Treatment of primary pulmonary hypertension with continuous intravenous prostacyclin (epoprostenol). Results of a randomized trial

Superoxide dismutase 1-modified dental pulp stem cells alleviate high-altitude pulmonary edema by inhibiting oxidative stress through the Nrf2/HO-1 pathway

High-altitude pulmonary edema (HAPE) is a deadly form of altitude sickness, and there is no effective treatment for HAPE. Dental pulp stem cells (DPSCs) are a type of mesenchymal stem cell isolated from dental pulp tissues and possess various functions, such as anti-inflammatory and anti-oxidative stress. DPSCs have been used to treat a variety of diseases, but there are no studies on treating HAPE. In this study, Sprague-Dawley rats were exposed to acute low-pressure hypoxia to establish the HAPE model, and SOD1-modified DPSCs (DPSCsHiSOD1) were administered through the tail vein. Pulmonary arterial pressure, lung water content (LWC), total lung protein content of bronchoalveolar lavage fluid (BALF) and lung homogenates, oxidative stress, and inflammatory indicators were detected to evaluate the effects of DPSCsHiSOD1 on HAPE. Rat type II alveolar epithelial cells (RLE-6TN) were used to investigate the effects and mechanism of DPSCsHiSOD1 on hypoxia injury. We found that DPSCs could treat HAPE, and the effect was better than that of dexamethasone treatment. SOD1 modification could enhance the function of DPSCs in improving the structure of lung tissue, decreasing pulmonary arterial pressure and LWC, and reducing the total lung protein content of BALF and lung homogenates, through anti-oxidative stress and anti-inflammatory effects. Furthermore, we found that DPSCsHiSOD1 could protect RLE-6TN from hypoxic injury by reducing the accumulation of reactive oxygen species (ROS) and activating the Nrf2/HO-1 pathway. Our findings confirm that SOD1 modification could enhance the anti-oxidative stress ability of DPSCs through the Nrf2/HO-1 signalling pathway. DPSCs, especially DPSCsHiSOD1, could be a potential treatment for HAPE. Schematic diagram of the antioxidant stress mechanism of DPSCs in the treatment of high-altitude pulmonary edema. DPSCs can alleviate oxidative stress by releasing superoxide dismutase 1, thereby reducing ROS production and activating the Nrf2/HO-1 signalling pathway to ameliorate lung cell injury in HAPE.

Pharmacological Update and Emerging Treatments of Pulmonary Hypertension

Pulmonary hypertension (PH) is defined as elevated pressures in the pulmonary artery and is associated with significant morbidity and mortality. The World Health Organization classifies PH into 5 distinct groups based on underlying etiology, pathology, and modality of treatment. Therapeutic approach may be challenging due to the extensive spectrum of causes and underlying mechanisms mediating PH. The 5 groups include pulmonary arterial hypertension (group 1), PH secondary to left heart disease (group 2), PH secondary to chronic lung disease (group 3), chronic thromboembolic pulmonary hypertension (group 4), and PH due to miscellaneous causes (group 5). Although significant progress has been made in the treatment of group 1 PH, there is a continued need to develop new therapies for all types of PH. Additionally, most treatments currently available improve functional capacity and symptoms but without a significant benefit in mortality. In this review, we aim to describe the various etiologies of PH and their established pharmacotherapies, as well as expand on emerging therapeutic options for each group.

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.

[Targeted therapy for pulmonary arterial hypertension in patients without comorbidities]

The 2022 guidelines on pulmonary hypertension from the European Society of Cardiology (ESC) and the European Respiratory Society (ERS) provide therapeutic strategies that account for the variability in the clinical presentation of newly diagnosed patients. We summarize treatment recommendations for pulmonary arterial hypertension (PAH) in patients without significant comorbidities, particularly for idiopathic, hereditary, drug/toxin-induced, or connective tissue disease-associated PAH. In this group of patients, multidimensional assessments for short-term mortality risk guide initial treatment decisions and treatment decisions during follow-up. Upfront dual combination therapy (phosphodiesterase type-5 inhibitor and endothelin receptor antagonist) is recommended for low- and intermediate-risk patients, and triple therapy including a parenteral prostacyclin should be considered in high- or intermediate-high-risk patients. If a low or intermediate-low-risk profile cannot be achieved during therapy, sequential add-on therapy escalation with parenteral prostacyclin or a prostacyclin receptor agonist should be considered, and switching from a phosphodiesterase type-5 inhibitor to a guanylate cyclase stimulator may also be considered.

The role of vasoactive intestinal peptide in pulmonary diseases

Vasoactive intestinal peptide (VIP) is an abundant neurotransmitter in the lungs and other organs. Its discovery dates back to 1970. And VIP gains attention again due to the potential application in COVID-19 after a research wave in the 1980s and 1990s. The diverse biological impacts of VIP extend beyond its usage in COVID-19 treatment, encompassing its involvement in various pulmonary and systemic disorders. This review centers on the function of VIP in various lung diseases, such as pulmonary arterial hypertension, chronic obstructive pulmonary disease, asthma, cystic fibrosis, acute lung injury/acute respiratory distress syndrome, pulmonary fibrosis, and lung tumors. This review also outlines two main limitations of VIP as a potential medication and gathers information on extended-release formulations and VIP analogues.

Impact of Parenteral Prostanoids in Pulmonary Arterial Hypertension: The Relevance of Timing

Parenteral prostanoids are being recommended in pulmonary arterial hypertension (PAH) treatment, but the prognostic relevance of delayed treatment initiation is still debated. This study assessed the impact of the timing of prostacyclin treatment initiation on reducing PVR and achieving a low-risk profile in PAH patients. The study enrolled 151 patients who started on parenteral prostanoids with different treatment strategies. All patients underwent right heart catheterization, clinical evaluation, and risk assessments at baseline and after 1-year follow-up. Patients with an upfront strategy including parenteral prostanoid plus one oral drug had -5.3 ± 6.2 WU (-50 ± 19%) reduction in PVR, patients with an upfront strategy including parenteral prostanoid plus double oral drug had -12.8 ± 5.9 WU (-68 ± 17%) reduction in PVR, while patients with an add-on strategy including parenteral prostanoid after oral drugs had -3.9 ± 3.5 WU (-23 ± 19%) reduction in PVR. An upfront strategy including parenteral prostanoids was independently associated with an increased likelihood of achieving the greater reduction of PVR compared with an add-on strategy. Additionally, the greater the severity of PH at the time of diagnosis, in terms of PVR and RV reverse remodeling, the higher the probability of treatment failure. An upfront strategy including a parenteral prostanoid is associated with the highest likelihood of achieving a low-risk profile and a greater reduction of PVR compared with parenteral prostanoid as an add-on to oral treatment.

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare and progressive disease characterised by remodelling of the pulmonary arteries and progressive narrowing of the pulmonary vasculature. This leads to a progressive increase in pulmonary vascular resistance and pulmonary arterial pressure and, if left untreated, to right ventricular failure and death. A correct diagnosis requires a complete work-up including right heart catheterisation performed in a specialised centre. Although our knowledge of the epidemiology, pathology and pathophysiology of the disease, as well as the development of innovative therapies, has progressed in recent decades, PAH remains a serious clinical condition. Current treatments for the disease target the three specific pathways of endothelial dysfunction that characterise PAH: the endothelin, nitric oxide and prostacyclin pathways. The current treatment algorithm is based on the assessment of severity using a multiparametric risk stratification approach at the time of diagnosis (baseline) and at regular follow-up visits. It recommends the initiation of combination therapy in PAH patients without cardiopulmonary comorbidities. The choice of therapy (dual or triple) depends on the initial severity of the condition. The main treatment goal is to achieve low-risk status. Further escalation of treatment is required if low-risk status is not achieved at subsequent follow-up assessments. In the most severe patients, who are already on maximal medical therapy, lung transplantation may be indicated. Recent advances in understanding the pathophysiology of the disease have led to the development of promising emerging therapies targeting dysfunctional pathways beyond endothelial dysfunction, including the TGF-β and PDGF pathways.

Pharmacotherapy of refractory pulmonary arterial hypertension

INTRODUCTION

Treatment of refractory pulmonary arterial hypertension (PAH) is challenging and rarely the focus of reviews. The purpose of this review is to discuss current treatment options of refractory PAH, along with the state of research of several new medications.

AREAS COVERED

We conducted a comprehensive PubMed search on the relevant literature on treating PAH, with a focus on approved and investigational interventions for high-risk patients. Our strategy used keywords 'Treatment' AND 'Pulmonary Hypertension,' without date restrictions, ensuring a thorough survey of available literature for our review.

EXPERT OPINION

By utilizing serial risk assessment to identify patients remaining intermediate or high-risk, more patients are likely to survive longer. This is done by earlier use of combination or triple therapy with prostacyclin drugs. Current medications for PAH are all essentially vasodilators that improve physiology, but do not truly modify the disease process. The potential application of new investigational medications is exciting as they work by novel pathways likely to change the landscape of refractory PAH treatment.

Evolution and optimization of clinical trial endpoints and design in pulmonary arterial hypertension

Selection of endpoints for clinical trials in pulmonary arterial hypertension (PAH) is challenging because of the small numbers of patients and the changing expectations of patients, clinicians, and regulators in this evolving therapy area. The most commonly used primary endpoint in PAH trials has been 6-min walk distance (6MWD), leading to the approval of several targeted therapies. However, single surrogate endpoints such as 6MWD or hemodynamic parameters may not correlate with clinical outcomes. Composite endpoints of clinical worsening have been developed to reflect patients' overall condition more accurately, although there is no standard definition of worsening. Recently there has been a shift to composite endpoints assessing clinical improvement, and risk scores developed from registry data are increasingly being used. Biomarkers are another area of interest, although brain natriuretic peptide and its N-terminal prohormone are the only markers used for risk assessment or as endpoints in PAH. A range of other genetic, metabolic, and immunologic markers is currently under investigation, along with conventional and novel imaging modalities. Patient-reported outcomes are an increasingly important part of evaluating new therapies, and several PAH-specific tools are now available. In the future, alternative statistical techniques and trial designs, such as patient enrichment strategies, will play a role in evaluating PAH-targeted therapies. In addition, modern sequencing techniques, imaging analyses, and high-dimensional statistical modeling/machine learning may reveal novel markers that can play a role in the diagnosis and monitoring of PAH.

Pathophysiology and pathogenic mechanisms of pulmonary hypertension: role of membrane receptors, ion channels, and Ca2+ signaling

The pulmonary circulation is a low-resistance, low-pressure, and high-compliance system that allows the lungs to receive the entire cardiac output. Pulmonary arterial pressure is a function of cardiac output and pulmonary vascular resistance, and pulmonary vascular resistance is inversely proportional to the fourth power of the intraluminal radius of the pulmonary artery. Therefore, a very small decrease of the pulmonary vascular lumen diameter results in a significant increase in pulmonary vascular resistance and pulmonary arterial pressure. Pulmonary arterial hypertension is a fatal and progressive disease with poor prognosis. Regardless of the initial pathogenic triggers, sustained pulmonary vasoconstriction, concentric vascular remodeling, occlusive intimal lesions, in situ thrombosis, and vascular wall stiffening are the major and direct causes for elevated pulmonary vascular resistance in patients with pulmonary arterial hypertension and other forms of precapillary pulmonary hypertension. In this review, we aim to discuss the basic principles and physiological mechanisms involved in the regulation of lung vascular hemodynamics and pulmonary vascular function, the changes in the pulmonary vasculature that contribute to the increased vascular resistance and arterial pressure, and the pathogenic mechanisms involved in the development and progression of pulmonary hypertension. We focus on reviewing the pathogenic roles of membrane receptors, ion channels, and intracellular Ca2+ signaling in pulmonary vascular smooth muscle cells in the development and progression of pulmonary hypertension.

Pulmonary arterial hypertension trials put to the test: Using the fragility index to assess trials robustness

BACKGROUND

Randomized clinical trials (RCTs) are considered the gold standard for evidence-based medicine. The Fragility Index (FI) is a tool to assess the robustness of RCT results. FI was validated for dichotomous outcomes and recent work expanded its use to continuous outcomes. Studying the robustness of RCTs in Pulmonary Arterial Hypertension (PAH) treatments is crucial due to the severity and mortality risks associated with this rare condition.

OBJECTIVES

Analyze FI and Fragility quotient (FQ) of significant primary outcomes in PAH RCTs and study FI correlation with sample size and journal impact factor.

METHODS

FI and FQ calculation followed by Spearman correlation to assess the correlation between FI and sample size, and FI and impact factor.

RESULTS

The median sample size of the 21 trials was 202 patients (IQR 106-267), with 6 trials reporting primary outcomes as dichotomous and 15 reporting continuous primary outcomes. The median FI was 10 (IQR 3-20), and the median FQ was 0.044 (0.026-0.097). A moderate correlation was found between FI and sample size, with r = 0.56; P = 0.008 and FI and journal impact factor (r=0.50; P=0.019). The FI for continuous outcomes was similar to that for dichotomous outcomes.

CONCLUSIONS

This study represents the first analysis of the FI and FQ of PAH treatment RCTs, and expands the use of FI to continuous outcomes in this context. The moderate correlation between FI and sample size suggests that increasing sample size alone is partially correlated to a higher FI. The similarity between FI for continuous and dichotomous outcomes supports the broader use of FI in PAH RCTs.

[Physiopathology and treatment of pulmonary arterial hypertension]

Pulmonary arterial hypertension (PAH) is a rare disease affecting mainly the pre-capillary pulmonary vascular bed. However, some forms of the disease have venous/capillary involvement. It is an obstructive remodelling of the pulmonary arterioles coupled with vascular pruning, increasing right ventricular afterload and leading to right heart failure. PAH has a complex pathogeny that is detailed in this review. Current specific treatments target endothelial dysfunction, and primarily aim at vasodilatation. Promising innovative treatments targeting the pulmonary artery remodelling are under development.

Incidence of Bloodstream Infection in Patients with Pulmonary Hypertension under Intravenous Epoprostenol or Iloprost—A Multicentre, Retrospective Study

Intravenous synthetic prostacyclin analogs (iPCAs), such as epoprostenol, treprostinil and iloprost have been widely used for the treatment of pulmonary arterial hypertension (PAH). Despite having good outcomes, continuous infusion of iPCAs has been associated with some adverse effects. Bloodstream infection (BSI) is one of the most severe complications, although poorly recognized, especially under iloprost administration, which few studies have addressed. This study aimed to compare the BSI incidence rates between intravenous iloprost and epoprostenol administration. Patients with pulmonary hypertension (PH) functional class III or IV receiving intravenous iloprost or epoprostenol through Hickman catheter, between 2004 and 2019, were retrospectively selected from two PH treatment centers. From a total of 36 patients (13 for iloprost and 23 for epoprostenol), 75% (n = 27) fulfilled the PAH criteria, mainly belonging to the idiopathic group. Overall BSI rate was 1.5/1000 days of treatment (3.38 and 0.09/1000 days for iloprost and epoprostenol, respectively). Patients receiving iloprost were at a higher risk of developing BSI than those receiving epoprostenol (HR: 12.5; 95% CI: 1.569–99.092). A higher mortality rate from BSI was also identified in the iloprost group (p = 0.04). Twenty-seven patients developed BSI, with 92% of them requiring hospitalization. A total of 29 agents were found, 10 Gram-positive (mainly Staphylococcus aureus; n = 5) and 19 Gram-negative (mainly Pseudomonas aeruginosa; n = 6) bacteria. Iloprost administration was linked to a significantly higher incidence of BSI, worse prognosis, and more BSI-related deaths than epoprostenol. BSI due to Gram-negative, commensal, low-virulence bacteria was also higher in the iloprost group. In short, physicians should be aware when prescribing iPCA to guarantee their patients’ safety and best medical care.

The Evolving Management and Treatment Options for Patients with Pulmonary Hypertension: Current Evidence and Challenges

Pulmonary hypertension may develop as a disease process specific to pulmonary arteries with no identifiable cause or may occur in relation to other cardiopulmonary and systemic illnesses. The World Health Organization (WHO) classifies pulmonary hypertensive diseases on the basis of primary mechanisms causing increased pulmonary vascular resistance. Effective management of pulmonary hypertension begins with accurately diagnosing and classifying the disease in order to determine appropriate treatment. Pulmonary arterial hypertension (PAH) is a particularly challenging form of pulmonary hypertension as it involves a progressive, hyperproliferative arterial process that leads to right heart failure and death if untreated. Over the last two decades, our understanding of the pathobiology and genetics behind PAH has evolved and led to the development of several targeted disease modifiers that ameliorate hemodynamics and quality of life. Effective risk management strategies and more aggressive treatment protocols have also allowed better outcomes for patients with PAH. For those patients who experience progressive PAH with medical therapy, lung transplantation remains a life-saving option. More recent work has been directed at developing effective treatment strategies for other forms of pulmonary hypertension, such as chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary hypertension due to other lung or heart diseases. The discovery of new disease pathways and modifiers affecting the pulmonary circulation is an ongoing area of intense investigation.

Tolerability, safety and survival in patients with severe pulmonary arterial hypertension treated with intravenous epoprostenol (Veletri®): a prospective, 6-months, open label, observational, non-interventional study

BACKGROUND

Epoprostenol AS (Veletri^®), a thermostable epoprostenol formulation, provides better drug stability and improved clinical use compared to previous epoprostenol formulations. This study aims to expand clinical experience in the use of Veletri^®, especially regarding tolerability, safety and survival.

METHODS

Pulmonary arterial hypertension (PAH) patients at high risk despite pretreatment with at least double oral combination therapy and with clinical indication for epoprostenol (Veletri^®) treatment were consecutively included in this prospective, open label, observational, non-interventional study. Clinical data were assessed at baseline, after 3 and 6 months. Adverse events (AEs) and serious adverse events (SAEs) were documented. Survival from initiation of Veletri^® was assessed at last patient out.

RESULTS

Fifteen patients (60 ± 13.7 years, WHO functional class III (n = 10) or IV (n = 5), severely impaired right ventricular function, mean pulmonary arterial pressure 54.8 ± 8.9 mmHg, mean pulmonary vascular resistance 4.4 ± 0.7 (median 3.8) Wood Units) were enrolled and treated with a mean dosage of 7.9 ± 3.9 (median 7.5) ng/kg/min. Eleven patients completed the study (treatment withdrawal n = 1, death n = 3). After a mean follow-up of 19.1 ± 13.5 (median 18.0) months, seven patients died and three were listed for lung transplantation. Seven AEs (nausea n = 3, diarrhea n = 1, flushing n = 2, headaches n = 1) and three SAEs (catheter infection n = 2, catheter occlusion n = 1) were related to Veletri^®. The 1- and 2-year survival rates were 73.3% and 52.4%, respectively.

CONCLUSIONS

The study showed that safety and tolerability of epoprostenol AS (Veletri^®) was comparable to previous prostacyclin formulations and was feasible for most patients. The maximum tolerable dosage was lower than dosages reported in the literature. In future applications/trials the up-titration process should be pushing for higher dosages of epoprostenol in the occurrence of side effects, as the achievement of a high and effective dosage is crucial for the clinical benefit of the patients. Survival was as expected in these prevalent severely impaired patients. Trial registration The study was registered in the EUPAS registry (EUPAS32492).

Pharmacological treatment of cardiogenic shock - A state of the art review

Cardiogenic shock is a clinical syndrome of impaired tissue perfusion caused by primary cardiac dysfunction and inadequate cardiac output. It represents one of the most lethal clinical conditions in intensive care medicine with mortality >40%. Management of different clinical presentations of cardiogenic shock includes guidance of cardiac preload, afterload, heart rate and contractility by differential pharmacological modulation of volume, systemic and pulmonary vascular resistance and cardiac output besides reversing the triggering cause. Data from large registries and randomized controlled trials on optimal diagnostic guidance as well as choice of pharmacological agents has accrued significantly in recent years. This state-of-the-art review summarizes the basic concepts of cardiogenic shock, the diagnostic work-up and currently available evidence and guideline recommendations on pharmacological treatment of cardiogenic shock.

Medications for the treatment of pulmonary arterial hypertension: a systematic review and network meta-analysis

BACKGROUND

There is no consensus on the most effective treatments of pulmonary arterial hypertension (PAH). Our objective was to compare effects of medications for PAH.

METHODS

We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and Clinicaltrials.gov from inception to December 2021. We performed a frequentist random-effects network meta-analysis on all included trials. We rated the certainty of the evidence using the Grades of Recommendation, Assessment, Development, and Evaluation approach.

RESULTS

We included 53 randomised controlled trials with 10 670 patients. Combination therapy with endothelin receptor antagonist (ERA) plus phosphodiesterase-5 inhibitors (PDE5i) reduced clinical worsening (120.7 fewer events per 1000, 95% CI 136.8-93.4 fewer; high certainty) and was superior to either ERA or PDE5i alone, both of which reduced clinical worsening, as did riociguat monotherapy (all high certainty). PDE5i (24.9 fewer deaths per 1000, 95% CI 35.2 fewer to 2.1 more); intravenous/subcutaneous prostanoids (18.3 fewer deaths per 1000, 95% CI 28.6 fewer deaths to 0) and riociguat (29.1 fewer deaths per 1000, 95% CI 38.6 fewer to 8.7 more) probably reduce mortality as compared to placebo (all moderate certainty). Combination therapy with ERA+PDE5i (49.9 m, 95% CI 25.9-73.8 m) and riociguat (49.5 m, 95% CI 17.3-81.7 m) probably increase 6-min walk distance as compared to placebo (moderate certainty).

CONCLUSION

Current PAH treatments improve clinically important outcomes, although the degree and certainty of benefit vary between treatments.

Epoprostenol‐Associated Ascites in Pulmonary Arterial Hypertension

The development of ascites in pulmonary arterial hypertension (PAH) in the absence of pre‐existing hepatic dysfunction is usually associated with decompensated right heart failure or cardiac cirrhosis. Ascites in PAH has rarely been associated with intravenous epoprostenol, a synthetic form of the prostaglandin PGI₂.

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.

A narrative review on adverse effects of dasatinib with a focus on pharmacotherapy of dasatinib-induced pulmonary toxicities

Chronic myeloid leukemia (CML), a myeloproliferative disorder caused by the over activity of BCR-ABL1 (breakpoint cluster region-Abelson), has been successfully treated by Tyrosine kinase inhibitors (TKIs). While imatinib is known as the first-line treatment of CML, in some cases other TKIs including dasatinib, nilotinib, bosutinib, and ponatinib may be preferred. Dasatinib, a second-generation TKI, inhibits multiple family kinases including BCR-ABL, SRC family kinases, receptor kinases, and TEC family kinases. It is effective against most imatinib-resistant cases except T315I mutation. Despite the superiority of dasatinib in its hematologic and cytogenetic responses in CML compared to imatinib, its potentially harmful pulmonary complications including pleural effusion (PE) and pulmonary arterial hypertension (PAH) may limit its use. Appropriate management of these serious adverse reactions is critical in both improving the quality of life and the outcome of the patient. In this narrative review, we will scrutinize the pulmonary complications of dasatinib and focus on the management of these toxicities.

Strategies for optimizing intravenous prostacyclin-analog therapy in patients with pulmonary arterial hypertension

INTRODUCTION

Intravenous prostacyclin-analogs (PCA, e.g. epoprostenol, treprostinil, iloprost) have become an essential part in the therapy of patients with pulmonary hypertension (PH), mainly pulmonary arterial hypertension (PAH). They show considerable differences in pharmacology. A combination therapy including intravenous drugs is regarded as the 'gold standard' in most of PAH patients.

AREAS COVERED

This review discusses and summarizes the studies and concepts on which this therapy is based. To date, intravenous prostacyclin-analogs are mainly administered when standard therapy fails to improve patients to low-risk status. However, preliminary data from uncontrolled studies suggest that an 'upfront triple' therapy including intravenous or subcutaneous prostacyclin-analogs could be preferable in selected patients.

EXPERT OPINION

Various IV PCA have been evaluated in the treatment of patients with PAH. Today, combination therapy is the 'gold standard' for the majority of patients. Intravenous PCA is recommended from functional class III onwards. Timing of its initiation is still a point of discussion. An escalation of therapy to IV or SC PCA is always necessary if a low-risk status cannot be achieved with other targeted therapies. Preliminary data suggest that selected patients could benefit from an 'upfront triple' therapy. Controlled studies on which such recommendation could be based are lacking.

The Pathobiology of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension is characterized by obliteration and obstruction of the pulmonary arterioles that in turn results in high right ventricular afterload and right heart failure. The pathobiology of pulmonary arterial hypertension is complex, with contributions from multiple pathophysiologic processes that are regulated by a variety of molecular mechanisms. This nature likely explains the limited efficacy of our current therapies, which only target a small portion of the pathobiological mechanisms that underlie advanced disease. Here we review the pathobiology of pulmonary arterial hypertension, focusing on the systemic, cellular, and molecular mechanisms that underlie the disease.

Cardiovascular Diseases That Have Emerged From the Darkness

It is important for both the patient and physician communities to have timely access to information recognizing rapid progress in the diagnosis and treatment of familiar but relatively uncommon cardiovascular diseases. Patients with 3 cardiovascular diseases (ie, hypertrophic cardiomyopathy, pulmonary arterial hypertension, and transthyretin (TTR) cardiac amyloidosis (ATTR)]), once considered rare without effective management options and associated with malignant prognosis, have now benefited substantially from the development of a variety of innovative therapeutic strategies. In addition, in each case, enhanced diagnostic testing has expanded the patient population and allowed for more widespread administration of contemporary treatments. In hypertrophic cardiomyopathy, introduction of implantable defibrillators to prevent sudden death as well as high-benefit:low-risk septal reduction therapies to reverse heart failure have substantially reduced morbidity and disease-related mortality (to 0.5% per year). For pulmonary arterial hypertension, a disease once characterized by a particularly grim prognosis, prospective randomized drug trials with aggressive single (or combined) pharmacotherapy have measurably improved survival and quality of life for many patients. In cardiac amyloidosis, development of disease-specific drugs can for the first time reduce morbidity and mortality, prominently with breakthrough ATTR-protein-stabilizing tafamidis. In conclusion, in less common and visible cardiovascular diseases, it is crucial to recognize substantial progress and achievement, given that penetration of such information into clinical practice and the patient community can be inconsistent. Diseases such as hypertrophic cardiomyopathy, pulmonary arterial hypertension, and ATTR cardiac amyloidosis, once linked to a uniformly adverse prognosis, are now associated with the opportunity for patients to experience satisfactory quality of life and extended longevity.

Maximal Exercise Testing Using the Incremental Shuttle Walking Test Can Be Used to Risk-Stratify Patients with Pulmonary Arterial Hypertension

Rationale: Exercise capacity predicts mortality in pulmonary arterial hypertension (PAH), but limited data exist on the routine use of maximal exercise testing.

Objectives: This study evaluates a simple-to-perform maximal test (the incremental shuttle walking test) and its use in risk stratification in PAH.

Methods: Consecutive patients with pulmonary hypertension were identified from the ASPIRE (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre) registry (2001–2018). Thresholds for levels of risk were identified at baseline and tested at follow-up, and their incorporation into current risk stratification approaches was assessed.

Results: Of 4,524 treatment-naive patients with pulmonary hypertension who underwent maximal exercise testing, 1,847 patients had PAH. A stepwise reduction in 1-year mortality was seen between levels 1 (≤30 m; 32% mortality) and 7 (340–420 m; 1% mortality) with no mortality for levels 8–12 (≥430 m) in idiopathic and connective tissue disease–related PAH. Thresholds derived at baseline of ≤180 m (>10%; high risk), 190–330 m (5–10%; intermediate risk), and ≥340 m (<5%; low risk of 1-yr mortality) were applied at follow-up and also accurately identified levels of risk. Thresholds were incorporated into the REVEAL (Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management) 2.0 risk score calculator and French low-risk approach to risk stratification, and distinct categories of risk remained.

Conclusions: We have demonstrated that maximal exercise testing in PAH stratifies mortality risk at baseline and follow-up. This study highlights the potential value of the incremental shuttle walking test as an alternative to the 6-minute walking test, combining some of the advantages of maximal exercise testing and maintaining the simplicity of a simple-to-perform field test.

Insomnia symptoms are associated with metabolic syndrome in patients with severe psychiatric disorders

OBJECTIVE

To examine the relationship between insomnia symptoms and metabolic syndrome in patients with severe psychiatric disorders.

METHODS

We conducted a cross-sectional study including 272 inpatients (mean age: 34.06 ± 11.52 years, 67.3% males) with severe psychiatric disorders consecutively admitted in Shantou University Mental Health Center Inpatient Department. All patients underwent a psychiatric evaluation. Insomnia symptoms were assessed by the Pittsburgh Sleep Quality Index (PSQI) and defined present if PSQI>7. The diagnosis of metabolic syndrome was defined using the new International Diabetes Federation definition based on clinical and laboratory evaluation.

RESULTS

Among the 272 patients, 94 (34.6%) presented insomnia symptoms. Overall, patients with insomnia symptoms had significantly higher percentage of metabolic syndrome (23.4% vs. 12.4%, p = 0.019) and hypertriglyceridemia (30.9% vs. 19.1%, p = 0.029), and marginally significantly higher levels of fasting insulin (58.75 ± 37.22 pmol/L vs. 51.72 ± 34.09 pmol/L, p = 0.050), homeostasis model assessment of insulin resistance (1.83 ± 1.31 vs. 1.62 ± 1.25, p = 0.055) and percentage of insulin resistance (55.3% vs. 44.4%, p = 0.086) compared to those without insomnia symptoms. Multiple logistic regressions showed that patients with insomnia symptoms had significantly higher odds for metabolic syndrome [odds ratio (OR) = 2.99, 95% confidence interval (CI) = 1.25-7.14], central obesity (OR = 3.02, 95% CI = 1.18-7.76), hypertriglyceridemia (OR = 2.46, 95% CI = 1.28-4.76) and marginally significantly higher odds for insulin resistance (OR = 1.68, 95% CI = 0.93-3.02) after controlling for potential confounders.

CONCLUSIONS

Within severely mentally ill patients, insomnia symptoms are associated with metabolic syndrome and insulin resistance. It appears that insomnia symptoms are independent clinical indicators of underlying metabolic syndrome in patients with severe psychiatric disorders.

Intravenous prostanoids in systemic sclerosis-associated pulmonary arterial hypertension: a single centre experience

OBJECTIVES

The current study evaluates survival rates among Systemic Sclerosis-associated Pulmonary Arterial Hypertension (SSc-PAH) patients on intravenous (IV) prostanoids, and short-term impact of IV prostanoids on clinical and haemodynamic parameters.

METHODS

Baseline demographics, invasive and non-invasive data, ESC (European Society of Cardiology) score and REVEAL score of 81 SSc-PAH patients (median age 61 years, interquartile range 54-67 years, 84% females) were prospectively recorded, from November 2006 till November 2020, before initiation of IV prostanoids, and at first formal reassessment. Survival data were retrieved from National Health Service Spine and hospital databases.

RESULTS

Significant improvements in clinical and haemodynamic parameters in response to IV prostanoid therapy were documented. Functional class (FC) (16.6% improved by 1FC, p = 0.041), mean pulmonary arterial pressure (-6.5mmHg, p = 0.036), pulmonary vascular resistance (PVR) (-2.6 WU, p = 0.012), cardiac index (CI) (+0.7l/min/m2, p = 0.003) and mixed venous oxygen saturation (SvO2) (+3%, p = 0.036), improved. Estimated survival for CTD-PAH patients on IV prostanoids was 64%, 31%, and 18%, at 1-year, 3-years, and 5-years, respectively. Independent baseline predictors of mortality were older age (HR:1.043, 95% CI: 1.011-1.075, p = 0.007), higher N-terminal pro-brain natriuretic peptide levels (HR:2.191, 95% CI: 1.131-4.243, p = 0.020), and lower SvO2 levels (HR:0.962, 95% CI:0.926-0.998, p = 0.039). High ESC risk or high and very high REVEAL score was associated with significantly worse survival compared to patients with lower risk scores, both at baseline and when reassessed after a median of 6.5 months.

CONCLUSIONS

Survival among SSc-PAH patients on IV prostanoids remains poor, risk scoring at baseline and after 6.5-months therapy improves prognostication.

Epoprostenol for the treatment of pulmonary arterial hypertension

Introduction: Pulmonary arterial hypertension (PAH) is a rare, progressive, and severe disease. Since the first demonstration of survival benefit of intravenous epoprostenol in monotherapy in 1996, prostanoids remain the cornerstone for PAH patients at high risk. This review is essential to understand the current situation of this drug among all the therapeutic possibilities concerning this entity.Areas covered: The aim of this article is to review the pharmacological properties of epoprostenol and to update its clinical evidence in different specific clinical scenarios. A deep literature search was carried out on the MEDLINE database for published literature before March 2021.Expert opinion: Epoprostenol is still the best treatment option for high-risk PAH patients. Nevertheless, there are many unsolved questions: drug dosing, its use in combination therapy with other pulmonary vasodilators, and the utility in PAH associated with connective tissue disease, congenital heart disease, or pulmonary veno-occlusive disease are only a few examples. Its safety and efficacy are supported by clinical trials, observational work, and experience, both as monotherapy and in combination therapy. Epoprostenol should be considered a destination treatment in high-risk patients and not only as a bridge to pulmonary transplantation. However, it remains underused in clinical practice.

Intravenous prostacyclin-analogue therapy in pulmonary arterial hypertension - A review of the past, present and future

Therapy with intravenous prostacyclin analogues in patients with pulmonary arterial hypertension (PAH) has been established for decades and is an integral component of the current guidelines for the treatment of pulmonary hypertension. Initially, these drugs were infused by external pump systems via tunnelled right atrial catheters with the need for cooling and frequent exchange of drug reservoirs. Associated complications included, among others, catheter-related infections. More recently, fully implantable pump systems have been developed with drug reservoirs that are filled transcutaneously, allowing intervals between refills of several weeks. This technique results in a low rate of infections. Epoprostenol, iloprost and treprostinil have all been used intravenously in PAH, but titration, dosing and dose escalation in long-term therapy are not standardized. Intravenous prostacyclin analogues are still under-used, despite available data suggesting that early and broad application of these therapies as part of risk-oriented, guideline-directed combination therapy for patients with PAH may lead to a survival benefit. This review provides a detailed overview of the drugs, infusion systems and dosing strategies used for intravenous therapy in patients with PAH.

Selexipag for the treatment of pulmonary arterial hypertension

INTRODUCTION

: Pulmonary arterial hypertension (PAH) is a rare pulmonary vasculopathy. This review focuses on selexipag, a prostacyclin receptor agonist validated for the treatment of PAH.

AREAS COVERED

We review the structure, mechanisms of action, pharmacokinetics, and pharmacodynamics of selexipag. Clinical efficacy and tolerability are discussed using the main clinical trial published for selexipag (GRIPHON) and its post-hoc analysis.

EXPERT OPINION

Selexipag should be added as a triple oral combination therapy in case of insufficient response to oral combination therapy with endothelin receptor antagonist and phosphodiesterase 5 inhibitor. However, selexipag should not replace parenteral prostacyclin in high-risk patients.

Management of Pulmonary Arterial Hypertension

Purpose of Review

This review focuses on the therapeutic management and individualized approach to Group 1 pulmonary arterial hypertension (PAH), utilizing Food and Drug Administration-approved PAH-specific therapies and various interventional and surgical options for PAH.

Recent Findings

The paradigm for the optimal management of PAH has shifted in recent years. Upfront combination therapy with an endothelin receptor antagonist and a phosphodiesterase 5 inhibitor is now widely accepted as standard of care. In addition, there is increasing emphasis on starting prostanoids early in order to delay time to clinical worsening. However, less is known regarding which prostanoid agent to initiate and the optimum time to do so. In order to facilitate shared decision-making, there is an increasing need for decision tools based on guidelines and collective clinical experiences to navigate between pharmacologic and interventional treatments, as well as explore innovative, therapeutic pathways for PAH.

Summary

The management of PAH has become increasingly complex. With a growing number of PAH-specific therapies, intimate knowledge of the therapeutics and the potential barriers to adherence are integral to providing optimal care for this high-risk patient population. While current PAH-specific therapies largely mediate their effects through pulmonary vasodilation, ongoing research efforts are focused on ways to disrupt the mechanisms leading to pulmonary vascular remodeling. By targeting aberrations identified in the metabolism and proliferative state of pulmonary vascular cells, novel PAH treatment pathways may be just on the horizon.

Current and emerging therapeutic approaches to pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a progressive and fatal lung disease of multifactorial etiology. Most of the available drugs and FDA-approved therapies for treating pulmonary hypertension attempt to overcome the imbalance between vasoactive and vasodilator mediators, and restore the endothelial cell function. Traditional medications for treating PAH include the prostacyclin analogs and receptor agonists, phosphodiesterase 5 inhibitors, endothelin-receptor antagonists, and cGMP activators. While the current FDA-approved drugs showed improvements in quality of life and hemodynamic parameters, they have shown only very limited beneficial effects on survival and disease progression. None of them offers a cure against PAH, and the median survival rate remains less than three years from diagnosis. Extensive research efforts have led to the emergence of innovative therapeutic approaches in the area of PAH. In this review, we provide an overview of the current FDA-approved therapies in PAH and discuss the associated clinical trials and reported-side effects. As recent studies have led to the emergence of innovative therapeutic approaches in the area of PAH, we also focus on the latest promising therapies in preclinical studies such as stem cell-based therapies, gene transfer, and epigenetic therapies.

The endothelin receptor antagonist macitentan for the treatment of pulmonary arterial hypertension: A cross-species comparison of its cytochrome P450 induction pattern

The dual endothelin receptor antagonist macitentan was approved in 2013 for the treatment of pulmonary arterial hypertension. Macitentan is an inducer of cytochrome P450 expression in vivo in animal species but not in man. In rat and dog, changes in P450 expression manifest as autoinduction upon repeat dosing. The induction pattern, however, significantly differed between both species, and between male and female rats. While macitentan exposure steadily declined with dose in the dog, P450 induction was saturable in the rat reaching levels of 40%-60% and 60%-80% at steady-state in male and female animals, respectively. The nature and number of P450 enzymes involved in macitentan clearance were identified as a major reason for the observed species differences. In the dog, macitentan was metabolized by a single P450 enzyme, that is, Cyp3a12, whereas several members of the Cyp2c and Cyp3a families were involved in the rat. Macitentan selectively upregulated Cyp3a expression in rat, whereas the expression of the Cyp2c enzymes involved in macitentan metabolism remained mostly unchanged, eventually leading to a higher contribution of Cyp3a upon induction. Macitentan also induced CYP3A4 expression in human hepatocytes via initial activation of the human pregnane X receptor. No such induction was evident in humans at the therapeutic macitentan dose of 10 mg as shown in a clinical drug-drug interaction study with the CYP3A4 substrate sildenafil.

Evidence synthesis in pulmonary arterial hypertension: a systematic review and critical appraisal

BACKGROUND

The clinical landscape of pulmonary arterial hypertension (PAH) has evolved in terms of disease definition and classification, trial designs, available therapies and treatment strategies as well as clinical guidelines. This study critically appraises published evidence synthesis studies, i.e. meta-analyses (MA) and network-meta-analyses (NMA), to better understand their quality, validity and discuss the impact of the findings from these studies on current decision-making in PAH.

METHODS

A systematic literature review to identify MA/NMA studies considering approved and available therapies for treatment of PAH was conducted. Embase, Medline and the Cochrane's Database of Systematic Reviews were searched from database inception to April 22, 2020, supplemented by searches in health technology assessment websites. The International Society for Pharmacoeconomics and Outcomes Research (ISPOR) checklist covering six domains (relevance, credibility, analysis, reporting quality and transparency, interpretation and conflict of interest) was selected for appraisal of the included MA/NMA studies.

RESULTS

Fifty-two full publications (36 MAs, 15 NMAs, and 1 MA/NMA) in PAH met the inclusion criteria. The majority of studies were of low quality, with none of the studies being scored as 'strong' across all checklist domains. Key limitations included the lack of a clearly defined, relevant decision problem, shortcomings in assessing and addressing between-study heterogeneity, and an incomplete or misleading interpretation of results.

CONCLUSIONS

This is the first critical appraisal of published MA/NMA studies in PAH, suggesting low quality and validity of published evidence synthesis studies in this therapeutic area. Besides the need for direct treatment comparisons assessed in long-term randomized controlled trials, future efforts in evidence synthesis in PAH should improve analysis quality and scrutiny in order to meaningfully address challenges arising from an evolving therapeutic landscape.

Pulmonary arterial hypertension specific therapy: The old and the new

Pulmonary arterial hypertension (PAH) is a vascular disorder associated with high morbidity and mortality rate and is characterized by pulmonary vascular remodeling and increased pulmonary vascular resistance, ultimately resulting in right ventricular failure and death. Over the past few decades, significant advances in the understanding of the epidemiology, pathogenesis, and pathophysiology of pulmonary arterial hypertension have occured. This has led to the development of disease specific treatment including prostanoids, endothelin receptor antagonists, phosphodiesterase inhibitors, and soluble guanylate cyclase stimulators. These therapies significantly improve exercise capacity, quality of life, pulmonary hemodynamics, but none of the current treatments are actually curative and long-term prognosis remains poor. Thus, there is a clear need to develop new therapies. Several potential pharmacologic agents for the treatment of pulmonary arterial hypertension are under clinical development and some promising results with these treatments have been reported. These agents include tyrosine protein kinase inhibitors, rho-kinase inhibitors, synthetically produced vasoactive intestinal peptide, antagonists of the 5-HT2 receptors, and others. This article will review several of these promising new therapies and will discuss the current evidence regarding their potential benefit in pulmonary arterial hypertension.

"Treat and repair" strategy for shunt lesions: a critical review

The issue of operability in patients with shunt lesions and raised pulmonary vascular resistance is contentious. Several reports suggest that patients traditionally considered inoperable may be operated after treatment with targeted drug therapy for pulmonary arterial hypertension. We reviewed all the published literature of "treat and repair" approach to gain more insights into the utility of this approach. A critical appraisal of the published literature suggests that this approach is less established for patients with post tricuspid shunts, and for patients with pre-tricuspid shunts with modestly elevated indexed pulmonary vascular resistance (possibly greater than 11 WU.m²). Targeted drug therapy may be able to extend the therapeutic window in carefully selected patients, but its use as a routine in this setting seems unwarranted.

Pulmonary Arterial Hypertension: A Palliative Medicine Review of the Disease, Its Therapies, and Drug Interactions

Pulmonary arterial hypertension (PAH) is often a progressive and ultimately fatal disease. It is characterized by an elevated mean pulmonary arterial pressure because of disease of the small pulmonary arterioles. PAH leads to a constellation of symptoms, including dyspnea, fatigue, syncope, chest discomfort, and peripheral edema. Disease-targeted therapies for PAH produce symptomatic and functional improvement, but long-term survival remains uncommon without lung transplantation. Palliative care is appropriate to support patients with advanced PAH who typically have a high symptom burden. However, palliative care has historically focused on supporting patients with malignant disease, rather than progressive chronic disease such as PAH. Our aim is to provide palliative care clinicians with a background in the classification, pathophysiology, and modern treatment of PAH. This review describes disease-targeted therapies and their effects on symptoms, physical functioning, and health-related quality of life. We also review the unique physiology of PAH and its implication for palliative interventions. Pharmacological interactions with, and precautions related to commonly used palliative care medications, are discussed.

Influence of Pharmaceutical Company Engagement Activities on the Decision to Prescribe: A Pilot Survey of UK Rare Disease Medicine Prescribers

INTRODUCTION

Traditionally, the pharmaceutical industry has used 'promotional personal engagement' activities, which involve interactions between sales forces and prescribers, in order to generate 'sales'-or prescriptions-of their new medicinal product(s). There appears to be now a favouring of 'non-personal engagement' (external information sources or activities existing outside the direct control of the company) and 'non-promotional personal engagement' activities (focused around creating peer-to-peer relationships between prescribers and pharmaceutical physicians).

OBJECTIVES

The purpose of this study was to examine the influence of non-personal engagement and non-promotional personal engagement activities on the prescribing habits of British healthcare professionals, using the traditional promotional personal engagement activities as a comparator.

METHODS

A questionnaire was distributed to 122 prescribers (physicians, nurses and pharmacists) working with two selected products for pulmonary arterial hypertension. The participants were asked to rate the influence that the listed activities had on their decision to prescribe each of the two products using a scale of 0-10, where 0 = 'no influence' and 10 = 'most important influence'.

RESULTS

Of the 122 targeted healthcare professionals who received the questionnaire, 34 (27.9%) responded within the 2-week time limit (24 physicians, 5 nurse prescribers and 5 pharmacists). The findings of the survey had a confidence level of 90% and a margin of error of 12%, given that 34 of 122 people responded. All proposed activities were scored by the respondents as having some influence on their prescribing. Personal engagement activities are effective for influencing prescribing, but non-promotional personal engagement activities may be more influential than promotional personal engagement activities. Furthermore, non-personal engagement activities may be more effective in influencing prescriptions of a product than either non-promotional or promotional personal engagement activities.

CONCLUSIONS

All personal engagement activities affect HCP prescribing behaviours; however, they appear to be more influential when performed on a non-promotional basis by representatives of the company's medical department.

"Endothelial Dysfunction in Resuscitated Cardiac Arrest (ENDO-RCA): Safety and efficacy of low-dose Iloprost, a prostacyclin analogue, in addition to standard therapy, as compared to standard therapy alone, in post-cardiac-arrest-syndrome patients."

OBJECTIVE

An increasingly recognized prognostic factor for out-of-hospital-cardiac-arrest (OHCA) patients is the ischemia-reperfusion injury after restored blood circulation. Endothelial injury is common in patients resuscitated from cardiac arrest and is associated with poor outcome. This study was designed to investigate if iloprost infusion, a prostacyclin analogue, reduces endothelial damage in OHCA patients.

METHODS

50 patients were randomized in a placebo controlled double-blinded trial and allocated 1:2 to 48-hours iloprost infusion, (1 ng/kg/min) or placebo (saline infusion). Endothelial biomarkers (soluble thrombomodulin (sTM), sE-selectin, syndecan-1, soluble vascular endothelial growth factor (sVEGF), vascular endothelial cadherine (VEcad), nucleosomes) and sympathoadrenal activation (epinephrine/norepinephrine) from baseline to 48 and 96-hours were evaluated.

RESULTS

Iloprost infusion did not influence endothelial biomarkers by the 48-hour endpoint. A rebound effect was observed with higher biomarker plasma values in the iloprost group (sTM p=0.02; Syndecan p=0.004; nucleosomes p<0.001; VEcad p<0.03) after 96-hours. There was a significant difference in 180-day mortality in favor of placebo. There was no difference regarding total adverse events between groups (p=0.73). Two patients were withdrawn in the iloprost group due to hypotension.

CONCLUSIONS

The administration of low-dose iloprost (1ng/kg/min) to OHCA patients did not significantly influence endothelial biomarkers as measured by the 48- hour endpoint. A rebound effect was however observed in the 96-hour statistical model, with increasing endothelial biomarker levels after cessation of the iloprost-infusion.

Comparative effectiveness of pulmonary arterial hypertension drugs in treatment-naive patients: a network meta-analysis

Aim: No network meta-analysis has been conducted to study efficacy of drug therapies specific for treatment of pulmonary arterial hypertension in treatment-naive patients only. Methods: Randomized controlled trials on pulmonary arterial hypertension-specific drug therapies were searched and a Bayesian network meta-analysis was performed. The 6-min walking distance (6MWD) and all-cause mortality were efficacy outcomes, whereas discontinuation due to adverse events was a safety-related outcome. Results: Analysis included 3.713 patients from 21 trials. Combination of ambrisentan and tadalafil showed the greatest impact on 6MWD, followed by epoprostenol and intravenous treprostinil (high dose). The latter two demonstrated marked effect size on mortality, although not statistically significant. Conclusion: According to 6MWD, ambrisentan/tadalafil combination was considered as most effective among all comparisons. Prospero ID: CRD42019110832.

Therapeutic Challenges And Advances In The Management Of Systemic Sclerosis-Related Pulmonary Arterial Hypertension (SSc-PAH)

Systemic sclerosis (SSc) is a rare autoimmune disorder with multi-organ involvement. SSc-associated pulmonary arterial hypertension (SSc-PAH) is one of the leading causes of morbidity and mortality in the SSc population. With advances in our understanding of pulmonary arterial hypertension (PAH) diagnosis and treatment, outcomes for all PAH patients have significantly improved. While SSc-PAH patients have also benefited from these advances, significant challenges remain. Diagnosis of PAH is a challenging endeavor in SSc patients who often have many co-existing pulmonary and cardiac comorbidities. Given the significantly elevated prevalence and lifetime risk of PAH in the SSc population, screening for SSc-PAH is a critically useful strategy. Treatment with pulmonary arterial (PA) vasodilators has resulted in a dramatic improvement in the survival and quality of life of PAH patients. While therapy with PA vasodilators is beneficial in SSc-PAH patients, therapy effects appear to be attenuated when compared to responses in patients with idiopathic PAH (IPAH). This review attempts to chronicle and summarize the advances in our understanding of the optimal screening strategies to identify PAH in patients with SSc. The article also reviews the advances in the therapeutic and risk stratification strategies for SSc-PAH patients.

Pulmonary arterial hypertension: the case for a bioelectronic treatment

Pulmonary arterial hypertension (PAH) is a rare disease of unknown etiology that progresses to right ventricular failure. It has a complex pathophysiology, which involves an imbalance between vasoconstrictive and vasodilative processes in the pulmonary circulation, pulmonary vasoconstriction, vascular and right ventricular remodeling, systemic inflammation, and autonomic imbalance, with a reduced parasympathetic and increased sympathetic tone. Current pharmacological treatments for PAH include several classes of drugs that target signaling pathways in vascular biology and cardiovascular physiology, but they can have severe unwanted effects and they do not typically stop the progression of the disease. Pulmonary artery denervation has been tested clinically as a method to suppress sympathetic overactivation, however it is a nonspecific and irreversible intervention. Bioelectronic medicine, in particular vagus nerve stimulation (VNS), has been used in cardiovascular disorders like arrhythmias, heart failure and arterial hypertension and could, in principle, be tested as a treatment in PAH. VNS can produce pulmonary vasodilation and renormalize right ventricular function, via activation of pulmonary and cardiac vagal fibers. It can suppress systemic inflammation, via activation of fibers that innervate the spleen. Finally, VNS can gradually restore the balance between parasympathetic and sympathetic tone by regulating autonomic reflexes. Preclinical studies support the feasibility of using VNS in PAH. However, there are challenges with such an approach, arising from the need to affect a relatively small number of relevant vagal fibers, and the potential for unwanted cardiac and noncardiac effects of VNS in this sensitive patient population.

Current Treatment Strategies and Nanoparticle-Mediated Drug Delivery Systems for Pulmonary Arterial Hypertension

There are three critical pathways for the pathogenesis and progression of pulmonary arterial hypertension (PAH): the prostacyclin (prostaglandin I₂) (PGI₂), nitric oxide (NO), and endothelin pathways. The current approved drugs targeting these three pathways, including prostacyclin (PGI₂), phosphodiesterase type-5 (PDE5) inhibitors, and endothelin receptor antagonists (ERAs), have been shown to be effective, however, PAH remains a severe clinical condition and the long-term survival of patients with PAH is still suboptimal. The full therapeutic abilities of available drugs are reduced by medication, patient non-compliance, and side effects. Nanoparticles are expected to address these problems by providing a novel drug delivery approach for the treatment of PAH. Drug-loaded nanoparticles for local delivery can optimize the efficacy and minimize the adverse effects of drugs. Prostacyclin (PGI₂) analogue, PDE5 inhibitors, ERA, pitavastatin, imatinib, rapamycin, fasudil, and oligonucleotides-loaded nanoparticles have been reported to be effective in animal PAH models and in vitro studies. However, the efficacy and safety of nanoparticle mediated-drug delivery systems for PAH treatment in humans are unknown and further clinical studies are required to clarify these points.

Thyroid Dysfunction in Patients with Pulmonary Artery Hypertension (PAH): The Effect of Therapies Affecting the Prostanoid Pathway

INTRODUCTION

Epoprostenol, a synthetic prostaglandin I2 (PGI₂) analog, has been the mainstay of treatment for severe pulmonary arterial hypertension (PAH) for the last two decades. Treprostinil, another synthetic prostaglandin analog, and selexipag, an oral selective Inositol Phosphate (IP) prostacyclin receptor agonist, have also been approved for treatment of PAH. Prostacyclin and its analogs cause a variety of side effects in patients with PAH; however, thyroid dysfunction is rarely reported.

METHODS

After treating an index case of thyroid dysfunction occurring after initiation of epoprostenol, we reviewed our databases of PAH patients treated with epoprostenol, treprostinil or selexipag to identify the occurrence of this association.

RESULTS

We identified six cases of thyroid dysfunction in our cohort: five after initiation of an intravenous prostacyclin (epoprostenol) and one after initiation of an oral prostacyclin receptor agonist (selexipag). Four of the patients presented with hyperthyroidism and two with a large autoimmune goiter. Graves' disease was seen in three patients, Hashimoto's disease in two patients and thyrotoxicosis in one patient.

CONCLUSION

Therapy with medications targeting the prostacyclin pathway is a potential risk factor for the development of symptomatic thyroid disease.

Effectiveness of epoprostenol in the management of pulmonary arterial hypertension: findings of an Australian retrospective chart review

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressively fatal disease. Parenteral prostanoids, including intravenous (IV) epoprostenol, are the most effective therapies for PAH. As epoprostenol requires continuous infusion, therapy is challenging and use is managed by specialist units.

AIMS

To describe the clinical outcomes for the use of IV epoprostenol in an Australian pulmonary vascular disease unit and identify opportunities to improve its use.

METHOD

We conducted a retrospective chart review of all adult patients who received IV epoprostenol for PAH at Prince Charles Hospital. Data were collected at baseline, initiation of epoprostenol and quarterly to the end of the audit period or the discontinuation of epoprostenol. Descriptive statistics were performed and comparisons made to epoprostenol initiation. Kaplan-Meier curves were used to estimate survival outcomes.

RESULTS

Thirty-nine patients received epoprostenol therapy. Most (87.2%) were female, had connective tissue disease (46.2%) or idiopathic PAH (35.9%) and had a World Health Organization functional Class of III or IV at initiation. The mean duration of epoprostenol therapy was 2.9 years. Intravenous epoprostenol was associated with favourable outcomes; 1, 3 and 5-year survival rates since initiation of 90.0, 75.8 and 68.2%; robust improvements in functional class; and improvements in 6-min walking distance of 160.4 m at 3 years; 94.9% patients experienced at least one drug-related adverse event and line complications were common.

CONCLUSION

Epoprostenol therapy was associated with impressive survival rates and durable improvements in functional outcomes. Epoprostenol therapy is challenging; however, it is manageable by the majority of patients with most experiencing positive, sustainable outcomes.