Adult patients with congenital heart disease and pulmonary arterial hypertension: first open prospective multicenter study of bosentan therapy

Pulmonary Hypertension in Adult Congenital Heart Disease-Related Heart Failure

Already a challenging condition to define, adult congenital heart disease (ACHD) -associated heart failure (HF) often incorporates specific anatomies, including intracardiac and extracardiac shunts, which require rigorous diagnostic characterization and heighten the importance of clinicians proactively considering overall hemodynamic impacts of using specific therapies. The presence of elevated pulmonary vascular resistance dramatically increases the complexity of managing patients with ACHD-HF. Total circulatory management in patients with ACHD-HF requires input from multidisciplinary care teams and thoughtful and careful utilization of medical, interventional, and surgical approaches.

Pulmonary vasodilator therapies in pulmonary arterial hypertension associated with CHD: a systematic review and network meta-analysis

The optimal treatment strategy using pulmonary vasodilators in pulmonary arterial hypertension associated with CHD (PAH-CHD) remains controversial. We aimed to compare the efficacy and safety of pulmonary vasodilators in PAH-CHD. PubMed and EMBASE databases were searched through May 2022 and a network meta-analysis was conducted. The primary outcomes were mean difference of changes in 6-minute walk distance, NYHA functional class, and N-terminal pro-brain natriuretic peptide. The secondary outcomes included pulmonary vascular resistance, mean pulmonary arterial pressure, and resting oxygen saturation. We identified 14 studies, yielding 807 patients with PAH-CHD. Bosentan and sildenafil were associated with a significant increase in 6-minute walk distance from baseline compared with placebo (MD 48.92 m, 95% CI 0.32 to 97.55 and MD 59.70 m, 95% CI 0.88 to 118.53, respectively). Bosentan, sildenafil, and combination of bosentan and sildenafil were associated with significant improvement in NYHA functional class compared with placebo (MD -0.33, 95% CI -0.51 to -0.14, MD -0.58, 95% CI -0.75 to -0.22 and MD -0.62, 95% CI -0.92 to -0.31, respectively). Bosentan and sildenafil were also associated with significant improvements in secondary outcomes. These findings were largely confirmed in the subgroup analysis. Various adverse events were reported; however, serious adverse event rates were relatively low (4.8-8.7%), including right heart failure, acute kidney injury, respiratory failure, hypotension, and discontinuation of pulmonary vasodilators. In conclusion, bosentan and sildenafil were the most effective in improving prognostic risk factor such as 6-minute walk distance and NYHA class. Overall, pulmonary vasodilators were well tolerated in PAH-CHD.

Pulmonary Hypertension in Adults with Congenital Heart Disease

Pulmonary arterial hypertension related to congenital heart disease (PAH-CHD) affects 5% to 10% of adults with CHD and is associated with significant morbidity and mortality. PAH-CHD develops as a consequence of intracardiac or extracardiac systemic-to-pulmonary shunts that lead to pulmonary vascular remodeling through a pathologic process that is similar to other causes of PAH. Eisenmenger syndrome is the most severe phenotype of PAH-CHD and is characterized by severe elevation in pulmonary vascular resistance, with shunt reversal causing hypoxemia and central cyanosis. The primary management strategy for most patients with PAH-CHD is medical therapy, although defect closure is considered in select cases.

Evidence base for specific pulmonary vasodilators in adults with congenital heart disease

After reviewing the current definitions and classification of pulmonary hypertension (PH) associated with congenital heart disease (CHD), based on an analysis of 59 clinical trials (of which 14 are randomized controlled trials) drugs registered in the Russian Federation, the evidence base for PH therapy in adults with CHD is provided. The presence of a randomized controlled trial of bosentan BREATHE-5 and uncontrolled trials of other drugs became the basis for a higher class and level of evidence of bosentan (IB) compared to other drugs (IIaC) for Eisenmenger syndrome in the current European (ERS/ESC 2015) and updated Russian (2020) guidelines. According to the updated European (ESC 2020) guidelines for congenital heart disease in adults, in Eisenmenger patients with reduced exercise capacity (6MWT distance 450 m), a treatment strategy with initial endothelin receptor antagonist monotherapy should be considered followed by combination therapy if patients fail to improve (IIaB), in low- and intermediate-risk patients with repaired simple lesions and pre-capillary PH, initial oral combination therapy or sequential combination therapy is recommended and high-risk patients should be treated with initial combination therapy including parenteral prostanoids (IA) and endothelin receptor antagonists and phosphodiesterase 5 inhibitors may be considered in selected patients with elevated pulmonary pressure/resistance in the absence of elevated ventricular end diastolic pressure (IIbC). Only three (bosentan, macitentan and selexipag) out of seven specific pulmonary vasodilators registered in the Russian Federation have indications for pulmonary arterial hypertension associated with congenital heart disease and Eisenmenger syndrome or pulmonary arterial hypertension associated with corrected simple congenital heart disease in the instructions for use.

Efficacy and Safety of Long-Term Oral Bosentan in Different Types of Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review and meta-analysis was conducted to identify if long-term bosentan is an effective and safe treatment for pulmonary arterial hypertension (PAH) regardless of type, including idiopathic PAH (IPAH), and PAH associated with congenital heart disease (APAH-CHD), connective tissue disease (APAH-CTD), and human immunodeficiency virus (APAH-HIV).

METHODS

All relevant observations were systematically searched by two independent investigators and obtained from three databases, including PubMed, EMBASE and the Cochrane Library, from the inception of each database to February 2020. Currently, long-term administration was defined as no less than 12 months. A random-effects or fixed-effects model was selected according to outcomes of the heterogeneity test for meta-analysis, where standardized mean difference (SMD) with 95% confidence intervals (CIs) was used for continuous outcomes, in addition to the estimated effect (ES; 95% CI) for the synthesized survival rate. Furthermore, subgroup analysis was applied to analyze the differences of efficacy and survivals in each type of PAH cohort.

RESULTS

Fifteen studies including a total of 659 subjects undergoing oral bosentan administration for at least 12 months were pooled in this quantitative review. Meta-analysis and subgroup analysis indicated that significant clinical benefits existed, including an improved 6-min walk distance (6MWD) and functional class (FC), in patients with APAH-CHD (6MWD: SMD 0.72, 95% CI 0.52-0.93, p < 0.0001; functional benefits: 50.4%, 95% CI 43.7-57.1%), APAH-HIV (6MWD: SMD 0.83, 95% CI 0.36-1.30, p = 0.001; functional benefits: 80.4%), and IPAH (SMD 0.54, 95% CI 0.28-0.80, p < 0.0001; functional benefits: 61.4%, 95% CI 54.2-68.5%), but a non-significant change in APAH-CTD (6MWD: SMD 0.18, 95% CI - 0.60 to 0.95, p = 0.656; functional benefits: 27.5%). Furthermore, among the hemodynamic parameters, long-term bosentan led to a significant decrease in mean pulmonary artery pressure (SMD - 0.86, p < 0.0001) in APAH-CTD, and a decrease in pulmonary vascular resistance (SMD - 0.65, p < 0.0001) and elevated oxygen saturation (SMD 0.30, p = 0.006) in APAH-CHD. Importantly, in all pooled studies, the overall survival indicated 1-, 2-, and 3-year survival rates of 94.3%, 88.8%, and 81.7%, respectively, in all-cause PAH, and subgroup analysis demonstrated a relative decreasing trend in patients with HIV, from a 2-year survival of 89.8% to a 3-year survival of 66.1%. Adverse drug reactions were relatively mild.

CONCLUSION

In this systematic review and meta-analysis, long-term administration of oral bosentan has been identified as a well-tolerated and effective agent in different types of PAH. In addition, we conclude that long-term oral bosentan should be considered for patients with CTD to achieve a satisfactory exercise capacity, and for those with APAH-HIV to improve survivals, where more attention on adverse events is required.

Macitentan in infants and children with pulmonary hypertensive vascular disease. Feasibility, tolerability and practical issues - a single-centre experience

Macitentan is a safe and effective substance for treatment of adults with pulmonary arterial hypertension. Data on its use in paediatric patients are limited. In this single-centre prospective study, we report on our experience with macitentan in children focusing on applicability and practical aspects. Between December 2014 and July 2018, macitentan was introduced to paediatric patients according to a dosing protocol adjusted to body weight. Blood pressure, heart rate, saturation and clinical symptoms were recorded daily during introduction. Liver function parameters and haemoglobin levels were measured at baseline, four weeks and three months after initiation and after one year of treatment. Twenty-four patients (14 male, 10 female) were enrolled for treatment with macitentan. The mean age was 10.7 ± 7.6 years (range: 0.1 year-23 years). Fifteen out of 24 patients were World Health Organization functional class (FC) II, 7 patients in FC III and 2 patients in FC IV. Twenty out of 24 patients (83%) received additional advanced therapy with sildenafil and/or prostacyclines. We had two early discontinuations because of clinical relevant oedema. In the remaining 22 patients, macitentan was well tolerated. Liver function parameters and blood count levels remained stable during the observational time. The introduction of macitentan was feasible and mostly well tolerated in paediatric patients. Special attention should be paid to oedema during introduction of the drug. To the best of our knowledge, this is the first study to report on its applicability in infants and children. However, larger prospective trials are warranted to verify these preliminary findings.

Clinical and hemodynamic effect of endothelin receptor antagonists in Eisenmenger Syndrome

Introduction:

Endothelin receptor antagonists (ERAs) are widely accepted as a specific treatment for pulmonary arterial hypertension. Unfortunately, consensus and recommendations are lacking for the treatment of patients who suffer from pulmonary arterial hypertension and congenital heart disease, including Eisenmenger syndrome.

Objective:

This meta-analysis aimed to compare the effect of ERA on patients with Eisenmenger syndrome.

Methods:

Electronic search on PubMed (MEDLINE), EBSCO, EuropePMC, Clinicaltrials.gov, and Google Scholar was done. Studies involving the use of ERAs on Eisenmenger syndrome patients were included. There were 18 studies included. The primary outcome of interest was the 6-min walking test distance before and after exposure to ERA.

Results:

There were 517 patients with Eisenmenger syndrome. The subjects had Eisenmenger syndrome secondary to congenital heart disorders, with WHO functional Class ranging from Class I–IV. The follow-up ranges from a mean of 4–60 months. Seventeen studies reported a statistically significant difference between pretreatment and the posttreatment result of 6-min walking test distance. Pooled mean difference comparing pre and posttreatment values yielded an increase of 55.24 m (42.15, 68.33) P < 0.001; moderate heterogeneity I² 51% P = 0.008. Pooled mean pulmonary vascular resistance index difference comparing pre and posttreatment values yielded a decrease of 4.76 woods unit (−6.86, −2.66), P < 0.001 favoring posttreatment; low heterogeneity I2 0%, P = 0.82. Pooled mean mean pulmonary arterial pressure difference comparing pre and posttreatment values yielded a decrease of 5.40 mmHg (−7.53, −3.28), P < 0.001 favoring posttreatment, low heterogeneity I² 0%, P = 0.65.

Conclusion:

Implementation of ERA in Eisenmenger improves 6-min walking distance and pulmonary vascular pressure indices. Earlier administration of ERA might be beneficial, further studies are needed to assess mortality benefit of this agent.

The efficiency of endothelin receptor antagonist bosentan for pulmonary arterial hypertension associated with congenital heart disease: A systematic review and meta-analysis

BACKGROUND

Oral bosentan has been widely applied in pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD). A systemic review and meta-analysis was conducted for a therapeutic evaluation of oral bosentan in both adult and pediatric patients with PAH-CHD. The acute responses and a long-term effect were respectively assessed in a comparison with baseline characteristics, and the improvement of exercise tolerance was analyzed.

METHODS

PubMed, Medline, Embase, and Cochrane Central Register of clinical controlled trails or observational studies have been searched for a recording of bosentan effects on the PAH-CHD participants. For mortality and rate of adverse events (AEs), it was described in detail. Randomized-effects model or fixed-effects model was used to calculate different effective values with a sensitivity analysis.

RESULTS

Seventeen studies were pooled in this review, and 3 studies enrolled the pediatric patients. Among all studies, 456 patients were diagnosed with PAH-CHD, and 91.7% were treated with oral bosentan. With a term less than 6 months of bosentan therapy, there existed a significant improvement in 6-minute walk distance (6MWD) and the World Health Organization functional class (WHO-FC), but no such differences in Borg dyspnea index scores (BDIs) and the resting oxygen saturation (SpO2). Although with a prolonged treatment, not only 6MWD and FC, but also the resting SpO2 and heart rate were changed for a better exercise capability. Additionally, compared with the basic cardiopulmonary hemodynamics, it showed a statistically significant difference in mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance index (PVRi). Although a limitation of pooled studies with comparative outcomes of different terms, outcomes presented a lower WHO-FC which contributes to a success in a prolonged treatment.

CONCLUSIONS

Bosentan in PAH-CHD is well established and still requires clinical trials for an identification of its efficiency on CHD patients for an optimized period lessening a serious complication and the common AEs.

Advanced therapies for the management of adults with pulmonary arterial hypertension due to congenital heart disease: a systematic review

Pulmonary arterial hypertension (PAH) secondary to congenital heart disease (CHD) is the third most common cause of PAH, and it is becoming increasingly common as improvements in the management of CHD have led to increased life expectancy for these patients. The medical management of PAH due to CHD (PAH-CHD) is largely the same as what has been used for the treatment of idiopathic PAH, though the body of literature supporting this management decision is very small. There are currently few studies available which specifically focus on the treatment of PAH-CHD. The purpose of this literature review is to compare the results of those studies that assessed the response to medical therapy among adults with PAH-CHD; studies were excluded if they focused on paediatric patients, did not include an assessment of 6 min walking distance or specifically assessed combination therapies. This review found that riociguat, bosentan, epoprostenol and sildenafil were all capable of improving functional capacity and haemodynamic parameters in patients with PAH-CHD, but whether this corresponds to an increase in mortality remains to be seen. Limitations of this review include the small sample size and variable duration of the included studies, which makes drawing direct comparisons between studies and the study drugs difficult. The lack of large, randomised double-blind clinical trials comparing different drugs head to head highlights an area that is ripe for ongoing medical research, the results of which may help shape future treatment algorithms tailored specifically for adults with PAH-CHD.

Decreased circulating thrombomodulin is improved by tadalafil therapy in hypoxemic patients with advanced pulmonary arterial hypertension

INTRODUCTION

Advanced pulmonary arterial hypertension (PAH) in patients with congenital cardiac communications and right-to-left shunting (Eisenmenger syndrome - PAH-ES) is associated with hypoxemia and decreased circulating levels of thrombomodulin (TM), probably reflecting decreased endothelial TM production. The combination of these two factors has been shown to induce fibrin deposition, with increased risk of thrombosis, a well known complication in this syndrome.

PATIENTS AND METHODS

We tested the hypothesis that vasodilator therapy with the phosphodiesterase-5 inhibitor tadalafil, an approved drug for management of PAH could improve endothelial dysfunction markers, in particular plasma TM, in addition to improving the physical capacity (expected effect of pulmonary vasodilatation) in PAH-ES patients. This was a prospective observational study of treatment-naïve patients subjected to specific PAH therapy. Fifteen patients aged 12 to 51years (median 30years) were treated for 6months with a single daily dose of 40mg oral tadalafil. The physical capacity (distance walked during the 6-min walk test - 6MWD), systemic oxygen saturation and laboratory parameters were measured at baseline, and 90days and 180days of treatment.

RESULTS

Plasma TM, which was decreased at baseline compared to controls (p<0.001) increased at 90 and 180days (p=0.003), and this was directly related (r=0.57, p=0.026) to improvement of oxygen saturation (p=0.008). Heightened baseline tissue-type plasminogen activator decreased during treatment (p=0.010), while heightened von Willebrand factor antigen remained unchanged. The 6MWD improved significantly (p<0.001).

CONCLUSION

Tadalafil therapy improved circulating TM and tissue-type plasminogen activator, in addition to improving the physical capacity and oxygen saturation in PAH-ES patients.

Tailored circulatory intervention in adults with pulmonary hypertension due to congenital heart disease

BACKGROUND

Adults with pulmonary hypertension associated with congenital heart disease (PH-CHD) often have residual shunts. Invasive interventions aim to optimise pulmonary flow and prevent right ventricular failure. However, eligibility for procedures strongly depends on the adaptation potential of the pulmonary vasculature and right ventricle to resultant circulatory changes. Current guidelines are not sufficiently applicable to individual patients, who exhibit great diversity and complexity in cardiac anomalies.

METHODS AND RESULTS

We present four complex adult PH-CHD patients with impaired pulmonary flow, including detailed graphics of the cardiopulmonary circulation. All these patients had an ambiguous indication for shunt intervention. Our local multidisciplinary Grown-Ups with Congenital Heart Disease team reached consensus regarding a patient-tailored invasive treatment strategy, adjacent to relevant guidelines. Interventions improved pulmonary haemodynamics and short-term clinical functioning in all cases.

CONCLUSIONS

Individual evaluation of disease characteristics is mandatory for tailored interventional treatment in PH-CHD patients, adjacent to relevant guidelines. Both strict registration of cases and multidisciplinary and multicentre collaboration are essential in the quest for optimal therapy in this patient population.

Use of outcome measures in pulmonary hypertension clinical trials

OBJECTIVES

To evaluate the use of surrogate measures in pulmonary hypertension (PH) clinical trials and how it relates to clinical practice.

BACKGROUND

Studies of pulmonary arterial hypertension (PAH) employ a variety of surrogate measures in addition to clinical events because of a small patient population, participant burden, and costs. The use of these measures in PH drug trials is poorly defined.

METHODS

We searched PubMed/MEDLINE/Embase for randomized or prospective cohort PAH clinical treatment trials from 1985 to 2013. Extracted data included intervention, trial duration, study design, patient characteristics, and primary and secondary outcome measures. To compare with clinical practice, we assessed the use of surrogate measures in a clinical sample of patients on PH medications at Duke University Medical Center between 2003 and 2014.

RESULTS

Between 1985 and 2013, 126 PAH trials were identified and analyzed. Surrogate measures served as primary endpoints in 119 trials (94.0%). Inclusion of invasive hemodynamics decreased over time (78.6%, 75.0%, 52.2%; P for trend = .02), while functional testing (7.1%, 60.0%, 81.5%; P for trend < .0001) and functional status or quality of life (0%, 47.6%, 62.8%; P for trend < .0001) increased in PAH trials over the same time periods. Echocardiography data were reported as a primary or secondary outcome in 32 trials (25.4%) with increased use from 1985-1994 to 1995-2004 (7.1% vs 35.0%, P = .04), but the trend did not continue to 2005-2013 (25.0%). In comparison, among 450 patients on PAH therapies at our institution between 2003 and 2013, clinical assessments regularly incorporated serial echocardiography and 6-minute walk distance tests (92% and 95% of patients, respectively) and repeat measurement of invasive hemodynamics (46% of patients).

CONCLUSIONS

The majority of PAH trials have utilized surrogate measures as primary endpoints. The use of these surrogate endpoints has evolved significantly over time with increasing use of patient-centered endpoints and decreasing or stable use of imaging and invasive measures. In contrast, imaging and invasive measures are commonly used in contemporary clinical practice. Further research is needed to validate and standardize currently used measures.

[Pulmonary hypertension associated with congenital heart disease and Eisenmenger syndrome]

Pulmonary arterial hypertension is a common complication of congenital heart disease (CHD). Congenital cardiopathies are the most frequent congenital malformations. The prevalence in our country remains unknown, based on birthrate, it is calculated that 12,000 to 16,000 infants in our country have some cardiac malformation. In patients with an uncorrected left-to-right shunt, increased pulmonary pressure leads to vascular remodeling and endothelial dysfunction secondary to an imbalance in vasoactive mediators which promotes vasoconstriction, inflammation, thrombosis, cell proliferation, impaired apotosis and fibrosis. The progressive rise in pulmonary vascular resistance and increased pressures in the right heart provocated reversal of the shunt may arise with the development of Eisenmenger' syndrome the most advanced form de Pulmonary arterial hypertension associated with congenital heart disease. The prevalence of Pulmonary arterial hypertension associated with CHD has fallen in developed countries in recent years that is not yet achieved in developing countries therefore diagnosed late as lack of hospital infrastructure and human resources for the care of patients with CHD. With the development of targeted medical treatments for pulmonary arterial hypertension, the concept of a combined medical and interventional/surgical approach for patients with Pulmonary arterial hypertension associated with CHD is a reality. We need to know the pathophysiological factors involved as well as a careful evaluation to determine the best therapeutic strategy.

The exceptional and far-flung manifestations of heart failure in Eisenmenger syndrome

Dramatic advances in the diagnosis and treatment of congenital heart disease (CHD), the most common inborn defect, has resulted in a growing population of adults with CHD. Eisenmenger syndrome (ES) represents the extreme form of pulmonary arterial hypertension associated with CHD, characterized by markedly increased pulmonary vascular resistance with consequently reversed or bidirectional shunting. While ES is a direct consequence of a heart defect, it is a fundamentally multisystem syndrome with wide-ranging clinical manifestations. The introduction of targeted pulmonary hypertension therapies aimed has subtly shifted clinical focus from preventing iatrogenic and other adverse events toward cautious therapeutic activism.

Perioperative pharmacological management of pulmonary hypertensive crisis during congenital heart surgery

Pulmonary hypertensive crisis is an important cause of morbidity and mortality in patients with pulmonary arterial hypertension secondary to congenital heart disease (PAH-CHD) who require cardiac surgery. At present, prevention and management of perioperative pulmonary hypertensive crisis is aimed at optimizing cardiopulmonary interactions by targeting prostacyclin, endothelin, and nitric oxide signaling pathways within the pulmonary circulation with various pharmacological agents. This review is aimed at familiarizing the practitioner with the current pharmacological treatment for dealing with perioperative pulmonary hypertensive crisis in PAH-CHD patients. Given the life-threatening complications associated with pulmonary hypertensive crisis, proper perioperative planning can help anticipate cardiopulmonary complications and optimize surgical outcomes in this patient population.

Effect of bosentan therapy on ventricular and atrial function in adults with Eisenmenger syndrome. A prospective, multicenter study using conventional and Speckle tracking echocardiography

BACKGROUND

The effect of bosentan on the ventricular and atrial performance in patients with Eisenmenger syndrome is unclear. In adult patients with Eisenmenger syndrome, we aimed to evaluate the midterm effect of bosentan on physical exercise, ventricular and atrial function, and pulmonary hemodynamics.

METHODS

Forty adult patients before and after 24 weeks bosentan therapy underwent 6 min walk test, two-dimensional speckle tracking echocardiography, plasma NT-proBNP measurement and cardiac catheterization.

RESULTS

After 24 weeks, bosentan therapy an improvement was observed regarding the 6 min walk distance from a median (quartile 1-quartile 3) of 382.5 (312-430) to 450 (390-510) m (p = 0.0001), NT-proBNP from 527.5 (201-1,691.25) to 369 (179-1,246) pg/ml (p = 0.021), right ventricular mean longitudinal systolic strain from 18 (13-22) to 19 (14.5-25) % (p = 0.004), left ventricular mean longitudinal systolic strain from 16 (12-21) to 17 (16-22) % (p = 0.001), right atrial mean peak longitudinal strain from 26 (18-34) to 28 (22-34) % (p = 0.01) and right atrial mean peak contraction strain from 11 (8-16) to 13 (11-16) % (p = 0.005). The invasively obtained Qp:Qs and Rp:Rs did not significantly change under bosentan therapy.

CONCLUSIONS

In adult patients with Eisenmenger syndrome, bosentan therapy improves ventricular and atrial functions resulting in enhancement of physical exercise and reduction in the NT-proBNP level, while the pulmonary vascular resistance does not change substantially.

Therapeutic effect of eNOS-transfected endothelial progenitor cells on hemodynamic pulmonary arterial hypertension

Hemodynamic pulmonary arterial hypertension (HPAH) is a common symptom in congenital heart disease (CHD) patients with a left-to-right shunt. Endothelial NO synthase (eNOS) and endothelial-like progenitor cells result in significant improvement of right ventricular systolic pressure in established pulmonary arterial hypertension (PAH) models. We hypothesized that bone marrow (BM)-derived endothelial progenitor cells (EPCs) and eNOS would prevent HPAH in a newly established rat model. The heNOS gene was cloned into a PSUCMV vector, and a high-titer adenovirus was generated. Mononuclear cells (MNCs) from rat BM were differentiated into EPCs by treatment with various cytokines, and a high purity of EPCs (>70%) was confirmed using the markers DiI ac-LDL, UEA-1, vWF and Flk-1. An ideal rat HPAH model was successfully established based on right lung lobectomy, and was confirmed by pressure measurement and histological staining. heNOS was successfully transfected into EPCs, which were then transplanted into HPAH rats. Two weeks after transplantation, the systolic pulmonary arterial blood pressure (sPAP) was significantly reduced by heNOS-EPCs treatment and by transplantation of control EPCs. The high number of muscular pulmonary arteries and the thickness of the muscular coat characteristic of HPAH rats were clearly reversed or even restored to normal levels following transplantation of EPCs, particularly eNOS-EPCs. These findings indicate a critical role of eNOS in HPAH treatment and suggest that eNOS-transfected EPCs may provide an effective strategy for HPAH treatment in CHD patients.

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.

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.

Efficacy and safety of bosentan for pulmonary arterial hypertension in adults with congenital heart disease

The dual endothelin receptor antagonist, bosentan, has been shown to be well tolerated and effective in improving pulmonary arterial hypertension (PAH) symptoms in patients with Eisenmenger syndrome but data from longer-term studies are lacking. The aim of this study was to retrospectively analyze the long-term efficacy and safety of bosentan in adults with PAH secondary to congenital heart disease (PAH-CHD). Prospectively collected data from adult patients with PAH-CHD (with and without Down syndrome) initiated on bosentan from October 2007 through June 2010 were analyzed. Parameters measured before bosentan initiation (62.5 mg 2 times/day for 4 weeks titrated to 125 mg 2 times/day) and at each follow-up (1 month and 3, 6, 9, 12, 18, and 24 months) included exercise capacity (6-minute walk distance [6MWD]), pretest oxygen saturation, liver enzymes, and hemoglobin. Data were analyzed from 39 patients with PAH-CHD (10 with Down syndrome) who had received ≥ 1 dose of bosentan (mean duration of therapy 2.1 ± 1.5 years). A significant (p < 0.0001) average improvement in 6MWD of 54 m over a 2-year period in patients with PAH-CHD without Down syndrome was observed. Men patients had a 6MWD of 33 m greater than women (p < 0.01). In all patients, oxygen saturation, liver enzymes, and hemoglobin levels remained stable. There were no discontinuations from bosentan owing to adverse events. In conclusion, patients with PAH-CHD without Down syndrome gain long-term symptomatic benefits in exercise capacity after bosentan treatment. Men seem to benefit more on bosentan treatment. Bosentan appears to be well tolerated in patients with PAH-CHD with or without Down syndrome.

The Adult Patient with Eisenmenger Syndrome: A Medical Update after Dana Point Part II: Medical Treatment - Study Results

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 the medical treatment and corresponding study results.

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.

Pulmonary arterial hypertension: a comparison between children and adults

The characteristics of pulmonary arterial hypertension (PAH), including pathology, symptoms, diagnosis and treatment are reviewed in children and adults. The histopathology seen in adults is also observed in children, although children have more medial hypertrophy at presentation. Both populations have vascular and endothelial dysfunction. Several unique disease states are present in children, as lung growth abnormalities contribute to pulmonary hypertension. Although both children and adults present at diagnosis with elevations in pulmonary vascular resistance and pulmonary artery pressure, children have less heart failure. Dyspnoea on exertion is the most frequent symptom in children and adults with PAH, but heart failure with oedema occurs more frequently in adults. However, in idiopathic PAH, syncope is more common in children. Haemodynamic assessment remains the gold standard for diagnosis, but the definition of vasoreactivity in adults may not apply to young children. Targeted PAH therapies approved for adults are associated with clinically meaningful effects in paediatric observational studies; children now survive as long as adults with current treatment guidelines. In conclusion, there are more similarities than differences in the characteristics of PAH in children and adults, resulting in guidelines recommending similar diagnostic and therapeutic algorithms in children (based on expert opinion) and adults (evidence-based).

Pharmacokinetic evaluation of ambrisentan

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a life-threatening and progressive disease characterized by increasing pulmonary vascular resistance leading to right ventricular failure and premature death. Current therapies target three major pathways involving endothelin, prostacyclin and NO. Ambrisentan is an oral, once daily, selective endothelin receptor antagonist.

AREAS COVERED

This review focuses on, and critically appraises, the clinical efficacy and safety of ambrisentan as well as its pharmacokinetic and pharmacodynamic properties. The article also gives an expert perspective on the role of ambrisentan in the management of PAH.

EXPERT OPINION

Ambrisentan is an effective and safe treatment which is, in the authors' opinion, a valuable addition to the armamentarium against PAH. Ambrisentan offers a relative lack of drug interactions, once daily dosing and reassuring liver safety, offering safety and convenience advantages over bosentan. Presently, there is a lack of comparative studies between PDE5 inhibitors and endothelin receptor antagonists and a lack of data comparing bosentan with ambrisentan. This is hindering data-based conclusions regarding relative efficacy and further studies are needed to define the role of ambrisentan in the management of PAH.

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.

Endothelin receptor antagonists are an effective long term treatment option in pulmonary arterial hypertension associated with congenital heart disease with or without trisomy 21

INTRODUCTION

Traditionally, treatment options for patients with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) are limited. Bosentan has been shown to improve pulmonary haemodynamics and exercise tolerance short term but long term clinical studies are lacking.

AIM

To report long term efficacy and safety data with endothelin receptor antagonists (ERA) in patients with PAH associated CHD.

METHODS

Prospective, open label, uncontrolled, single centre study of 53 patients (33 females, 17 Trisomy 21, mean age 34 ± 12 years) prescribed ERA (48 bosentan, 5 sitaxentan) from 2003 to August 2009. Outcome measurements of oxygen saturation (SaO2), WHO functional class, 6-minute walk test distance (6MWD) and adverse events were analysed.

RESULTS

Mean duration of therapy was 15 ± 13 months in 53 patients with CHD. Four patients failed ERA, seven died (five progressive RHF) and one delisted from transplantation. No abnormal liver transaminases occurred on bosentan, with one case on sitaxentan. After 3, 6, 12, 18 and 24 months of treatment a significant improvement was seen in WHO functional class (mean 3.15 vs 2.8 vs 2.5 vs 2.5 vs 2.4 vs 2.4; p<0.01) and 6MWD (344 ± 18 vs 392 ± 17 vs 411 ± 17 vs 420 ± 17 vs 442 ± 18 vs 417 ± 23: p<0.0005, p<0.01) compared with baseline. The Trisomy 21 and PAH-CHD showed a significant improvement in 6MWD at 6 and 12 months (263 ± 24 vs 348 ± 29 vs 360 ± 32, p<0.01, p<0.05) respectively. No changes in SaO2, BNP, RV or LV function were demonstrated during follow-up.

CONCLUSION

This large single centre study demonstrates that endothelin receptor antagonism is an effective and safe treatment in PAH associated CHD with or without Trisomy 21. The improvements in exercise tolerance are similar to reported benefits in other forms of PAH.

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.

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.

Advances in diagnosis and treatment of pulmonary arterial hypertension in neonates and children with congenital heart disease

BACKGROUND

This article aims to review recent advances in the diagnosis and treatment of pulmonary arterial hypertension in neonates and children with congenital heart disease.

DATA SOURCES

Articles on pulmonary arterial hypertension in congenital heart disease were retrieved from PubMed and MEDLINE published after 1958.

RESULTS

A diagnosis of primary (or idiopathic) pulmonary arterial hypertension is made when no known risk factor is identified. Pulmonary arterial hypertension associated with congenital heart disease constitutes a heterogenous group of conditions and has been characterized by congenital systemic-to-pulmonary shunts. Despite the similarities in histologic appearance of pulmonary vascular disease, there are differences between pulmonary arterial hypertension secondary to congenital systemic-to-pulmonary shunts and those with other conditions with respect to pathophysiology, therapeutic strategies, and prognosis. Revision and subclassification within the category of secondary pulmonary arterial hypertension based on pathophysiology were conducted to improve specific treatments. The timing of surgical repair is crucial to prevent and minimize risk of postoperative pulmonary arterial hypertension. Drug therapies including prostacyclin, endothelin-receptor antagonist, phosphodiesterase inhibitor, and nitric oxide have been evolved with promising results in neonates and children.

CONCLUSIONS

Among the different forms of congenital heart diseases, an early correction generally prevents subsequent development of pulmonary arterial hypertension. Emerging therapies for treatment of patients with idiopathic pulmonary arterial hypertension also improve quality of life and survival in neonates and children with congenital heart disease associated with pulmonary arterial hypertension. Heart and lung transplantation or lung transplantation in combination with repair of the underlying cardiac defect is a therapeutic option in a minority of patients. Partial repair options are also beneficial in some selected cases. Randomized controlled trials are needed to evaluate the safety and efficacy of these therapies including survival and long-term outcome.

Anaesthesia and right ventricular failure

Acute right ventricular (RV) failure has until recently received relatively little attention in the cardiology, critical care or anaesthesia literature. However, it is frequently encountered in cardiac surgical cases and is a significant cause of mortality in patients with severe pulmonary hypertension who undergo non-cardiac surgery. RV dysfunction may be primarily due to impaired RV contractility, or volume or pressure overload. In these patients, an increased pulmonary vascular resistance (PVR) or a decreased aortic root pressure may lead to RV ischaemia, resulting in a rapid, downward haemodynamic spiral. The key aspects of 'RV protection' in patients who are at risk of perioperative decompensation are prevention, detection and treatment aimed at reversing the underlying pathophysiology. Minimising PVR and maintaining systemic blood pressure are of central importance in the prevention of RV decompensation, which is characterised by a rising central venous pressure and a falling cardiac output. Although there are no outcome data to support any therapeutic strategy for RV failure when PVR is elevated, the combination of inhaled iloprost or intravenous milrinone with oral sildenafil produces a synergistic reduction in PVR, while sparing systemic vascular resistance. Levosimendan is a promising new inotrope for the treatment of RV failure, although its role in comparison to older agents such as dobutamine, adrenaline and milrinone has yet to be determined. This is also the case for the use of vasopressin as an alternative pressor to noradrenaline. If all else has failed, mechanical support of the RV should be considered in selected cases.

Endothelin receptor antagonist therapy in congenital heart disease with shunt-associated pulmonary arterial hypertension: a qualitative systematic review

BACKGROUND

Congenital heart disease (CHD) with systemic-topulmonary shunting is associated with pulmonary arterial hypertension (PAH). There are similar clinical and pathophysiological features between CHD with shunt-associated PAH and idiopathic PAH. Endothelin-receptor antagonists (ERAs) are oral medications that improve pulmonary hemodynamics, symptoms and functional capacity in many PAH patients. However, the role of ERAs in CHD with shunt-associated PAH is unclear.

METHODS

MEDLINE, EMBASE and the Cumulative Index of Nursing and Allied Health Literature (CINAHL) databases were searched for articles published from 1966 through September 2006, as well as bibliographies of all retrieved papers. All published English-language studies of adult CHD patients with shunt-associated PAH treated with ERAs were reviewed for clinical, functional and hemodynamic outcomes.

RESULTS

Ten studies of 174 adult CHD subjects with shunt-associated PAH were identified. Other than one placebo-controlled, randomized clinical trial, all studies were open-label, uncontrolled observational trials. Subjects were treated with the ERA bosentan for a mean (+/- SD) of 9+/-7 months. Nine studies reported improved World Health Organization (WHO) modification of the New York Heart Association functional class, with 95 of 164 subjects (58%) improving by at least one functional class. The 6 min walk distance improved in all eight studies in which it was assessed. Bosentan was generally well tolerated; 2.3% of subjects withdrew because of elevated liver enzymes. Two patients with WHO functional class IV PAH died during bosentan therapy.

CONCLUSION

Treatment of CHD patients with shunt-associated PAH with the ERA bosentan is associated with an improvement in functional class and objectively measured exercise capacity. The consistency of the uncontrolled data and the positive results of a single randomized clinical trial suggest a role for ERA therapy in CHD patients with shunt-associated PAH. Caution is suggested when considering bosentan therapy for CHD patients with WHO functional class IV PAH.

Effect of bosentan on exercise capacity and quality of life in adults with pulmonary arterial hypertension associated with congenital heart disease with and without Down's syndrome

Pulmonary arterial hypertension associated with congenital heart disease caused by systemic-to-pulmonary shunting was associated with a high risk of morbidity and mortality. In this retrospective study, the longer term treatment effect of bosentan on exercise capacity and quality of life (QoL) were evaluated in 58 adult patients (>18 years) with pulmonary arterial hypertension associated with congenital heart disease, including patients with Down's syndrome. All patients were evaluated at baseline and during follow-up using laboratory tests, 6-minute walk test, QoL questionnaires, and Doppler echocardiography. Treatment efficacy was analyzed separately for patients without (n = 30) and with Down's syndrome (n = 28). Median follow-up of all patients treated with bosentan was 22 months (range 3 to 36). In patients without Down's syndrome, mean 6-minute walk distance increased from 427 +/- 97 to 461 +/- 104 m (p <0.01) after 6 months of treatment, followed by a gradual return to baseline and disease stabilization. QoL improved significantly during treatment and was maintained during 18 months of follow-up (p <0.05). In patients with Down's syndrome, 6-minute walk distance and QoL were stable during treatment. In conclusion, findings suggested that in patients without Down's syndrome, longer term bosentan treatment resulted in a persistent improvement in QoL and stabilization of exercise capacity.

Effects of bosentan on the skin lesions: an observational study from a single center in Japan

Effects of a dual endothelin receptor antagonist, bosentan on peripheral circulatioin and skin lesions as well as pulmonary arterial hypertension (PAH) were investigated in Japanese patients with connective tissue diseases (CTD). Fifteen patients with PAH associated with CTD [systemic sclerosis (SSc) 13, mixed connective tissue disease (MCTD) 2] were treated with bosentan for 40-96 weeks, and changes of exercise capacity (6-min walk distance and Borg's dyspnea scale), cardio-pulmonary hemodynamics (right ventricular pressure, specific activity scale and cardiac index), Raynaud's phenomenon, digital ulcers and dermal sclerosis were observed. Bosentan improved exercise capacity, had a positive effect on hemodynamic parameters, and was well tolerated as previously reported. After a median 8 weeks of treatment, 13 out of 15 patients had improved Raynaud's phenomenon. Digital ulcers also improved after a median 12 weeks' treatment in all of 8 patients. Modified Rodnan total skin score decreased from 21.0 +/- 5.9 to 11.5 +/- 3.9 in diffuse cutaneous SSc and from 17.0 +/- 6.5 to 9.5 +/- 4.5 in limited cutaneous SSc after 24 months' treatment, reaching significance after 6 months in both groups. These data suggest that bosentan is effective for both PAH and peripheral vascular diseases in Japanese patients with CTD. The pathological background to the improvement in dermal sclerosis observed in this study should be further investigated.

Longer-term bosentan therapy improves functional capacity in Eisenmenger syndrome: Results of the BREATHE-5 open-label extension study

BACKGROUND

Bosentan, an oral endothelin ET(A)/ET(B) receptor antagonist, improves hemodynamics and exercise capacity in patients with Eisenmenger syndrome but longer-term effects are unknown. This study investigated the efficacy and safety of bosentan up to 40 weeks in these patients.

METHODS

Following the 16-week, double blind, placebo-controlled BREATHE-5 study of bosentan in patients with Eisenmenger syndrome, an open-label extension (OLE) was performed. Patients who completed BREATHE-5 received bosentan for an additional 24 weeks (62.5 mg b.i.d. for 4 weeks, then 125 mg b.i.d.) and were analyzed in two groups; ex-placebo and ex-bosentan, according to BREATHE-5 treatment.

RESULTS

Thirty-seven patients with Eisenmenger syndrome who participated in BREATHE-5 were included in the OLE. At week 24, the 6-minute walk distance (mean+/-SE) increased from OLE baseline for the ex-placebo (+33.2+/-23.9 m) and ex-bosentan group (+6.7+/-10.0 m). The overall improvement from baseline of BREATHE-5 was +61.3+/-8.1 m (95% confidence interval: [44.7, 78.0]) for the ex-bosentan group. WHO functional class was improved in both groups. Bosentan did not reduce systemic arterial blood oxygen saturation; safety profile was comparable to previous trials.

CONCLUSIONS

In conclusion, these longer follow-up data support the efficacy and safety profile reported in the preceding BREATHE-5 study of bosentan treatment of Eisenmenger syndrome, challenging the notion that pulmonary vascular disease and severe functional impairment in these patients are not amenable to therapy.

Long-term effect of bosentan in adults versus children with pulmonary arterial hypertension associated with systemic-to-pulmonary shunt: does the beneficial effect persist?

BACKGROUND

Data on long-term response to bosentan in adults and especially children with pulmonary arterial hypertension (PAH) associated with systemic-to-pulmonary shunt are scarce.

METHODS

We studied bosentan efficacy in 30 patients (20 adults, 10 children) with the disease at short- (4 months), and long-term follow-up (through 2.7 years). World Health Organization functional class (WHO class), transcutaneous oxygen saturation, and 6-minute walk distance were assessed at baseline, 4 months, 1 year, 1.5 years, and at latest follow-up (median 2.7 years).

RESULTS

At baseline, children tended to have more severe disease compared with adults with regard to WHO class and congenital heart defects. At 4 months' follow-up, WHO class and 6-minute walk distance significantly improved in both adults and children. During long-term follow-up, this improvement persisted through 1 year but declined thereafter in the total group. In the children, a progressive decline in exercise capacity was observed from 1-year follow-up, whereas in the adults, improvement lasted longer. No change from baseline was seen in transcutaneous oxygen saturation. Three (10%) patients died, 2 (7%) discontinued bosentan, and 5 (17%) required additional PAH therapy (of whom 1 eventually died). One- and 2-year persistence of beneficial bosentan effect was 68% and 43% (total group), 78% and 57% (adults), and 50% and 20% (children), respectively.

CONCLUSIONS

Our experience with bosentan suggests short-term improvement in both adults and children with PAH associated with systemic-to-pulmonary shunt. At long-term follow-up, a progressive decline in beneficial bosentan effect was observed. The decline appeared most pronounced in the pediatric patients, who, in this study, tended to have more severe disease at baseline.

Long-term safety, tolerability and efficacy of bosentan in adults with pulmonary arterial hypertension associated with congenital heart disease

OBJECTIVE

To examine long-term safety and efficacy of bosentan--an oral dual endothelin receptor antagonist--in patients with pulmonary hypertension associated with congenital heart disease or Eisenmenger's syndrome.

DESIGN

Retrospective study.

SETTING

Tertiary cardiology referral centre.

PATIENTS

All adult patients with pulmonary arterial hypertension associated with congenital heart disease treated with bosentan at the Royal Brompton Adult Congenital Heart Centre were included.

MAIN OUTCOME MEASURES

Oxygen saturation, functional (WHO) class, 6-minute walk test distance and liver enzymes were analysed.

RESULTS

Eighteen patients (14 female) with pulmonary arterial hypertension associated with congenital heart disease (15 patients with Eisenmenger's syndrome) with a mean (SD) age of 41 (9) years (range 23-69) were included. Median follow-up was 29 months (range 1-39). One patient died during follow-up. Patients tolerated bosentan well and no significant rise in liver transaminases was seen. Arterial oxygen saturation remained stable throughout follow-up. Mean (SD) functional class (p = 0.001) and the 6-minute walk test distance improved compared with baseline (284 (144) vs 363 (124) m, 380 (91) m and 408 (114) m at baseline, 0-6 months, 6-12 months and 1-2 years of treatment, respectively; p<0.05 for each).

CONCLUSIONS

Bosentan appears to be safe and well tolerated in adults with pulmonary arterial hypertension associated with congenital heart disease or Eisenmenger's syndrome during mid- to long-term follow-up. In addition, functional class and the 6-minute walk test distance improved and this effect was maintained for up to 2 years of bosentan treatment.