting and chronic increased flow that ultimately results in adaptations of pulmonary vasculature and endothelial dysfunction. The advanced stage is called Eisenmenger syndrome which forms a small percentage (1%) of all CHD patients. Therapies targeted on PAH symptoms are called primary therapy for PAH, but most CHD-PAH patients progress to advanced therapy which is directed at the PAH itself. In CHD-PAH, advanced therapies are extensively investigated for all three major pathways: endothelin-1 receptor antagonists such as bosentan, prostanoids such as epoprostenol and phosphodiesterase 5 inhibitors such as sildenafil. Endpoints in most trials were catheterization hemodynamics, World Health Organization functional class, six-minute walking distance and patient-focused outcomes, based on quality of life questionnaires and Borg dyspnea index. The BREATHE-5 and EARLY study were two important randomized controlled trials showing efficacy of bosentan at short follow-up. Moreover in patients with Eisenmenger syndrome, one recent survival retrospective study with majority of patients on bosentan showed strong survival benefit over conservative therapy. A diversity of prospective cohort and retrospective studies were performed but all with limited data, due to small numbers and heterogeneity of underlying CHD diagnoses. Further larger studies are needed to determine optimal treatment for adults with CHD-PAH. This review focuses on bosentan in CHD-PAH. In particular, we discuss outcome of various clinical trials and compare efficacy and safety of bosentan to other advanced therapies.

The role of calcium channel blockers, steroids, anticoagulation, antiplatelet drugs, and endothelin receptor antagonists

The rationale for the drug therapy of pulmonary artery hypertension is to reduce mortality and morbidity caused by failure of right ventricular adaptation to an elevated pulmonary vascular resistance. We review the evidence for the use of calcium-channel blockers, steroids, anticoagulation, antiplatelet drugs, and endothelin receptor antagonists in the management of pulmonary artery hypertension. The drugs we discuss are more suited to long-term outpatient therapy. These drugs have not found a routine place in intensive care management, and calcium-channel blockers are contraindicated in patients with right-heart failure. The efficacy of many agents has been extrapolated from data acquired in adult patients and applied to children. All of us involved in the care of young patients with pulmonary artery hypertension should advocate for both the inclusion of younger patients in clinical trials and the design of distinctly pediatric trials with pharmaceutical and drug administration agencies. It is only with data derived from pediatric inclusive studies that we shall be able to recommend therapy with strong evidence. However, it is important to point out that the use of newer agents for the treatment of chronic pulmonary artery hypertension (prostacyclin, endothelin receptor antagonists, nitric oxide, and sildenafil) have not been shown to improve survival unequivocally and have relied on surrogates, such as exercise capacity. There are no long-term studies of survival benefit. Recent studies have included data on time to clinical worsening, which may be a more predictive surrogate of survival.

Six-minute walk test in patients with Down syndrome: validity and reproducibility

OBJECTIVES

To examine the validity of the six-minute walk test (6MWT) as a tool to evaluate functional exercise performance in patients with Down syndrome (DS).

DESIGN

Comparison of the six-minute walk distance (6MWD) in 2 distinct groups of DS patients: with and without severe cardiac disease. To test reproducibility, a group of patients with DS performed the 6MWT twice.

SETTING

Tertiary referral centers for patients with congenital heart defects and outpatient clinics for people with intellectual disabilities.

PARTICIPANTS

Adult patients with DS with (n=29) and without (n=52) severe cardiac disease categorized by cardiac echocardiography.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Distance walked on the 6MWT.

RESULTS

The mean 6MWD in the group with severe cardiac disease was 289+/-104 m and in the group without severe cardiac disease 280+/-104 m (P=.70). Older age, female sex, and severe level of intellectual disability were all found to be independently and significantly correlated with a lower 6MWD (r=.67, P<.001). The paired 6MWD was not significantly different (310+/-88 m vs 317+/-85 m; P=.40) in patients who performed the 6MWT twice. The coefficient of variation was 11%.

CONCLUSIONS

The 6MWD between the 2 groups was not significantly different. However, the walking distance inversely correlated with the level of intellectual disability. Therefore, the 6MWT is not a valid test to examine cardiac restriction in adult patients with DS.