Clinical outcomes stratified by baseline functional class after initial combination therapy for pulmonary arterial hypertension

Future Perspectives of Pulmonary Arterial Hypertension: A Review of Novel Pipeline Treatments and Indications

Pulmonary arterial hypertension is characterized by elevated blood pressure and pathological changes in the pulmonary arterioles, leading to the development of right-heart failure and potentially fatal outcomes if left untreated. This review aims to provide an overview of novel drugs or formulations and new drug indications for pulmonary arterial hypertension that are currently in phases II-III of randomized controlled trials, and describe the rationale for the use of these targeted therapies, as well as their efficacy, safety profile, and impact on quality of life and survival. The literature research was conducted using data from ClinicalTrials.gov for the period between 1 January 2016 up to 31 December 2022. The population of interest includes individuals aged ≥ 18 years who have been diagnosed with pulmonary arterial hypertension. The review selection criteria included trials with recruiting, enrolling by invitation, active, terminated or completed status in 2022 and 2023. A total of 24 studies were selected for evaluation based on the inclusion and exclusion criteria. This review summarizes the updated information from randomized clinical trials involving novel therapies for pulmonary arterial hypertension. However, larger clinical trials are required to validate their clinical safety and effects. In the future, clinicians should choose therapies based on the patient's individual situation and requirements when developing treatment strategies.

Sleep-disordered breathing patterns and prognosis in pulmonary arterial hypertension: A cluster analysis of nocturnal cardiorespiratory signals

BACKGROUND

Sleep-disordered breathing (SDB) is common among pulmonary arterial hypertension (PAH) patients and has been associated with unfavorable outcomes. This study aims to cluster overnight cardiorespiratory signals to investigate PAH phenotypes and examining their prognostic implications.

METHODS

In this retrospective cohort study, we recruited consecutive PAH patients who underwent right heart catheterization and nocturnal cardiorespiratory polygraphy to evaluate SDB. Cluster analysis was employed to classify patients based on their SDB patterns. Cox regression analysis and Kaplan-Meier curves were utilized to assess the association between cluster membership and clinical outcomes. Logistic regression was used to identify risk factors associated with the cluster at higher risk of adverse outcomes.

RESULTS

The study comprised 386 PAH patients, with a mean age of 44.7 ± 17.0 years, of which 46.6 % were male. Three distinct clusters of PAH patients were identified: Cluster 1 (N = 182) presented with minimal SDB, Cluster 2 (N = 125) displayed obstructive sleep apnea (OSA) without significant hypoxemia, and Cluster 3 (N = 79) exhibited predominantly severe hypoxemic burden along with comorbid OSA. Notably, patients in Cluster 3 had an independent association with an increased risk of clinical worsening (hazard ratio 1.96, 95 % confidence interval [CI] 1.08-3.56, P = 0.027) compared to those in Clusters 1, even after adjusting for common confounders. The rate of clinical worsening for PAH-related events and mortality was higher in Cluster 3 than in Clusters 1 and 2 (26.6 % vs. 12.6 % and 19.2 %, respectively, log-rank P = 0.024). Moreover, the left ventricular mass index was identified as an independent risk factor for Cluster 3 (odds ratios 1.01, 95 % CI 1.00-1.02, P = 0.004).

CONCLUSIONS

Patients with PAH who have nocturnal hypoxemia and OSA had worse clinical outcomes compared to those with only minimal SDB. Tailored management strategies that address both PAH and nocturnal hypoxemia may be effective in improving clinical outcomes.

Multifunctional nanoparticle-mediated combining therapy for human diseases

Combining existing drug therapy is essential in developing new therapeutic agents in disease prevention and treatment. In preclinical investigations, combined effect of certain known drugs has been well established in treating extensive human diseases. Attributed to synergistic effects by targeting various disease pathways and advantages, such as reduced administration dose, decreased toxicity, and alleviated drug resistance, combinatorial treatment is now being pursued by delivering therapeutic agents to combat major clinical illnesses, such as cancer, atherosclerosis, pulmonary hypertension, myocarditis, rheumatoid arthritis, inflammatory bowel disease, metabolic disorders and neurodegenerative diseases. Combinatorial therapy involves combining or co-delivering two or more drugs for treating a specific disease. Nanoparticle (NP)-mediated drug delivery systems, i.e., liposomal NPs, polymeric NPs and nanocrystals, are of great interest in combinatorial therapy for a wide range of disorders due to targeted drug delivery, extended drug release, and higher drug stability to avoid rapid clearance at infected areas. This review summarizes various targets of diseases, preclinical or clinically approved drug combinations and the development of multifunctional NPs for combining therapy and emphasizes combinatorial therapeutic strategies based on drug delivery for treating severe clinical diseases. Ultimately, we discuss the challenging of developing NP-codelivery and translation and provide potential approaches to address the limitations. This review offers a comprehensive overview for recent cutting-edge and challenging in developing NP-mediated combination therapy for human diseases.

Dynamic Prediction of Pulmonary Hypertension in Systemic Sclerosis Using Landmark Analysis

OBJECTIVE

Pulmonary hypertension (PH) is a serious complication of systemic sclerosis (SSc). In this study, we explored the prediction of short-term risk for PH using serial pulmonary function tests (PFTs) and other disease features.

METHODS

SSc patients in whom disease onset occurred ≥10 years prior to data retrieval and for whom autoantibody specificity and PFT data were available were included in this study. Mixed-effects modeling was used to describe changes in PFTs over time. Landmarking was utilized to include serial assessments and stratified Cox proportional hazards regression analysis with landmarks as strata was used to develop the PH prediction models.

RESULTS

We analyzed data from 1,247 SSc patients, 16.3% of whom were male and 35.8% of whom had diffuse cutaneous SSc. Anticentromere, antitopoisomerase, and anti-RNA polymerase antibodies were observed in 29.8%, 22.0%, and 11.4% of patients, respectively, and PH developed in 13.6% of patients. Over time, diffusing capacity for carbon monoxide (DLco) and carbon monoxide transfer coefficient (Kco) declined in all SSc patients (up to 1.5% per year) but demonstrated much greater annual decline (up to 4.5% and 4.8%, respectively) in the 5-7 years preceding PH diagnosis. Comparisons between multivariable models including either DLco, Kco, or forced vital capacity (FVC)/DLco ratio, demonstrated that both absolute values and change over the preceding year in those measurements were strongly associated with the risk of PH (hazard ratio [HR] 0.93 and 0.76 for Kco and its change; HR 0.90 and 0.96 for DLco and its change; and HR 1.08 and 2.01 for FVC/DLco ratio and its change; P < 0.001 for all). The Kco-based model had the greatest discriminating ability (Harrell's C-statistic 0.903).

CONCLUSION

Our findings strongly support the importance of PFT trends over time in identifying patients at risk of developing PH.

Assessment of Clinical Worsening End Points as a Surrogate for Mortality in Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Clinical worsening (CW) is a composite end point commonly used in pulmonary arterial hypertension (PAH) trials. We aimed to assess the trial-level surrogacy of CW for mortality in PAH trials, and whether the various CW components were similar in terms of frequency of occurrence, treatment-related relative risk (RR) reduction, and importance to patients.

METHODS

We searched MEDLINE, Embase, and the Cochrane Library (January 1990 to December 2020) for trials evaluating the effects of PAH therapies on CW. The coefficient of determination between the RR for CW and mortality was assessed by regression analysis. The frequency of occurrence, RR reduction, and importance to patients of the CW components were assessed.

RESULTS

We included 35 independent cohorts (9450 patients). PAH therapies significantly reduced CW events (RR, 0.64 [95% CI, 0.55-0.73]), including PAH-related hospitalizations (RR, 0.61 [95% CI, 0.47-0.79]), treatment escalation (RR, 0.57 [95% CI, 0.38-0.84]) and symptomatic progression (RR, 0.58 [95% CI, 0.48-0.69]), and modestly reduced all-cause mortality when incorporating deaths occurring after a primary CW-defining event (RR, 0.860 [95% CI, 0.742-0.997]). However, the effects of PAH-specific therapies on CW only modestly correlated with their effects on mortality (R²_trial, 0.35 [95% CI, 0.10-0.59]; P<0.0001), and the gradient in the treatment effect across component end points was large in the majority of trials. The weighted proportions of CW-defining events were hospitalization (33.5%) and symptomatic progression (32.3%), whereas death (6.7%), treatment escalation (5.6%), and transplantation/atrioseptostomy (0.2%) were infrequent. CW events were driven by the occurrence of events of major (49%) and mild-to-moderate (37%) importance to patients, with 14% of the events valued as critical.

CONCLUSIONS

PAH therapies significantly reduced CW events, but study-level CW is not a surrogate for mortality in PAH trials. Moreover, components of CW largely vary in frequency, response to therapy, and importance to patients and are thus not interchangeable.

REGISTRATION

URL: https://www.crd.york.ac.uk/PROSPERO; Unique identifier: CRD42020178949.

Profiles and treatment patterns of patients with pulmonary arterial hypertension on monotherapy at experienced centres

AIMS

Guideline recommendations highlight the critical role of combination therapy for the treatment of pulmonary arterial hypertension (PAH). Conversely, registry data demonstrate that a considerable number of PAH patients remain on monotherapy. The reasons for this discrepancy remain elusive. The aim of this study was to assess the patient profiles, treatment patterns, and disease characteristics of patients diagnosed with PAH who were kept on monotherapy at experienced pulmonary hypertension (PH) centres and to capture potential reasons for monotherapy.

METHODS AND RESULTS

We analysed the patient profiles of 182 patients on monotherapy with PAH-targeted drugs, managed at experienced PH expert centres (Cologne, Giessen, Heidelberg, and Dresden). Patients were identified based on their latest follow-up visit and analysed retrospectively from the time of PAH diagnosis to last follow-up. Patients were dichotomized by age, and patient characteristics, treatment patterns, response to therapy, change in risk status, and drug tolerability were recorded during the course of their disease. Patients' mean age was 69.1 ± 13.1 years at the most recent follow-up (Key Time Point 1) and 64.5 ± 14.9 years at the time of diagnosis (Key Time Point 2). The mean time on monotherapy was 60.7 ± 53.8 months; 35.7/64.3% of patients were male/female. The majority (66.5%) had idiopathic PAH, followed by PAH associated with connective tissue disease (17.0%) and portopulmonary PH (8.2%). Among patients on monotherapy, there were five main clusters: (i) patients with failed escalation attempts mostly because of intolerability (26.9%); (ii) low risk on monotherapy, favourable response, and no reason for escalation (24.2%); (iii) patients with mild PAH (36.3%); (iv) elderly patients with PAH and multiple co-morbidities (38.5%); and (v) patients with associated forms of PAH where the level of evidence for combination therapies is considered low (16.5%). There were substantial differences between patients above or below the median age (68 years). The most frequently used monotherapy for PAH was phosphodiesterase type 5 inhibitors (75.3%).

CONCLUSIONS

A considerable number of PAH patients are on monotherapy at large PH expert centres, characterized by specific reasons that justify this kind of treatment. Nevertheless, as comprehensive treatment strategies have shown improved long-term outcomes even in mildly symptomatic patients, each case of monotherapy should be justified.

Real-World Analysis of Treatment Patterns Among Hospitalized Patients with Pulmonary Arterial Hypertension

Introduction

Hospitalization is an important clinical factor associated with survival and rehospitalization in patients with pulmonary arterial hypertension (PAH). Thus, this study examined treatment patterns before and after hospitalization in the US-specific population.

Methods

Adult PAH patients in the United States were identified using the Optum^® Clinformatics^® database from January 1, 2014, to June 30, 2019, and were required to have continuous health plan enrollment for at least 6 months prior to the first (index) hospitalization through at least 90 days post-discharge. Baseline patient characteristics were evaluated from 6 months prior to through the index hospitalization. PAH treatment patterns were examined from 30 days pre-index admission (pre-hospitalization) and 90 days post-index hospital discharge (post-hospitalization), and stratified by therapy type: monotherapy, double- or triple-combination therapy, or no PAH therapy.

Results

A total of 3116 hospitalized patients with PAH met selection criteria. The mean age and Charlson comorbidity index score were 68.1 years and 5.1, respectively. In the pre- and post-hospitalization periods (all-cause), respectively, patients prescribed monotherapy were most common (from 64.8% pre- to 51.9% post-hospitalization), followed by patients with no evidence of PAH therapy (from 14.6 to 28.5%). Among PAH-related hospitalizations, patients with monotherapy were also most common (from 60.8% pre- to 49.1% post-hospitalization), followed by patients with no evidence of PAH therapy (from 10.0 to 22.8%). The majority of patients with all-cause hospitalizations (72.8%) had no therapy modification; 20.0% de-escalated therapy (including 15.0% from monotherapy to no therapy) and 6.1% escalated therapy (including 2.2% from no therapy to monotherapy and 3.2% from monotherapy to double or triple therapy).

Conclusion

Inpatient admissions did not appear to drive changes in PAH therapy management, as monotherapy predominated, and most patients had no therapy modification within 90 days of a hospitalization. These results warrant future research to understand the reasons behind the limited treatment intensification observed and the impact of post-hospitalization optimization on clinical and economic outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41030-021-00173-6.

Pulmonary hypertension phenotypes in patients with systemic sclerosis

Pulmonary hypertension (PH) commonly affects patients with systemic sclerosis (SSc) and is associated with significant morbidity and increased mortality. PH is a heterogenous condition and several different forms can be associated with SSc, including pulmonary arterial hypertension (PAH) resulting from a pulmonary arterial vasculopathy, PH due to left heart disease and PH due to interstitial lung disease. The incidence of pulmonary veno-occlusive disease is also increased. Accurate and early diagnosis to allow optimal treatment is, therefore, essential. Recent changes to diagnostic haemodynamic criteria at the 6th World Symposium on Pulmonary Hypertension have resulted in therapeutic uncertainty regarding patients with borderline pulmonary haemodynamics. Furthermore, the optimal pulmonary vascular resistance threshold for diagnosing PAH and the role of exercise in identifying early disease require further elucidation. In this article we review the epidemiology, diagnosis, outcomes and treatment of the spectrum of pulmonary vascular phenotypes associated with SSc.

Efficacy and safety of novel-targeted drugs in the treatment of pulmonary arterial hypertension: a Bayesian network meta-analysis

Background: Pulmonary arterial hypertension (PAH) is a severe and fatal clinical syndrome characterized by high blood pressure and vascular remodeling in the pulmonary arterioles, which is also a rapidly progressing disease of the lung vasculature with a poor prognosis. Although PAH medication made great advances in recent years, the efficacy and safety of the medication are unsatisfactory. Therefore, we aimed to update and expand previous studies to explore the efficacy and safety of PAH-targeted medications. Methods: Relevant articles were searched and selected from published or publicly available data in PubMed, Cochrane Library, CNKI, PsycInfo, and MEDLINE (from inception until October 1^st, 2020). To assess the efficacy and safety of PAH therapies, five efficacy outcomes [6-minute walking distance (6MWD), mean pulmonary arterial pressure (mPAP), WHO functional class (WHO FC) improvement, clinical worsening, death] and two safety outcomes [adverse events (AEs), serious adverse events (SAEs)] were selected. And 6MWD was regarded as the primary efficacy outcome.

Results: 50 trials included with 10 996participants were selected. In terms of efficacy, all targeted drugs were more effective than placebo. For 6MWD, Bosentan + Sildenafil, Sildenafil, Bosentan + Iloprost were better than others. Bosentan + Iloprost and Bosentan + Sildenafil were better for mPAP. Bosentan + Iloprost and Ambrisentan + Tadalafil were more effective in improving WHO FC. Bosentan + Tadalafil and Bosentan + Iloprost had the Ambrisentan probability to reduce the incidence of clinical worsening. It is demonstrated that Ambrisentan had clear benefits in reducing all-cause mortality. In terms of safety, no therapies had been shown to reduce the incidence of SAEs significantly, and Ambrisentan + Tadalafil significantly increased the incidence of AEs.

Conclusions: Phosphodiesterase 5 inhibitor (PDE5i) + Endothelin Receptor Antagonists (ERA) seems to be better therapy for PAH. Prostacyclin analogs (ProsA) + ERA appear promising, though additional data is warranted.

Registration PROSPERO CRD42020218818.

Recent advances in the management of pulmonary arterial hypertension: lessons from the upfront combination of ambrisentan and tadalafil

INTRODUCTION

The sixth World Symposium of Pulmonary Hypertension (sixth WSPH) brought to the forefront for the first time the value of earlier, aggressive management with an upfront oral combination in patients with pulmonary arterial hypertension (PAH) of low or intermediate risk. This was prompted by results from the AMBITION study (ambrisentan + tadalafil). A literature search was conducted to collect all evidence provided by upfront treatment with this combination, as well as other combinations under investigation at the time the manuscript was prepared.

AREAS COVERED

The value of an upfront oral combination with ambrisentan and tadalafil is reviewed on the basis of topics discussed at the sixth WSPH, such as evidence in different PAH etiologies, according to risk stratification and in so-called 'atypical' patients where monotherapy is still recommended. Evidence in clinical practice is also reviewed. New evidence about the value of the upfront oral combination is also commented. Finally, tendencies in primary endpoints to assess the effect of PAH-targeted therapies (time to clinical worsening and hemodynamics) and their value are also reviewed.

EXPERT OPINION

All above-mentioned aspects are put into perspective with regard to the impact of new advances on improving PAH management in clinical practice.

Dringende Notwendigkeit des Off-label-Einsatzes von PAH-Medikamenten und deren Erstattung bei Kindern mit pulmonaler Hypertonie (Lungenhochdruck)

Die pulmonale Hypertonie (PH, Lungenhochdruck), und insbesondere die pulmonalarterielle Hypertonie (PAH), ist eine chronisch-progressive, fatale Erkrankung, für die aktuell – abgesehen von einer bilateralen Lungentransplantation – kein kurativer Therapieansatz besteht. Durch die jüngste Entwicklung und Verfügbarkeit von neuen „zielgerichteten“ PAH-Medikamenten („advanced“ oder „targeted therapies“), die mittlerweile für PAH im Erwachsenenalter zugelassen sind, haben sich allerdings die Lebenserwartung und -qualität von Erwachsenen und Kindern mit PAH erheblich verbessert.

Wegen (1) des Mangels an für Kinder zugelassenen PAH-Medikamenten, (2) der gut begründeten Rationale für eine PAH-Pharmakokombinationstherapie im Kindesalter und (3) dem Fehlen schwerwiegender unerwünschter Wirkungen, sollten gerade jungen PH-Patienten die vorhandenen modernen pharmakologischen Therapiemöglichkeiten nicht vorenthalten bleiben. Ein solcher „Off-label“-Einsatz und dessen unbürokratische Erstattung (Finanzierung) durch die Kostenträger sind dringend erforderlich. Die Entscheidung zur spezifischen Therapie der pulmonalen Hypertonie mit Möglichkeit der Kombination von Medikamenten aller Substanzklassen – auch unter Einschluss von „Off-label-Präparaten“ – sollte durch einen Kinderkardiologen erfolgen, der ausreichend Erfahrung mit der Behandlung von Kindern mit pulmonaler Hypertonie – insbesondere mit vasoaktiven Medikamenten – hat, gefolgt von einer engmaschigen ambulanten Anbindung und Nachsorge dieser Patienten. Die mangelnde Zulassung moderner, gegen PAH gerichteter Arzneimittel oder die relativ dünne, evidenzbasierte Datenlage bei Kindern sollte die behandelnden Ärzte nicht davon abhalten, den jungen Patienten diese Therapien anbieten zu können.

Pulmonary Vasodilator Therapy in Children with Single Ventricle Physiology: Effects on Saturation and Pulmonary Arterial Pressure

In children with single ventricle physiology, increased pulmonary vascular resistance may impede surgical progression or result in failing single ventricle physiology. The use of pulmonary vasodilators has been suggested as a potential therapy. However, knowledge on indication, dosage, and effect is limited. A retrospective case notes review of all (n = 36) children with single ventricle physiology, treated with pulmonary vasodilators by the UK Pulmonary Hypertension Service for Children 2004-2017. Therapy was initiated in Stage 1 (n = 12), Glenn (n = 8), or TCPC (n = 16). Treatment indications were high mean pulmonary arterial pressure, cyanosis, reduced exercise tolerance, protein-losing enteropathy, ascites, or plastic bronchitis. Average dose of sildenafil was 2.0 mg/kg/day and bosentan was 3.3 mg/kg/day. 56% had combination therapy. Therapy was associated with a reduction of the mean pulmonary arterial pressure from 19 to 14 mmHg (n = 17, p < 0.01). Initial therapy with one or two vasodilators was associated with an increase in the mean saturation from 80 to 85%, (n = 16, p < 0.01). Adding a second vasodilator did not give significant additional effect. 5 of 12 patients progressed from Stage 1 to Glenn, Kawashima, or TCPC, and 2 of 8 from Glenn to TCPC during a mean follow-up time of 4.7 years (0-12.8). Bosentan was discontinued in 57% and sildenafil in 14% of treated patients and saturations remained stable. Pulmonary vasodilator therapy was well tolerated and associated with improvements in saturation and mean pulmonary arterial pressure in children with single ventricle physiology. It appears safe to discontinue when no clear benefit is observed.

Clinical studies on digoxin intoxication II. Relationship between plasma and erythrocyte digoxin concentrations

We measured the digoxin concentration in both plasma and erythrocytes in 75 patients by radioimmunoassay during digoxin maintenance therapy. Mean plasma digoxin concentration was 0.90 ng/ml and mean erythrocyte digoxin concentration was 1.44 ng/ml in 75 patients. The ratio of digoxin concentration of erythrocyte to plasma during maintenance therapy was 2.24 in all patients, 1.63 in patients with therapeutic plasma digoxin levels, and 3.52 in patients with subtherapeutic plasma levels. There was a significant correlation between erythrocyte and plasma digoxin concentrations in therapeutic plasma levels (r=0.53, p<0.001). Patients on maintenance digoxin therapy were classified into 6 groups according to plasma and erythrocyte digoxin concentrations; in group I, 7 patients with both low plasma and erythrocyte digoxin concentrations, were poorly controlled in respect to heart failure; in group II, 19 patients with low plasma and medium erythrocyte digoxin concentrations failed to show compliance; in group III also, 3 patients with therapeutic plasma and low erythrocyte digoxin levels showed poor compliance; in group IV, 41 patients with both medium plasma and erythrocyte digoxin levels, were well controlled in respect to heart failure and all were compliant. Careful observation was required to avoid digoxin intoxication in group V with therapeutic plasma and high erythrocyte digoxin concentrations, and in group VI with high plasma and high erythrocyte digoxin concentrations.