Therapy for Pulmonary Arterial Hypertension in Adults

A Case Report of a Patient With Pulmonary Arterial Hypertension Transitioned From Inhaled Iloprost to Selexipag

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by elevated pulmonary vascular resistance that can lead to right ventricular failure and death. The use of medications that affect the prostacyclin pathway is an important treatment strategy in PAH. Inhaled iloprost is a prostacyclin analogue, and selexipag is an oral, non-prostanoid, prostacyclin IP receptor agonist. Data are limited on transitioning patients from inhaled iloprost to selexipag. In this case report, we describe the successful transition of a 57-year-old female with heritable PAH from inhaled iloprost to selexipag over 8 weeks in an out-patient setting. After initiation of selexipag, the patient's inhaled iloprost dose was gradually reduced and eventually discontinued. The patient tolerated the transition well with stable symptoms, 6-minute walk distance, and pulmonary hemodynamics. Additional studies are needed to better define the comparative efficacy and safety of inhaled iloprost and selexipag.

Pharmacologic therapy for pulmonary artery hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) is a disease that carries a significant mortality left untreated. This article aims to review pharmacotherapeutics for PAH.

RECENT FINDINGS

PAH-specific therapies have evolved over the last three decades and have expanded from one therapy in the 1990s to 14 FDA-approved medications. Current therapies are directed at restoring the imbalance of vasoactive mediators that include nitric oxide, endothelin and prostacyclin. Although these agents are effective as monotherapy, recent trials have promulgated the strategy of upfront combination therapy. The availability of oral prostacyclin agonists has also allowed for expanded treatment options. Risk assessment is vital in guiding therapy for PAH patients. There is ongoing focus on targeting pathological mechanisms of the disease via novel therapies and repurposing existing drugs.

SUMMARY

There is an array of medications available for the treatment of PAH. Prudent combination of therapies to maximize treatment effect can improve morbidity and mortality. This article reviews the data supporting these therapies and attempts to outline an approach to patient management.

Medication Adherence and Healthcare Costs Among Patients with Pulmonary Arterial Hypertension Treated with Oral Prostacyclins: A Retrospective Cohort Study

BACKGROUND

Given the improved convenience of oral prostacyclins, there is a shift toward their use in treating pulmonary arterial hypertension (PAH).

OBJECTIVES

Our objective was to compare patient characteristics, medication adherence, healthcare resource use (HCRU), and costs among patients receiving oral treprostinil or selexipag.

METHODS

We used Truven Health MarketScan Commercial and Medicare databases to identify patients with PAH with a diagnosis code for pulmonary hypertension (PH) plus a prescription for oral treprostinil or selexipag from July 2013 to September 2017. Medication adherence, persistence, and all-cause and PAH-related HCRU and costs were compared between cohorts during the 6-month follow-up. Adjusted healthcare costs were obtained using recycled predictions and bootstrapped samples.

RESULTS

A total of 256 (130 oral treprostinil, 126 selexipag) patients fulfilled the study criteria. The oral treprostinil cohort was more likely to be male, to have previously used parenteral prostacyclins, and to have higher outpatient costs at baseline than the selexipag cohort. During follow-up, both cohorts had similar proportions of patients who were adherent to and persistent with their respective therapies. All-cause and PAH-related medical utilization was generally similar between cohorts. The oral treprostinil cohort had 66.9% lower total PAH-related healthcare costs (mean difference - $75,183; 95% confidence interval [CI] - 102,584 to - 49,771) and 70.6% lower PAH-related pharmacy costs (mean difference - $76,439; 95% CI - 104,512 to - 51,458) than the selexipag cohort, with similar differences in all-cause healthcare and pharmacy costs.

CONCLUSIONS

Lower all-cause and PAH-related total healthcare and pharmacy costs were observed in patients receiving oral treprostinil compared with those receiving selexipag. It will be important to study longer-term costs and clinical outcomes.

Pulmonary Hypertension: A Brief Guide for Clinicians

Pulmonary hypertension (PH) is classified into 5 clinical subgroups: pulmonary arterial hypertension (PAH), PH due to left-sided heart disease, PH due to chronic lung disease, chronic thromboembolic PH (CTEPH), and PH with an unclear and/or multifactorial mechanisms. A range of underlying conditions can lead to these disorders. Overall, PH affects approximately 1% of the global population, and over half of patients with heart failure may be affected. Cardiologists are therefore likely to encounter PH in their practice. Routine tests in patients with symptoms and physical findings suggestive of PH include electrocardiography, chest radiography, and pulmonary function tests. Transthoracic echocardiography is used to estimate the probability of PH. All patients with suspected or confirmed PH, without confirmed left-sided heart or lung diseases, should have a ventilation-perfusion scan to exclude CTEPH. Right-sided heart catheterization is essential for accurate diagnosis and classification. All patients with PAH or CTEPH must be referred to a specialist center. Surgical pulmonary endarterectomy is the treatment of choice for eligible patients with CTEPH. Targeted treatments (phosphodiesterase type 5 inhibitors, soluble guanylate cyclase stimulators, endothelin receptor antagonists, prostacyclin analogues, and prostacyclin receptor agonists) are licensed for patients with PAH. The soluble guanylate cyclase stimulator riociguat is the only licensed targeted therapy for patients with inoperable or persistent/recurrent CTEPH. Management of PH resulting from left-sided heart disease primarily involves treatment of the underlying condition.

An evaluation of selexipag for the treatment of pulmonary hypertension

INTRODUCTION

Selexipag is a first-in-class, oral, long-acting, selective, non-prostanoid agonist of the prostacyclin receptor (IP receptor), indicated for the treatment of symptomatic adult pulmonary arterial hypertension (PAH). It was designed with the objective to surpass the inconveniences associated with standard prostanoid therapy, presenting fewer adverse effects and comparable hemodynamic benefits.

AREAS COVERED

This review describes the pharmacologic properties of selexipag and presents the clinical trials that have been completed or are currently ongoing regarding its clinical efficacy, safety, and tolerability. The pivotal GRIPHON study is extensively presented.

EXPERT OPINION

Selexipag is the first IP receptor to reduce the morbidity/mortality composite endpoint of the GRIPHON study, a large, randomized, placebo-controlled study. The TRITON study failed to demonstrate a clear benefit of initial triple oral therapy including selexipag compared to initial double oral therapy. Current guidelines do not provide definitive recommendations regarding the place of selexipag in the treatment algorithm of PAH. Finally, the possibility of transition between the several drugs acting in the prostacyclin pathway, and the potential role of selexipag in chronic thromboembolic pulmonary hypertension and pediatric PAH is currently being examined, possibly expanding its future use.

United States Pulmonary Hypertension Scientific Registry: Baseline Characteristics

BACKGROUND

The treatment, genotyping, and phenotyping of patients with World Health Organization Group 1 pulmonary arterial hypertension (PAH) have evolved dramatically in the last decade.

RESEARCH QUESTION

The United States Pulmonary Hypertension Scientific Registry was established as the first US PAH patient registry to investigate genetic information, reproductive histories, and environmental exposure data in a contemporary patient population.

STUDY DESIGN AND METHODS

Investigators at 15 US centers enrolled consecutively screened adults diagnosed with Group 1 PAH who had enrolled in the National Biological Sample and Data Repository for PAH (PAH Biobank) within 5 years of a cardiac catheterization demonstrating qualifying hemodynamic criteria. Exposure and reproductive histories were collected by using a structured interview and questionnaire. The biobank provided genetic data.

RESULTS

Between 2015 and 2018, a total of 499 of 979 eligible patients with clinical diagnoses of idiopathic PAH (IPAH) or familial PAH (n = 240 [48%]), associated PAH (APAH; n = 256 [51%]), or pulmonary venoocclusive disease/pulmonary capillary hemangiomatosis (n = 3 [1%]) enrolled. The mean age was 55.8 years, average BMI was 29.2 kg/m², and 79% were women. Mean duration between symptom onset and diagnostic catheterization was 1.9 years. Sixty-six percent of patients were treated with more than one PAH medication at enrollment. Past use of prescription weight loss drugs (16%), recreational drugs (27%), and oral contraceptive pills (77%) was common. Women often reported miscarriage (37%), although PAH was rarely diagnosed within 6 months of pregnancy (1.9%). Results of genetic testing identified pathogenic or suspected pathogenic variants in 13% of patients, reclassifying 18% of IPAH patients and 5% of APAH patients to heritable PAH.

INTERPRETATION

Patients with Group 1 PAH remain predominately middle-aged women diagnosed with IPAH or APAH. Delays in diagnosis of PAH persist. Treatment with combinations of PAH-targeted medications is more common than in the past. Women often report pregnancy complications, as well as exposure to anorexigens, oral contraceptives, and/or recreational drugs. Results of genetic tests frequently identify unsuspected heritable PAH.

Inpatient Palliative Care Use in Patients With Pulmonary Arterial Hypertension: Temporal Trends, Predictors, and Outcomes

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive disease associated with significant morbidity and mortality. Despite the negative impact of PAH on quality of life and survival, data on use of specialty palliative care services (PCS) is scarce.

RESEARCH QUESTION

We sought to evaluate the inpatient use of PCS in patients with PAH.

STUDY DESIGN AND METHODS

Using the National (Nationwide) Inpatient Sample, 30,495 admissions with a primary diagnosis of PAH were identified from 2001 through 2017. The primary outcome of interest was temporal trends and predictors of inpatient PCS use in patients with PAH.

RESULTS

The inpatient use of PCS was low (2.2%), but increased during the study period from 0.5% in 2001 to 7.6% in 2017, with a significant increase starting in 2009. White race, private insurance, higher socioeconomic status, hospital-specific factors, higher comorbidity burden (Charlson Comorbidity Index), cardiac and noncardiac organ failure, and use of extracorporeal membrane oxygenation and noninvasive mechanical ventilation were independent predictors of increased PCS use. PCS use was associated with a higher prevalence of do-not-resuscitate status, a longer length of stay, higher hospitalization costs, and increased in-hospital mortality with less frequent discharges to home, likely because these patients were also sicker (higher comorbidity index and illness acuity).

INTERPRETATION

The inpatient use of PCS in patients with PAH is low, but has been increasing over recent years. Despite increased PCS use over time, patient- and hospital-specific disparities in PCS use continue. Further studies evaluating these disparities and the role of PCS in the comprehensive care of PAH patients are warranted.

Niclosamide attenuates lung vascular remodeling in experimental pulmonary arterial hypertension

Despite advances in medical therapy, pulmonary arterial hypertension (PAH) remains an inexorably progressive and highly lethal disease. Signal transducer and activator of transcription (STAT)-3 is one of the main intracellular transcription factors implicated in PAH vascular remodeling. We hypothesized that niclosamide, a STAT3 inhibitor, would reduce vascular remodeling in an established pulmonary arterial hypertension model, thus enhancing cardiac function. Male Wistar rats were treated either with monocrotaline (60 mg/kg), to induce PAH, or saline (C group) by intraperitoneal injection. On day 14, PAH animals were randomly assigned to receive oral (1) saline (PAH-SAL); (2) niclosamide (75 mg/kg/day) (PAH-NICLO); (3) sildenafil (20 mg/kg/day) (PAH-SIL); or (4) niclosamide + sildenafil (PAH-NICLO + SIL), once daily for 14 days. On day 28, right ventricular systolic pressure was lower in all treated groups compared to PAH-SAL. Pulmonary vascular collagen content was lower in PAH-NICLO (37 ± 3%) and PAH-NICLO + SIL (37 ± 6%) compared to PAH-SAL (68 ± 4%), but not in PAH-SIL (52 ± 1%). CD-34, an endothelial cell marker, was higher, while vimentin, a mesenchymal cell marker, was lower in PAH-NICLO and PAH-NICLO + SIL compared to PAH-SAL, suggesting attenuation of endothelial-mesenchymal transition. Expression of STAT3 downstream targets such as transforming growth factor (TGF)-β, hypoxia-inducible factor (HIF)-1, and provirus integration site for Moloney murine leukemia virus (PIM-1) in lung tissue was reduced in PAH-NICLO and PAH-NICLO + SIL compared to PAH-SAL. In conclusion, niclosamide, with or without sildenafil, mitigated vascular remodeling and improved right ventricle systolic pressure. This new role for a well-established drug may represent a promising therapy for PAH.

Guidelines for the Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a rare form of pulmonary hypertension characterized by a progressive obliterative vasculopathy of the distal pulmonary arterial circulation that usually leads to right ventricular failure and death. Over the last 25 years, more than a dozen drugs representing five drug classes have been developed and approved for the treatment of this devastating disease. Due to the small number of patients afflicted by PAH, most health care providers have little experience with its management. To address this gap in medical knowledge, treatment guidelines have been developed by professional organizations and expert committees. Over the last few years, these guidelines have been updated to address findings from recent clinical trials and ongoing experience with these drugs. This review provides an update on the most recently published treatment guidelines for pharmacologic treatment of PAH and incorporates them into a contemporary approach to the treatment of this disease.

Nutraceuticals in the Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a severe disease characterized by the loss and obstructive remodeling of the pulmonary arterial wall, causing a rise in pulmonary arterial pressure and pulmonary vascular resistance, which is responsible for right heart failure, functional decline, and death. Although many drugs are available for the treatment of this condition, it continues to be life-threatening, and its long-term treatment is expensive. On the other hand, many natural compounds present in food have beneficial effects on several cardiovascular conditions. Several studies have explored many of the potential beneficial effects of natural plant products on PAH. However, the mechanisms by which natural products, such as nutraceuticals, exert protective and therapeutic effects on PAH are not fully understood. In this review, we analyze the current knowledge on nutraceuticals and their potential use in the protection and treatment of PAH, as well as whether nutraceuticals could enhance the effects of drugs used in PAH through similar mechanisms.

ProT-α gene transfer attenuates cardiopulmonary remedying and mortality in a flow-induced pulmonary hypertension rat model

BACKGROUND

ProT is a cell survival gene, which modulates oxidative stress and transforming growth factor (TGF)-β signaling. We hypothesized that the delivery of the ProT cDNA gene in rats could protect against right heart dysfunction secondary to pulmonary hypertension (PH) induced by left-to-right shunt.

METHODS

A 2-hit rat model of flow-induced PH was used, and a single intravenous injection of adenoviral vectors (2 billion plaque-forming unit) carrying ProT or Luc gene was administered. The animals were euthanized 21 days after gene delivery to assess cardiopulmonary function, serum biochemistry, pulmonary artery (PA), and vasomotor reactivity. Immunohistology and immunoblotting of PA tissues were also performed.

RESULTS

ProT transduction significantly reduced PA pressure, right ventricle muscle mass, and wall stress, thereby improving the overall survival of the treated rat. Increased production of ProT through gene therapy preserved both the smooth muscle myosin heavy chain-II and α-smooth muscle actin while counteracting the abundance of TGF-β in PA. Protein abundances of phosphorylated p47-phox, heme oxygenase-1, caspase-3, inducible nitric oxide synthase, cyclo-oxygenase 2, and monocyte chemoattractant protein-1 in PA tissues were reduced. ProT also preserved microRNA-223, thereby suppressing the abundance of PARP-1, which is independent of hypoxia-inducible factor-1α signaling.

CONCLUSIONS

ProT gene transduction improved PA function by reducing oxidative stress, attenuating inflammation, and preserving the contractile phenotype of vascular smooth muscle cells. The modification of microRNA-223-associated downstream signaling through ProT transduction may play an important role in mitigating cardiopulmonary remodeling in flow-induced PH.

Management of interstitial lung diseases: A consensus statement of the Indian Chest Society (ICS) and National College of Chest Physicians (NCCP)

BACKGROUND

Interstitial lung disease (ILD) is a complex and heterogeneous group of acute and chronic lung diseases of several known and unknown causes. While clinical practice guidelines (CPG) for idiopathic pulmonary fibrosis (IPF) have been recently updated, CPG for ILD other than IPF are needed.

METHODS

A working group of multidisciplinary clinicians familiar with clinical management of ILD (pulmonologists, radiologist, pathologist, and rheumatologist) and three epidemiologists selected by the leaderships of Indian Chest Society and National College of Chest Physicians, India, posed questions to address the clinically relevant situation. A systematic search was performed on PubMed, Embase, and Cochrane databases. A modified GRADE approach was used to grade the evidence. The working group discussed the evidence and reached a consensus of opinions for each question following face-to-face discussions.

RESULTS

Statements have been made for each specific question and the grade of evidence has been provided after performing a systematic review of literature. For most of the questions addressed, the available evidence was insufficient and of low to very low quality. The consensus of the opinions of the working group has been presented as statements for the questions and not as an evidence-based CPG for the management of ILD.

CONCLUSION

This document provides the guidelines made by consensus of opinions among experts following discussion of systematic review of evidence pertaining to the specific questions for management of ILD other than IPF. It is hoped that this document will help the clinician understand the accumulated evidence and help better management of idiopathic and nonidiopathic interstitial pneumonias.

Current and Future Outlook on Disease Modification and Defining Low Disease Activity in Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune rheumatic disease with heterogeneous clinical manifestations and a variable course in which the severity of the pathology dictates the disease prognosis and course. Among autoimmune rheumatic diseases, SSc has the highest mortality rate among all rheumatic diseases, though there are exciting new therapeutic targets that appear to halt the progression of SSc manifestations such as skin or lung fibrosis. In selected patients, high-intensity regimens with autologous stem cell transplantation can favorably modify the course. In what was once thought to be an untreatable disease, targeted therapies have now changed the outlook of SSc to a treatable disorder. Herein, we discuss the targeted therapies modifying the outlook on selected organ involvement and creating opportunities for future treatment. We also present a framework for defining low disease activity in SSc.

Hoeper M, Hofbeck M, Hohenfrost-Schmidt W, Jurevičienė E, Gumbienè L, Kabitz HJ, Klose H, Köhler T, Konstantinides S, Köestenberger M, Kozlik-Feldmann R, Kramer HH, Kropf-Sanchen C, Lammers A, Lange T, Meyn P, Miera O, Milger-Kneidinger K, Neidenbach R, Neurohr C, Opitz C, Perings C, Remppis BA, Riemekasten G, Scelsi L, Scholtz W, Simkova I, Skowasch D, Skride A, Stähler G, Stiller B, Tsangaris I, Vizza CD, Vonk Noordegraaf A, Wilkens H, Wirtz H, Diller GP, Grünig E, Rosenkranz S. Pulmonary Hypertension in Adults with Congenital Heart Disease: Real-World Data from the International COMPERA-CHD Registry

INTRODUCTION

Pulmonary hypertension (PH) is a common complication in patients with congenital heart disease (CHD), aggravating the natural, post-operative, or post-interventional course of the underlying anomaly. The various CHDs differ substantially in characteristics, functionality, and clinical outcomes among each other and compared with other diseases with pulmonary hypertension.

OBJECTIVE

To describe current management strategies and outcomes for adults with PH in relation to different types of CHD based on real-world data.

METHODS AND RESULTS

COMPERA (Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension) is a prospective, international PH registry comprising, at the time of data analysis, >8200 patients with various forms of PH. Here, we analyzed a subgroup of 680 patients with PH due to CHD, who were included between 2007 and 2018 in 49 specialized centers for PH and/or CHD located in 11 European countries. At enrollment, the patients´ median age was 44 years (67% female), and patients had either pre-tricuspid shunts, post-tricuspid shunts, complex CHD, congenital left heart or aortic disease, or miscellaneous other types of CHD. Upon inclusion, targeted therapies for pulmonary arterial hypertension (PAH) included endothelin receptor antagonists, PDE-5 inhibitors, prostacyclin analogues, and soluble guanylate cyclase stimulators. Eighty patients with Eisenmenger syndrome were treatment-naïve. While at inclusion the primary PAH treatment for the cohort was monotherapy (70% of patients), with 30% of the patients on combination therapy, after a median observation time of 45.3 months, the number of patients on combination therapy had increased significantly, to 50%. The use of oral anticoagulants or antiplatelets was dependent on the underlying diagnosis or comorbidities. In the entire COMPERA-CHD cohort, after follow-up and receiving targeted PAH therapy (n = 511), 91 patients died over the course of a 5-year follow up. The 5-year Kaplan-Meier survival estimate for CHD associated PH was significantly better than that for idiopathic PAH (76% vs. 54%; p < 0.001). Within the CHD associated PH group, survival estimates differed particularly depending on the underlying diagnosis and treatment status.

CONCLUSIONS

In COMPERA-CHD, the overall survival of patients with CHD associated PH was dependent on the underlying diagnosis and treatment status, but was significantly better as than that for idiopathic PAH. Nevertheless, overall survival of patients with PAH due to CHD was still markedly reduced compared with survival of patients with other types of CHD, despite an increasing number of patients on PAH-targeted combination therapy.

Soluble Guanylate Cyclase Stimulators for Chronic Thromboembolic Pulmonary Hypertension Patients Treatment: New Data

This narrative review describes and appraises some relatively new studies investigating the efficacy and safety profile of soluble guanylate cyclase stimulator riociguat in patients suffering from pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). It has been a while since the publication date of pivotal CHEST-1 trial in 2013. New studies available complement existing evidence, expound on specific questions and open new frontiers for CTEPH investigations going forward. In this paper authors attempted to present data from post-hocanalysis of the CHEST-1 study and real-world data on riociguat treatment, confirming the positive effect of the drug on hemodynamic parameters of the pulmonary circulation and the functional status of patients. This effect was shown previously in large randomized trials. The extremely important positive effect of riociguat demonstrated both in the group of inoperable patients with CTEPH and in patients with residual pulmonary hypertension after pulmonary thrombendarterectomy. Of great interest are the presented some authors results of reverse remodelling of the right heart chambers during riociguat therapy in CTEPH patients, including using unique imaging methods (magnetic resonance imaging and positron emission tomography) to evaluate targeted medicinal therapy in terms of right heart remodelling. The safety profile of the drug was analyzed in the long-term post-registration international, multicenter, prospective, observational study EXPERT (NCT02092818), which confirmed the good tolerability and safety of riociguat therapy in PAH and CTEPH patients.

Implantable system for treprostinil: a real-world patient experience study

Parenteral prostanoids are effective for improving outcomes in patients with pulmonary arterial hypertension. However, subcutaneous or intravenous delivery via an external pump places a significant burden on patients. Consequently, the Implantable System for Remodulin© (treprostinil) was developed and is associated with a low rate of complications (United Therapeutics (Research Triangle Park, NC) in collaboration with Medtronic, Inc. (Mounds View, MN)). The current real-world experience study evaluated pulmonary arterial hypertension patients' perceptions of their quality of life, ability to perform activities of daily living, perceptions on the benefits and risks of the implantable system, and their social interactions before and after receiving the implantable system. Pulmonary arterial hypertension patients who had been transitioned from an external infusion pump to the implantable system completed a mix of quantitative and qualitative questions administered online over the course of a six-day period. A total of 20 patients completed the study. All patients reported that their quality of life, confidence out in public, and ability to travel long distances had improved. Over 90% of patients reported that their overall level of independence was better since receiving the implantable system, and most patients indicated that their ability to independently perform specific activities of daily living had improved. Responses to the qualitative questions suggested that the implantable system saved time, improved interpersonal relationships, and increased freedom. Results from this real-world patient experience study suggest this novel delivery system provides improvements in factors that are of substantial importance to patients.

NTP42, a novel antagonist of the thromboxane receptor, attenuates experimentally induced pulmonary arterial hypertension

BACKGROUND

NTP42 is a novel antagonist of the thromboxane prostanoid receptor (TP), currently in development for the treatment of pulmonary arterial hypertension (PAH). PAH is a devastating disease with multiple pathophysiological hallmarks including excessive pulmonary vasoconstriction, vascular remodelling, inflammation, fibrosis, in situ thrombosis and right ventricular hypertrophy. Signalling through the TP, thromboxane (TX) A₂ is a potent vasoconstrictor and mediator of platelet aggregation. It is also a pro-mitogenic, pro-inflammatory and pro-fibrotic agent. Moreover, the TP also mediates the adverse actions of the isoprostane 8-iso-prostaglandin F_2α, a free-radical-derived product of arachidonic acid produced in abundance during oxidative injury. Mechanistically, TP antagonists should treat most of the hallmarks of PAH, including inhibiting the excessive vasoconstriction and pulmonary artery remodelling, in situ thrombosis, inflammation and fibrosis. This study aimed to investigate the efficacy of NTP42 in the monocrotaline (MCT)-induced PAH rat model, alongside current standard-of-care drugs.

METHODS

PAH was induced by subcutaneous injection of 60 mg/kg MCT in male Wistar-Kyoto rats. Animals were assigned into groups: 1. 'No MCT'; 2. 'MCT Only'; 3. MCT + NTP42 (0.25 mg/kg BID); 4. MCT + Sildenafil (50 mg/kg BID), and 5. MCT + Selexipag (1 mg/kg BID), where 28-day drug treatment was initiated within 24 h post-MCT.

RESULTS

From haemodynamic assessments, NTP42 reduced the MCT-induced PAH, including mean pulmonary arterial pressure (mPAP) and right systolic ventricular pressure (RSVP), being at least comparable to the standard-of-care drugs Sildenafil or Selexipag in bringing about these effects. Moreover, NTP42 was superior to Sildenafil and Selexipag in significantly reducing pulmonary vascular remodelling, inflammatory mast cell infiltration and fibrosis in MCT-treated animals.

CONCLUSIONS

These findings suggest that NTP42 and antagonism of the TP signalling pathway have a relevant role in alleviating the pathophysiology of PAH, representing a novel therapeutic target with marked benefits over existing standard-of-care therapies.

Endothelin Receptor Antagonists: Status Quo and Future Perspectives for Targeted Therapy

The endothelin axis, recognized for its vasoconstrictive action, plays a central role in the pathology of pulmonary arterial hypertension (PAH). Treatment with approved endothelin receptor antagonists (ERAs), such as bosentan, ambrisentan, or macitentan, slow down PAH progression and relieves symptoms. Several findings have indicated that endothelin is further involved in the pathogenesis of certain other diseases, making ERAs potentially beneficial in the treatment of various conditions. In addition to PAH, this review summarizes the use and perspectives of ERAs in cancer, renal disease, fibrotic disorders, systemic scleroderma, vasospasm, and pain management. Bosentan has proven to be effective in systemic sclerosis PAH and in decreasing the development of vasospasm-related digital ulcers. The selective ERA clazosentan has been shown to be effective in preventing cerebral vasospasm and delaying ischemic neurological deficits and new infarcts. Furthermore, in the SONAR (Study Of Diabetic Nephropathy With Atrasentan) trial, the selective ERA atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease. These data suggest atrasentan as a new therapy in the treatment of diabetic nephropathy and possibly other renal diseases. Preclinical studies regarding heart failure, cancer, and fibrotic diseases have demonstrated promising effects, but clinical trials have not yet produced measurable results. Nevertheless, the potential benefits of ERAs may not be fully realized.

A randomized controlled trial on inspiratory muscle training in pulmonary hypertension: Effects on respiratory functions, functional exercise capacity, physical activity, and quality of life

BACKGROUND

Impaired respiratory muscle function may be one of the causes of increased dyspnea, reduced exercise capacity, and physical activity (PA), and poor quality of life in pulmonary hypertension (PH).

OBJECTIVE

To investigate the effects of threshold inspiratory muscle training (TIMT) on respiratory functions, functional exercise capacity, PA, and QoL in patients with PH.

METHODS

Thirty patients with PH were randomly allocated to a TIMT (n = 15) and sham group (n = 15). Three patients in the sham group could not participate in the program. The TIMT group (n = 15) trained at 30% of the maximal inspiratory pressure (MIP), and the sham group (n = 12) performed at lowest pressure without change in threshold pressure. In both groups, patients performed TIMT at home for 15 min, twice per day, with the MIP load determined by the trainer, and were supervised once weekly at the hospital for eight weeks. The primary outcomes were MIP and maximal expiratory pressure (MEP). The secondary outcome measures included spirometric measurements, six-minute walking distance (6MWD), PA (SenseWear armband and International Physical Activity Questionnaire-Short Form-IPAQ-Short Form), and QoL (Minnesota Living with Heart Failure-MLHF).

RESULTS

After the training, changes in MIP (p = 0.023) were higher in the intervention group compared with the sham group. Differences in MEP, FEV1 (%), FVC (%), FEV1/FVC (%), 6MWD, %6MWD, IPAQ-SF, MLHFQ, and armband parameters were not significantly different between the groups (p > 0.05).

CONCLUSIONS

The results of the study demonstrated that TIMT could increase MIP and did not improve other parameters of respiratory functions, functional exercise capacity, PA, and QoL in patients with PH.

Real-world experience using combination therapy with riociguat and risk assessment using REVEAL Lite 2.0 in patients with pulmonary arterial hypertension

Pulmonary arterial hypertension is a progressive disease that can lead to right-sided ventricular failure and premature death. Tailoring therapy to individual patient’s needs, along with regular risk assessment, is integral for optimal outcomes in patients with pulmonary arterial hypertension. Results from the AMBITION trial support the use of upfront combination of tadalafil and ambrisentan. In a recent analysis of risk assessment in pulmonary arterial hypertension, abridged versions of the REVEAL 2.0 risk score were shown to be comparable to the full tools. In this report, we present a case series of the use of riociguat in upfront combination or sequentially, and the impact on risk scores as determined by the abridged REVEAL Lite 2.0 approach.

Outcomes of Pulmonary Arterial Hypertension Are Improved in a Specialty Care Center

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial pressures and is managed by vasodilator therapies. Current guidelines encourage PAH management in specialty care centers (SCCs), but evidence is sparse regarding improvement in clinical outcomes and correlation to vasodilator use with referral.

RESEARCH QUESTION

Is PAH management at SCCs associated with improved clinical outcomes?

STUDY DESIGNAND METHODS

A single-center, retrospective study was performed at the University of Pittsburgh Medical Center (UPMC; overseeing 40 hospitals). Patients with PAH were identified between 2008 and 2018 and classified into an SCC or non-SCC cohort. Cox proportional hazard modeling was done to compare for all-cause mortality, as was negative binomial regression modeling for hospitalizations. Vasodilator therapy was included to adjust outcomes.

RESULTS

Of 580 patients with PAH at UPMC, 455 (78%) were treated at the SCC, comprising a younger (58.8 vs 64.8 years; P < .001) and more often female (68.4% vs 51.2%; P < .001) population with more comorbidities without differences in race or income. SCC patients demonstrated improved survival (hazard ratio, 0.68; P = .012) and fewer hospitalizations (incidence ratio, 0.54; P < .001), and provided more frequent disease monitoring. Early patient referral to SCC (< 6 months from time of diagnosis) was associated with improved outcomes compared with non-SCC patients. SCC patients were more frequently prescribed vasodilators (P < .001) and carried more diagnostic PAH coding (P < .001). Vasodilators were associated with improved outcomes irrespective of location but without statistical significance when comparing between locations (P > .05).

INTERPRETATION

The UPMC SCC demonstrated improved outcomes in mortality and hospitalizations. The SCC benefit was multifactorial, with more frequent vasodilator therapy and disease monitoring. These findings provide robust evidence for early and regular referral of patients with PAH to SCCs.

ACVIM consensus statement guidelines for the diagnosis, classification, treatment, and monitoring of pulmonary hypertension in dogs

Pulmonary hypertension (PH), defined by increased pressure within the pulmonary vasculature, is a hemodynamic and pathophysiologic state present in a wide variety of cardiovascular, respiratory, and systemic diseases. The purpose of this consensus statement is to provide a multidisciplinary approach to guidelines for the diagnosis, classification, treatment, and monitoring of PH in dogs. Comprehensive evaluation including consideration of signalment, clinical signs, echocardiographic parameters, and results of other diagnostic tests supports the diagnosis of PH and allows identification of associated underlying conditions. Dogs with PH can be classified into the following 6 groups: group 1, pulmonary arterial hypertension; group 2, left heart disease; group 3, respiratory disease/hypoxia; group 4, pulmonary emboli/pulmonary thrombi/pulmonary thromboemboli; group 5, parasitic disease (Dirofilaria and Angiostrongylus); and group 6, disorders that are multifactorial or with unclear mechanisms. The approach to treatment of PH focuses on strategies to decrease the risk of progression, complications, or both, recommendations to target underlying diseases or factors contributing to PH, and PH‐specific treatments. Dogs with PH should be monitored for improvement, static condition, or progression, and any identified underlying disorder should be addressed and monitored simultaneously.

Pediatric Living Donor Liver Transplantation for Congenital Absence of the Portal Vein With Pulmonary Hypertension: A Case Report

Few reports of liver transplantation exist in patients with congenital absence of the portal vein and pulmonary hypertension. Living donor liver transplantation is usually performed before exacerbation of pulmonary hypertension. A 7-year-old girl (height: 131.5 cm; weight: 27.4 kg) with congenital absence of the portal vein was diagnosed with pulmonary hypertension (mean pulmonary artery pressure 35 mm Hg), and liver transplantation was planned before exacerbation of pulmonary hypertension. We successfully managed her hemodynamic parameters using low-dose dopamine and noradrenaline under monitoring of arterial blood pressure, central venous pressure, cardiac output, and stroke volume variation. Anesthesia was maintained using air-oxygen-sevoflurane and remifentanil 0.1 to 0.6 μg∙kg^-1∙min^-1. It is necessary to understand the potential perioperative complications in such cases and to adopt a multidisciplinary team approach in terms of the timing of transplantation and readiness to deal with exacerbation of pulmonary hypertension.

Resveratrol Prevents Right Ventricle Remodeling and Dysfunction in Monocrotaline-Induced Pulmonary Arterial Hypertension with a Limited Improvement in the Lung Vasculature

Pulmonary arterial hypertension (PAH) is a life-threatening disease that is characterized by an increase in pulmonary vascular pressure, leading to ventricular failure and high morbidity and mortality. Resveratrol, a phenolic compound and a sirtuin 1 pathway activator, has known dietary benefits and is used as a treatment for anti-inflammatory and cardiovascular diseases. Its therapeutic effects have been published in the scientific literature; however, its benefits in PAH are yet to be precisely elucidated. Using a murine model of PAH induced by monocrotaline, the macroscopic and microscopic effects of a daily oral dose of resveratrol in rats with PAH were evaluated by determining its impact on the lungs and the right and left ventricular function. While most literature has focused on smooth muscle cell mechanisms and lung pathology, our results highlight the relevance of therapy-mediated improvement of right ventricle and isolated cardiomyocyte physiology in both ventricles. Although significant differences in the pulmonary architecture were not identified either micro- or macroscopically, the effects of resveratrol on right ventricular function and remodeling were observed to be beneficial. The values for the volume, diameter, and contractility of the right ventricular cardiomyocytes returned to those of the control group, suggesting that resveratrol has a protective effect against ventricular dysfunction and pathological remodeling changes in PAH. The effect of resveratrol in the right ventricle delayed the progression of findings associated with right heart failure and had a limited positive effect on the architecture of the lungs. The use of resveratrol could be considered a future potential adjunct therapy, especially when the challenges to making a diagnosis and the current therapy limitations for PAH are taken into consideration.

Impact of race on survival in pulmonary arterial hypertension: Results from the REVEAL registry

BACKGROUND

Prior research has suggested that the prevalence and outcomes of pulmonary arterial hypertension (PAH) may vary by race or ethnicity. However, these studies have been limited by small sample size or methodological techniques relying on epidemiologic data. The purpose of this study is to evaluate the relationship between race/ethnicity and survival in a large U.S.-based prospective multicenter registry.

METHODS

Patients in the Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL), a 5-year observational study of Group 1 PAH, were categorized by race/ethnicity. Baseline hemodynamic characteristics, clinical characteristics, and medication use was described. The relationship between race/ethnicity and outcome was evaluated by Kaplan-Meier and Cox proportional hazards modeling techniques. Left-truncation analysis, which adjusted for time from diagnosis to study enrollment, was used to minimize the effect of survivor bias.

RESULTS

This analysis included 3,046 patients; 2,202 identified as white, 393 as black, 263 as Hispanic, 100 as Asian or Pacific Islander, and 88 as other. Unadjusted Kaplan-Meier survival analysis indicated that white patients had the lowest survival rates. After adjusting for variables of prognostic impact, race/ethnicity was no longer significantly associated with survival. Other results showed that black patients were more likely to have connective tissue disease-associated PAH, Hispanic patients were more likely to have portopulmonary hypertension, and Asian patients were more likely to have congenital heart disease-associated PAH.

CONCLUSIONS

Analysis of the REVEAL registry did not find race/ethnicity to be a significant predictor of mortality. This is the largest analysis to date evaluating the role of race/ethnicity on outcomes in PAH.

[A systematic review as a method of gathering scientific evidence into clinical guidelines: CHEST-2019 guideline for the therapy pulmonary arterial hypertension in adults]

The updated fourth version of the CHEST guideline presents the evidence base and treatment algorithm for pulmonary arterial hypertension in adults. The CHEST approach to creating clinical guidelines differs from the European one (ESC/ERS) and, in fact, consists in a systematic review of clinical trials and a sammary of their postulates.

Effects of the FGF receptor-1 inhibitor, infigratinib, with or without sildenafil, in experimental pulmonary arterial hypertension

BACKGROUND AND PURPOSE

Pulmonary arterial hypertension (PAH) is a progressive disease associated with high morbidity and mortality, despite advances in medical therapy. We compared the effects of infigratinib (NVP-BGJ398), a new FGF receptor-1 inhibitor, with or without the PDE-5 inhibitor sildenafil, on vascular function and remodelling as well as on gene expression of signal transducers for receptors of TGF-β (Smads-1/2/4) and transcription factor of endothelial-mesenchymal transition (Twist-1) in established experimental PAH. Types I and III pro-collagen and TGF-β expressions in lung fibroblasts were analysed in vitro after the different treatments.

EXPERIMENTAL APPROACH

PAH was induced in male Wistar rats with monocrotaline. 14 days later, treatments [sildenafil (SIL), infigratinib (INF) or their combination (SIL+INF)] were given for another 14 days. On Day 28, echocardiography and haemodynamic assays were performed, and lungs and pulmonary vessels were removed for analysis by histology, immunohistochemistry and RT-PCR. Fibroblasts prepared from PAH lungs were also analysed for TGF-β and pro-collagen.

KEY RESULTS

Only the combination of infigratinib and sildenafil significantly improved right ventricular systolic pressure and vascular remodelling parameters (right ventricular hypertrophy, smooth muscle α-actin, vessel wall thickness, and vascular collagen content). Infigratinib may act by reducing gene expression of Smads-1/4 and Twist-1 in lung tissue, as well as TGF-β and types I and III pro-collagen in lung fibroblasts.

CONCLUSIONS AND IMPLICATIONS

In this model of monocrotaline-induced PAH, the combination of the new inhibitor of FGF receptor-1, infigratinib, and sildenafil effectively improved haemodynamics and decreased vascular remodelling.

Effects of Pulmonary Hypertension on Exercise Capacity in Patients With Chronic Obstructive Pulmonary Disease

INTRODUCTION

The impact of pulmonary hypertension (PH) on exercise tolerance in chronic obstructive pulmonary disease (COPD) has not been fully elucidated. It is necessary to characterize pulmonary hemodynamics in patients with moderate to severe COPD in order to improve their management. The aim of the study was to determine whether in COPD the presence of PH is associated with reduced exercise tolerance in a cohort of stable COPD patients.

METHODS

Cross-sectional analysis of 174 COPD patients clinically stable: 109 without PH and 65 with PH (COPD-PH). We assessed socio-demographic data, lung function, quality of life, dyspnea, cardiopulmonary exercise testing (CPET), constant workload endurance time (CWET), and six-minute walk test (6MWT). We elaborated a logistic regression model to explore the impact of PH on exercise capacity in COPD patients.

RESULTS

COPD-PH patients showed lower exercise capacity both at maximal (CPET) (43(20) versus 68(27) Watts and 50(19)% versus 71(18)% predicted peak oxygen consumption (VO₂peak), COPD-PH and COPD, respectively), and at submaximal tests (6MWT) (382(94) versus 486(95) m). In addition, the COPD-PH group had lower endurance time than the non-PH COPD group (265(113) s and 295(164) s, respectively).

CONCLUSIONS

The presence of PH is an independent factor that impairs exercise capacity in COPD.

[Systemic sclerosis]

Systemic sclerosis (SSc) is a rare fibrosing rheumatic multi-systemic disease involving many medical specialties. The mortality of SSc is determined by lung fibrosis, pulmonary arterial hypertension and cardiac involvement. With early and intensive treatment, the disease can be stabilized and symptoms relieved. This review summarizes insights into pathophysiology, disease classification, clinical manifestations and successful therapies, as well as recent studies on new immunosuppressant, biological and vasoactive therapies.

Acute Respiratory Failure in Interstitial Lung Disease Complicated by Pulmonary Hypertension

Interstitial lung disease represents a group of diffuse parenchymal lung diseases with overwhelming morbidity and mortality when complicated by acute respiratory failure. Recently, trials investigating outcomes and their determinants have provided insight into these high mortality rates. Pulmonary hypertension is a known complication of interstitial lung disease and there is high prevalence in idiopathic pulmonary fibrosis, connective tissue disease, and sarcoidosis subtypes. Interstitial lung disease associated pulmonary hypertension has further increased mortality with acute respiratory failure, and there is limited evidence to guide management. This review describes investigations and management of interstitial lung disease associated acute respiratory failure complicated by pulmonary hypertension. Despite the emerging attention on interstitial lung disease associated acute respiratory failure and the influence of pulmonary hypertension, critical care management remains a clinical and ethical challenge.

Linking lncRNAs to regulation, pathogenesis, and diagnosis of pulmonary hypertension

Pulmonary hypertension (PH) is a syndrome characterized by a persistent increase in pulmonary vascular resistance. Due to the lack of specificity in clinical manifestations, patients are usually diagnosed at the late stage of PH, which is hard to treat and often causes right heart failure and death. Furthermore, the regulation and pathogenesis of PH remain obscure. Recently, long noncoding RNAs (lncRNAs), a type of transcript longer than 200 nt that lacks protein-coding ability, have been found to substantially influence the incidence and progression of various diseases through regulating gene expression at the chromatin, transcriptional, post-transcriptional, translational, and even post-translational levels. The crucial roles of lncRNAs in PH have started to draw widespread attention. This review summarizes the regulatory, pathogenic, and diagnostic roles of lncRNAs in PH, in the hope to facilitate the search for early diagnostic markers of and effective therapeutic targets for this devastating disease.

A Bayesian Network Meta-analysis of Add-on Drug Therapies Specific for Pulmonary Arterial Hypertension

Background: Recently published meta-analyses did not discriminate between drug agents used for initial and sequential combination therapy. Objective: To assess the comparative efficacy of drugs specific for the treatment of pulmonary arterial hypertension (PAH) as add-on therapies based on 6-minute walk distance (6MWD), all-cause mortality, and discontinuation due to adverse events (AEs). Methods: EMBASE, PubMed, Cochrane Library, and ClinicalTrials.gov were searched until December 9, 2018, for the randomized, placebo-controlled clinical trials (RCTs) conducted on primarily adult patients diagnosed with PAH. Data extracted from applicable RCTs were as follows: for 6MWD mean change from baseline, the total number of patients, and the number of patients with events, per treatment. Network meta-analysis (NMA) was conducted in a Bayesian framework. Results: A total of 16 RCTs were eligible for analysis, with 4112 patients. Add-on therapy with tadalafil or inhaled treprostinil performed better than endothelin receptor antagonists alone [27 m; 95% credible interval (CrI): (11, 43); and 19 m; 95% CrI: (10, 27); respectively]. Add-on therapy with macitentan or bosentan performed better than phosphodiesterase type 5 inhibitors alone [26 m; 95% CrI: (6.4, 45); and 22 m; 95% CrI: (5.1, 38); respectively]. Differences in all-cause mortality and discontinuation due to AEs were nonsignificant. Conclusion and Relevance: Our NMA evaluated efficacy and safety of add-on therapies in patients with PAH. None of the previous meta-analyses evaluated RCTs focusing solely on patients pretreated with another PAH-specific drug therapy. Our results support guideline recommendations on combination therapy in PAH patients and add the quantitative perspective on which sequential therapy demonstrated the greatest effect size.

Results of an Expert Consensus Survey on the Treatment of Pulmonary Arterial Hypertension With Oral Prostacyclin Pathway Agents

BACKGROUND

Treatment of pulmonary arterial hypertension (PAH) has evolved substantially over the past two decades and varies according to etiology, functional class (FC), hemodynamic parameters, and other clinical factors. Current guidelines do not provide definitive recommendations regarding the use of oral prostacyclin pathway agents (PPAs) in PAH. To provide guidance on the use of these agents, an expert panel was convened to develop consensus statements for the initiation of oral PPAs in adults with PAH.

METHODS

A systematic literature search was conducted using MEDLINE. The established RAND/University of California Los Angeles appropriateness method, which incorporates the Delphi method and the nominal group technique, was used to create consensus statements. Idiopathic, heritable, repaired congenital heart defect, and drug- or toxin-induced PAH (IPAH+) was considered as one etiologic grouping. The process was focused on the use of oral treprostinil or selexipag in patients with IPAH+ or connective tissue disease-associated PAH and FC II or III symptoms receiving background dual endothelin receptor antagonist/phosphodiesterase type 5 inhibitor therapy.

RESULTS

The panel developed 14 consensus statements regarding the appropriate use of oral PPAs in the target population. The panel identified 13 clinical scenarios in which selexipag may be considered as a treatment option.

CONCLUSIONS

The paucity of clinical evidence overall, and particularly from randomized trials in this setting, creates a gap in knowledge. These consensus statements are intended to aid physicians in navigating treatment options and using oral PPAs in the most appropriate manner in patients with PAH.

Treatment Discontinuation or Interruption in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease, which can be potentially fatal. The management of a complex disease like PAH requires a multidisciplinary approach from a team consisting of physicians, nurses, social workers, and pharmacists. Adherence to PAH-specific therapy is one of the key factors in the management of this disease. Poor adherence to treatment is a common problem in PAH as it is in many chronic diseases. Management of medication interruptions is a challenge in patients with PAH that can lead to negative consequences. However, for most PAH-specific drugs, there are no clear guidelines on how to manage temporary or abrupt medication discontinuations. In this review, we summarized the available literature and provide suggestions on how to manage interruptions of PAH-specific therapies.

Current status of pulmonary arterial hypertension in Korea

Pulmonary arterial hypertension (PAH) is characterized by remodeling of the distal pulmonary arteries resulting in high pulmonary vascular resistance and, eventually, right ventricular heart failure. Although current advances in PAH therapy have improved outcomes, poor survival remains a reality worldwide, including Korea. One of the most important issues in PAH is the late diagnosis, since screening or diagnostic efforts are often overlooked due to the rarity of disease. Data from Korean registries and observational cohorts show that delayed detection leads to increased morbidity. Additionally, low percentages of Korean patients are committed to intensive PAH-targeted therapy. Current Korean health insurance policies' lack of coverage for new PAH-targeted drugs and upfront combination therapy may also hamper the improvement of treatment outcomes. Understanding individual variability in response to therapeutics through deep phenotyping is a novel strategy that should be considered when treating PAH. Overall, early detection of PAH by proactive screening together with early, intensive, individualized PAH therapy using deep phenotyping is crucial for improving prognoses for PAH patients in Korea.