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

Genetic syndromes associated with congenital heart disease

Congenital heart defects are the most common type of birth defect, affecting 1% of live births. The underlying cause of congenital heart disease is frequently unknown. However, advances in human genetics and genome technologies have helped expand congenital heart disease pathogenesis knowledge during the last few decades. When the cardiac defects are part of a genetic syndrome, they are associated with extracardiac conditions and require multidisciplinary care and surveillance. Some genetic syndromes can have subtle clinical findings and remain undiagnosed well into adulthood. Each syndrome is associated with specific congenital and acquired comorbidities and a particular clinical risk profile. A timely diagnosis is essential for risk stratification, surveillance of associated conditions and counselling, particularly during family planning. However, genetic testing and counselling indications can be challenging to identify in clinical practice. This document intends to provide an overview of the most clinically relevant syndromes to consider, focusing on the phenotype and genotype diagnosis, outcome data, clinical guidelines and implications for care.

Eisenmenger Syndrome Among Children with Unrepaired Congenital Heart Defects in Yunnan, China

Eisenmenger syndrome is a life-threatening complication of congenital heart defects (CHD). Since Eisenmenger syndrome among children of repaired CHD is rare, very few studies have had the necessary data to investigate its distribution in children. The current study used data collected in rural China to investigate the prevalence of Eisenmenger syndrome in children with unrepaired CHD. Data were from the 2006 to 2016 patient medical records of China California Heart Watch, which is a traveling cardiology clinic in Yunnan Province, China. Patients were included if they (1) aged 18 or below, (2) had CHD(s), and (3) the defect was not repaired by the time of the clinic visit. The prevalence of Eisenmenger syndrome was calculated in each age and defect group. Using logistic regression models, we tested whether oxygen saturation, Down syndrome, sex, and age were significantly associated with Eisenmenger syndrome. Of the 1301 study participants, ventricular septum defect (VSD), atrial septal defect (ASD), and patent ductus arteriosus (PDA) were the most common CHD. About one-sixth of the patients had pulmonary hypertension and 1.5% had Eisenmenger syndrome. The percentages of Eisenmenger syndrome were 1.8% in VSD patients, 0 in ASD patients, and 0.9% in PDA patients. Patients in the age group between 15 and 18 years had the highest percentages of Eisenmenger syndrome (11.5%). Age and presence of Down syndrome were significantly associated with the presence of Eisenmenger syndrome. Our finding highlights the importance of early detection and correction of CHD.

Altered Lung Microbiome and Metabolome Profile in Children With Pulmonary Arterial Hypertension Associated With Congenital Heart Disease

Backgrounds

Pulmonary arterial hypertension (PAH) is characterized by progressive pulmonary vascular functional and structural changes, resulting in increased pulmonary vascular resistance and eventually right heart failure and death. Congenital Left-to-Right shunts (LTRS) is one type of congenital heart disease (CHD) and PAH associated with the congenital Left-to-Right shunt (PAH-LTRS) is a severe disease in children. However, changes in the lung microbiome and their potential impact on PAH-LTRS have not been not fully studied. We hypothesized that lung microbiota and their derived metabolites have been disturbed in children with PAH-LTRS, which might contribute to the progression and outcomes of PAH-LTRS.

Methods

In this study, 68 age- and sex-matched children of three different groups (patients with PAH-LTRS cohort, patients with LTRS but have no pathologic features of PAH cohort, and healthy reference cohort) were enrolled in the current study. Bronchoalveolar lavage fluid samples from these participants were conducted for multi-omics analysis, including 16S rRNA sequencing and metabolomic profiling. Data progressing and integration analysis were performed to identify pulmonary microbial and metabolic characteristics of PAH-LTRS in children.

Results

We found that microbial community density was not significantly altered in PAH-LTRS based on α-diversity analysis. Microbial composition analysis indicated phylum of Bacteroidetes was that less abundant while Lactobacillus, Alicycliphilus, and Parapusillimonas were significantly altered and might contribute to PAH in children with LTRS. Moreover, metabolome profiling data showed that metabolites involved in Purine metabolism, Glycerophospholipid metabolism, Galactose metabolism, and Pyrimidine metabolism were also significantly disturbed in the PAH-LTRS cohort. Correlation analysis between microbes and metabolites indicated that alterations in the microbial composition from the lung microbiota could eventually result in the disturbance in certain metabolites, and might finally contribute to the pathology of PAH-LTRS.

Conclusion

Lung microbial density was not significantly altered in patients with PAH-LTRS. Composition analysis results showed that the relative microbiome abundance was different between groups. Metabolome profiling and correlation analysis with microbiota showed that metabolome also altered in children with PAH-LTRS. This study indicated that pulmonary microbes and metabolites disturbed in PAH-LTRS could be potentially effective biomarkers and provides valuable perspectives on clinical diagnosis, treatment, and prognosis of pediatric PAH-LTRS.

Eisenmenger Syndrome: JACC State-of-the-Art Review

Although major breakthroughs in the field of pediatric cardiology, cardiac surgery, intervention, and overall care improved the outlook of congenital heart disease, Eisenmenger syndrome (ES) is still encountered and remains a complex clinical entity with multisystem involvement, including secondary erythrocytosis, increased thrombotic and bleeding diathesis, high arrhythmogenic risk, progressive heart failure, and premature death. Clearly, care for ES is best delivered in multidisciplinary expert centers. In this review, we discuss the considerable recent progress in understanding the complex pathophysiology of ES, means of prognostication, and improvement in clinical outcomes achieved with pulmonary arterial hypertension-targeted therapies. Additionally, we delineate areas of uncertainty in various aspects of care, discuss gaps in current evidence, and review current status in less privileged countries and propose initiatives to reduce disease burden. Finally, we propose the application of emerging technologies to enhance the delivery and quality of health care related to ES and beyond.

The use of pulmonary arterial hypertension therapies in Eisenmenger syndrome

INTRODUCTION

For many years, treatment options for patients with Eisenmenger physiology had been restricted to conservative measures to alleviate multi-system complications. The use of pulmonary arterial hypertension (PAH)-targeted therapies in patients with Eisenmenger syndrome (ES) changed the course of the disease, since they substantially improved clinical outcomes and increased survival.

AREAS COVERED

In this review, we primarily focus on the use of PAH pharmacotherapies in ES. A literature search was carried out in PubMed, Scopus and Cochrane Database up to May 2021. We thoroughly discuss current evidence about mechanisms of action, safety, and efficacy of these agents and present challenges and gaps in literature regarding the recommended treatment approach.

EXPERT OPINION

Unlike other forms of PAH, we usually treat patients with ES more conservatively as we lack evidence that aggressive management is safe and effective in this complex population. Several issues on the time of initiation of PAH-targeted therapies, choice between monotherapy vs. upfront combination therapy, and time of escalation still remain challenging and require further investigation. Therapeutic management should be guided by patients' individual evaluation based on available prognostic markers. More well-designed trials are warranted to assess the benefits of new PAH-targeted agents and combination therapies.

Clinical application of pulmonary vascular resistance in patients with pulmonary arterial hypertension

Pulmonary arterial hypertension is a type of malignant pulmonary vascular disease, which is mainly caused by the increase of pulmonary vascular resistance due to the pathological changes of the pulmonary arteriole itself, which eventually leads to right heart failure and death. As one of the diagnostic indicators of hemodynamics, pulmonary vascular resistance plays an irreplaceable role in the pathophysiology, diagnosis and treatment of pulmonary arterial hypertension. It provides more references for the evaluation of pulmonary arterial hypertension patients. This article summarizes the clinical application of pulmonary vascular resistance in patients with pulmonary arterial hypertension.

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.

Evaluation and Management of Pulmonary Arterial Hypertension in Congenital Heart Disease

Pulmonary arterial hypertension is a common complication in patients with congenital heart disease (CHD), aggravating the natural course of the underlying defect. Pulmonary arterial hypertension (PAH) has a multifactorial etiology depending on the size and nature of the cardiac defect as well as environmental factors. Although progress has been made in disease-targeting therapy using pulmonary vasodilators to treat Eisenmenger syndrome, important gaps still exist in the evaluation and management of adult patients with CHD-associated PAH (PAH-CHD) who have systemic-to-pulmonary shunts. The choice of interventional, medical, or both types of therapy is an ongoing dilemma that requires further data. This review focuses on the evaluation and management of PAH-CHD in the contemporary era.

Brain abscess associated with ventricular septal defect and Eisenmenger syndrome: A case report

INTRODUCTION AND IMPORTANCE

Brain abscess is a potentially fatal neurological infection, despite the development of new antimicrobial agents and modern neurosurgical techniques.

CASE PRESENTATION

We present an uncommon case where a large brain abscess was treated successfully in a patient with Eisenmenger syndrome. He was underwent neurosurgical treatment and eventually recovered.

CLINNICAL DISCUSSION

The etiology of a brain abscess in patients with congenital cyanotic heart disease has multiple aspects. In this patient population was high risk for developing perioperative complications.The preoperative evaluation, intraoperative management and postoperative care are important steps in the treatment of cardiac patients undergoing noncardiac surgery, and essential for patient's safe and fast recovery.

CONCLUSIONS

We highlight the importance of the diagnosis and management of Eisenmenger syndrome to help us further understand this rare and fatal disease.

Transcatheter closure for patent ductus arteriosus in patients with Eisenmenger syndrome: to do or not?

BACKGROUND

Patent ductus arteriosus (PDA) complicated by Eisenmenger syndrome (ES) remains to be a major cause of morbidity and mortality worldwide. Giving increasing evidences of benefit from targeted therapies, ES patients once thought to be inoperable may have increasing options for management. This study aims to explore whether PDA in patients with ES can be treated with transcatheter closure (TCC).

METHODS

Between August 2014 and July 2016, four of fifteen PDA-ES patients whose Qp/Qs improved significantly and Qp/Qs > 1.5 after acute vasodilator testing with 100% oxygen were selected to receive TCC and pulmonary vasodilator therapy. PAH-targeted drugs were prescribed before and after occlusion for all. Trial occlusion was performed before permanent closure.

RESULTS

The first TCC failed after initiation of PAH-targeted drugs for 6 months in four patients. After the medication was adjusted and extended to 12 months, TCC was performed for all without hemodynamic intolerances during perioperative period. Pulmonary artery systolic pressure (PASP) was significantly decreased (≥ 40%) immediately after TCC. During a mean follow-up of 48 ± 14.70 months, there were a further decrease of PASPs in two patients, the other two showed improved pulmonary vascular resistance, WHO functional class and six-minute walking distance despite deteriorated PASP.

CONCLUSION

Some selected PDA-ES patients might benefit from TCC and combined PAH-targeted drugs play a crucial role.

Focused Update on Pulmonary Hypertension in Children-Selected Topics of Interest for the Adult Cardiologist

Pulmonary hypertensive vascular disease (PHVD), and pulmonary hypertension (PH), which is a broader term, are severe conditions associated with high morbidity and mortality at all ages. Treatment guidelines in childhood are widely adopted from adult data and experience, though big differences may exist regarding aetiology, concomitant conditions and presentation. Over the past few years, paediatric aspects have been incorporated into the common guidelines, which currently address both children and adults with pulmonary hypertension (PH). There are multiple facets of PH in the context of cardiac conditions in childhood. Apart from Eisenmenger syndrome (ES), the broad spectrum of congenital heart disease (CHD) comprises PH in failing Fontan physiology, as well as segmental PH. In this review we provide current data and novel aspects on the pathophysiological background and individual management concepts of these conditions. Moreover, we focus on paediatric left heart failure with PH and its challenging issues, including end stage treatment options, such as mechanical support and paediatric transplantation. PH in the context of rare congenital disorders, such as Scimitar Syndrome and sickle cell disease is discussed. Based on current data, we provide an overview on multiple underlying mechanisms of PH involved in these conditions, and different management strategies in children and adulthood. In addition, we summarize the paediatric aspects and the pros and cons of the recently updated definitions of PH. This review provides deeper insights into some challenging conditions of paediatric PH in order to improve current knowledge and care for children and young adults.

Predicting the Risk of Adverse Events in Pregnant Women With Congenital Heart Disease

Background

Women with congenital heart disease are considered at high risk for adverse events. Therefore, we aim to establish 2 prediction models for mothers and their offspring, which can predict the risk of adverse events occurred in pregnant women with congenital heart disease.

Methods and Results

A total of 318 pregnant women with congenital heart disease were included; 213 women were divided into the development cohort, and 105 women were divided into the validation cohort. Least absolute shrinkage and selection operator was used for predictor selection. After validation, multivariate logistic regression analysis was used to develop the model. Machine learning algorithms (support vector machine, random forest, AdaBoost, decision tree, k‐nearest neighbor, naïve Bayes, and multilayer perceptron) were used to further verify the predictive ability of the model. Forty‐one (12.9%) women experienced adverse maternal events, and 93 (29.2%) neonates experienced adverse neonatal events. Seven high‐risk factors were discovered in the maternal model, including New York Heart Association class, Eisenmenger syndrome, pulmonary hypertension, left ventricular ejection fraction, sinus tachycardia, arterial blood oxygen saturation, and pregnancy duration. The machine learning–based algorithms showed that the maternal model had an accuracy of 0.76 to 0.86 (area under the receiver operating characteristic curve=0.74–0.87) in the development cohort, and 0.72 to 0.86 (area under the receiver operating characteristic curve=0.68–0.80) in the validation cohort. Three high‐risk factors were discovered in the neonatal model, including Eisenmenger syndrome, preeclampsia, and arterial blood oxygen saturation. The machine learning–based algorithms showed that the neonatal model had an accuracy of 0.75 to 0.80 (area under the receiver operating characteristic curve=0.71–0.77) in the development cohort, and 0.72 to 0.79 (area under the receiver operating characteristic curve=0.69–0.76) in the validation cohort.

Conclusions

Two prenatal risk assessment models for both adverse maternal and neonatal events were established, which might assist clinicians in tailoring precise management and therapy in pregnant women with congenital heart disease.

Combined effects of AKT serine/threonine kinase 1 polymorphisms and environment on congenital heart disease risk: A case-control study

This study aimed to explore the combined association between AKT serine/threonine kinase 1 (AKT1) polymorphisms and congenital heart disease (CHD) risk, meanwhile, the role of AKT1 single polymorphism on CHD was also analyzed.In the first, AKT1 polymorphisms were genotyped in 130 CHD patients and 145 healthy people with the way of polymerase chain reaction-direct sequencing. The clinical data and genotypes, alleles between 2 groups were compared by χ test and the genotype distributions in the control group were checked by Hardy-Weinberg equilibrium. The relative risk strength of disease based on genetic variant was revealed using odds ratio (OR) with 95% confidence interval (95%CI).In 3 polymorphisms of AKT1 (rs1130214, rs2494732, rs3803300), the GT/TT genotype of rs1130214 in cases and controls had a significant frequency difference (P = .04) and was 1.71 times risk developing CHD, compared with AA (OR = 1.71, 95%CI = 1.02-2.86), and T allele had 1.63 times risk for carriers (OR = 1.63, 95%CI = 1.05-2.54). Similarly, both rs3803300 GG genotype and G allele had obvious differences between case and control groups (P < .05) and it was closely associated with CHD susceptibility. At the same time, the combined effects of rs1130214, rs3803300 and family history, smoking were found in our study.AKT1 rs1130214, rs3803300 polymorphisms are associated with the increased susceptibility to CHD. Environmental factors are found the interaction with AKT1 polymorphisms. Further study is needed to verify this conclusion.

Improving medical care and prevention in adults with congenital heart disease-reflections on a global problem-part II: infective endocarditis, pulmonary hypertension, pulmonary arterial hypertension and aortopathy

Despite relevant residua and sequels, follow-up care of adults with congenital heart disease (ACHD) is too often not performed by/in specialized and/or certified physicians or centers although major problems in the long-term course may develop. The most relevant encompass heart failure, cardiac arrhythmias, heart valve disorders, pulmonary vascular disease, infective endocarditis (IE), aortopathy and non-cardiac comorbidities. The present publication emphasizes current data on IE, pulmonary and pulmonary arterial hypertension and aortopathy in ACHD and underlines the deep need of an experienced follow-up care by specialized and/or certified physicians or centers, as treatment regimens from acquired heart disease can not be necessarily transmitted to CHD. Moreover, the need of primary and secondary medical prevention becomes increasingly important in order to reduce the burden of disease as well as the socioeconomic burden and costs in this particular patient group.

When the Heart Is Not to Blame: Managing Lung Disease in Adult Congenital Heart Disease

It is well-recognized now that adult survivors with congenital heart disease (CHD) are at risk for non-cardiac co-morbidities and complications that can impact symptoms and clinical outcomes. Lung disease, in particular, is common in this population, but likely an under-recognized and undertreated cause for long-term morbidity. Abnormal lung function contributes to exercise intolerance and is associated with a higher risk for mortality in this population. The exact mechanisms that contribute to abnormal measurements of lung function are not entirely known, and are likely multifactorial and variable depending on the underlying CHD. Nevertheless, lung disease is a potentially modifiable risk factor in this patient population, the management of which may result in improved clinical outcomes. This review summarizes our current understanding of the prevalence, impact and management of lung disease in adults with CHD.

Factors influencing outcomes in patients with Eisenmenger syndrome: a nine-year follow-up study

In patients with Eisenmenger syndrome, life expectancy is usually longer than in patients with other forms of pulmonary arterial hypertension (PAH). We conducted a cohort study in which patients were followed over a long period of time in an attempt to identify potential predictors of clinical outcomes. Sixty-seven treatment-naïve patients were enrolled (age range = 12-60 years; median age = 33 years). Baseline demographic, diagnostic, and functional parameters, plasma levels of endothelial dysfunction markers, and treatment-related data were tested for possible correlations with event-free survival. Patients were started on oral PAH drugs at the beginning of follow-up (n = 23), during follow-up (n = 33), or remained untreated (n = 11). The duration of follow-up was 0.54-9.89 years (median = 7.13 years), with an overall survival rate of 82% and an event-free survival rate of 70%. The estimated mean for event-free survival time was 7.71 years (95% confidence interval [CI] = 6.86-8.55 years). Of the 16 variables that were analyzed, the duration of exposure to PAH drugs was identified as an independent protective factor (hazard ratio [HR] = 0.25 for quartiles, 95% CI = 0.14-0.47, P < 0.001). The initial functional class (HR = 3.07; 95% CI = 1.01-9.34; P = 0.048), the severity of right ventricular dysfunction (HR = 2.51 [mild, moderate or severe dysfunction]; 95% CI = 1.22-5.19; P = 0.013) and plasma von Willebrand factor concentration (HR = 1.74 for quartiles; 95% CI = 1.07-2.83; P = 0.026) were identified as risk factors. The length of exposure to oral PAH therapies influences survival favorably in Eisenmenger patients. This may be of interest for communities where access to medications is restricted.

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.

Current therapy and outcome of Eisenmenger syndrome: data of the German National Register for congenital heart defects

AIMS

We aimed to assess the contemporary outcome of Eisenmenger syndrome (ES), delineate the use of disease targeting therapies (DTT) in these patients and to investigate the effect of treatment on outcome in the community.

METHODS AND RESULTS

Patients with ES were systematically identified from the German National Register for Congenital Heart Defects. Data on underlying diagnosis, medical therapy, and survival were collected. The impact of DTT on survival was assessed using time-dependant Cox analysis. Overall, 153 ES patients were included (mean age 34.0 ± 13.3 years, 46% females). Of these, 88 (57.5%) were treated with at least one DTT (76.1% Bosentan, 20.5% Sildenafil) while 17.6% were on dual DTT. In addition, 24.8% of patients received digoxin, 10.5% angiotensin-converting enzyme-inhibitors/angiotensin receptor blockers, and 17.6% β-blockers. Moreover, 17.6% of patients were treated with oral anticoagulants, while 23.5% of patients received Aspirin. The survival rate at 1, 5, and 10 years of follow-up was only 92, 75, and 57% in the entire cohort, and was even worse in treatment naive ES patients (survival rate 86, 60, and 34% at 1, 5, and 10 years). Use of DTT was independently associated with a better survival (hazard ratio 0.42, P= 0.015).

CONCLUSION

This study illustrates the alarmingly poor survival prospects of Eisenmenger patients by community-based data even in the current era with advanced DTT and in a country with a wealthy health system. Treatment naive ES patients had especially high mortality rates approaching 60-70% at 10 years of follow-up. Treatment with DTT was associated with better survival.

Advanced therapies in patients with congenital heart disease-related pulmonary arterial hypertension: results from a long-term, single center, real-world follow-up

Pulmonary arterial hypertension (PAH) is a common finding in patients with congenital heart disease (CHD), and has relevant prognostic implications. The recent introduction of advanced therapies (AT) considerably improved the clinical outcome of these patients, but real-world data are still lacking. We aimed at reporting the results of a long-term follow-up of CHD patients with PAH undergoing AT, followed at a tertiary Center during the two last decades. The study population included a total of 34 patients with an established diagnosis of CHD-related PAH. In addition to conventional treatment, 97% of patients started AT during the follow-up. Over a median follow-up of 9 [3-31] years, 11 (32.4%) patients died: 7 of them were affected by Eisenmenger syndrome and the majority of patients were in NYHA class ≥3 at the time of death. Among the 23 patients who were alive at the last follow-up, the majority were in NYHA class I-II. Oxygen saturation and 6-min walking distance improved in all subjects within the first 6 months after starting of AT. One patient with ventricular septum defect and high pulmonary resistances was successfully treated with AT to lower resistances and underwent defect closure. A good clinical outcome was also observed in the subset (n = 8) with Down syndrome. The results of this real-world experience suggest that, despite a relatively high mortality rate mostly related to late commencement of AT, the clinical outcome of subjects with CHD-related PAH undergoing AT are characterized by a good quality of life and clinical improvement in most patients.

Bardoxolone methyl (CDDO-Me) as a therapeutic agent: an update on its pharmacokinetic and pharmacodynamic properties

Triterpenoids have been used for medicinal purposes in many Asian countries because of their anti-inflammatory, antioxidant, antiproliferative, anticancer, and anticarcinogenic properties. Bardoxolone methyl, the C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) known as CDDO-Me or RTA 402, is one of the derivatives of synthetic triterpenoids. CDDO-Me has been used for the treatment of chronic kidney disease, cancer (including leukemia and solid tumors), and other diseases. In this review, we will update our knowledge of the clinical pharmacokinetics and pharmacodynamics of CDDO-Me, highlighting its clinical benefits and the underlying mechanisms involved. The role of the Kelch-like erythroid cell-derived protein with CNC homology-associated protein 1 (Keap1)/the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in the therapeutic activities of CDDO-Me will be discussed. CDDO-Me contains α,β-unsaturated carbonyl groups on rings A and C that can generate reversible adducts with the thiol groups of Cys residues in target proteins such as Keap1 and IκB kinase. At low nanomolar concentrations, CDDO-Me protects the cells against oxidative stress via inhibition of reactive oxygen species generation, while CDDO-Me at low micromolar concentrations induces apoptosis by increasing reactive oxygen species and decreasinging intracellular glutathione levels. Through Keap1/Nrf2 and nuclear factor-κB pathways, this agent can modulate the activities of a number of important proteins that regulate inflammation, redox balance, cell proliferation and programmed cell death. In a Phase I trial in cancer patients, CDDO-Me was found to have a slow and saturable oral absorption, a relatively long terminal phase half-life (39 hours at 900 mg/day), nonlinearity (dose-dependent) at high doses (600-1,300 mg/day), and high interpatient variability. As a multifunctional agent, CDDO-Me has improved the renal function in patients with chronic kidney disease associated with type 2 diabetes. CDDO-Me has shown a promising anticancer effect in a Phase I trial. This agent is generally well tolerated, but it may increase adverse cardiovascular events. Presently, it is being further tested for the treatment of patients with chronic kidney disease, cancer, and pulmonary arterial hypertension.