Initial experience with bosentan (Tracleer) as treatment for pulmonary arterial hypertension (PAH) due to congenital heart disease in infants and young children

Long-Term Follow-Up of Pediatric Patients with Severe Postoperative Pulmonary Hypertension After Correction of Congenital Heart Defects

The surgical repair of congenital heart defects in children with preoperative pulmonary hypertension (PH) is to varying degree associated with the occurrence of postoperative PH. The objective of this study was to follow up children with severe postoperative PH (pulmonary arterial/aortic pressure ratio ≥ 1.0) to evaluate if pulmonary arterial pressure spontaneously normalized or needed PH-targeting therapy and to identify potential high-risk diagnoses for bad outcome. Twenty-five children who developed clinically significant severe PH on at least three occasions postoperatively were included in the follow-up (20-24 years). Data from chart reviews, echocardiographic investigations, and questionnaires were obtained. Three children died within the first year after surgery. Three children were lost to follow-up. The remaining 17 children normalized their pulmonary arterial pressure without the use of PH-targeting drugs at any time during the follow-up. Two children had a remaining mild PH with moderate mitral valve insufficiency. All three children with bad outcome had combined cardiac lesions causing post-capillary pulmonary hypertension. Normalization of the pulmonary arterial pressure occurred in almost all children with severe postoperative PH, without any need of supplemental PH-targeting therapies. All children with bad outcome had diagnoses conformable with post-capillary PH making the use of PH-targeting therapies relatively contraindicated. These data emphasize the need to perform randomized, blinded trials on the use of PH-targeting drugs in children with postoperative PH before accepting it as an indication for routine treatment.

Comparative assessment of efficacy and safety of ambrisentan and bosentan in patients with pulmonary arterial hypertension: A meta-analysis

WHAT IS KNOWN AND OBJECTIVE

Two endothelin receptor antagonists, ambrisentan and bosentan, have been demonstrated to be effective individually compared with placebo in the treatment of patients with pulmonary arterial hypertension (PAH). This network meta-analysis compared the efficacy and safety of ambrisentan and bosentan in patients with PAH.

METHODS

Clinical trials were identified from the Cochrane Central Register of Controlled Trials (CENTRAL/CCTR), EMBASE and PubMed databases. Weighted mean differences (MD) with 95% confidence intervals (CI) were calculated for continuous outcomes (6-min walk distance [6MWD] and Borg dyspnoea index [BDI]). Hazard ratio (HR) was calculated for binary outcomes, including clinical worsening, discontinuation due to adverse events (AEs) and liver dysfunction. Surface under cumulative ranking curve (SUCRA) was used to rank the treatments in each index.

RESULTS

Five clinical trials from four published studies (total patients: n = 920) were included. Ambrisentan and bosentan showed no significant difference in 6MWD (MD: -1.32; 95% CI: -27.87, 25.31, SUCRA score: ambrisentan 0.73, bosentan 0.77), BDI (MD: -0.16; 95% CI: -0.98, 0.65, SUCRA score: ambrisentan 0.83, bosentan 0.66), clinical worsening (HR: 0.99; 95% CI: 0.33, 2.94, SUCRA score: ambrisentan 0.75, bosentan 0.74) and discontinuation due to AEs (HR: 0.84; 95% CI: 0.11, 5.86, SUCRA score: ambrisentan 0.47, bosentan 0.57). However, ambrisentan was significantly better than bosentan with respect to abnormal liver function (HR: 23.18; 95% CI: 2.24, 377.20, SUCRA score: ambrisentan 0.99, bosentan 0.02).

WHAT IS NEW AND CONCLUSION

The results of this network meta-analysis suggest that ambrisentan was similar to bosentan in efficacy, while it exhibited better tolerability with respect to abnormal liver function in comparison with bosentan, in patients with PAH.

Inadequate Dosage May Lead to the Recurrence of Postoperative Pulmonary Hypertension in Patients With Congenital Heart Disease

Background: Pulmonary arterial hypertension (PAH) associated with congenital heart disease (PAH-CHD) occurs predominantly among patients with uncorrected congenital heart disease (CHD). It is an intractable problem to control PAH continuously and stably after an operation.

Methods: 1) OPLS-DA combined with S-plot was used to retrospectively analyze the results of preoperative and postoperative PAH and 39 biochemical indicators of 235 patients admitted to Fuwai Yunnan Cardiovascular Hospital from January 2019 to December 2020. 2) Combined with Meta-analysis, the recurrence in postoperative PAH was analyzed in terms of operation factors, doses administered, and age factors.

Results: 1) 4 indicators (PAH, RBC, HGB, and CO₂) that reflect the prognosis of patients had been found by OPLS-DA combined with S-plot. 2) The recurrence rate of postoperative PAH was 37.02%. The comprehensive therapeutic effect of interventional closure was better than that of surgical operation. PAH was not significantly higher again in patients who received either the instruction dose or the literature dose. Postoperative combination therapy (bosentan and sildenafil) was more effective than bosentan alone. Recovery after treatment was better in infants than in the other four age groups.

Conclusion: OPLS-DA combined with S-plot was used for the first time to analyze clinical examination data. In this study, this method proved to be a feasible method for analyzing clinical data We recommend interventional closure as the first choice for patients with PAH-CHD. For postoperative oral therapy, we recommend the combination therapy (bosentan with sildenafil). To prevent the recurrence, the dose should be strictly prescribed according to the instructions, literature, or body surface area converted. Moreover, we recommend treatment at a young age in these patients.

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.

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.

Advances in therapies for pediatric pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by progressive obliteration of the pulmonary vasculature, leading to right heart failure and death if left untreated. Prior to the current treatment era, pulmonary hypertension carried a poor prognosis with a high mortality rate, but its prognosis has changed over the past decades in relation to new therapeutic agents. Nevertheless, pulmonary hypertension continues to be a serious condition, which is extremely challenging to manage. The data in children are often limited owing to the small number of patients, and extrapolation from adults to children is not straightforward. While none of these new therapeutic agents have been specifically approved for children, there is evidence that each can appropriately benefit the PAH child. We review the current understanding of pediatric pulmonary hypertension, classification, diagnostic evaluation and available treatment. A description of targeted pharmacological therapy and new treatments in children is outlined.

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.

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.

Pharmacologic treatment for pulmonary arterial hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) has been a disease with limited treatment options and poor prognosis. This article reviews the recent advances that took place in the medical management of PAH.

RECENT FINDINGS

Sildenafil is a type 5 cGMP-specific phosphodiesterase inhibitor originally developed to treat erectile dysfunction. Multiple uncontrolled and randomized controlled trials have proven that it is useful in the treatment of PAH and it was approved by the US Food and Drug Administration. The switch from continuous intravenous infusion of epoprostenol to subcutaneous infusion of treprostinil has been proven feasible and safe. Bosentan has been shown effective as a monotherapy and it also improves survival in patients with functional classes III and IV. In smaller clinical trials bosentan has improved symptoms in different forms of PAH. Combinations of drugs of different classes such as prostanoids, endothelin receptor blockers and sildenafil are tested, and such a strategy improves both symptoms and survival. Animal models and anecdotal clinical experience suggest the possibility of using imatinib mesylate in PAH.

SUMMARY

With the approval of sildenafil, treatment options for this difficult disease have improved significantly. Combinations of drugs of different groups are promising and need further exploration.

Current treatment options in children with pulmonary arterial hypertension and experiences with oral bosentan

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by vasoconstriction and progressive remodelling of the pulmonary arterial wall leading to right ventricular failure and death. Idiopathic PAH (IPAH) and PAH associated with congenital heart defects account for the majority of paediatric patients with PAH. During the last few decades, several pharmacological approaches have been introduced, including calcium channel-blockers (CCBs), prostacyclin analogues, endothelin receptor antagonists and, most recently, phosphodiesterase inhibitors. This paper reviews the treatment options available to children with a special focus on the initial experience with bosentan. Although CCBs have been shown to increase survival in IPAH, the beneficial effect appears to be limited to a small number of patients, defined as 'responders' to the vasoreactivity testing. With the availability of prostacyclin (intravenous epoprostenol) and then prostacyclin analogues, the treatment options have increased markedly and particularly in patients who have not responded to conventional therapy. Although epoprostenol has been shown to be efficacious in PAH, the drug is not ideal owing to serious complications arising from the invasive mode of application, particularly in children. Phosphodiesterase-5 inhibitors have also shown beneficial effects. Targeting the endothelin (ET) system with the oral, dual ET(A)/ET(B) receptor antagonist, bosentan has been demonstrated to improve the cardiopulmonary haemodynamics, exercise capacity, quality-of-life and survival in adult patients with PAH. Specific ET(A) antagonists may also present the same beneficial profile. Recent experience with bosentan in paediatric patients with PAH indicates that the results obtained in adult patients may be extrapolated to children, thus offering a safe and effective therapy that is easy to administer.