Initial combination therapy of macitentan and tadalafil in pulmonary arterial hypertension

Real-world effectiveness and safety of macitentan in patients with pulmonary artery hypertension: a multicenter, retrospective, observational study in China

BACKGROUND

Macitentan, either as monotherapy or part of combination therapy, improved clinical outcomes in patients with pulmonary artery hypertension (PAH) in clinical trials. Evidence on the effectiveness and safety of macitentan administered in real-world clinical practice in China is limited.

METHODS

This real-world, retrospective, multicenter chart review study was conducted at seven hospitals in China. Adult patients with a diagnosis of PAH who initiated macitentan and had medical assessments at 3-7 months after macitentan initiation were included. The primary outcomes were changes in the World Health Organization functional class (WHO-FC), 6-min walk distance (6MWD), and N-terminal pro-B-type natriuretic peptide (NT-proBNP)/B-type natriuretic peptide from baseline to first follow-up visit (months 3-7). Serious adverse events (SAEs) and adverse drug reactions (ADRs) of macitentan were collected.

RESULTS

From 30 August 2021 to 31 March 2022, 214 eligible patients were included in the safety analysis set and 105 patients were included in the analysis of effectiveness. At the first follow-up visit compared with baseline, significant changes in WHO-FC were observed (p = .04), 93.5% patients had their WHO-FC improved (25.8%) or maintained (67.7%). 6MWD changed by a mean (standard deviation [SD]) of 45.0 (81.4) meters (p < .001), with 94.7% having their 6MWD improved (34.7%) or maintained (60.0%). The mean (SD) of NT-proBNP decreased from 1667.4 (3233.0) ng/L to 1090.0 (2230.1) ng/L (p < .001). In the safety analysis set, 24 (11.2%) patients experienced at least one ADR and/or SAE. ADRs and SAEs were reported in 11 (5.1%) and 18 (8.4%), respectively. No deaths or unexpected safety events were observed.

CONCLUSION

This study provided real-world evidence on the clinical benefits and good tolerance of macitentan in Chinese patients with PAH treated in routine clinical practice.

Survival in systemic sclerosis associated pulmonary arterial hypertension in the current treatment era-results from a nationwide study

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a leading cause of mortality in systemic sclerosis (SSc). This nationwide study aims to describe real world treatment characteristics and assess survival rates of patients with SSc-PAH.

METHODS

In this retrospective cohort study, patients with SSc-PAH were identified from Turkish Ministry of Health National Electronic Database (from January 2016 to September 2022), using ICD-10 codes. Data on demographics, treatment characteristics, and death was collected. Kaplan-Meier curves were used to calculate cumulative probabilities of survival at 1, 3, and 5 years.

RESULTS

Five hundred forty-seven patients (90.7% female) with SSc-PAH were identified. Median age at PAH diagnosis was 59.9 (50.0-67.4) years. During a median follow-up duration of 3.2 (1.5-4.8) years, 199 (36.4%) deaths occurred. Estimated survival rates at 1, 3, and 5 years were 90.2%, 73.2%, and 56.6%, respectively. Survival was similar among patients with and without interstitial lung disease (p = 0.20). Patients who used immunosuppressives had better survival than those who did not (p < 0.001). No difference was observed in survival rates according to initial PAH-specific treatment regimen (monotherapy or combination) (p = 0.49).

CONCLUSION

Compared to most of historical cohorts, higher survival rates for SSc-PAH were observed in this study. Early diagnosis of PAH may have contributed to these findings. The impact of immunosuppressive therapy on prognosis of SSc-PAH needs to be further investigated in prospective studies. Key Points • Early diagnosis is pivotal for better outcomes in SSc-PAH. • Implementation of PAH treatment guidelines in routine clinical practice is still poor and should be improved. • Effect of immunosuppressive therapies on disease course has to be defined in SSc-PAH.

Randomized Trial of Macitentan/Tadalafil Single-Tablet Combination Therapy for Pulmonary Arterial Hypertension

BACKGROUND

Endothelin receptor antagonist (ERA) and phosphodiesterase 5 inhibitor (PDE5i) combination therapy is recommended for low-/intermediate-risk pulmonary arterial hypertension (PAH) patients. A fixed-dose combination of the ERA macitentan and PDE5i tadalafil (M/T FDC) in a once-daily, single tablet would simplify treatment.

OBJECTIVES

The multicenter, double-blind, adaptive phase 3 A DUE study investigated the efficacy and safety of M/T FDC vs macitentan 10 mg and vs tadalafil 40 mg monotherapies in PAH patients, including treatment-naïve and prior ERA or PDE5i monotherapy-treated patients.

METHODS

World Health Organization functional class II-III patients were randomized to M/T FDC, macitentan, or tadalafil depending on their PAH treatment (treatment-naïve, ERA, or PDE5i monotherapy) at baseline. The primary endpoint was change in pulmonary vascular resistance (PVR) at week 16.

RESULTS

In total, 187 patients were randomized to single-tablet M/T FDC (n = 108), macitentan (n = 35), or tadalafil (n = 44). PVR reduction with M/T FDC was significantly greater vs macitentan (29%; geometric mean ratio 0.71; 95% CL: 0.61-0.82; P < 0.0001) and vs tadalafil (28%; geometric mean ratio 0.72; 95% CL: 0.64-0.80; P < 0.0001). Three patients died in the M/T FDC arm (judged unrelated to treatment). Adverse events (AEs) leading to discontinuation, serious AEs, and those of special interest (anemia, hypotension, and edema) were more frequent with M/T FDC.

CONCLUSIONS

Macitentan and tadalafil FDC significantly improved PVR vs monotherapies in PAH patients, with a safety and tolerability profile consistent with the individual components. The A DUE study supports M/T FDC as a once-daily, single-tablet combination for initial therapy and escalation to double combination therapy in patients with PAH. (Clinical Study to Compare the Efficacy and Safety of Macitentan and Tadalafil Monotherapies With the Corresponding Fixed-dose Combination Therapy in Subjects With Pulmonary Arterial Hypertension [PAH]) [A DUE]; NCT03904693).

Contribution of pressure and flow changes to resistance reduction after pulmonary arterial hypertension treatment: a meta-analysis of 3898 patients

Background

Pulmonary arterial hypertension (PAH)-targeted therapies exert significant haemodynamic changes; however, systematic synthesis is currently lacking.

Methods

We searched PubMed, CENTRAL and Web of Science for studies evaluating mean pulmonary artery pressure (mPAP), cardiac index/cardiac output (CI/CO) and pulmonary vascular resistance (PVR) of PAH-targeted therapies either in monotherapy or combinations as assessed by right heart catheterisation in treatment-naïve PAH patients. We performed a random-effects meta-analysis with meta-regression.

Results

We included 68 studies (90 treatment groups) with 3898 patients (age 47.4±13.2 years, 74% women). In studies with small PVR reduction (<4 WU), CI/CO increase (R2=62%) and not mPAP reduction (R2=24%) was decisive for the PVR reduction (p<0.001 and p=0.36, respectively, in the multivariable meta-regression model); however, in studies with large PVR reduction (>4 WU), both CI/CO increase (R2=72%) and mPAP reduction (R2=35%) contributed significantly to the PVR reduction (p<0.001 and p=0.01, respectively). PVR reduction as a percentage of the pre-treatment value was more pronounced in the oral+prostanoid intravenous/subcutaneous combination therapy (mean difference -50.0%, 95% CI -60.8- -39.2%), compared to oral combination therapy (-41.7%, -47.6- -35.8%), prostanoid i.v./s.c. monotherapy (-31.8%, -37.6- -25.9%) and oral monotherapy (-21.6%, -25.4- -17.8%). Changes in haemodynamic parameters were significantly associated with changes in functional capacity of patients with PAH as expressed by the 6-min walking distance.

Conclusion

Combination therapies, especially with the inclusion of parenteral prostanoids, lead to remarkable haemodynamic improvement in treatment-naïve PAH patients and may unmask the contribution of mPAP reduction to the overall PVR reduction in addition to the increase in CO.

Current Management and Future Directions for Pulmonary Arterial Hypertension Associated with Congenital Heart Disease

Current management of patients with congenital heart disease has increased their survival into adulthood. This is accompanied by potential cardiac complications, including pulmonary hypertension associated with congenital heart disease (PAH-CHD). PAH-CHD constitutes a challenging subgroup of pulmonary hypertension and requires expert management to improve quality of life and prognosis. Novel agents have shown a significant improvement in morbidity and mortality in patients with pulmonary arterial hypertension. However, the long-term effects of these medications on PAH-CHD patients remain somewhat uncertain, necessitating treatment plans largely founded on the clinical experience of the healthcare providers. The aim of this review is to summarize the current evidence and future perspectives regarding treatment strategies for PAH-CHD to help better guide management of this complex disease.

Management of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a rare pulmonary vascular disease characterized by progressive pulmonary arterial remodeling, increased pulmonary vascular resistance, right ventricular dysfunction, and reduced survival. Effective therapies have been developed that target three pathobiologic pathways in PAH: nitric oxide, endothelin-1, and prostacyclin. Approved therapies for PAH include phosphodiesterase type-5 inhibitors, soluble guanylate cyclase stimulators, endothelin receptor antagonists, prostacyclin analogs, and prostacyclin receptor agonists. Management of PAH in the modern era incorporates multidimensional risk assessment to guide the use of these medications. For patients with PAH and without significant comorbidities, current guidelines recommend two oral medications (phosphodiesterase type-5 inhibitor and endothelin receptor antagonist) for low- and intermediate-risk patients, with triple therapy including a parenteral prostacyclin to be considered in those at high or intermediate-high risk. Combination therapy may be poorly tolerated and less effective in patients with PAH and cardiopulmonary comorbidities. Thus, a single-agent approach with individualized decisions to add-on other PAH therapies is recommended in older patients and those with significant comorbid conditions. Management of PAH is best performed in multidisciplinary teams located in experienced centers. Other core pillars of PAH management include supportive and adjunctive treatments including oxygen, diuretics, rehabilitation, and anticoagulation in certain patients. Patients with PAH who progress despite optimal treatment or who are refractory to best medical care should be referred for lung transplantation, if eligible. Despite considerable progress, PAH is often fatal and new therapies that reverse the disease and improve outcomes are desperately needed.

Real-World Treatment Patterns Among Patients with Connective Tissue Disorder-Related Pulmonary Arterial Hypertension in the United States: A Retrospective Claims-Based Analysis

INTRODUCTION

Connective tissue disorders (CTDs) are the most frequent diseases associated with pulmonary arterial hypertension (PAH). Despite advances in treatment, the prognosis of CTD-related PAH remains poor. To help identify areas for improvement in the management of CTD-related PAH, this study assessed real-world PAH treatment patterns in this population in the US.

METHODS

Eligible adult patients with PAH initiated on a PAH treatment (index date: 1st initiation date) were identified from Optum's de-identified Clinformatics® Data Mart Database (10/01/2015-09/30/2021) and categorized into mutually exclusive cohorts (CTD + PAH; PAH) based on the presence of CTD diagnosis claims. Treatment patterns were assessed from the index date to the earliest of death or end of continuous insurance eligibility, or data availability. Treatment persistence was assessed using Kaplan-Meier analysis.

RESULTS

A total of 4751 patients were included (CTD + PAH: n = 728, mean follow-up of 18.8 months; PAH: n = 4023, mean follow-up of 19.6 months). For both cohorts, the most common first treatment regimens were sildenafil (CTD + PAH: 38.7%; PAH: 51.5%), tadalafil (10.0%; 9.4%), and macitentan (8.1%; 5.4%) monotherapy; these were also the most frequent agents included in any of the first 3 treatment regimens. Combination therapy was more frequent in the CTD + PAH versus PAH cohort (any regimen: 40.9% vs. 27.2%; 1st treatment regimen: 26.9% vs. 18.5%; 2nd: 52.8% vs. 42.0%; 3rd: 55.2% vs. 48.5%). Treatment persistence was similar across cohorts and the first three treatment regimens, with persistence rates ranging from 42.6 to 49.7% at 12 months.

CONCLUSIONS

Treatment patterns were generally similar between the CTD + PAH and PAH cohorts, although combination therapy was more frequent in the CTD + PAH cohort. Both cohorts may benefit from broader use of all available PAH treatment classes, including combination therapy. Considering the life-threatening nature of PAH, our findings also highlight the need to address the low persistence rates with PAH therapies regardless of etiology.

[Diagnosis and therapy of pulmonary arterial hypertension]

2022, the updated guidelines for the diagnosis and treatment of pulmonary hypertension (PH) of the European Societies of Cardiology and Pneumology were published. This resulted in important innovations concerning the hemodynamic definition as well as diagnosis and therapy of PH. In the following, an overview of the definition and classification of PH will be given, followed by a discussion of risk stratification and therapy of pulmonary arterial hypertension (PAH).

Pharmacological management of connective tissue disease-associated pulmonary arterial hypertension

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a severe, progressive pulmonary vasculopathy (Group 1 Pulmonary Hypertension (PH)) that complicates the course of many connective tissue diseases (CTD). Detailed testing is required to differentiate PAH from other types of PH caused by CTD such as left heart disease (Group 2 PH), pulmonary parenchymal disease (Group 3 PH), and chronic thromboembolic pulmonary hypertension (Group 4 PH). PAH is most frequently seen in systemic sclerosis but can also be seen with systemic lupus erythematosus, mixed CTD, and primary Sjogren's syndrome.

AREAS COVERED

This review discusses the epidemiology of CTD-associated PAH, outlines the complex diagnosis approach, and finishes with an in-depth discussion on the current treatment paradigm. Focus is placed on challenges faced in the treatment of CTD-associated PAH, (decreased efficacy and poorer tolerance of pharmacological therapies) and includes a discussion on the future investigational treatments.

EXPERT OPINION

Despite significant advances over the past decades with more aggressive treatment algorithms, CTD-associated PAH patients continue to have poorer survival compared to those with idiopathic PAH. This review highlights factors leading to disparate outcomes compared to other forms of PAH, and discusses on further improvements that may increase quality of life and survival for CTD-associated PAH patients.

Should We Change the Target of Therapy in Pulmonary Hypertension?

Despite the evolution of drug therapy in pulmonary arterial hypertension and the more aggressive treatment approach according to the guidelines, patients continue to have unacceptable mortality rates. Furthermore, specific drug therapy alone in chronic thromboembolic pulmonary hypertension also does not seem to have any beneficial impact on survival. As the function of the right ventricle (RV) determines the prognosis of patients with pulmonary hypertension, the treatment strategy should focus on modifying factors involved in RV dysfunction. Although some previous reports demonstrated that the survival of patients with pulmonary hypertension was associated with mPAP, nevertheless, mPAP is still not considered as a target of therapy. There are many examples of effective mPAP lowering with early and aggressive drug therapy in pulmonary arterial hypertension, or with interventions in chronic thromboembolic pulmonary hypertension. This effective mPAP reduction can lead to reverse RV remodeling, and thus, improvement in survival. In this article, the importance of mPAP lowering is stated, as well as why the change of our current strategy and considering mPAP reduction as the target of therapy could make pulmonary hypertension a chronic but not fatal disease.

Economic burden of illness among patients with pulmonary arterial hypertension (PAH) associated with connective tissue disorders (CTD)

Pulmonary arterial hypertension (PAH) is commonly associated with connective tissue disorders (CTDs). This study provides a contemporary assessment of the economic burden of CTD + PAH and PAH in the United States. Eligible adult patients identified from Optum's deidentified Clinformatics® Data Mart Database (10/01/2015-09/30/2021) were classified into mutually exclusive cohorts based on recorded diagnoses: (1) CTD + PAH, (2) PAH, (3) CTD, (4) control without CTD/PAH. The index date was a randomly selected diagnosis date for PAH (CTD + PAH, PAH cohorts) or CTD (CTD cohort), or a random date (control cohort). Entropy balancing was used to balance characteristics across cohorts. Healthcare costs and healthcare resource utilization (HRU) per patient per month (PPPM) were assessed for ≤12 months postindex and compared among balanced cohorts. A total of 552,900 patients were included (CTD + PAH: n = 1876; PAH: n = 8177; CTD: n = 209,156; control: n = 333,691). Average total all-cause costs were higher for CTD + PAH than PAH cohort ($16,854 vs. $15,686 PPPM; p = 0.02); both cohorts incurred higher costs than CTD and control cohorts ($4476 and $2170 PPPM; all p < 0.001). Average HRU PPPM was similar between CTD + PAH and PAH cohorts (inpatient stay: 0.15 vs. 0.15, outpatient visits: 4.23 vs. 4.11; all p > 0.05), while CTD and control cohorts incurred less HRU (inpatient stay: 0.07 and 0.03, outpatient visits: 2.67 and 1.69; all p < 0.001). CTD + PAH and PAH are associated with a substantial economic burden. The incremental burden attributable to PAH versus the general population and patients with CTD without PAH highlights significant unmet needs among PAH patients.

Early echocardiographic evaluation of right ventricular load adaptability after sequential combination treatment in pulmonary arterial hypertension

BACKGROUND

Using the tricuspid annular plane systolic excursion (TAPSE)/pulmonary arterial systolic pressure (PASP) ratio as an index of right ventricular load adaptability, we aimed to evaluate early changes in right heart contractile function of patients with group 1 pulmonary artery hypertension (PAH) after sequential combination PAH-specific therapy.

METHODS

A total of 49 patients with group 1 PAH and 31 control participants were included in the study. The baseline clinical and echocardiographic data of the control and PAH group were compared. Subsequently, clinical and echocardiographic data of PAH patients before treatment and at 6 months after PAH-specific treatment were analyzed.

RESULTS

A significant increase in the TAPSE/PASP ratio was found in patients at 6 months of PAH-specific treatment (0.25 ± 0.14; 0.33 ± 0.16, p < 0.001). Right atrial pressure (8 mm Hg [5-10]; 5 mm Hg [3-8], p < 0.001) and PASP (80.8 ± 30.6 mm Hg; 65.9 ± 25.7 mm Hg, p < 0.001) were significantly lower after sequential combination PAH-specific therapy. Negative correlations were found between the TAPSE/PASP ratio and N‑terminal pro-B-type natriuretic peptide (r = -0.524, p < 0.001), tricuspid regurgitation velocity (r = -0.749, p < 0.001), right atrial area (r = -0.298, p = 0.037), and right atrial pressure (r = -0.463, p = 0.001).

CONCLUSION

In patients with group 1 PAH, echocardiographic evaluation at the early stage of treatment (6 months) shows a significant improvement in the TAPSE/PASP ratio indicating right ventricular load adaptation. Comprehensive studies are needed on the routine use of the TAPSE/PASP ratio in the risk assessment of PAH patients.

Mixed venous oxygen tension is a crucial prognostic factor in pulmonary hypertension: a retrospective cohort study

BACKGROUND

The prognostic value of mixed venous oxygen tension (PvO2) at pulmonary hypertension diagnosis treated with selective pulmonary vasodilators remains unclear. This study sought to investigate the association of PvO2 with long-term prognosis in pulmonary arterial hypertension (PAH) and medically treated chronic thromboembolic pulmonary hypertension (CTEPH) and to identify the distinct mechanisms influencing tissue hypoxia in patients with CTEPH or PAH.

METHODS

We retrospectively analyzed data from 138 (age: 50.2 ± 16.6 years, 81.9% women) and 268 (age: 57.4 ± 13.1 years, 72.8% women) patients with PAH and CTEPH, respectively, diagnosed at our institution from 1983 to 2018. We analyzed the survival rates of patients with/without tissue hypoxia (PvO2 < 35 mmHg) and identified their prognostic factors based on the pulmonary hypertension risk stratification guidelines.

RESULTS

Survival was significantly poorer in patients with tissue hypoxia than in those without it for PAH (P = 0.001) and CTEPH (P = 0.017) treated with selective pulmonary vasodilators. In patients with PAH, PvO2 more strongly correlated with prognosis than other hemodynamic prognostic factors regardless of selective pulmonary vasodilators usage. PvO2 was the only significant prognostic factor in patients with CTEPH treated with pulmonary hypertension medication. Patients with CTEPH experiencing tissue hypoxia exhibited significantly poorer survival than those in the intervention group (P < 0.001). PvO2 more strongly correlated with the cardiac index (CI) than the alveolar-arterial oxygen gradient (A-aDO2) in PAH; whereas in CTEPH, PvO2 was more strongly correlated with A-aDO2 than with CI.

CONCLUSIONS

PvO2 may represent a crucial prognostic factor for pulmonary hypertension. The prognostic impact of tissue hypoxia affects different aspects of PAH and CTEPH, thereby reflecting their distinct pathogenesis.

Prognostic impact of follow-up pulmonary vascular resistance in pulmonary arterial hypertension

Objective

Pulmonary arterial hypertension (PAH), caused by pulmonary artery remodelling and increased pulmonary vascular resistance (PVR) due to an unknown mechanism, is an intractable disease with a poor prognosis. The recent development of PAH-specific treatment medications may allow for higher PVR reduction than previously achieved. This study aimed to identify the prognostic significance of follow-up PVR levels achieved shortly after the initiation of targeted treatment in patients with idiopathic/heritable pulmonary arterial hypertension (I/H-PAH).

Methods

We analysed the data of all patients with I/H-PAH admitted to our hospital between 1998 and 2019. We collected data at baseline and during the first invasive haemodynamic evaluation. The primary outcome was death or lung transplantation.

Results

Of the 133 treatment-naïve patients enrolled in this study, 47 experienced adverse events during a median follow-up period of 6.4 (IQR 3.5–11.5) years. The median time interval to first follow-up from diagnosis was 162 (IQR 117–253) days. Incidence of the primary outcome was significantly lower in patients who achieved low PVR at follow-up. Of risk factors evaluated at follow-up, the multivariate Cox regression analysis revealed PVR as an independent predictor of the primary outcome (HR 1.103, 95% CI 1.029 to 1.183; p=0.006). The results were consistent across risk profiles according to the simplified risk stratification recommended by the European Society of Cardiology and European Respiratory Society guidelines.

Conclusion

Follow-up PVR was an independent predictor of transplant-free survival in patients with I/H-PAH. Evaluation of haemodynamic status shortly after initiating treatment may help predict long-term prognosis.

Changes in the Characteristics and Initial Treatments of Pulmonary Hypertension Between 2008 and 2020 in Japan

Background

Pulmonary arterial hypertension (PAH) is a rare, progressive disease. The treatment landscape for PAH in Japan has evolved considerably in recent years, but there is limited knowledge of the changes in treatment practices or patient characteristics.

Objectives

The aim of this study was to evaluate the changes in characteristics and initial treatments for PAH in Japan over time.

Methods

This study used data from the Japan Pulmonary Hypertension Registry (JAPHR) to compare patient characteristics and treatment practices between 2008-2015 (n = 316) and 2016-2020 (n = 315).

Results

The mean ± standard deviation age at diagnosis increased from 47.9 ± 16.7 years in 2008-2015 to 52.7 ± 16.9 years in 2016-2020. The mean pulmonary arterial pressure decreased from 45.4 ± 15.0 to 38.6 ± 13.1 mm Hg. Idiopathic/hereditary PAH was the most common etiology in both periods (50.0% and 51.1%, respectively). The proportion of patients prescribed oral/inhaled combination therapies increased from 47.8% to 57.5%. Oral/inhaled combination therapies were frequently prescribed to patients with congenital heart disease-related PAH (81.8%). There was no significant trend in prescribing practices based on French low-risk criteria: among patients with 0, 1, 2, 3, or 4 criteria, 53.8%, 68.8%, 52.8%, 66.7%, and 39.4% were prescribed oral/inhaled combination therapies, and 0%, 16.7%, 27.0%, 17.3%, and 15.2% were prescribed oral/inhaled monotherapies. Macitentan, tadalafil, selexipag, and epoprostenol were the most frequently prescribed drugs.

Conclusions

The severity of PAH decreased over time in Japan. Oral/inhaled combination therapies were generally preferred. Physicians generally prescribed therapies after considering the patients’ hemodynamics and clinical severity. (Japan Pulmonary Hypertension Registry [JAPHR]; UMIN000026680)

Risk assessment tools for survival prognosis: An era of new surrogacy endpoints for clinical outcome measurement in pulmonary arterial hypertension clinical trials?

Developing a new medication in a rare disease indication like pulmonary arterial hypertension (PAH) is very challenging. This is especially true now that clinical trials often employ time to clinical worsening (TTCW) as an endpoint (thus requiring a relatively large and lengthy trial) and since patients are more frequently prescribed combination therapy. During the last few decades, several tools have been developed to predict mortality in PAH and have demonstrated generally good discrimination. The objective of this review article is to assess the available data on the different tools and methods described in the literature and identify potential candidates that could be used as surrogate endpoints in pivotal randomized clinical trials in future. Some of these tools have been validated in various registries and in post-hoc analyses of clinical trial data, but none have been assessed in a prospective clinical trial and we still lack the evidence necessary for endorsement by health authorities. In this review, we identify several promising options that warrant further investigation as potential surrogate endpoints in clinical trials to replace TTCW or 6-minute walk distance. Prospective inclusion of such tools in new clinical trials may help build a stronger surrogacy for prognosis of disease progression and mortality.

Echocardiographic Evaluation of Initial Ambrisentan Plus Phosphodiesterase Type 5 Inhibitor on Right Ventricular Pulmonary Artery Coupling in Severe Pulmonary Arterial Hypertension Patients

Introduction

ambrisentan and phosphodiesterase type 5 inhibitor (PDE5i) have been approved for treating patients with pulmonary arterial hypertension (PAH). Echocardiographic right ventricular pulmonary artery coupling (RVPAC) has been shown to be a valid non-invasive and alternative measurement method to assess the predicted outcomes in PAH patients. The aim of this study was to study the effect and clinical correlates of initial ambrisentan plus PDE5i combination therapy on RVPAC in patients with severe PAH.

Method and Results

We retrospectively studied and analyzed comprehensive clinical data, hemodynamics, and echocardiography in 27 patients with severe PAH before and after 6 months of initial combination therapy. Compared with the baseline, significant improvements in RVPAC ratios were observed, including RVFAC/PASP (0.31 ± 0.10 vs. 0.44 ± 0.15%/mmHg, p &lt; 0.001), TAPSE/PASP (0.15 ± 0.05 vs. 0.21 ± 0.06 mm/mmHg, p = 0.001), S’/PASP (0.10 ± 0.03 vs. 0.14 ± 0.05 cm/s∙mmHg, p = 0.001), and RVSV/RVESV (0.79 ± 0.22 vs. 1.02 ± 0.20, p &lt; 0.001). Functional status indices [World Health Organization functional classifications (WHO-FC) and 6 min walk distance (6MWD) and N-terminal pro B-type natriuretic peptide (NT-proBNP) levels] showed significant improvements. Right heart catheterization (RHC) evaluations for hemodynamic measurements between baseline and the 6–12 month follow-up were sPAP (96 ± 22 vs. 86 ± 24 mmHg, p = 0.002), mPAP (64 ± 18 vs. 56 ± 17 mmHg, p &lt; 0.001) and TPVR (17.3 ± 6.7 vs. 12.1 ± 5.4 WU, p = 0.001). Simultaneously, significant associations between RVPAC ratios and NT-proBNP levels and WHO-FC and 6MWD were observed.

Conclusion

Ambrisentan plus PDE-5i combination therapy resulted in a significant improvement in RVPAC in severe PAH. Importantly, RVPAC parameters correlated with known prognostic markers of PAH.

Aggressive Afterload Lowering to Improve the Right Ventricle: A New Target for Medical Therapy in Pulmonary Arterial Hypertension?

Despite numerous therapeutic advances in pulmonary arterial hypertension, patients continue to suffer high morbidity and mortality, particularly considering a median age of 50 years. This article explores whether early, robust reduction of right ventricular afterload would facilitate substantial improvement in right ventricular function and thus whether afterload reduction should be a treatment goal for pulmonary arterial hypertension. The earliest clinical studies of prostanoid treatment in pulmonary arterial hypertension demonstrated an important link between lowering mean pulmonary arterial pressure (or pulmonary vascular resistance) and improved survival. Subsequent studies of oral monotherapy or sequential combination therapy demonstrated smaller reductions in mean pulmonary arterial pressure and pulmonary vascular resistance. More recently, retrospective reports of initial aggressive prostanoid treatment or initial combination oral and parenteral therapy have shown marked afterload reduction along with significant improvements in right ventricular function. Some data suggest that reaching threshold levels for pressure or resistance (components of right ventricular afterload) may be key to interrupting the self-perpetuating injury of pulmonary vascular disease in pulmonary arterial hypertension and could translate into improved long-term clinical outcomes. Based on these clues, the authors postulate that improved clinical outcomes might be achieved by targeting significant afterload reduction with initial oral combination therapy and early parenteral prostanoids.

Pulmonary arterial hypertension in hereditary hemorrhagic telangiectasia associated with ACVRL1 mutation: a case report

INTRODUCTION

Hereditary hemorrhagic telangiectasia is an autosomal dominant condition with an estimated prevalence of 1 in 5000. It is characterized by the presence of abnormalities of vascular structures, and may affect many organ systems, including the lungs, brain, spinal cord, gastrointestinal tract, and liver. A causative mutation is identified in approximately 97% of patients with definite hereditary hemorrhagic telangiectasia in one of three genes including a mutation in endoglin, a mutation in a locus mapped to chromosome 5, and an activin receptor-like kinase-1 (ACVRL1) mutation that is associated with an increased incidence of primary pulmonary hypertension. Pulmonary arterial hypertension is a rare (15-25 cases per million people) but severe vascular disorder. Heritable pulmonary arterial hypertension is associated with several gene mutations, with 75% having a mutation in the bone morphogenetic protein receptor 2 (BMPR2). However, the remaining 25% of patients have other associated genetic mutations including ACVLR1, which is also associated with hereditary hemorrhagic telangiectasia. Pulmonary arterial hypertension is a rare complication in patients with hereditary hemorrhagic telangiectasia (< 1% of the hereditary hemorrhagic telangiectasia population). We describe a case report with this rare occurrence.

CASE PRESENTATION

A 70-year-old white/caucasian Irish male presented for screening for hereditary hemorrhagic telangiectasia due to a history of recurrent epistaxis (once/week) and a family history suggestive of pulmonary hypertension. Genetic testing confirmed an ACVRL1 mutation, while an echocardiogram and right heart catheterization confirmed pulmonary arterial hypertension. On examination, he had several mucocutaneous telangiectasia across his face. He was commenced on tadalafil and macitentan. However, this led to increased iron deficiency anemia and pedal edema. Selexipag was also added to his drug regime. He continues to require intermittent admissions for diuresis and blood transfusions.

CONCLUSION

The association of hereditary hemorrhagic telangiectasia and pulmonary arterial hypertension is rare (< 1%). Here we describe a case of hereditary hemorrhagic telangiectasia complicated with pulmonary arterial hypertension as a result of an ACVRL1 mutation. We also describe the clinical challenges of treating these two conditions together, as treatment options for pulmonary arterial hypertension tend to worsen hereditary hemorrhagic telangiectasia symptoms.

Topic-Based, Recent Literature Review on Pulmonary Hypertension

Pulmonary hypertension is a complex condition but a relatively common manifestation of severe cardiopulmonary disease. By contrast, pulmonary arterial hypertension is uncommon and is more prevalent in young women. To better categorize patients and to guide clinical decision-making, 5 diagnostic groups and associated subgroups characterize the spectrum of disease. A multidisciplinary approach to evaluation and treatment is recommended by published guidelines and often entails referral to a designated pulmonary hypertension center. Several key publications during the last couple of years merit review. The PubMed database was searched for English-language studies and guidelines relating to pulmonary hypertension. The following terms were searched, alone and in combination: pulmonary hypertension, pulmonary arterial hypertension, portopulmonary hypertension, and chronic thromboembolic pulmonary hypertension. The focus was on those publications with new information on evaluation and management of pulmonary hypertension between January 1, 2019, and January 31, 2021. Of the subgroups, 2 were of particular interest for this review: portopulmonary hypertension and chronic thromboembolic pulmonary hypertension. Last, available data on the impact of the coronavirus disease 2019 pandemic and newer treatment agents in early trials were selectively reviewed. The review is therefore intended to serve as a practical, focused review of important topics germane to those clinicians caring for patients with pulmonary hypertension.

Three- Versus Two-Drug Therapy for Patients With Newly Diagnosed Pulmonary Arterial Hypertension

BACKGROUND

In pulmonary arterial hypertension (PAH), there are no data comparing initial triple oral therapy with initial double oral therapy.

OBJECTIVES

TRITON (The Efficacy and Safety of Initial Triple Versus Initial Dual Oral Combination Therapy in Patients With Newly Diagnosed Pulmonary Arterial Hypertension; NCT02558231), a multicenter, double-blind, randomized phase 3b study, evaluated initial triple (macitentan, tadalafil, and selexipag) versus initial double (macitentan, tadalafil, and placebo) oral therapy in newly diagnosed, treatment-naive patients with PAH.

METHODS

Efficacy was assessed until the last patient randomized completed week 26 (end of main observation period). The primary endpoint was change in pulmonary vascular resistance (PVR) at week 26.

RESULTS

Patients were assigned to initial triple (n = 123) or initial double therapy (n = 124). At week 26, both treatment strategies reduced PVR compared with baseline (by 54% and 52%), with no significant difference between groups (ratio of geometric means: 0.96; 95% confidence interval: 0.86-1.07; P = 0.42). Six-minute walk distance and N-terminal pro-brain natriuretic peptide improved by week 26, with no difference between groups. Risk for disease progression (to end of main observation period) was reduced with initial triple versus initial double therapy (hazard ratio: 0.59; 95% confidence interval: 0.32-1.09). Most common adverse events with initial triple therapy included headache, diarrhea, and nausea. By the end of the main observation period, 2 patients in the initial triple and 9 in the initial double therapy groups had died.

CONCLUSIONS

In patients with newly diagnosed PAH, both treatment strategies markedly reduced PVR by week 26, with no significant difference between groups (primary endpoint not met). Exploratory analyses suggested a possible signal for improved long-term outcomes with initial triple versus initial double oral therapy.

Sudden Cardiac Death in Systemic Sclerosis: Diagnostics to Assess Risk and Inform Management

Cardiac disease is a leading cause of death in systemic sclerosis (SSc) and sudden cardiac death (SCD) is thought to occur more commonly in SSc than in the general population. Diffuse myocardial fibrosis, myocarditis and ischaemic heart disease are all prevalent in SSc and can be reasonably hypothesised to contribute to an increased risk of SCD. Despite this, SCD remains a relatively understudied area of SSc with little understood about SSc-specific risk factors and opportunities for primary prevention. In this review, we present an overview of the possible mechanisms of SCD in SSc and our current understanding of how each of these mechanisms may contribute to cardiac death. This review highlights the need for a future research agenda that addresses the underlying epidemiology of SCD in SSc and identifies opportunities for intervention to modify the disease course of heart disease in SSc.

Relationship Between Time From Diagnosis and Morbidity/Mortality in Pulmonary Arterial Hypertension: Results From the Phase III GRIPHON Study

BACKGROUND

Early initiation of pulmonary arterial hypertension (PAH) therapies is associated with improved long-term outcomes, yet data on the early use of prostacyclin pathway agents are limited. In these post hoc analyses of the Prostacyclin (PGI₂) Receptor Agonist In Pulmonary Arterial Hypertension (GRIPHON) study, the largest randomized controlled trial for PAH to date, the prognostic value of time from diagnosis and its impact on treatment response were examined.

RESEARCH QUESTION

How does time from diagnosis impact morbidity/mortality events and response to selexipag treatment in patients with PAH?

STUDY DESIGN AND METHODS

The GRIPHON study randomly assigned 1,156 patients with PAH to selexipag or placebo treatment. Patients were categorized post hoc into a time from diagnosis of ≤ 6 months and > 6 months at randomization. Hazard ratios (selexipag vs placebo) were calculated for the primary end point of morbidity/mortality by time from diagnosis using Cox proportional hazard models.

RESULTS

Time from diagnosis was ≤ 6 months in 34.9% and > 6 months in 65.1% of patients. Time from diagnosis was prognostic of morbidity/mortality, with newly diagnosed patients having a poorer long-term outcome than patients diagnosed for longer. Compared with placebo, selexipag reduced the risk of morbidity/mortality in patients with a time from diagnosis of ≤ 6 months and > 6 months, with a more pronounced effect in newly diagnosed patients (hazard ratio, 0.45 [95% CI, 0.33-0.63] and 0.74 [95% CI, 0.57-0.96], respectively; P = .0219 for interaction).

INTERPRETATION

In the GRIPHON study, newly diagnosed PAH patients had a worse prognosis than patients with a longer time from diagnosis. The benefit of selexipag treatment on disease progression was more pronounced in patients treated earlier than in patients treated later.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01106014; URL: www.clinicaltrials.gov.

Strategies for the management of pulmonary arterial hypertension in patients with congenital heart disease

Background

Pulmonary hypertension (PH) is commonly seen in adults who have congenital heart disease (CHD). Therapy is available for pulmonary arterial hypertension (PAH) and has greatly benefitted many patients with PAH related to CHD (PAH-CHD) over the last 15 years, with evidence of improved quality of life and prognosis in those with Eisenmenger syndrome and repaired PAH-CHD.

In this review, we describe the standard management and advanced therapies for PAH, which are available in specialist PH centres around the UK and Ireland, and how these are used in PAH-CHD. Decisions around the choice of therapy are governed by commissioning and available evidence.

Conclusion

We explain the different pathways for action and the variety of medications now at our disposal to help this important group of patients.