Pulmonary arterial hypertension in congenital heart disease: An epidemiologic perspective from a Dutch registry

Classification of pulmonary hypertension

Pulmonary hypertension (PH) can develop in association with many different diseases and risk factors, and its presence is nearly always associated with reduced survival. The prognosis and management of PH is largely dependent upon its underlying etiology and severity of disease. The combination of clinical and hemodynamic classifications of PH provides a framework for the diagnostic evaluation of PH to establish a final clinical diagnosis that guides therapy. As our understanding of the different pathologic mechanisms that underlie the syndrome of PH evolves, so too will the classification and treatment of PH.

Congenital heart disease and pulmonary hypertension

Many patients with congenital heart disease and systemic-to-pulmonary shunts develop pulmonary arterial hypertension (PAH), particularly if the cardiac defect is left unrepaired. A persistent increase in pulmonary blood flow may lead to obstructive arteriopathy and increased pulmonary vascular resistance, a condition that can lead to reversal of shunt and cyanosis (Eisenmenger syndrome). Cardiac catheterization is crucial to confirm diagnosis and facilitate treatment. Bosentan is the only medication to date to be compared with placebo in a randomized controlled trial specifically targeting congenital heart disease-associated PAH. Lung transplantation with repair of the cardiac defect or combined heart-lung transplantation is reserved for recalcitrant cases.

Congenital heart disease in pregnancy

Heart disease is a main cause of maternal mortality in the United States and the United Kingdom. Most deaths are from acquired conditions. However, due to the increased survival of children born with congenital heart disease (CHD) over the past 30 years, the population of adults with congenital heart disease in the U.S. now exceeds 1 million. Thus, there are now more adults with CHD than children with CHD. Many of these adult survivors of pediatric heart disease are of childbearing age and are considering pregnancy. This article reviews the literature concerning pregnancy and CHD.

Mechanisms of exercise-induced pulmonary hypertension in patients with cardiac septal defects

The objective of this study was to investigate mechanisms of exercise-induced pulmonary hypertension in patients with congenital cardiac septal defects. This was a randomized, placebo controlled, crossover drug trial in a single national pediatric cardiology centre that performs congenital cardiac defect surgery. There were 14 patients with cardiac septal defects and known exercise-induced pulmonary hypertension. The intervention consisted of 50 mg oral sildenafil versus placebo. Measurements included supine bicycle exercise echocardiography and oxygen uptake. The outcome measure was right-ventricular systolic pressure as estimated by Doppler tracings of tricuspid regurgitant jet as well as systolic and diastolic longitudinal myocardial velocities by color tissue Doppler echocardiography. Sildenafil did not change exercise right-ventricular systolic pressure during exercise; however, decreased systemic systolic pressure was seen. Enhanced biventricular longitudinal function with sildenafil compared with placebo was indicated by greater tissue Doppler velocities and displacement measurements during exercise. Finally, a less steep increase of right-ventricular pressure during exercise was associated with greater left-ventricular diastolic myocardial tissue Doppler velocity. Exercise-induced pulmonary hypertension in cardiac septal defects does not seem to have a pulmonary vasoconstrictive component, but it may be related to left-ventricular filling pressure. Furthermore, sildenafil improved biventricular systolic performance in this patient group, possibly related to decreased systemic afterload.

Adult congenital heart disease and pulmonary arterial hypertension: the Texas Adult Congenital Heart Program experience

Congenital heart disease (CHD) is a common structural defect of the heart or major blood vessels. Patients with adult congenital heart disease (ACHD) have medical needs that are distinct from those of pediatric patients with CHD, and the transition into adult health care is important for management of the patient with ACHD. A large proportion of patients with CHD develop diseases and complications associated with the long-term stress of intracardiac shunts. Pulmonary arterial hypertension (PAH) is a significant complication of some CHD lesions. The treatment of these patients remains challenging due to their combined heart and lung disease, and multidisciplinary care is ofen necessitated for a variety of secondary conditions. A number of treatment options are available for the management of PAH associated with CHD, including prostanoids, phosphodiesterase type-5 inhibitors, and endothelin receptor antagonists. This article discusses the diagnosis and management of such ACHD patients with PAH.

Pulmonary arterial hypertension: an update

Pulmonary arterial hypertension (PAH), defined as group 1 of the World Heart Organisation (WHO) classification of pulmonary hypertension, is an uncommon disorder of the pulmonary vascular system. It is characterised by an increased pulmonary artery pressure, increased pulmonary vascular resistance and specific histological changes. It is a progressive disease finally resulting in right heart failure and premature death. Typical symptoms are dyspnoea at exercise, chest pain and syncope; furthermore clinical signs of right heart failure develop with disease progression. Echocardiography is the key investigation when pulmonary hypertension is suspected, but a reliable diagnosis of PAH and associated conditions requires an intense work-up including invasive measurement by right heart catheterisation. Treatment includes general measures and drugs targeting the pulmonary artery tone and vascular remodelling. This advanced medical therapy has significantly improved morbidity and mortality in patients with PAH in the last decade. Combinations of these drugs are indicated when treatment goals of disease stabilisation are not met. In patients refractory to medical therapy lung transplantation should be considered an option.

Pediatric Pulmonary Hypertension in the Netherlands

Background—

Incidence and prevalence rates for pediatric pulmonary hypertension (PH) and pulmonary arterial hypertension (PAH) are unknown. This study describes the nationwide epidemiological features of pediatric PH in the Netherlands during a 15-year period and the clinical course of pediatric PAH.

Methods and Results—

Two registries were used to retrospectively identify children (0–17 years) with PH. Overall, 3263 pediatric patients were identified with PH due to left heart disease (n=160; 5%), lung disease/hypoxemia (n=253; 8%), thromboembolic disease (n=5; <1%), and transient (n=2691; 82%) and progressive (n=154; 5%) PAH. Transient PAH included persistent PH of the newborn and children with congenital heart defects (CHD) and systemic-to-pulmonary shunt, in whom PAH resolved after successful shunt correction. Progressive PAH mainly included idiopathic PAH (n=36; iPAH) and PAH associated with CHD (n=111; PAH-CHD). Pulmonary arterial hypertension associated with CHD represented highly heterogeneous subgroups. Syndromes were frequently present, especially in progressive PAH (n=60; 39%). Survival for PAH-CHD varied depending on the subgroups, some showing better and others showing worse survival than for iPAH. Survival of children with Eisenmenger syndrome appeared worse than reported in adults. For iPAH and PAH-CHD, annual incidence and point prevalence averaged, respectively, 0.7 and 4.4 (iPAH) and 2.2 and 15.6 (PAH-CHD) cases per million children. Compared to studies in adults, iPAH occurred less whereas PAH-CHD occurred more frequently.

Conclusions—

Pediatric PH is characterized by various age-specific diagnoses, the majority of which comprise transient forms of PAH. Incidence of pediatric iPAH is lower whereas incidence of pediatric PAH-CHD is higher than reported in adults. Pediatric PAH-CHD represents a heterogeneous group with highly variable clinical courses.

Bosentan in pulmonary arterial hypertension: a comparison between congenital heart disease and chronic pulmonary embolism

Background. In patients with pulmonary hypertension, it is unknown whether the treatment effect of bosentan is dependent on the duration of pulmonary vessel changes. Therefore, we studied the response to bosentan in patients with life-long pulmonary vessel changes (pulmonary arterial hypertension (PAH) due to congenital heart disease (CHD)) and in patients with subacutely induced pulmonary vessel changes (chronic thromboembolic pulmonary hypertension (CTEPH)).Methods. In this open-label study, 18 patients with PAH due to CHD and 16 patients with CTEPH were treated with bosentan for at least one year. All patients were evaluated at baseline and during follow-up by means of the six-minute walk distance (6-MWD) and laboratory tests.Results. Improvement of 6-MWD was comparable in patients with PAH due to CHD (444+/-112 m to 471+/-100 m, p=0.02), and in CTEPH (376+/-152 m to 423+/-141 m, p=0.03) after three months of treatment. After this improvement, 6-MWD stabilised in both groups.Conclusion. Although duration of pulmonary vessel changes is strikingly different in patients with PAH due to CHD and CTEPH, the effect of one year of bosentan treatment was comparable. The main treatment effect appears to be disease stabilisation and decreasing the rate of deterioration. (Neth Heart J 2009;17:334-8.).

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.

Early detection of pulmonary vascular disease in pulmonary arterial hypertension: time to move forward

Pulmonary arterial hypertension (PAH) can be a rapidly progressive disorder and is associated with high rate of mortality, despite medical intervention. With the availability of effective therapy, early disease detection is an important strategic objective to improve treatment outcomes. Resting echocardiography is currently the recommended screening modality for high-risk population groups. However, it is clear that derangements in resting haemodynamics (and symptoms) are late sequelae of the pathobiological processes that begin in the distal pulmonary arteries. Exercise stress may unmask early pulmonary vascular dysfunction but the definition, clinical significance, and natural history of 'exercise PAH' remain undefined. We will review the currently available and potential future strategies aimed at early disease detection, and propose that ultimately the way forward is to detect disease at a stage prior to the rise in resting pulmonary artery pressure.

No inflammatory response related to pulmonary hemodynamics in children with systemic to pulmonary shunts

OBJECTIVE

The hypothesis was that the levels of circulating inflammatory mediators are related to the degree of volume and pressure stress on the pulmonary vasculature in children with congenital systemic to pulmonary shunts.

DESIGN

Prospective, cross-sectional study.

SETTING

Tertiary center covering all pediatric heart surgery and interventions in Norway.

PATIENTS

Seventy-four children, aged 0-12 years, admitted for surgical or interventional treatment of congenital systemic to pulmonary shunts.

OUTCOME MEASURES

Plasma levels of eight mediators of vascular inflammation and endothelial activation, sampled from different vascular compartments.

RESULTS

Patients with the most pronounced pulmonary flow and pressure stress demonstrated no elevation of inflammatory mediator levels when compared with healthy controls. No pulmonary production or uptake of the measured markers was found. Hemodynamic explanatory factors showed weak correlations to the inflammatory marker levels by univariate analysis. Age was the only factor that significantly explained inflammatory response in the multivariate model. The presence of Down syndrome, irrespective of hemodynamic category, was associated with elevated plasma levels of soluble tumor necrosis factor receptor I, when controlling for age.

CONCLUSIONS

Inflammatory mediators show no significant relationship to pulmonary hemodynamics in children with systemic to pulmonary shunts. Children with Down syndrome may have an increased inflammatory response.

Ventricular septal defect

Ventricular septal defects account for up to 40% of all congenital cardiac malformations. The diagnosis encompasses a broad range of anomalies, including isolated defects and those associated with other congenital cardiac malformations. Presentation, symptoms, natural history, and management of ventricular septal defects depend on size and anatomical associations of the anomaly, patient's age, and local diagnostic and interventional expertise. In this Seminar, we describe the anatomical range of ventricular septal defects and discuss present management of these malformations. Genetic determinants, diagnostic techniques, physiological considerations, and management challenges are examined in detail. Unfortunately, in many circumstances, evidence on which to guide optimum management is scarce. We present some longer term considerations of ventricular septal defects in adolescents and adults, with particular emphasis on patients with raised pulmonary vascular resistance and Eisenmenger's syndrome.

Pulmonary hypertension in congenital shunts

Pulmonary arterial hypertension frequently arises in patients with congenital heart disease. The vast majority present with congenital cardiac shunts. Initially these may manifest as left-to-right (i.e. systemic-to-pulmonary) shunts. The natural history of disease progression involves vascular remodeling and dysfunction that lead to increased pulmonary vascular resistance and, finally, to the development of Eisenmenger's syndrome, which is the most advanced form. The anatomical, pathological and structural abnormalities occurring in the pulmonary circulation of these patients are, to some extent, similar to those observed in other forms of pulmonary arterial hypertension. This understanding has recently led to significant changes in the management of Eisenmenger's syndrome, with the introduction of treatment specifically targeting pulmonary vascular disease. Early closure of the cardiac shunt remains the best way of preventing pulmonary vascular lesions. However, it is still not clear which preoperative parameters predict safe and successful repair, though hemodynamic evaluation is still routinely used for assessment. Postoperative pulmonary hypertension, both in the immediate period after surgical repair and during long-term follow-up, remains a real therapeutic challenge. The clinical situation of a single ventricle with Fontan circulation also presents difficulties when pulmonary vascular lesions are present. This article reviews pulmonary hypertension associated with congenital shunts and discusses a number of the specific problems encountered.

Pulmonary arterial hypertension in adults with congenital heart disease

Pulmonary arterial hypertension (PAH) is a common problem in adult patients with congenital heart disease. We review available data on aetiology, clinical presentation, prognosis and management of PAH in this setting. In addition, we discuss general management strategies and emerging disease-targeting therapies.

The changing epidemiology of congenital heart disease

Congenital heart disease is the most common congenital disorder in newborns. Advances in cardiovascular medicine and surgery have enabled most patients to reach adulthood. Unfortunately, prolonged survival has been achieved at a cost, as many patients suffer late complications, of which heart failure and arrhythmias are the most prominent. Accordingly, these patients need frequent follow-up by physicians with specific knowledge in the field of congenital heart disease. However, planning of care for this population is difficult, because the number of patients currently living with congenital heart disease is difficult to measure. Birth prevalence estimates vary widely according to different studies, and survival rates have not been well recorded. Consequently, the prevalence of congenital heart disease is unclear, with estimates exceeding the number of patients currently seen in cardiology clinics. New developments continue to influence the size of the population of patients with congenital heart disease. Prenatal screening has led to increased rates of termination of pregnancy. Improved management of complications has changed the time and mode of death caused by congenital heart disease. Several genetic and environmental factors have been shown to be involved in the etiology of congenital heart disease, although this knowledge has not yet led to the implementation of preventative measures. In this Review, we give an overview of the etiology, birth prevalence, current prevalence, mortality, and complications of congenital heart disease.

The adult patient with eisenmenger syndrome: a medical update after dana point part I: epidemiology, clinical aspects and diagnostic options

Eisenmenger syndrome is the most severe form of pulmonary arterial hypertension and arises on the basis of congenital heart disease with a systemic-to-pulmonary shunt. Due to the chronic slow progressive hypoxemia with central cyanosis, adult patients with the Eisenmenger syndrome suffer from a complex and multisystemic disorder including coagulation disorders (bleeding complications and paradoxical embolisms), renal dysfunction, hypertrophic osteoarthropathy, heart failure, reduced quality of life and premature death.For a long time, therapy has been limited to symptomatic options or lung or combined heart-lung transplantation. As new selective pulmonary vasodilators have become available and proven to be beneficial in various forms of pulmonary arterial hypertension, this targeted medical treatment has been expected to show promising effects with a delay of deterioration also in Eisenmenger patients. Unfortunately, data in Eisenmenger patients suffer from small patient numbers and a lack of randomized controlled studies.To optimize the quality of life and the outcome, referral of Eisenmenger patients to spezialized centers is required. In such centers, specific interdisciplinary management strategies of physicians specialized on congenital heart diseases and PAH should be warranted. This medical update emphasizes the current diagnostic and therapeutic options for Eisenmenger patients with particularly focussing on epidemiology, clinical aspects and specific diagnostic options.

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.

Worldwide physician education and training in pulmonary hypertension: pulmonary vascular disease: the global perspective

Pulmonary hypertension (PH) affects > 25 million individuals worldwide and causes premature disability and death for many. The diagnosis and treatment of PH have advanced dramatically through the development of a clearly defined diagnostic classification, an evidence-based treatment algorithm for adults with pulmonary arterial hypertension using life-saving medications, and life-saving surgical procedures. However, worldwide education and training of physicians has lagged behind advances in the management of PH. Expertise in the diagnosis and management of PH is uncommon, even though physicians receive training on PH during their graduate and postgraduate education. Advances in worldwide physician education and training in PH will require substantial organization and work. Organizations working in this field will need to work collaboratively to maximize funding for education and to optimize the achievement of educational goals. Political, economic, and cultural barriers must be identified and overcome as part of any strategic plan. Global education should include training objectives for generalist, non-PH specialist, and PH specialist physicians.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: complex congenital cardiac lesions

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. They have distinctive forms of heart failure and their cardiac disease can be associated with pulmonary hypertension, thromboemboli, complex arrhythmias and sudden death. Medical aspects that need to be considered relate to the long-term and multisystemic effects of single ventricle physiology, cyanosis, systemic right ventricles, complex intracardiac baffles and failing subpulmonary right ventricles. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part III of the guidelines includes recommendations for the care of patients with complete transposition of the great arteries, congenitally corrected transposition of the great arteries, Fontan operations and single ventricles, Eisenmenger's syndrome, and cyanotic heart disease. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts, which are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

[Eisenmenger syndrome. Pathophysiology]

Eisenmenger syndrome is the most feared complication by patients with congenital heart disorders with left-to-right shunt. This complication became rare in industrial countries thanks to optimized perinatal patient management and precocious elimination of the shunt. The presence of endothelial circulatory cells is a poor prognosis factor.