End-of-Life and Palliative Care Issues for Patients Living with Pulmonary Arterial Hypertension: Barriers and Opportunities.

Pulmonary arterial hypertension (PAH) is a progressive, incurable disease that results in significant symptom burden, health care utilization, and eventually premature death. Despite the advancements made in treatment and management strategies, survival has remained poor. End-of-life care is a challenging issue in management of PAH, especially when patients are in younger age group. End-of-life care revolves around symptom palliation and reducing psychosocial disease burden for a dying patient and entails advanced care planning that are often challenging. Thus, support from palliative care specialist becomes extremely important in these patients. Early introduction to palliative care in patients with high symptom burden and psychosocial suffering is suggested. Despite of the benefits of an early intervention, palliative care remains underutilized in patients with PAH, and this significantly raises issues around end-of-life care in PAH. In this review, we will discuss the opportunities offered and the existing barriers in addressing high symptom burden and end-of-life care issues. We will focus on the current evidence, identify areas for future research, and provide a call-to-action for better guidance to PAH specialists in making timely, appropriate interventions that can help mitigate end-of-life care issues.

Therapeutic effects of hypoxia-preconditioned bone marrow-derived mesenchymal stromal cells and their extracellular vesicles in experimental pulmonary arterial hypertension.

AIMS: To evaluate BM-MSCs and their extracellular vesicles (EVs) preconditioned with hypoxia or normoxia in experimental pulmonary arterial hypertension (PAH). MAIN METHODS: BM-MSCs were isolated and cultured under normoxia (MSC-N, 21%O2) or hypoxia (MSC-H, 1%O2) for 48 h. EVs were then isolated from MSCs under normoxia (EV-N) or hypoxia (EV-H). PAH was induced in male Wistar rats (n = 35) with monocrotaline (60 mg/kg); control animals (CTRL, n = 7) were treated with saline. On day 14, PAH animals received MSCs or EVs under normoxia or hypoxia, intravenously (n = 7/group). On day 28, right ventricular systolic pressure (RVSP), pulmonary acceleration time (PAT)/pulmonary ejection time (PET), and right ventricular hypertrophy (RVH) index were evaluated. Perivascular collagen content, vascular wall thickness, and endothelium-mesenchymal transition were analyzed. KEY FINDINGS: PAT/PET was lower in the PAH group (0.26 ± 0.02, P < 0.001) than in CTRLs (0.43 ± 0.02) and only increased in the EV-H group (0.33 ± 0.03, P = 0.014). MSC-N (32 ± 6 mmHg, P = 0.036), MSC-H (31 ± 3 mmHg, P = 0.019), EV-N (27 ± 4 mmHg, P < 0.001), and EV-H (26 ± 5 mmHg, P < 0.001) reduced RVSP compared with the PAH group (39 ± 4 mmHg). RVH was higher in the PAH group than in CTRL and reduced after all therapies. All therapies decreased perivascular collagen fiber content, vascular wall thickness, and the expression of endothelial markers remained unaltered; only MSC-H and EV-H decreased expression of mesenchymal markers in pulmonary arterioles. SIGNIFICANCE: MSCs and EVs, under normoxia or hypoxia, reduced right ventricular hypertrophy, perivascular collagen, and vessel wall thickness. Under hypoxia, MSCs and EVs were more effective at improving endothelial to mesenchymal transition in experimental PAH.

Stem cell therapy for pulmonary arterial hypertension: An update.

Pulmonary arterial hypertension (PAH) remains a deadly disease, and there currently is no cure for this life-threating medical problem. The average lifespan is about 5 to 7 years after diagnosis of PAH. Therefore, a conceptual breakthrough to develop new therapeutic strategies for PAH is urgently needed. Growing evidence shows that stem cells are emerging as a novel effective treatment, but the understanding of its underlying mechanisms is still limited. This review highlights the mechanisms through which stem cells successfully reverse pulmonary vascular endothelial dysfunction, pulmonary artery smooth muscle cell over-proliferation, and mitochondrial dysfunction in PAH patients and common rodent models used in PAH research. They can modulate common underlying pathways involved in PAH, including the nitric oxide synthase, mitochondrial regulators, microRNAs and STAT3-BMPR signaling. Genetic modifications further enhance the therapeutic effects of stem cells on PAH. Clinical trials showed promising therapeutic potential of mesenchymal stem cells and endothelial progenitor cells for PAH. Potential limitations and challenges are also discussed. The current findings support the need for further investigation and validation of stem cell therapy for PAH.

Hipertensión pulmonar. Definiendo la estructura y la función departamental a partir del riesgo / Pulmonary hypertension. Defining the structure and the departmental function based on risk

Se presenta un modelo departamental para la atención integral de pacientes con hipertensión pulmonar. Se resume el conocimiento actual de la hipertensión pulmonar, su mortalidad, pronóstico y la estratificación de su severidad que justifican la propuesta de la estructura y la función departamental.

A departmental model for the comprehensive care of patients with pulmonary hypertension is presented. The current knowledge of pulmonary hypertension, its mortality, prognosis and the stratification of its severity that justify the proposal of the departmental structure and function are summarized.

Aerobic training-mediated DNA hypermethylation of Agtr1a and Mas1 genes ameliorate mesenteric arterial function in spontaneously hypertensive rats.

BACKGROUND: The imbalance of vasoconstrictor and vasodilator axes of the renin-angiotensin system (RAS) is observed in hypertension. Exercise regulates RAS level and improves vascular function. This study focused on the contribution of RAS axes in vascular function of mesenteric arteries and exercise-induced DNA methylation of the Agtr1a (AT1aR) and Mas1 (MasR) genes in hypertension. METHODS: Spontaneously hypertensive rats (SHRs) and Wistar-Kyoto rats were randomized into exercise or sedentary group. Levels of plasma RAS components, vascular tone, and DNA methylation markers were measured. RESULTS: Blood pressure of SHR was markedly reduced after 12 weeks of aerobic exercise. RAS peptides in plasma were all increased with an imbalanced upregulation of Ang II and Ang-(1-7) in SHR, exercise revised the level of RAS and increased Ang-(1-7)/Ang II. The vasoconstriction response induced by Ang II was mainly via type 1 receptors (AT1R), while this contraction was inhibited by Mas receptor (MasR). mRNA and protein of AT1R and MasR were both upregulated in SHR, whereas exercise significantly suppressed this imbalanced increase and increased MasR/AT1R ratio. Exercise hypermethylated Agtr1a and Mas1 genes, associating with increased DNMT1 and DNMT3b and SAM/SAH. CONCLUSIONS: Aerobic exercise ameliorates vascular function via hypermethylation of the Agtr1a and Mas1 genes and restores the vasoconstrictor and vasodilator axes balance.

Treatment of systemic sclerosis.

Systemic sclerosis (SSc) is a rare connective tissue disease characterized by skin and visceral fibrosis, vascular hyperreactivity and obliterative vasculopathy. Some of its complications such as interstitial lung disease (ILD), pulmonary arterial hypertension (PAH) and heart involvement can be life-threatening and are associated with a high mortality and a poor prognosis. Many clinical trials were carried out in order to improve the survival and prognosis of SSc patients. The management of SSc is based on the frequent and regular assessment of the potential organ damage, and if present, the establishment of graduated pharmacological therapeutic strategies, associated with non-pharmacological procedures. Several randomized clinical trials have showed significant positive outcomes regarding some specific involvements. Many advances have been made, especially in the field of targeted therapies and personalized medicine, based on specific characteristics of the patient and the SSc.

Regulation of the Methylation and Expression Levels of the BMPR2 Gene by SIN3a as a Novel Therapeutic Mechanism in Pulmonary Arterial Hypertension.

BACKGROUND: Epigenetic mechanisms are critical in the pathogenesis of pulmonary arterial hypertension (PAH). Previous studies have suggested that hypermethylation of the BMPR2 (bone morphogenetic protein receptor type 2) promoter is associated with BMPR2 downregulation and progression of PAH. Here, we investigated for the first time the role of SIN3a (switch-independent 3a), a transcriptional regulator, in the epigenetic mechanisms underlying hypermethylation of BMPR2 in the pathogenesis of PAH. METHODS: We used lung samples from PAH patients and non-PAH controls, preclinical mouse and rat PAH models, and human pulmonary arterial smooth muscle cells. Expression of SIN3a was modulated using a lentiviral vector or a siRNA in vitro and a specific adeno-associated virus serotype 1 or a lentivirus encoding for human SIN3a in vivo. RESULTS: SIN3a is a known transcriptional regulator; however, its role in cardiovascular diseases, especially PAH, is unknown. It is interesting that we detected a dysregulation of SIN3 expression in patients and in rodent models, which is strongly associated with decreased BMPR2 expression. SIN3a is known to regulate epigenetic changes. Therefore, we tested its role in the regulation of BMPR2 and found that BMPR2 is regulated by SIN3a. It is interesting that SIN3a overexpression inhibited human pulmonary arterial smooth muscle cells proliferation and upregulated BMPR2 expression by preventing the methylation of the BMPR2 promoter region. RNA-sequencing analysis suggested that SIN3a downregulated the expression of DNA and histone methyltransferases such as DNMT1 (DNA methyltransferase 1) and EZH2 (enhancer of zeste 2 polycomb repressive complex 2) while promoting the expression of the DNA demethylase TET1 (ten-eleven translocation methylcytosine dioxygenase 1). Mechanistically, SIN3a promoted BMPR2 expression by decreasing CTCF (CCCTC-binding factor) binding to the BMPR2 promoter. Last, we identified intratracheal delivery of adeno-associated virus serotype human SIN3a to be a beneficial therapeutic approach in PAH by attenuating pulmonary vascular and right ventricle remodeling, decreasing right ventricle systolic pressure and mean pulmonary arterial pressure, and restoring BMPR2 expression in rodent models of PAH. CONCLUSIONS: All together, our study unveiled the protective and beneficial role of SIN3a in pulmonary hypertension. We also identified a novel and distinct molecular mechanism by which SIN3a regulates BMPR2 in human pulmonary arterial smooth muscle cells. Our study also identified lung-targeted SIN3a gene therapy using adeno-associated virus serotype 1 as a new promising therapeutic strategy for treating patients with PAH.

Selective deletion of connective tissue growth factor attenuates experimentally-induced pulmonary fibrosis and pulmonary arterial hypertension.

Connective tissue growth factor (CTGF, CCN2) is a matricellular protein which plays key roles in normal mammalian development and in tissue homeostasis and repair. In pathological conditions, dysregulated CCN2 has been associated with cancer, cardiovascular disease, and tissue fibrosis. In this study, genetic manipulation of the CCN2 gene was employed to investigate the role of CCN2 expression in vitro and in experimentally-induced models of pulmonary fibrosis and pulmonary arterial hypertension (PAH). Knocking down CCN2 using siRNA reduced expression of pro-fibrotic markers (fibronectin p < 0.01, collagen type I p < 0.05, α-SMA p < 0.0001, TIMP-1 p < 0.05 and IL-6 p < 0.05) in TGF-ß-treated lung fibroblasts derived from systemic sclerosis patients. In vivo studies were performed in mice using a conditional gene deletion strategy targeting CCN2 in a fibroblast-specific and time-dependent manner in two models of lung disease. CCN2 deletion significantly reduced pulmonary interstitial scarring and fibrosis following bleomycin-instillation, as assessed by fibrotic scores (wildtype bleomycin 3.733 ± 0.2667 vs CCN2 knockout (KO) bleomycin 4.917 ± 0.3436, p < 0.05) and micro-CT. In the well-established chronic hypoxia/Sugen model of pulmonary hypertension, CCN2 gene deletion resulted in a significant decrease in pulmonary vessel remodelling, less right ventricular hypertrophy and a reduction in the haemodynamic measurements characteristic of PAH (RVSP and RV/LV + S were significantly reduced (p < 0.05) in CCN2 KO compared to WT mice in hypoxic/SU5416 conditions). These results support a prominent role for CCN2 in pulmonary fibrosis and in vessel remodelling associated with PAH. Therefore, therapeutics aimed at blocking CCN2 function are likely to benefit several forms of severe lung disease.

Comparative analysis on the anti-inflammatory/immune effect of mesenchymal stem cell therapy for the treatment of pulmonary arterial hypertension.

Despite the advancement of targeted therapy for pulmonary arterial hypertension (PAH), poor prognosis remains a reality. Mesenchymal stem cells (MSCs) are one of the most clinically feasible alternative treatment options. We compared the treatment effects of adipose tissue (AD)-, bone marrow (BD)-, and umbilical cord blood (UCB)-derived MSCs in the rat monocrotaline-induced pulmonary hypertension (PH) model. The greatest improvement in the right ventricular function was observed in the UCB-MSCs treated group. The UCB-MSCs treated group also exhibited the greatest improvement in terms of the largest decrease in the medial wall thickness, perivascular fibrosis, and vascular cell proliferation, as well as the lowest levels of recruitment of innate and adaptive immune cells and associated inflammatory cytokines. Gene expression profiling of lung tissue confirmed that the UCB-MSCs treated group had the most notably attenuated immune and inflammatory profiles. Network analysis further revealed that the UCB-MSCs group had the greatest therapeutic effect in terms of the normalization of all three classical PAH pathways. The intravenous injection of the UCB-MSCs, compared with those of other MSCs, showed superior therapeutic effects in the PH model for the (1) right ventricular function, (2) vascular remodeling, (3) immune/inflammatory profiles, and (4) classical PAH pathways.

Pulmonary hypertension in connective tissue diseases, new evidence and challenges.

Pulmonary arterial hypertension is a lethal complication of different connective tissue diseases such as systemic sclerosis, mixed connective tissue disease and systemic lupus erythematosus. Although the treatment possibilities for patients with pulmonary arterial hypertension have increased in the last two decades and survival of patients with idiopathic pulmonary arterial hypertension has improved, the latter is not the case for patients with pulmonary arterial hypertension associated with connective tissue disease. In this narrative review, we review recent literature and describe the improvement of early diagnostic possibilities, screening modalities and treatment options. We also point out the pitfalls in diagnosis in this patient category and describe the unmet needs and what the focus of future research should be.

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.

Critical care of patients with pulmonary arterial hypertension.

PURPOSE OF REVIEW: Need for intensive care in the patient with pulmonary arterial hypertension is associated with high mortality. This review will provide an overview of causes of ICU admission for patients with pulmonary hypertension and provide guidance on management. RECENT FINDINGS: There is a paucity of evidence-based medical literature on management of patients with pulmonary arterial hypertension. This article will summarize the available literature and expert guidance on the topic. Patients with pulmonary arterial hypertension may require ICU care as a direct consequence of decompensated right heart failure. Alternatively, patients with pulmonary arterial hypertension may be affected by the myriad of maladies encountered every day in the ICU including acute respiratory failure, septic shock, and gastrointestinal bleeding. The treatment plan should focus on identifying and treating the cause for decompensation. In addition, optimization of right ventricular preload, reduction of right ventricular afterload, correction of hypotension and augmentation of right ventricular inotropy should be considered. SUMMARY: The approach to ICU care of patients with pulmonary arterial hypertension requires special consideration with regard to intubation and mechanical ventilation and management of volume status and hemodynamics. Whenever possible, these patients should be transferred to centers with experience in treating this complex, vulnerable population.

A Survey-based Estimate of COVID-19 Incidence and Outcomes among Patients with Pulmonary Arterial Hypertension or Chronic Thromboembolic Pulmonary Hypertension and Impact on the Process of Care.

Rationale: Patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) typically undergo frequent clinical evaluation. The incidence and outcomes of coronavirus disease (COVID-19) and its impact on routine management for patients with pulmonary vascular disease is currently unknown.Objectives: To assess the cumulative incidence and outcomes of recognized COVID-19 for patients with PAH/CTEPH followed at accredited pulmonary hypertension centers, and to evaluate the pandemic's impact on clinic operations at these centers.Methods: A survey was e-mailed to program directors of centers accredited by the Pulmonary Hypertension Association. Descriptive analyses and linear regression were used to analyze results.Results: Seventy-seven center directors were successfully e-mailed a survey, and 58 responded (75%). The cumulative incidence of COVID-19 recognized in individuals with PAH/CTEPH was 2.9 cases per 1,000 patients, similar to the general U.S. population. In patients with PAH/CTEPH for whom COVID-19 was recognized, 30% were hospitalized and 12% died. These outcomes appear worse than the general population. A large impact on clinic operations was observed including fewer clinic visits and substantially increased use of telehealth. A majority of centers curtailed diagnostic testing and a minority limited new starts of medical therapy. Most centers did not use experimental therapies in patients with PAH/CTEPH diagnosed with COVID-19.Conclusions: The cumulative incidence of COVID-19 recognized in patients with PAH/CTEPH appears similar to the broader population, although outcomes may be worse. Although the total number of patients with PAH/CTEPH recognized to have COVID-19 was small, the impact of COVID-19 on broader clinic operations, testing, and treatment was substantial.

Combination of PGE1 and Pulmonary Vasodilator Therapy in Managing a Challenging Case of Severe PAH Secondary to CDH.

Congenital diaphragmatic hernia (CDH) is a rare disease, which affects 1 in 2,500 newborns. Congenital diaphragmatic hernia can interfere with the normal development of the pulmonary parenchyma and vascular bed, and in severe cases, it can lead to the development of severe pulmonary arterial hypertension (PAH) and right ventricular failure. We present a neonate with CDH who developed severe PAH and right ventricular dysfunction and was managed with a unique strategy combining venoarterial extracorporeal membrane oxygenation, prostaglandin E1, and a variety of PAH therapies.

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.

Beyond the genome: challenges and potential for epigenetics-driven therapeutic approaches in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a devastating disease of the cardiopulmonary system caused by the narrowing of the pulmonary arteries, leading to increased vascular resistance and pressure. This leads to right ventricle remodeling, dysfunction, and eventually, death. While conventional therapies have largely focused on targeting vasodilation, other pathological features of PAH including aberrant inflammation, mitochondrial dynamics, cell proliferation, and migration have not been well explored. Thus, despite some recent improvements in PAH treatment, the life expectancy and quality of life for patients with PAH remains poor. Showing many similarities to cancers, PAH is characterized by increased pulmonary arterial smooth muscle cell proliferation, decreased apoptotic signaling pathways, and changes in metabolism. The recent successes of therapies targeting epigenetic modifiers for the treatment of cancer has prompted epigenetic research in PAH, revealing many new potential therapeutic targets. In this minireview we discuss the emergence of epigenetic dysregulation in PAH and highlight epigenetic-targeting compounds that may be effective for the treatment of PAH.

Extracorporeal Membrane Oxygenation and Lung Transplantation: Initial Experience at a Single Brazilian Center.

OBJECTIVE: To report initial experience from the use of extracorporeal membrane oxygenation (ECMO) in patients who received lung transplantation. METHODS: Retrospective study of a single tertiary center in the Brazilian state of São Paulo, a national reference in lung transplantation, based on the prospective collection of data from electronic medical records. The period analyzed extended from January 2009 (beginning of the program) until December 2018. RESULTS: A total of 75 lung transplants were performed, with ECMO used in 8 (10.7%) cases. Of the patients, 4 (50%) were female. The mean age was 46.4±14.3 years. The causes of the end-stage lung disease that led to transplantation were pulmonary arterial hypertension in 3 (37.5%) patients, bronchiectasis in 2 (25%) patients, pulmonary fibrosis in 2 (25%) patients, and pulmonary emphysema in 1 (12.5%) patient. In our series, 7 (87.5%) cases were sequential bilateral transplantations. Prioritization was necessary in 4 (50%) patients, and in 1 patient, ECMO was used as a bridge to transplantation. The ECMO route was central in 4 (50%), peripheral venovenous in 2 (25%) and peripheral venoarterial in 2 (25%) patients. The mean length of the intensive care unit (ICU) stay was 14±7.5 days and of the hospital stay was 34.1±34.2 days. The mean ECMO duration was 9.3±6.6 days with a 50% decannulation rate. Three patients were discharged (37.5%). CONCLUSION: Lung transplantation requires complex treatment, and ECMO has allowed extending the indications for transplantation and provided adjuvant support in the clinical management of these patients.