Cause Of Pulmonary Arterial Hypertension Research Articles

Bioinformatics Analysis of Common Genetic and Molecular Traits and Association of Portal Hypertension with Pulmonary Hypertension.

Portal hypertension (PH) is an important cause of pulmonary arterial hypertension(PAH), but its mechanism is still unclear. We used genetic data analysis to explore the shared genes and molecular mechanisms of PH and PAH. We downloaded the PH and PAH data from the GEO database, and used the weighted gene coexpression network analysis method (WGCNA) to analyze the coexpression modules of idiopathic noncirrhotic portal hypertension (INCPH) and cirrhotic portal hypertension (CPH) and pulmonary hypertension, respectively. Enrichment analysis was performed on the common genes, and differential gene expressions (DEGs) were used for verification. The target genes of INCPH and PAH were obtained by string and cytoscape software, and the miRNAs of target genes were predicted by miRwalk, miRDB, and TargetScan and their biological functions were analyzed; finally, we used PanglaoDB to predict the expression of target genes in cells. In WGCNA, gene modules significantly related to PAH, CPH, and INCPH were identified, and enrichment function analysis showed that the common pathway of PAH and CPH were “P53 signaling pathway,” “synthesis of neutral lipids”; PAH and INCPH are “terminal,” “Maintenance Regulation of Granules,” and “Toxin Transport.” DEGs confirmed the results of WGCNA; the common miRNA functions of PAH and cirrhosis were enriched for “P53 signaling pathway,” “TGF-β signaling pathway,” “TNF signaling pathway,” and “fatty acid metabolism,” and the miRNAs-mRNAs network suggested that hsa-miR-22a-3p regulates MDM2 and hsa-miR-34a-5p regulates PRDX4; the target genes of PAH and INCPH are EIF5B, HSPA4, GNL3, RARS, UTP20, HNRNPA2B1, HSP90B1, METAP2, NARS, SACM1L, and their target miRNA function enrichment showed EIF5B, HNRNPA2B1, HSP90B1, METAP2, NARS, SACM1L, and HSPA4 are associated with telomeres and inflammation, panglaoDB showed that target genes are located in endothelial cells, smooth muscle cells, etc. In conclusion, the mechanism of pulmonary hypertension induced by portal hypertension may be related to telomere dysfunction and P53 overactivation, and lipid metabolism and intestinal inflammation are also involved in this process.

Strategizing Drug Therapies in Pulmonary Hypertension for Improved Outcomes.

Pulmonary hypertension (PH) is characterized by a resting mean pulmonary artery pressure (PAP) of 20 mmHg or more and is a disease of multiple etiologies. Of the various types of PH, pulmonary arterial hypertension (PAH) is characterized by elevated resistance in the pulmonary arterial tree. It is a rare but deadly disease characterized by vascular remodeling of the distal pulmonary arteries. This paper focuses on PAH diagnosis and management including current and future treatment options. Over the last 15 years, our understanding of this progressive disease has expanded from the concept of vasoconstrictive/vasodilatory mismatch in the pulmonary arterioles to now a better appreciation of the role of genetic determinants, numerous cell signaling pathways, cell proliferation and apoptosis, fibrosis, thrombosis, and metabolic abnormalities. While knowledge of its pathophysiology has expanded, the majority of the treatments available today still modulate the same three vasodilatory pathways that have been targeted for over 30 years (endothelin, nitric oxide, and prostacyclin). While modifying these pathways may help improve symptoms and quality of life, none of these directly modify the underlying disease pathogenesis. However, there are now studies ongoing with new drugs that can prevent or reverse these underlying causes of PAH. This review discusses the evidence base for the current treatment algorithms for PAH, as well as discusses novel therapies in development.

Bmpr2 mutant mice are an inadequate model for studying iron deficiency in pulmonary hypertension.

As bone morphogenetic protein receptor type II (Bmpr2) mutations are the most common genetic cause of pulmonary arterial hypertension (PAH), and iron deficiency(ID) is associated with worse clinical outcomes in PAH patients, we proposed to use Bmpr2 ± mice to induce a model of ID in pulmonary vascular disease. Our study shows that these transgenic mice are not a good model for this clinical phenomenon.

Pulmonary Hypertension in Scleroderma– Evaluation and Management

Pulmonary Arterial Hypertension (PAH) is a clinical syndrome consisting of physiologic/hemodynamic criteria that are a consequence of several etiologies. Systemic Sclerosis (SSc), one of the most common causes of PAH, is an autoimmune disorder of the connective tissue leading to fibrosis that involves the skin, gastrointestinal tract, lungs, heart, kidney etc. SSc has an annual prevalence of one to five cases for every 1000 individuals and nearly 15 percent of all cases develop PAH.At its core, Pulmonary hypertension (PH) in SSc is an obliterative vasculopathy in small to medium-sized pulmonary arterioles. A host of other local and systemic mechanisms operate in concert to gradually alter the hemodynamics resulting in elevated pulmonary vascular resistance and thus right ventricular afterload. A diagnosis of PAH in SSc is virtually a death sentence, with studies reporting a mortality rate of 50 per cent in the 3 years of diagnosis. Therefore, developing and implementing a robust screening and diagnosis protocol is crucial in the fight against this pervasive disease.This review aims to summarize the current literature of PAH in SSc, with a special focus on the screening and diagnosis protocols, newer treatment options and prognostic indicators for the same.

Potassium Channels as Therapeutic Targets in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a devastating disease with high morbidity and mortality. Deleterious remodeling in the pulmonary arterial system leads to irreversible arterial constriction and elevated pulmonary arterial pressures, right heart failure, and eventually death. The difficulty in treating PAH stems in part from the complex nature of disease pathogenesis, with several signaling compounds known to be involved (e.g., endothelin-1, prostacyclins) which are indeed targets of PAH therapy. Over the last decade, potassium channelopathies were established as novel causes of PAH. More specifically, loss-of-function mutations in the KCNK3 gene that encodes the two-pore-domain potassium channel KCNK3 (or TASK-1) and loss-of-function mutations in the ABCC8 gene that encodes a key subunit, SUR1, of the ATP-sensitive potassium channel (KATP) were established as the first two potassium channelopathies in human cohorts with pulmonary arterial hypertension. Moreover, voltage-gated potassium channels (Kv) represent a third family of potassium channels with genetic changes observed in association with PAH. While other ion channel genes have since been reported in association with PAH, this review focuses on KCNK3, KATP, and Kv potassium channels as promising therapeutic targets in PAH, with recent experimental pharmacologic discoveries significantly advancing the field.

Methamphetamine-associated pulmonary arterial hypertension.

Methamphetamine use is increasing in popularity globally, and chronic users suffer from various drug toxicities, including the development of pulmonary arterial hypertension. Although it was previously thought to be a possible cause of pulmonary arterial hypertension, as of the sixth World Symposium on Pulmonary Hypertension, methamphetamine use is now recognized as a definite cause of pulmonary arterial hypertension. This review will discuss the history of methamphetamine use, the link between methamphetamine use and pulmonary arterial hypertension, and the clinical characteristics of patients with pulmonary hypertension from methamphetamine use. The mechanism by which methamphetamine abuse leads to pulmonary hypertension is unclear. However, recent studies have suggested that reduced expression of carboxylesterase 1 may be implicated due to maladaptation to the environmental injury of methamphetamine abuse. Based on the report of two recent cohort studies, patients with methamphetamine-associated pulmonary arterial hypertension have a worse functional class, less favorable hemodynamics, impaired health-related quality of life, increased health-care utilization, and attenuated survival, as compared to those with idiopathic pulmonary arterial hypertension. Future studies are needed to better understand the mechanism by which methamphetamine use leads to pulmonary arterial hypertension. Methamphetamine-associated pulmonary arterial hypertension likely represents a more advanced disease state than idiopathic pulmonary arterial hypertension, however, it is treated less aggressively in clinical practice.

Multiple congenital visceral abnormalities as a rare cause of pulmonary arterial hypertension

BackgroundPulmonary arterial hypertension (PAH) is a rare, progressive disorder. PAH is caused by a wide spectrum of pathologies but the cause remains undetermined on many occasions and patients are classified in the idiopathic group.Case presentationHere we report a young woman with rare congenital visceral abnormalities presenting with severe pulmonary hypertension.ConclusionsPulmonary hypertension is a complex disorder. Search for uncommon conditions that lead to pulmonary hypertension is necessary to determine the best management options.

Experimental Schistosoma japonicum-induced pulmonary hypertension.

Schistosomiasis, a major cause of pulmonary arterial hypertension (PAH) worldwide, is most clearly described complicating infection by one species, Schistosoma mansoni. Controlled exposure of mice can be used to induce Type 2 inflammation-dependent S. mansoni pulmonary hypertension (PH). We sought to determine if another common species, S. japonicum, can also cause experimental PH. Schistosome eggs were obtained from infected mice, and administered by intraperitoneal sensitization followed by intravenous challenge to experimental mice, which underwent right heart catheterization and tissue analysis. S. japonicum sensitized and challenged mice developed PH, which was milder than that following S. mansoni sensitization and challenge. The degree of pulmonary vascular remodeling and Type 2 inflammation in the lungs was similarly proportionate. Cross-sensitization revealed that antigens from either species are sufficient to sensitize for intravenous challenge with either egg, and the degree of PH severity depended on primarily the species used for intravenous challenge. Compared to a relatively uniform distribution of S. mansoni eggs, S. japonicum eggs were observed in clusters in the lungs. S. japonicum can induce experimental PH, which is milder than that resulting from comparable S. mansoni exposure. This difference may result from the distribution of eggs in the lungs, and is independent of which species is used for sensitization. This result is consistent with the clearer association between S. mansoni infection and the development of schistosomiasis-associated PAH in humans.

Rationale and design of a screening study to detect schistosomiasis-associated pulmonary hypertension in Ethiopia and Zambia.

Schistosomiasis is a major cause of pulmonary arterial hypertension (PAH) worldwide, but the prevalence and risk factors for schistosomiasis‐associated PAH (SchPAH) development are not well understood. Schistosomiasis‐associated hepatosplenic disease (SchHSD) is thought to be a major risk factor for PAH development. Herein, we describe our plans for prospectively screening SchHSD subjects for clinical evidence of PAH at two major academic medical centers and national referral hospitals in Addis Ababa, Ethiopia and Lusaka, Zambia. The screening study will primarily be conducted by echocardiography, in addition to clinical assessments. Plasma samples will be drawn and banked for subsequent analysis based on preclinical animal model rationale. If successful, this study will demonstrate feasibility of conducting prospective cohort studies of SchPAH screening in schistosomiasis‐endemic regions of Africa, and provide initial data on clinic‐based disease prevalence and potential mechanistic biomarkers underlying disease pathogenesis.

Management and prognosis of HIV-associated pulmonary arterial hypertension: 20 Years of evidence from the REHAP registry.

Pulmonary arterial hypertension (PAH) is an independent predictor of death in patients with human immunodeficiency virus (HIV) infection. HIV is the leading cause of PAH (HIV-PAH) worldwide. We described the characteristics, treatment patterns, and prognosis of a cohort of HIV-PAH patients and compared them with those of an equivalent cohort of patients with idiopathic/familial PAH (IPAH/FPAH). We retrospectively analysed and compared the demographic, clinical, and treatment data from patients with HIV-PAH and those with IPAH/FPAH in the Spanish PAH registry (REHAP) from 1998 to 2018. The HIV-PAH overall survival (OS) rate up to 5 years was compared to the age- and sex-matched IPAH/FPAH population. Changes in treatment patterns in patients with HIV-PAH after 2010 and their effects on OS were also analysed. Compared to those with IPAH/FPAH (n = 739), patients with HIV-PAH (n = 132) were younger, mainly men, and had a better functional status. The clinical presentation, haemodynamics, and respiratory function were similar between the groups. Parenteral drug use was the most common mode of HIV transmission. Approximately 11% of patients with HIV-PAH did not receive PAH-targeted therapy. The age- and sex-adjusted 5-year OS rate from diagnosis was 74.0% for patients with HIV-PAH and 68.7% for those with IPAH (p < 0.159). During/after 2010, 23% of patients with IPAH/FPAH received upfront dual oral combination, while oral monotherapy remained the main first-line treatment in patients with HIV-PAH. The overall OS rate remained stable. Patients with HIV-PAH were predominantly young men. The short-term prognosis is similar to that of age- and sex-matched patients with IPAH/FPAH, despite a better functional status. Oral monotherapy remains the preferred first-line treatment in the current cohorts.

Systemic Lupus Erythematosus-associated Pulmonary Arterial Hypertension: Serial Case Report

One of the causes of pulmonary arterial hypertension (PAH) is connective tissue disease, including systemic lupus erythematosus (SLE). The prevalence of PAH in patients with SLE according to cohort studies varies widely between 0.5% and 43%. In some cases, PAH is the initial manifestation leading to the diagnosis of SLE. However, PAH can develop as a complication in patients who are initially diagnosed with SLE. We report two cases with a different approach to the diagnosis of pulmonary hypertension in SLE patients. These cases emphasize the importance of investigating examination results according to the guidelines to establish the diagnosis of PAH in SLE.

PH Roundtable: Genetics and Pulmonary Hypertension

PH Roundtable: Genetics and Pulmonary Hypertension

Abstract 13033: Cavin/Caveolin Interaction Modulates BMP/Smad Signaling in Pulmonary Artery Endothelial Cells

Background: Pulmonary hypertension (PH) is a progressive disease associated with poor prognosis. Caveolin-1 (Cav1) and Cavin-1 are components of caveolae, and both interact with each other and influence the composition and stabilization of caveolae. Cav1 is identified as a related gene of pulmonary arterial hypertension (PAH). Gene mutation of bone morphogenetic protein type II receptor (BMPRII) is the most common cause of PAH. BMPRII is localized in caveolae and associates with Cav1. However, the role of the Caveolin-Cavin system on the BMP/Smad signaling and the PAH progression has not been well-known. Methods and Results: As in previous reports, Cav1 knockout mice exhibited PH with pulmonary vascular remodeling and right ventricular hypertrophy. Caveolae disappeared in pulmonary microvascular endothelial cells of Cav1 knockout mice. We then examined the role of Caveolin-Cavin and the association with BMP/Smad signaling in human pulmonary artery endothelial cells (hPAECs). Cav1 knockdown in hPAECs reduced BMPRII at the plasma membrane and Smad 1/5/9 phosphorylation. Cav1 knockdown also significantly increased hypoxia-induced apoptosis in hPAECs. Cav1 was associated with BMPRII at the membrane of hPAECs. In addition, Cavin-1 inhibited the interaction of BMPRII with Cav1 and reduced BMPRII localization on the membrane of hPAECs. Cavin-1 knockdown reversed BMPRII localization at the plasma membrane and Smad 1/5/9 phosphorylation induced by Cav1 knockdown. Both Cavin-1 and BMPRII were associated with the Cav1 scaffolding domain. These results suggest that Cavin-1 interacts with Cav1 and inhibits the association of Cav1 with BMPRII, resulting in modulating Smad signaling pathway. Conclusions: Cavin-1 and BMPRII are competitively associated with Cav1 at the plasma membrane and modulating BMP/Smad signal transduction in PAECs. Our findings reveal a previously undescribed mechanism via Cavin-Caveolin interaction in BMP/Smad signaling-modulated PH development.

Cavin-1 modulates BMP/Smad signaling through the interaction of Caveolin-1 with BMPRII in pulmonary artery endothelial cells

Abstract Background Pulmonary hypertension (PH) is a progressive disease associated with poor outcomes. Caveolin-1 (Cav1) and Cavin-1 are components of caveolae, and Cav1 is identified as a related gene of pulmonary arterial hypertension (PAH). Gene mutations of bone morphogenetic protein type II receptor (BMPRII) is the most common cause of PAH. BMPRII is localized in caveolae and associates with Cav1. However, the role of the Caveolin-Cavin system on the BMP/Smad signaling and the PAH progression has not been well-known. Purpose Our study aims to investigate the relationship between Caveolin-Cavin system and BMP/Smad signaling pathway in pulmonary artery endothelial cells (PAECs). [Methods] Cav1 knockout mice were used to assess PH, and caveolae in PAECs were observed by electron microscope. After knocking down Cav1 and/or Cavin-1 in human PAECs (hPAECs) using siRNA, we evaluated the phosphorylation of Smad by Western blotting. Apoptosis was explored by flow cytometry. To assess the interaction between Cav1 and BMPRII, and the effect of Cavin-1 for this interaction and BMP/Smad signaling, we performed immunoprecipitation, Co-immunostaining, Proximal Ligation Assay (PLA), GST pulldown assay, and Western blotting. Results As in previous reports, Cav1 knockout mice exhibited PH with pulmonary vascular remodeling and right ventricular hypertrophy and PAECs isolated from Cav1 knockout mice showed caveolae disappearance. Cav1 knockdown in hPAECs reduced BMPRII at the plasma membrane and Smad 1/5/9 phosphorylation. Cav1 knockdown also significantly increased hypoxia-induced apoptosis in hPAECs. Co-immunostaining revealed that Cav1 was associated with BMPRII at the membrane of hPAECs. Cavin-1 inhibited the interaction of BMPRII with Cav1 and reduced BMPRII localization on the membrane of hPAECs. GST pulldown assay revealed that Cavin-1 and BMPRII were associated with Cav1 through the scaffolding domain in Cav1. These findings suggest that Cavin-1 and BMPRII are competitively associated with Cav1. Cavin-1 knockdown improved the interaction between Cav1 and BMPRII and inhibited both BMPRII reduction at the plasma membrane and Smad 1/5/9 dephosphorylation. Conclusions Cavin-1 affects the interaction of Cav1 with BMPRII at the plasma membrane and modulates BMP/Smad signaling in PAECs. The binding of Cavin-1 to Cav1 enhances the interaction between BMPR2 and Cav1, resulting in stabilization of BMPRII localization at the plasma membrane in PAECs and prevention of BMP/Smad signaling attenuation, which is important for PAH development. Funding Acknowledgement Type of funding sources: None.

Schistosome-Associated Pulmonary Arterial Hypertension: A Review Emphasizing Pathogenesis.

Schistosomiasis, especially due to Schistosoma mansoni, is a well-recognized cause of pulmonary arterial hypertension (PAH). The high prevalence of this helminthiasis makes schistosome-related PAH (Sch-PAH) one of the most common causes of this disorder worldwide. The pathogenic mechanisms underlying Sch-PAH remain largely unknown. Available evidence suggests that schistosome eggs reach the lung via portocaval shunts formed as a consequence of portal hypertension due to hepatosplenic schistosomiasis. Once deposited into the lungs, the eggs elicit an immune response resulting in periovular granuloma formation. Immune mediators drive transforming growth factor-β (TGF-β) release, which gives rise to pulmonary vascular inflammation with subsequent remodeling and development of angiomatoid and plexiform lesions. These mechanisms elicited by the eggs seem to become autonomous and the vascular lesions progress independently of the antigen. Portopulmonary hypertension, which pathogenesis is still uncertain, may also play a role in the genesis of Sch-PAH. Recently, there have been substantial advances in the diagnosis and treatment of PAH, but it remains a difficult condition to recognize and manage, and patients still die prematurely from right-heart failure. Echocardiography is used for screening, and the formal diagnosis requires right-heart catheterization. The experience in treating Sch-PAH is largely limited to the phosphodiesterase type 5 inhibitors, with evidence suggesting that these vasodilators improve symptoms and may also improve survival. Considering the great deal of uncertainty about Sch-PAH pathogenesis, course, and treatment, the aim of this review is to summarize current knowledge on this condition emphasizing its pathogenesis.

Significance of BMPR2 mutations in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a debilitating disease that results from progressive remodeling and inflammation of pulmonary arteries. PAH develops gradually, is difficult to diagnose, and has a high mortality rate. Although mutation in the bone morphogenetic protein receptor 2 (BMPR2) gene has been identified as the main genetic cause of PAH, the underlying pathways involving the pathophysiology of PAH are complex and still not fully understood. Endothelial dysfunction has been observed in PAH development that results in a multitude of disturbances in the cellular processes in pulmonary vessels. Changes in the pulmonary vasculature caused by the disruption of BMPR2 signaling are observed in three main vascular components; endothelial cells, smooth muscle cells, and fibroblasts. BMPR2 also has a prominent role in maintenance of the immune system. The disruption of BMPR2 signaling pathway causes an increased degree of inflammation and decreases the ability of the immune system to resolve it. Inflammatory processes and changes in pulmonary vasculature interact with one another, resulting in the progression of chronic PAH. In this review, we highlight the various components of vascular remodeling and immune response that are caused by disruption of BMPR2 signaling, including the clinical evidence and the prospects of these components as a potential target for PAH therapy. Indeed, development of drugs to target the pathogenic pathways involved in PAH may complement existing treatment regimens and improve patient prognosis.

Switching to riociguat versus maintenance therapy with phosphodiesterase-5 inhibitors in patients with pulmonary arterial hypertension (REPLACE): a multicentre, open-label, randomised controlled trial

Riociguat and phosphodiesterase-5 inhibitors (PDE5i), approved for the treatment of pulmonary arterial hypertension (PAH), act on the same pathway via different mechanisms. Riociguat might be an alternative option for patients with PAH who do not respond sufficiently to treatment with PDE5i, but comparisons of the potential benefits of riociguat and PDE5i in these patients are needed. The aim of this trial was to assess the effects of switching to riociguat from PDE5i therapy versus continued PDE5i therapy in patients with PAH at intermediate risk of 1-year mortality. Riociguat rEplacing PDE5i therapy evaLuated Against Continued PDE5i thErapy (REPLACE) was an open-label, randomised controlled trial in 81 hospital-based pulmonary hypertension centres in 22 countries. The study enrolled patients aged 18-75 years with symptomatic PAH at intermediate risk of 1-year mortality (based on the European Society for Cardiology-European Respiratory Society guideline thresholds for WHO functional class and 6-min walk distance [6MWD]) who were receiving treatment with a PDE5i with or without an endothelin receptor antagonist for at least 6 weeks before randomisation. Patients were excluded if they had been previously treated with riociguat, had used prostacyclin analogues or prostacyclin receptor agonists within 30 days before randomisation, had clinically significant restrictive or obstructive parenchymal lung disease, or had left heart disease. Patients were randomly assigned (1:1) to remain on PDE5i treatment (oral sildenafil [≥60 mg per day] or oral tadalafil [20-40 mg per day]; the PDE5i group) or to switch to oral riociguat (up to 2·5 mg three times per day; the riociguat group), using an interactive voice and web response system, stratified by cause of PAH. The primary endpoint was clinical improvement by week 24, defined as an absence of clinical worsening and prespecified improvements in at least two of three variables (6MWD, WHO functional class, and N-terminal prohormone of brain natriuretic peptide), analysed using last observation carried forward in all randomly assigned patients with observed values at baseline and week 24 who received at least one dose of study medication (the full analysis set). Secondary endpoints included clinical worsening events. The trial has been completed and is registered with ClinicalTrials.gov, NCT02891850. Between Jan 11, 2017, and July 31, 2019, 293 patients were screened, of which 226 patients were randomly assigned to the riociguat group (n=111) or to the PDE5i group (n=115). 211 patients completed the study and 14 patients discontinued (seven in each group). One patient assigned to the PDE5i group did not receive treatment, so 225 patients were included in the safety analysis, and one further patient in the PDE5i group had missing components of the composite primary endpoint at baseline, so 224 patients were included in the full analysis set. The primary endpoint was met by 45 (41%) of 111 patients in the riociguat group and 23 (20%) of 113 patients in the PDE5i group; odds ratio [OR] 2·78 (95% CI 1·53-5·06; p=0·0007). Clinical worsening events occurred in one (1%) of 111 patients in the riociguat group (hospitalisation due to worsening PAH) and 10 (9%) of 114 patients in the PDE5i group (hospitalisation due to worsening PAH [n=9]; disease progression [n=1]; OR 0·10 [0·01-0·73]; p=0·0047). The most frequently occurring adverse events were hypotension (15 [14%]), headache (14 [13%]), and dyspepsia (10 [9%]) in the riociguat group, and headache (eight [7%]), cough (seven [6%]), and upper respiratory tract infection (seven [6%]) in the PDE5i group. Serious adverse events were reported in eight (7%) of 111 patients in the riociguat group and 19 (17%) of 114 patients in the PDE5i group. During the study, four patients died in the PDE5i group, one of them during the safety follow-up period. Switching to riociguat from PDE5i treatment, both of which act via the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate pathway, could be a strategic option for treatment escalation in patients with PAH at intermediate risk of 1-year mortality. Bayer AG, Merck Sharp & Dohme.

Pulmonary Artery Hypertension

Pulmonary artery hypertension (PAH) is a rare progressive disease affecting pulmonary arterial vasculature and the right side of the heart. The disease is notorious for its ominous course and high accelerated rates of mortality. Due to its varied etiology, it requires stepwise evaluation to differentiate various causes of PAH. With the advent of new drugs and improved registry-based data, there has been a global effort to reduce the morbidity and mortality of this disease. Therefore, all efforts should be made for quick diagnosis and uniform workup to reach the etiologic and hemodynamic diagnosis. There is a need of specialized PAH clinics and PAH specialists to cater to the needs of these patients who require multidisciplinary clinical care. This review aims to discuss the important aspects of the disease and its management in a ward round scenario as a case-based discussion format to put emphasis on the recent guidelines and classification.

Pediatric subcutaneous treprostinil site maintenance and pain control strategies from the Pediatric Pulmonary Hypertension Network.

Pulmonary arterial hypertension is a chronic, progressive, and life-threatening disease in children with diverse causes of pulmonary arterial hypertension. The most severe cases of pulmonary arterial hypertension require aggressive treatments with systemic administration of continuous prostacyclin therapy, including treprostinil and epoprostenol. The successful use of continuous subcutaneous treprostinil therapy eliminates the need for an indwelling central venous catheter and its associated risks. However, pain at the subcutaneous infusion site, an expected side effect of this therapy, is often a deterrent to its widespread use. Effective subcutaneous treprostinil site maintenance and pain management is essential to achieve success with this therapy, but strategies surrounding site maintenance and pain control vary significantly between pediatric pulmonary hypertension treatment centers. In an attempt to standardize practice, a survey on the use of subcutaneous treprostinil and site maintenance and pain management strategies, as well as its perceived effectiveness, was disseminated to 13 pediatric pulmonary hypertension centers of the Pediatric Pulmonary Hypertension Network. Responses to the survey were collected and analyzed and were developed into a set of formalized strategies to facilitate knowledge sharing and standardization of practice.

Congenital extrahepatic portocaval malformation: Rare but potentially treatable cause of pulmonary hypertension

ObjectiveAbernethy malformation (congenital extrahepatic portosystemic shunt) is a rare anomaly of the splanchnic venous system. Though rare, it is an important cause of pulmonary artery hypertension (PAH) which is often missed. All patients with PAH should be carefully evaluated for presence of Abernethy malformation before labelling them as Idiopathic PAH. MethodsThis is a retrospective analysis of prospectively collected data. We reviewed the data of all patients referred to our center for evaluation of PAH. 10 patients were diagnosed to have an extrahepatic portocaval malformation. We reviewed their presentation, diagnosis, catheterization data, intervention and their outcome along with review of literature. Results10/104 patients with pulmonary hypertension and no intra or extracardiac shunt were found to have extrahepatic portocaval shunt (EHPCS). 3 patients had EHPCS type 1 and 7 had type 2 EHPCS. 6/7 patient with EHPCS type 2 underwent closure of the shunt. There was no procedure related complication. There was one death 3 months post procedure and one patient who was advised surgical closure was lost to follow up. Closure of the shunt resulted in normalization of the pulmonary artery pressures in 4/5 patients. ConclusionCongenital portosystemic malformations form an important and potentially treatable cause of pulmonary hypertension.