Predictors of early mortality after lung transplantation for idiopathic pulmonary arterial hypertension

Lung transplantation remains an important therapeutic option for idiopathic pulmonary arterial hypertension (IPAH), yet short-term survival is the poorest among the major diagnostic categories. We sought to develop a prediction model for 90-day mortality using the United Network for Organ Sharing database for adults with IPAH transplanted between 2005 and 2021. Variables with a p value ≤ 0.1 on univariate testing were included in multivariable analysis to derive the best subset model. The cohort comprised 693 subjects, of whom 71 died (10.2%) within 90 days of transplant. Significant independent predictors of early mortality were: extracorporeal circulatory support and/or mechanical ventilation at transplant (OR: 3; CI: 1.4-5), pulmonary artery diastolic pressure (OR: 1.3 per 10 mmHg; CI: 1.07-1.56), forced expiratory volume in the first second percent predicted (OR: 0.8 per 10%; CI: 0.7-0.94), recipient total bilirubin >2 mg/dL (OR: 3; CI: 1.4-7.2) and ischemic time >6 h (OR: 1.7, CI: 1.01-2.86). The predictive model was able to distinguish 25% of the cohort with a mortality of ≥20% from 49% with a mortality of ≤5%. We conclude that recipient variables associated with increasing severity of pulmonary vascular disease, including pretransplant advanced life support, and prolonged ischemic time are important risk factors for 90-day mortality after lung transplant for IPAH.

Identification of potential biomarkers for idiopathic pulmonary arterial hypertension using single-cell and bulk RNA sequencing analysis

Idiopathic pulmonary arterial hypertension (IPAH) is a rare and severe cardiopulmonary disease with a challenging prognosis, and its underlying pathogenesis remains elusive. A comprehensive understanding of IPAH is crucial to unveil potential diagnostic markers and therapeutic targets. In this study, we investigated cellular heterogeneity and molecular pathology in IPAH using single-cell RNA sequencing (scRNA-seq) analysis. Our scRNA-seq results revealed significant alterations in three crucial signaling pathways in IPAH: the hypoxia pathway, TGF β pathway, and ROS pathway, primarily attributed to changes in gene expression within arterial endothelial cells. Moreover, through bulk RNA sequencing analysis, we identified differentially expressed genes (DEGs) enriched in GO and KEGG pathways, implicated in regulating cell adhesion and oxidative phosphorylation in IPAH lungs. Similarly, DEGs-enriched pathways in IPAH arterial endothelial cells were also identified. By integrating DEGs from three IPAH datasets and applying protein-protein interaction (PPI) analysis, we identified 12 candidate biomarkers. Subsequent validation in two additional PAH datasets led us to highlight five potential biomarkers (CTNNB1, MAPK3, ITGB1, HSP90AA1, and DDX5) with promising diagnostic significance for IPAH. Furthermore, real-time quantitative polymerase chain reaction (RT-qPCR) confirmed significant differences in the expression of these five genes in pulmonary arterial endothelial cells from PAH mice. In conclusion, our findings shed light on the pivotal role of arterial endothelial cells in the development of IPAH. Furthermore, the integration of single-cell and bulk RNA sequencing datasets allowed us to pinpoint novel candidate biomarkers for the diagnosis of IPAH. This work opens up new avenues for research and potential therapeutic interventions in IPAH management.

Elderly Patients with Idiopathic Pulmonary Hypertension: Clinical Characteristics, Survival, and Risk Stratification in a Single-Center Prospective Registry

INTRODUCTION

The predictive value of the risk stratification scales in elderly patients with IPAH might differ from that in younger patients. It is unknown whether young and older IPAH patients have the same survival dependence on PAH-specific therapy numbers. The aim of this study was to evaluate the prognostic relevance of risk stratification scales and PAH medication numbers in elderly IPAH patients in comparison with young IPAH patients.

MATERIALS AND METHODS

A total of 119 patients from a prospective single-center PAH registry were divided into group I < 60 years old (n = 89) and group II ≥ 60 years old (n = 30). ESC/ERS, REVEAL, and REVEAL 2.0 risk stratification scores were assessed at baseline, as well as H2FpEF score and survival at follow-up.

RESULTS

During a mean follow-up period of 2.9 years (1.63; 6.0), 42 (35.3%) patients died; at 1, 2, 3, 5, 7, and 10 years, survival was 95%, 88.6%, 78.5%, 61.7%, 48.5%, and 33.7%, respectively. No survival differences were observed between the two groups, despite the use of monotherapy in the elderly patients. The best predictive REVEAL value in elderly patients (IPAH patients ≥ 60 years) was AUC 0.73 (0.56-0.91), p = 0.03; and in patients with LHD comorbidities in the entire cohort, it was AUC 0.73 (0.59-0.87), p < 0.009. Factors independently associated with death in the entire cohort were CKD (p = 0.01, HR 0.2), the right-to-left ventricle dimension ratio (p = 0.0047, HR 5.97), and NT-proBNP > 1400 pg/mL (p = 0.008, HR 3.18).

CONCLUSION

Risk stratification in the elderly IPAH patients requires a fundamentally different approach than that of younger patients, taking into account the initial limitations in physical performance and comorbidities that interfere with current assessment scores. The REVEAL score reliably stratifies patients at any age and LHD comorbidities. The initial monotherapy seems to be reasonable in patients over 60 years. Selection tools for initial combination PAH therapy in older IPAH patients with comorbidities need to be validated in prospective observational studies.

Comprehensive analysis of m6A methylomes in idiopathic pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is a serious and fatal disease. Recently, m6A has been reported to play an important role in the lungs of IPAH patients and experimental pulmonary hypertension models. However, the meaning of m6A mRNAs in the peripheral blood of IPAH patients remains largely unexplored. We aimed to construct a transcriptome-wide map of m6A mRNAs in the peripheral blood of IPAH patients. M6A RNA Methylation Quantification Kit was utilized to measure the total m6A levels in the peripheral blood of IPAH patients. A combination of MeRIP-seq, RNA-seq and bioinformatics analysis was utilized to select m6A-modified hub genes of IPAH. MeRIP-qPCR and RT-qPCR were used to measure the m6A levels and mRNA levels of TP53, RPS27A, SMAD3 and FoxO3 in IPAH patients. Western blot was performed to assess the protein levels of m6A related regulators and m6A related genes in experimental PH animal models, hypoxia-treated and PDGF-BB induced PASMCs. We found that the total m6A levels were increased in peripheral blood of IPAH patients and verified that m6A levels of RPS27A and SMAD3 were significantly elevated and m6A levels of TP53 and FoxO3 were significantly reduced. The mRNA or protein levels of RPS27A, SMAD3, TP53 and FoxO3 were changed in human blood samples, experimental PH animal models and PDGF-BB induced PASMCs. Moreover, METTL3 and YTHDF1 were increased in the hypoxia induced pulmonary hypertension rat model, hypoxia-treated and PDGF-BB induced PASMCs. These finding suggested that m6A may play an important role in IPAH.

A Case of Giant Goiter Associated with Airway Stenosis Caused by Long-Term Intravenous Epoprostenol Therapy for Idiopathic Pulmonary Arterial Hypertension

Idiopathic pulmonary arterial hypertension is a progressive and life-threatening disease with pulmonary vasculature remodeling, leading to right-sided heart failure. Epoprostenol (prostaglandin I2) is highly recommended for patients with severe pulmonary arterial hypertension (PAH) categorized by the World Health Organization as functional class III or IV. It has been reported that prostaglandin I2 analogs can cause thyroid gland swelling and abnormal thyroid function. A 34-year-old woman was diagnosed with idiopathic pulmonary arterial hypertension and started receiving continuous intravenous epoprostenol. Three years after starting epoprostenol, she began complaining of neck swelling and was diagnosed with Graves' disease. The patient's thyroid function was controlled by thiamazole and levothyroxine; nevertheless, her thyroid gland enlargement worsened as the epoprostenol dose was titrated. After 20 years, she developed respiratory failure with a giant goiter leading to airway stenosis, and she passed away. The pathological autopsy confirmed a massive goiter associated with hyperthyroidism and airway stenosis. We experienced a case of idiopathic pulmonary hypertension with a giant goiter and airway stenosis after long-term intravenous epoprostenol therapy.

The Impact of Abnormal Lipid Metabolism on the Occurrence Risk of Idiopathic Pulmonary Arterial Hypertension

The aim was to determine whether lipid molecules can be used as potential biomarkers for idiopathic pulmonary arterial hypertension (IPAH), providing important reference value for early diagnosis and treatment. Liquid chromatography-mass spectrometry-based lipidomic assays allow for the simultaneous detection of a large number of lipids. In this study, lipid profiling was performed on plasma samples from 69 IPAH patients and 30 healthy controls to compare the levels of lipid molecules in the 2 groups of patients, and Cox regression analysis was used to identify meaningful metrics, along with receiver operator characteristic curves to assess the ability of the lipid molecules to predict the risk of disease in patients. Among the 14 lipid subclasses tested, 12 lipid levels were significantly higher in IPAH patients than in healthy controls. Free fatty acids (FFA) and monoacylglycerol (MAG) were significantly different between IPAH patients and healthy controls. Logistic regression analysis showed that FFA (OR: 1.239, 95%CI: 1.101, 1.394, p < 0.0001) and MAG (OR: 3.711, 95%CI: 2.214, 6.221, p < 0.001) were independent predictors of IPAH development. Among the lipid subclasses, FFA and MAG have potential as biomarkers for predicting the pathogenesis of IPAH, which may improve the early diagnosis of IPAH.

Comprehensive analyses of m6A RNA methylation patterns and related immune microenvironment in idiopathic pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is a life-threatening disease with a poor prognosis and high heritability, characterized by elevated pulmonary vascular resistance (PVR) and pulmonary artery pressure. N6-methyladenosine (m6A) RNA modification influences many RNA metabolism pathways. However, the position of m6A methylation regulators in IPAH remains unknown. Therefore, the study aims to disclose the function m6A regulators exert in the pathological mechanisms of IPAH and the immune microenvironment involved. The GSE117261 dataset was downloaded from the Gene Expression Omnibus (GEO) to screen the differentially expressed genes (DEGs) between normal and IPAH samples. Functional and pathway enrichment analyses of DEGs were then conducted by Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG). We also identified the differentially-expressed m6A (DEm6A) regulators between normal and IPAH samples. Key m6A regulators related to the prediction of IPAH were selected using the random forest model. The results showed that FMR1, RBM15, HNRNPA2B1 and IGFBP3 were upregulated in IPAH. In contrast, LRPPRC was downregulated. The single sample gene set enrichment analysis (ssGSEA) method was then adopted to estimate the immune microenvironment in distinct m6A clusters and m6A phenotype-related genes (PRGs) clusters, respectively. Furthermore, we calculated the m6A score via principal component analysis (PCA), and the Sankey diagram was selected to present the correlation among the m6A clusters, m6A PRGs clusters and m6A score. Finally, quantitative RT-PCR and Western blotting were used to validate the key genes in human pulmonary artery smooth muscle cells (HPASMCs) treated by human platelet-derived growth factor-BB (PDGF-BB). The relative mRNA and protein expression levels of FMR1 were significantly elevated, however, the relative mRNA and protein expression levels of LRPPRC were downregulated. Besides, the relative mRNA level of HNRNPA2B1 was increased. Generally, this bioinformatics analysis might provoke more insights into diagnosing and treating IPAH.

Emerging pharmacotherapies for the treatment of pulmonary arterial hypertension

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a progressive and life-threatening disease. Approved treatment options currently primarily target abnormal cell signaling pathways involved in vasoconstriction and proliferation, such as those mediated by prostacyclin, cyclic guanosine monophosphate, and endothelin.

AREAS COVERED

Recent advancements have led to new applications and modes of delivery of currently approved PAH medications. At the same time, novel drugs targeting specific molecular pathways involved in PAH pathogenesis have been developed and are being investigated in clinical trials. This review summarizes investigational drug trials for PAH gathered from a comprehensive search using PubMed and ClinicalTrials.gov between 2003 and 2023. It includes both currently approved medications studied at different doses or new administration forms and experimental drugs that have not yet been approved.

EXPERT OPINION

Approved treatments for PAH target imbalances in pulmonary vasoactive pathways that work primarily on enhancing pulmonary vasodilation with less salient effects on pulmonary vascular remodeling. The advent of more locally acting inhaled medications offers additional therapeutic options that may improve the ease of drug delivery and reduce adverse systemic effects. The more recent emphasis on developing and applying therapeutics that directly impact the aberrant signaling pathways implicated in PAH appears more likely to advance the treatment of this devastating disease.

Single-Cell Transcriptome Analysis of Peripheral Neutrophils From Patients With Idiopathic Pulmonary Arterial Hypertension

BACKGROUND

Idiopathic pulmonary hypertension (IPAH) is a rare and devastating disease often accompanied by persistent inflammation and immune responses. We aim to provide a reference atlas of neutrophils to facilitate a better understanding of cellular phenotypes and discovery of candidate genes.

METHODS

Peripheral neutrophils from naive patients with IPAH and matched controls were profiled. Whole-exon sequencing was performed to exclude known genetic mutations before establishing single-cell RNA sequencing. Marker genes were validated by flow cytometry and histology in a separate validation cohort.

RESULTS

Seurat clustering analysis revealed that the landscape of neutrophils encompassed 5 clusters, including 1 progenitor, 1 transition, and 3 functional clusters. The intercorrelated genes in patients with IPAH were mainly enriched in antigen processing presentation and natural killer cell mediated cytotoxicity. We identified and validated differentially upregulated genes, including matrix metallopeptidase 9 (MMP9), ISG15 ubiquitin-like modifier (ISG15), and C-X-C motif ligand 8 (CXCL8). The positive proportions and fluorescence quantification of these genes were significantly increased in CD16⁺ neutrophils in patients with IPAH. The higher proportion of positive MMP9 (matrix metallopeptidase 9) neutrophils increased mortality risk after adjustment for age and sex. Patients with higher proportions of positive MMP9 neutrophils had worse survival, while the fraction of ISG15- or C-X-C motif chemokine ligand 8-positive expression neutrophils failed to predict outcome.

CONCLUSIONS

Our study yields a comprehensive dataset of the landscape of neutrophils in patients with IPAH. The predictive values of a neutrophil cluster characterized by higher MMP9 expression indicate a functional role for neutrophil-specific matrix metalloproteinases in the pathogenesis of pulmonary arterial hypertension.

Apelin-17 to diagnose idiopathic pulmonary arterial hypertension: A biomarker study

Background: NT-proBNP and GDF-15 are established blood-derived biomarkers for risk assessment in pulmonary hypertension (PH), despite limited sensitivity and specificity. Apelin has a crucial function in endothelial homeostasis, thus it might represent a new biomarker for PH. However, there are numerous circulating apelin isoforms, and their potential role in this setting is unknown. This study evaluated different apelin isoforms in PH patients and prospectively evaluated the role of apelin-17 in comparison with NT-proBNP and GDF-15 as diagnostic marker in idiopathic pulmonary arterial hypertension (IPAH). Methods: Based on our pilot study, we performed a power calculation for apelin-13, apelin-17, apelin-36, as predictor of IPAH vs healthy controls. Apelin-17 provided the best discriminatory power, and accordingly, we enrolled n = 31 patients with IPAH and n = 31 matched healthy controls in a prospective study. NT-proBNP and GDF-15 was determined in all patients. ROC curve analysis was performed to assess the diagnostic value of the markers and their combinations. Results: Apelin-17, NT-proBNP, and GDF-15 were significantly elevated in IPAH patients as compared to controls (p < .001). Apelin-17 detected IPAH with a sensitivity of 68% and a specificity of 93% at a cut-off value of >1,480 pg/ml (AUC 0.86, 95%CI:0.76-0.95) as compared to GDF-15 (sensitivity 86%; specificity 72%, AUC 0.81 (95%CI:0.7-0.92)) and NT-proBNP (sensitivity 86%; specificity 72% (AUC 0.85, 95%CI:0.75-0.95)). Combinations of these markers could be used to increase either specificity or sensitivity. Conclusion: Apelin-17 appears to be suitable blood derived diagnostic marker for idiopathic pulmonary arterial hypertension.

Transcatheter Valve Implantation in Reversed Potts Shunt in Pulmonary Arterial Hypertension: Keeping the Shunt Reversed

The reversed Potts shunt is designed to offload the right ventricle in severe pulmonary arterial hypertension. We present a case of bidirectional flow across a reversed Potts shunt leading to pulmonary edema, with clinical improvement after implantation of a transcatheter valve in the shunt to maintain unidirectional flow. (Level of Difficulty: Advanced.).

Differences in disease severity and prognosis of exercise-induced right-to-left shunt between idiopathic pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension patients

Objective

Whether exercise-induced venous-to-systemic shunt (EIS) during cardiopulmonary exercise testing (CPET) has different manifestations or characteristics in idiopathic pulmonary arterial hypertension (IPAH) and chronic thromboembolic pulmonary hypertension (CTEPH) patients remains unknown. We explored the differences in hemodynamics, echocardiography, and prognosis between IPAH and CTEPH patients with and without EIS.

Methods

We conducted a retrospective cross-sectional cohort study and included 161 PH patients at Shanghai Pulmonary Hospital. Demographic, echocardiography, pulmonary hemodynamic, and CPET variables were compared between patients with and without EIS stratified by IPAH and CTEPH. EIS was determined by CPET. Binary logistic regression analyses were performed to explore independent influencing factors of EIS. Cox survival analysis was used to quantify the impact of EIS on the prognosis of patients.

Results

Exercise-induced venous-to-systemic shunt was found in approximately 17.4% of 86 IPAH patients and 20% of 75 CTEPH patients. All-cause mortality occurred in 43 (26.7%) patients during a median follow-up of 6.5 years. Compared with those without EIS, patients with EIS had higher peak end-tidal O₂ and lower VO₂/VE and tricuspid annular plane systolic excursion (TAPSE). Among the IPAH patients, EIS was associated with lower cardiac output, cardiac index, mixed venous oxygen saturation, VO₂/VE, and TAPSE and higher VE/VCO₂ and right ventricular end-diastolic transverse diameter. Logistic regression analysis indicated that VO₂/VE was an independent factor influencing whether IPAH patients developed EIS during CPET. Cox logistic regression indicated that female IPAH patients or IPAH patients with higher VO₂/VE and EIS had a better prognosis. Female IPAH patients had better 10-year survival. In IPAH patients without EIS, patients with higher VO₂/VE had better 10-year survival. However, compared with CTEPH patients without EIS, those with EIS had similar echocardiographic, hemodynamic, CPET parameter results and 10-year survival.

Conclusion

Exercise-induced venous-to-systemic shunt exhibits different profiles among IPAH and CTEPH patients. Among IPAH patients, those with EIS had worse peak end-tidal O₂, VO₂/VE, and TAPSE than those without EIS. VO₂/VE was an independent factor of EIS among IPAH patients. IPAH patients with EIS, female sex or higher VO₂/VE had better survival. However, the association between EIS and PAH severity or prognosis in CTEPH patients needs to be further explored.

GDF-15 and soluble ST2 as biomarkers of right ventricular dysfunction in pulmonary hypertension

Background: This study analyzed the utility of soluble ST2 (sST2) and GDF-15 as biomarkers of right ventricular (RV) function in patients with pulmonary hypertension (PH). Methods: GDF-15 and sST2 serum concentrations were measured in patients with PH (n = 628), dilated cardiomyopathy (n = 31) and left ventricular hypertrophy (n = 47), and in healthy controls (n = 61). Results: Median sST2 and GDF-15 levels in patients with left ventricular hypertrophy were higher than in patients with PH and dilated cardiomyopathy. In tertile analysis GDF-15 >1363 pg/ml and sST2 >38 ng/ml were associated with higher N-terminal pro-brain natriuretic peptide, RV systolic dysfunction, RV-pulmonary arterial uncoupling and hemodynamic impairment. Conclusion: GDF-15 and sST2 are potential biomarkers of RV dysfunction in patients with PH.

Characteristics of Patients With Pulmonary Arterial Hypertension in a Pulmonary Hypertension Association-Accredited Comprehensive Care Center: A Contrast in Features When Compared With US National Registry Data

Background Since the initial description in the 1980s, our understanding of the diversity of pulmonary arterial hypertension (PAH) has continued to evolve. In this study, we report the characteristics of patients seen in an academic medical center for PAH from August 2020 through November 2021 and contrast those with nationally reported data from the United States Pulmonary Hypertension Scientific Registry (USPHSR).  Study Design Investigators at the University of Utah Pulmonary Hypertension Program prospectively enrolled adult patients diagnosed with WHO Group 1 PAH, who were evaluated between August 2020 and November 2021 in a program-specific registry. Patient exposure and health histories were collected through structured interviews and questionnaires, along with clinical data and medication use. A total of 242 patients were enrolled in the University of Utah Pulmonary Hypertension Registry (UUPHR).  Results Of the 242 enrolled patients, the most common etiology was associated PAH (APAH), accounting for 71.1% of the population. The second largest etiology was idiopathic PAH (IPAH) at 26.4%. The remaining patients were distributed between familial PAH (FPAH), pulmonary veno-occlusive disease (PVOD), and others. Of the total population classified as APAH, 39% of cases were noted as secondary to connective tissue disease (CTD) and 33% as toxin-induced. These represented 28% and 24% of the total population, respectively.  Conclusions In this US-based accredited academic medical center, the etiology of PAH in our patient population contrasts with national registry data. In the UUPHR, APAH, specifically CTD-PAH and toxin-associated PAH, accounts for the majority of patients with PAH. This contrasts with IPAH, which nationally is the most reported cause of PAH. Differences in our population may reflect the regional variation of the referral site, but it is noteworthy for its contrast with historically reported phenotypes.

Peripheral Blood T Cells of Patients with IPAH Have a Reduced Cytokine-Producing Capacity

Pulmonary arterial hypertension (PAH) is rare disease that is categorized as idiopathic (IPAH) when no underlying cause can be identified. Lungs of most patients with IPAH contain increased numbers of T cells and dendritic cells (DCs), suggesting involvement of the immune system in its pathophysiology. However, our knowledge on circulating immune cells in IPAH is rather limited. We used flow cytometry to characterize peripheral blood DCs and T cells in treatment-naive IPAH patients, compared with connective-tissue disease-PAH (CTD-PAH) patients and healthy controls (HCs). At diagnosis, T-helper (Th) cells of IPAH patients were less capable of producing TNFα, IFNγ, IL-4 and IL-17 compared to HCs. IPAH patients showed a decreased frequency of Th2 cells and significantly enhanced expression of the CTLA4 checkpoint molecule in naive CD4⁺ T cells and both naive and memory CD8⁺ T cells. Frequencies and surface marker expression of circulating DCs and monocytes were essentially comparable between IPAH patients and HCs. Principal component analysis (PCA) separated IPAH patients—but not CTD-PAH patients—from HCs, based on T-cell cytokine profiles. At 1-year follow-up, the frequencies of IL-17⁺ production by memory CD4⁺ T cells were increased in IPAH patients and accompanied by increased proportions of Th17 and Tc17 cells, as well as decreased CTLA4 expression. Treatment-naive IPAH patients displayed a unique T-cell phenotype that was different from CTD-PAH patients and was characterized by reduced cytokine-producing capacity. These findings point to involvement of adaptive immune responses in IPAH, which may have an implication for the development of therapeutic interventions.

Validity of the ESC Risk Assessment in Idiopathic Pulmonary Arterial Hypertension in China

Background: The 2015 European pulmonary hypertension (PH) guidelines recommend a risk stratification strategy for pulmonary arterial hypertension (PAH). We aimed to investigate the validation and potential prognostic information in Chinese patients. Methods: The risk assessment variables proposed by the PH guidelines were performed by using the WHO function class, 6-min walking distance, brain natriuretic peptide or its N-terminal fragment, right arterial pressure, cardiac index, mixed venous saturation, right atrium area, pericardial effusion, peak oxygen consumption, and ventilatory equivalents for carbon dioxide. An abbreviated version also was applied. Results: A total of 392 patients with idiopathic PAH (IPAH) were enrolled between 2009 and 2018. After a median interval of 13 months, re-evaluation assessments were available for 386 subjects. The PAH guidelines risk tool may effectively discriminate three risk groups and mortality (p < 0.001) both at the baseline and re-evaluation. Meanwhile, its simplified risk version was valid for baseline and accurately predicted the risk of death in all the risk groups (p < 0.001). At the time of re-evaluation, the percentage of low-risk group has an increase, but a greater proportion achieved the high-risk group and a lesser proportion maintained in the intermediate-risk group. Conclusion: The 2015 European PH guidelines and its simplified version risk stratification assessment present an effective discrimination of different risk groups and accurate mortality estimates in Chinese patients with IPAH. Changes of risk proportion at re-evaluation implicated that natural treatment decisions may not be consistently with goal-oriented treatment strategy.

Association of changes in NT-proBNP, hsTnT and uric acid levels with haemodynamic changes after targeted medical therapies in patients with idiopathic pulmonary arterial hypertension

BACKGROUND

During pulmonary arterial hypertension (PAH)-targeted therapies for patients with idiopathic pulmonary arterial hypertension (IPAH), regular follow up to evaluate treatment efficacy is essential. Serum biomarkers can reflect various pathobiological processes in IPAH and have the advantages of being non-invasive, simple to carry out and low cost. The aim of our study was to evaluate whether serum biomarkers could serve as non-invasive markers to reflect haemodynamic changes after PAH-targeted therapies in patients with IPAH.

METHODS

A total of 31 eligible patients aged 38.1 ± 12.1 years (25 were female) were included in this study. Changes in haemodynamic parameters and several serum biomarkers (cardiac markers, serum uric acid, high-sensitivity C-reactive protein, hepatic and kidney function markers) were compared before and after at least six months of PAH-targeted therapies. The time interval between the blood assays and right heart catheterisation was within five days.

RESULTS

After at least six months of PAH-targeted therapies, the N-terminal pro-brain natriuretic peptide (NT-proBNP) level decreased from 579 (191-905) to 135 pg/ml (60-395) (p < 0.01), high-sensitivity cardiac troponin T (hsTnT) level decreased from 0.009 (0.006-0.012) to 0.007 ng/ml (0.005-0.01) (p < 0.01), and serum uric acid level decreased from 381.5 ± 131.4 to 327.2 ± 110.0 µmol7sol;l (p = 0.011). The change in NT-proBNP level was positively correlated with changes in pulmonary vascular resistance (r = 0.538, p < 0.01) and mean pulmonary arterial pressure (r = 0.440, p = 0.013). The change in hsTnT level was positively correlated with the change in mean right atrium pressure (r = 0.504, p < 0.01). The change in serum uric acid level was negatively correlated with that of cardiac index (r = -0.471, p < 0.01).

CONCLUSION

NT-proBNP, hsTnT and serum uric acid levels can be used as non-invasive tools for evaluating the efficacy of PAH-targeted medications for IPAH patients. The role of these biomarkers in the follow up should be emphasised.

Pulmonary Arterial Hypertension as a Fatal Complication of Neurofibromatosis Type 1 in a Neonate: A Diagnostic Dilemma

Neurofibromatosis type 1 (NF1), or von Recklinghausen disease, is a genetically transmitted autosomal dominant disease, with a prevalence of one per 4000 live births. Pulmonary arterial hypertension (PAH) is a rare but potentially life-threatening complication of NF1. There are no confirmatory data about the congenital association between PAH and NF1. However, in most cases, PAH is observed in late childhood or adulthood. Herein, we present a preterm baby with genetically confirmed NF1 who presented with PAH.

Clinical Differences and Outcomes between Methamphetamine-associated and Idiopathic Pulmonary Arterial Hypertension in the Pulmonary Hypertension Association Registry

Rationale: Single-center studies demonstrated that methamphetamine use is associated with pulmonary arterial hypertension (Meth-APAH). We used the Pulmonary Hypertension Association Registry to evaluate the national distribution of Meth-APAH and to compare its impact on patient-reported and clinical outcomes relative to idiopathic PAH.Objectives: To determine if patients with Meth-APAH differ from those with idiopathic PAH in demographics, regional distribution in the United States, hemodynamics, health-related quality of life, PAH-specific treatment, and health care use.Methods: The Pulmonary Hypertension Association Registry is a U.S.-based prospective cohort of patients new to care at a Pulmonary Hypertension Care Center. The registry collects baseline demographics, clinical parameters, and repeated measures of health-related quality of life, World Health Organization functional class, 6-minute walk distance, therapy, and health care use. Repeated measures of functional class, health-related quality of life, type of therapy, emergency department visits, and hospitalizations were compared using generalized estimating equations.Results: Of 541 participants included, 118 had Meth-APAH; 83% of Meth-APAH arose in the western United States. The Meth-APAH group was younger and had a poorer socioeconomic status and lower cardiac index than the idiopathic PAH group, despite no difference in mean pulmonary artery pressure or pulmonary vascular resistance. The Meth-APAH group had a more advanced functional class in longitudinal models (0.22 points greater; 95% confidence interval [CI], 0.07 to 0.37) and worse PAH-specific (emPHasis-10) health-related quality of life (-5.4; 95% CI, -8.1 to -2.8). There was no difference in dual combination therapy; however, participants with Meth-APAH were less likely to be initiated on triple therapy (odds ratio [OR], 0.43; 95% CI, 0.24 to 0.77) or parenteral therapy (OR, 0.10; 95% CI, 0.04 to 0.24). Participants with Meth-APAH were more likely to seek care in the emergency department (incidence rate ratio, 2.30; 95% CI, 1.71 to 3.11) and more likely to be hospitalized (incidence rate ratio, 1.42; 95% CI, 1.10 to 1.83).Conclusions: Meth-APAH represents a unique clinical phenotype of PAH, most common in the western United States. It accounts for a notable proportion of PAH in expert centers. Assessment for methamphetamine use is necessary in patients with PAH.

Interventional and Surgical Treatments for Pulmonary Arterial Hypertension

Despite significant advancements in pharmacological treatment, interventional and surgical options are still viable treatments for patients with pulmonary arterial hypertension (PAH), particularly idiopathic PAH. Herein, we review the interventional and surgical treatments for PAH. Atrial septostomy and the Potts shunt can be useful bridging tools for lung transplantation (Ltx), which remains the final surgical treatment among patients who are refractory to any other kind of therapy. Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) remains the ultimate bridging therapy for patients with severe PAH. More importantly, VA-ECMO plays a crucial role during Ltx and provides necessary left ventricular conditioning during the initial postoperative period. Pulmonary denervation may potentially be a new way to ensure better transplant-free survival among patients with the aforementioned disease. However, high-quality randomized controlled trials are needed. As established, obtaining the Eisenmenger physiology among patients with severe pulmonary hypertension by creating artificial defects is associated with improved survival. However, right-to-left shunting may be harmful after Ltx. Closure of the artificially created defects may carry some risk associated with cardiac surgery, especially among patients with Potts shunts. In conclusion, PAH requires an interdisciplinary approach using pharmacological, interventional, and surgical modalities.

Potential of C-X-C motif chemokine ligand 1/8/10/12 as diagnostic and prognostic biomarkers in idiopathic pulmonary arterial hypertension

OBJECTIVE

This study aimed to evaluate the clinical role of C-X-C motif chemokine ligand (CXCL) family members in idiopathic pulmonary arterial hypertension (IPAH) patients.

METHODS

CXCL1, CXCL8, CXCL10 and CXCL12 expressions in the serum samples of IPAH patients (N=39) and age/gender-matched controls (N=40) were detected by enzyme-linked immunosorbent assay. In IPAH patients, clinical features were collected and survival information was documented.

RESULTS

CXCL1 (P<0.001), CXCL8 (P=0.001), CXCL10 (P<0.001) and CXCL12 (P<0.001) were increased in IPAH patients compared with controls, and receiver's operating characteristic curves showed that their combination was highly correlated with IPAH risk (area under curve: 0.881, 95% confidence interval: 0.805-0.958). Meanwhile, CXCL1 was positively correlated with mean pulmonary artery pressure (mPAP) (P=0.029) and high sensitive C-reactive protein (HsCRP) (P=0.015); CXCL8 was positively correlated with mPAP (P=0.044) and HsCRP (P=0.018) but negatively correlated with 6-minute walk test (6MWT) distance (P=0.029); CXCL10 was positively correlated with mean right artery pressure (P=0.002); and CXCL12 was positively correlated with World Health Organization functional class (P=0.047), mPAP (P=0.009), pulmonary vascular resistance (P=0.004), HsCRP (P=0.003) but negatively correlated with 6MWT distance (P=0.003) in IPAH patients. Moreover, CXCL12 was negatively correlated with overall survival (OS) (P=0.025), while CXCL1, CXCL8 and CXCL10 only showed minor tendencies to be negatively correlated with OS in IPAH patients without statistical significance (all P>0.05).

CONCLUSION

CXCL1, CXCL8, CXCL10 and CXCL12 associate with increased IPAH risk, unfavorable clinical features; besides, CXCL12 correlates with worse OS in IPAH patients.

Early implementation of renal replacement therapy after lung transplantation does not impair long-term kidney function in patients with idiopathic pulmonary arterial hypertension

OBJECTIVES

In patients with idiopathic pulmonary arterial hypertension, cardiac function can be impaired in the early postoperative phase after lung transplantation because the chronically untrained left ventricle is prone to fail. Thus, restrictive fluid management is pivotal to unload the left heart. In our institution, continuous renal replacement therapy is implemented liberally whenever a patient cannot be balanced negatively. It remains unclear whether such strategy impairs long-term kidney function.

METHODS

We retrospectively reviewed our institutional database for patients with idiopathic pulmonary arterial hypertension who underwent transplantation between 2000 and 2018. The impact of postoperative continuous renal replacement therapy on long-term outcomes was investigated using a linear mixed model and multivariable Cox regression.

RESULTS

A total of 87 idiopathic pulmonary arterial hypertension lung transplant recipients were included in this analysis. In 38 patients (43%), continuous renal replacement therapy was started in the early postoperative period for a median of 16 days (10-22). In this group, urine production significantly decreased and patients began to acquire a positive fluid balance; however, homeostatic functions of the kidney were still preserved at the time of continuous renal replacement therapy initiation. All patients were successfully weaned from continuous renal replacement therapy and fully recovered their kidney function at the time of hospital discharge. No difference in kidney function was found between continuous renal replacement therapy and noncontinuous renal replacement therapy in patients within 5 years.

CONCLUSIONS

Early implementation of continuous renal replacement therapy for perioperative volume management does not impair long-term kidney function in idiopathic pulmonary arterial hypertension lung transplant recipients. Our data suggest that such a strategy leads to excellent long-term outcomes.

May We Use Non-Invasive Indices of Aortic Stiffness and Endothelial Glycocalyx as Biomarkers for Idiopathic Pulmonary Artery Hypertension Follow-Up?

Idiopathic pulmonary arterial hypertension (IPAH) initial evaluation and follow-up, a rare and incurable disease if left untreated, is based on a multiparametric approach (functional status of the patient, biomarkers, hemodynamic parameters and imaging evaluation of right heart impairment). Arterial stiffness (AS) and endothelial glycocalyx are indices of systemic circulation. We present the 3-years follow-up of a female IPAH patient. We propose aortic stiffness and endothelial glycocalyx indices as non-invasive markers of either improvement or deterioration of IPAH disease.

The relationship between retinal microcirculation and right heart catheterization and echocardiography findings in patients with idiopathic pulmonary arterial hypertension

OBJECTIVE

To determine the possible alterations of retinal microcirculation associated with right-sided intracardiac pressures in patients with IPAH.

METHODS

Twenty patients with IPAH and 20 age- and sex-matched healthy controls were included in the study. Hemodynamic data were obtained from the most recent right heart catheterization. Echocardiographic examination was performed within 24 h of ophthalmological examination. For the right eyes of all participants, high-resolution scans of chorioretinal microvascular networks at different depths of the retina were captured via OCT angiography.

RESULTS

The perfusion of the superficial and deep capillary plexus (SCP and DCP), and choriocapillaris (CCP) flow area were significantly lower than those in healthy control subjects (p < .05 for all). In IPAH group, PVR and mPAP were correlated significantly with the perfusion measurements at SCP and DCP (r = .461, r = .626 and r = .625, r =0.730, respectively, p < .05). sPAP and TRV were positively correlated with the perfusion measurements at SCP and DCP (r = .600, r = .662 and r = .670, r = .655 p < .05).

CONCLUSIONS

The positive correlation of retinal perfusion at SCP and DCP with right-sided echocardiographic and hemodynamic measurements unveiled that retinal microcirculation is affected by the pressure alterations in the pulmonary circulation of IPAH patients.

Essential Genes and MiRNA-mRNA Network Contributing to the Pathogenesis of Idiopathic Pulmonary Arterial Hypertension

Background: Idiopathic pulmonary arterial hypertension (IPAH) is a life-threatening disease. Owing to its high fatality rate and narrow therapeutic options, identification of the pathogenic mechanisms of IPAH is becoming increasingly important. Methods: In our research, we utilized the robust rank aggregation (RRA) method to integrate four eligible pulmonary arterial hypertension (PAH) microarray datasets and identified the significant differentially expressed genes (DEGs) between IPAH and normal samples. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were performed to analyze their functions. The interaction network of protein-protein interaction (PPI) was constructed to explore the correlation between these DEGs. The functional modules and hub genes were further identified by the weighted gene coexpression network analysis (WGCNA). Moreover, a miRNA microarray dataset was involved and analyzed to filter differentially expressed miRNAs (DE-miRNAs). Potential target genes of screened DE-miRNAs were predicted and merged with DEGs to explore a miRNA-mRNA network in IPAH. Some hub genes were selected and validated by RT-PCR in lung tissues from the PAH animal model. Results: A total of 260 DEGs, consisting of 183 upregulated and 77 downregulated significant DEGs, were identified, and some of those genes were novel. Their molecular roles in the etiology of IPAH remained vague. The most crucial functional module involved in IPAH is mainly enriched in biological processes, including leukocyte migration, cell chemotaxis, and myeloid leukocyte migration. Construction and analysis of the PPI network showed that CXCL10, CXCL9, CCR1, CX3CR1, CX3CL1, CXCR2, CXCR1, PF4, CCL4L1, and ADORA3 were recognized as top 10 hub genes with high connectivity degrees. WGCNA further identified five main functional modules involved in the pathogenesis of IPAH. Twelve upregulated DE-miRNAs and nine downregulated DE-miRNAs were identified. Among them, four downregulated DEGs and eight upregulated DEGs were supposed to be negatively regulated by three upregulated DE-miRNAs and three downregulated DE-miRNAs, respectively. Conclusions: This study identifies some key and functional coexpression modules involved in IPAH, as well as a potential IPAH-related miRNA-mRNA regulated network. It provides deepening insights into the molecular mechanisms and provides vital clues in seeking novel therapeutic targets for IPAH.

Identification of Hub Genes and MicroRNAs Associated With Idiopathic Pulmonary Arterial Hypertension by Integrated Bioinformatics Analyses

Objective

The aim of this study is the identification of hub genes associated with idiopathic pulmonary arterial hypertension (IPAH).

Materials and Methods

GSE15197 gene expression data was downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified by screening IPAH patients and controls. The 5,000 genes with the greatest variances were analyzed using a weighted gene co-expression network analysis (WGCNA). Modules with the strongest correlation with IPAH were chosen, followed by a functional enrichment analysis. Protein–protein interaction (PPI) networks were constructed to identify hub gene candidates using calculated degrees. Real hub genes were found from the overlap of DEGs and candidate hub genes. microRNAs (miRNAs) targeting real hub genes were found by screening miRNet 2.0. The most important IPAH miRNAs were identified.

Results

There were 4,395 DEGs identified. WGCNA indicated that green and brown modules associated most strongly with IPAH. Functional enrichment analysis showed that green and brown module genes were mainly involved in protein digestion and absorption and proteoglycans in cancer, respectively. The top ten candidate hub genes in green and brown modules were identified, respectively. After overlapping with DEGs, 11 real hub genes were identified: EP300, MMP2, CDH2, CDK2, GNG10, ALB, SMC2, DHX15, CUL3, BTBD1, and LTN1. These genes were expressed with significant differences in IPAH versus controls, indicating a high diagnostic ability. The miRNA–gene network showed that hsa-mir-1-3p could associate with IPAH.

Conclusion

EP300, MMP2, CDH2, CDK2, GNG10, ALB, SMC2, DHX15, CUL3, BTBD1, and LTN1 may play essential roles in IPAH. Predicted miRNA hsa-mir-1-3p could regulate gene expression in IPAH. Such hub genes may contribute to the pathology and progression in IPAH, providing potential diagnostic and therapeutic opportunities for IPAH patients.

Prognostic Significance of Systemic Arterial Stiffness Evaluated by Cardio-Ankle Vascular Index in Patients with Idiopathic Pulmonary Hypertension

BACKGROUND

In a previous study, the cardio-ankle vascular index (CAVI) was increased significantly in idiopathic pulmonary arterial hypertension (IPAH) patients compared to the healthy group and did not much differ from one in systemic hypertensives. In this study the relations between survival and CAVI was evaluated in patients with IPAH.

PATIENTS AND METHODS

We included 89 patients with new-diagnosed IPAH without concomitant diseases. Standard examinations, including right heart catheterization (RHC) and systemic arterial stiffness evaluation, were performed. All patients were divided according to CAVI value: the group with CAVI ≥ 8 (n = 18) and the group with CAVI < 8 (n = 71). The mean follow-up was 33.8 ± 23.7 months. Kaplan-Meier and Cox regression analysis were performed for the evaluation of our cohort survival and the predictors of death.

RESULTS

The group with CAVI≥8 was older and more severe compared to the group with CAVI< 8. Patients with CAVI≥8 had significantly reduced end-diastolic (73.79±18.94 vs 87.35±16.69 mL, P<0.009) and end-systolic (25.71±9.56 vs 33.55±10.33 mL, P<0.01) volumes of the left ventricle, the higher right ventricle thickness (0.77±0.12 vs 0.62±0.20 mm, P < 0.006), and the lower TAPSE (13.38±2.15 vs 15.98±4.4 mm, P<0.018). RHC data did not differ significantly between groups, except the higher level of the right atrial pressure in patients with CAVI≥ 8-11.38±7.1 vs 8.76±4.7 mmHg, P<0.08. The estimated overall survival rate was 61.2%. The CAVI≥8 increased the risk of mortality 2.34 times (CI 1.04-5.28, P = 0.041). The estimated Kaplan-Meier survival in the patients with CAVI ≥ 8 was only 46.7 ± 7.18% compared to patients with CAVI < 8 - 65.6 ± 4.2%, P = 0.035. At multifactorial regression analysis, the CAVI reduced but saved its relevance as death predictor - OR = 1.13, CI 1.001-1.871.

SUMMARY

We suggested the CAVI could be a new independent predictor of death in the IPAH population and could be used to better risk stratify this patient population if CAVI is validated as a marker in a larger multicenter trial.

Disease-specific platelet signaling defects in idiopathic pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is a rapidly progressive disease with several treatment options. Long-term mortality remains high with great heterogeneity in treatment response. Even though most of the pathology of IPAH is observed in the lung, there is systemic involvement. Platelets from patients with IPAH have characteristic metabolic shifts and defects in activation; therefore, we investigated whether they could be used to identify other disease-specific abnormalities. We used proteomics to investigate protein expression changes in platelets from patients with IPAH compared with healthy controls. Key abnormalities of nitric oxide pathway were tested in platelets from a larger cohort of unique patients with IPAH. Platelets showed abnormalities in the prostacyclin and nitric oxide pathways, which are dysregulated in IPAH and hence targets of therapy. We detected reduced expression of G protein αs and increased expression of the regulatory subunits of the cAMP-dependent protein kinase (PKA) type II isoforms, supporting an overall decrease in the activation of the prostacyclin pathway. We noted reduced levels of the soluble guanylate cyclase (sGC) subunits and increased expression of the phosphodiesterase type 5 A (PDE5A), conditions that affect the response to nitric oxide. Ensuing analysis of 38 unique patients with IPAH demonstrated considerable variation in the levels and specific activity of sGC, a finding with novel implications for personalized therapy. Platelets have some of the characteristic vasoactive signal abnormalities seen in IPAH and may provide comprehensive ex vivo mechanistic information to direct therapeutic decisions.

Identification of Potential Biomarkers and Immune Infiltration Characteristics in Idiopathic Pulmonary Arterial Hypertension Using Bioinformatics Analysis

Objectives: Idiopathic pulmonary arterial hypertension (IPAH) is a rare but severe lung disorder, which may lead to heart failure and early mortality. However, little is known about the etiology of IPAH. Thus, the present study aimed to establish the differentially expressed genes (DEGs) between IPAH and normal tissues, which may serve as potential prognostic markers in IPAH. Furthermore, we utilized a versatile computational method, CIBERSORT to identify immune cell infiltration characteristics in IPAH.

Materials and Methods: The GSE117261 and GSE48149 datasets were obtained from the Gene Expression Omnibus database. The GSE117261 dataset was adopted to screen DEGs between IPAH and the control groups with the criterion of |log2 fold change| ≥ 1, adjusted P < 0.05, and to further explore their potential biological functions via Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes Pathway analysis, and Gene Set Enrichment Analysis. Moreover, the support vector machine (SVM)-recursive feature elimination and the least absolute shrinkage and selection operator regression model were performed jointly to identify the best potential biomarkers. Then we built a regression model based on these selected variables. The GSE48149 dataset was used as a validation cohort to appraise the diagnostic efficacy of the SVM classifier by receiver operating characteristic (ROC) analysis. Finally, immune infiltration was explored by CIBERSORT in IPAH. We further analyzed the correlation between potential biomarkers and immune cells.

Results: In total, 75 DEGs were identified; 40 were downregulated, and 35 genes were upregulated. Functional enrichment analysis found a significantly enrichment in heme binding, inflammation, chemokines, cytokine activity, and abnormal glycometabolism. HBB, RNASE2, S100A9, and IL1R2 were identified as the best potential biomarkers with an area under the ROC curve (AUC) of 1 (95%CI = 0.937–1.000, specificity = 100%, sensitivity = 100%) in the discovery cohort and 1(95%CI = 0.805–1.000, specificity = 100%, sensitivity = 100%) in the validation cohort. Moreover, immune infiltration analysis by CIBERSORT showed a higher level of CD8+ T cells, resting memory CD4+ T cells, gamma delta T cells, M1 macrophages, resting mast cells, as well as a lower level of naïve CD4+ T cells, monocytes, M0 macrophages, activated mast cells, and neutrophils in IPAH compared with the control group. In addition, HBB, RNASE2, S100A9, and IL1R2 were correlated with immune cells.

Conclusion:HBB, RNASE2, S100A9, and IL1R2 were identified as potential biomarkers to discriminate IPAH from the control. There was an obvious difference in immune infiltration between patient with IPAH and normal groups.

Identification of Potential Risk Genes and the Immune Landscape of Idiopathic Pulmonary Arterial Hypertension via Microarray Gene Expression Dataset Reanalysis

Gene dysfunction and immune cell infiltration play an essential role in the pathogenesis of idiopathic pulmonary arterial hypertension (IPAH). We aimed to investigate the immune landscape and novel differentially expressed genes (DEGs) of IPAH. In addition, potential druggable molecular targets for IPAH were also explored. In this study, the GSE117261 dataset was reanalyzed to explore the immune landscape and hub DEGs of IPAH. Lasso Cox regression analysis and receiver operating characteristic curve analysis were performed to detect the predictive value of IPAH. Additionally, the underlying drug targets for IPAH treatment were determined by drug-gene analysis. IPAH was significantly associated with the transforming growth factor-β (TGF-β) signaling pathway and Wnt signaling pathway as well as energetic metabolism dysfunction. We identified 31 upregulated and 39 downregulated DEGs in IPAH patients. Six hub genes, namely, SAA1, CCL5, CXCR1, CXCR2, CCR1, and ADORA3, were related to IPAH pathogenesis regardless of sex differences. Prediction model analysis showed that the area under the curve values of the hub DEGs except CXCR2 were all above 0.9 for distinguishing IPAH patients. In addition, the relative proportions of 5 subtypes of immune cells, namely, CD₈ ⁺ T cells, CD₄ ⁺ memory resting T cells, γ delta T cells, M1 macrophages, and resting mast cells, were significantly upregulated in the IPAH samples, while 6 subtypes of immune cells, namely, CD₄ ⁺ naive T cells, resting NK cells, monocytes, M0 macrophages, activated mast cells, and neutrophils, were downregulated. Additionally, a total of 17 intersecting drugs targeting 5 genes, CCL5, CXCR1, CXCR2, CCR1, and ADORA3, were generated as potential druggable molecular targets for IPAH. Our study revealed the underlying correlations between genes and immune cells in IPAH and demonstrated for the first time that SAA1, CCL5, CXCR1, CCR1, and ADORA3 may be novel genetic targets for IPAH.

Alteration of Extracellular Superoxide Dismutase in Idiopathic Pulmonary Arterial Hypertension

Background: Superoxide dismutases (SODs) are an important family of antioxidant enzymes that modulate reactive oxygen species levels. It is largely unknown which SOD isoform(s) change in vivo in idiopathic pulmonary arterial hypertension (IPAH) patients.

Methods: A total of 133 consecutive adult IPAH patients who underwent bone morphogenetic protein receptor type 2 (BMPR2) genetic counseling were enrolled in this prospective study. The plasma activities of three subtypes of SOD [copper–zinc (Cu/Zn-SOD), manganese (Mn-SOD), and extracellular SOD (Ec-SOD)] were examined.

Results: The activities of SODs were significantly lower in IPAH patients than in healthy subjects. However, only Ec-SOD activity in BMPR2 mutation patients was significantly decreased compared to those in patients without a mutation. The reduced Ec-SOD activity was markedly associated with mean pulmonary arterial pressure, pulmonary vascular resistance (PVR), and 6-min walking distance (6MWD). The reduction of Mn-SOD activity was only associated with 6MWD. There was no association between Cu/Zn-SOD and hemodynamics. Patients with a lower Ec-SOD level had a worse survival compared to those with a higher baseline. The reduced Ec-SOD activity and the raised PVR increased the mortality risk.

Conclusions: Ec-SOD was correlated with BMPR2 mutation, hemodynamic dysfunction, and poor outcomes. Circulating Ec-SOD could be a potentially vital antioxidant enzyme in the pathogenesis of IPAH.

Nocturnal hypoxia in patients with idiopathic pulmonary arterial hypertension

Background

Sleep-disordered breathing causes a variety of cardiovascular complications and increases the risk of a poor prognosis in patients. There is still some controversy regarding the clinical diagnosis and treatment of sleep-disordered breathing in patients with pulmonary hypertension. The aim of this study was to determine the incidence of desaturation in idiopathic pulmonary arterial hypertension (IPAH) patients, evaluate the effect of desaturation on the clinical status of patients with IPAH, and identify possible influencing factors.

Methods

Patients with IPAH diagnosed by right heart catheterization who underwent overnight cardiorespiratory monitoring from January 2018 to July 2019 were enrolled. Nocturnal hypoxic time was defined as the time that oxygen saturation remained below 90%. Desaturation was defined as a nocturnal oxygen saturation level less than 90% for more than 10% of the total recording time. Baseline clinical characteristics and parameters were collected to compare IPAH patients with and without desaturation. In addition, logistic regression was performed to identify possible factors associated with desaturation in IPAH patients.

Results

Fifty patients with IPAH were included. Among them, 17 patients presented desaturation. Patients with desaturation were older, had a shorter six-min walking distance (6MWD), had a higher mean right atrial pressure, and had a lower daytime arterial oxygen partial pressure than patients without desaturation, and there were significant differences in the VE/VCO₂ and VE/VCO₂ slope (P < 0.05). The multivariate logistic regression analysis indicated that the 6 MWD (OR = 0.971, 95% CI: 0.948-0.994, P = 0.013) and; VE/VCO₂ slope (OR = 1.095, 95% CI: 1.010-1.307, P = 0.032) were independently associated with desaturation after adjusting for age, sex, and body mass index.

Conclusion

Nocturnal hypoxia is common in IPAH patients. Desaturation may aggravate the clinical situation of patients with IPAH. In IPAH patients, a poor exercise capacity (6 MWD) and the VE/VCO₂ slope can predict desaturation after adjusting for age, sex, and body mass index.

Increased Levels of Runt-Related Transcription Factor 2 Are Associated With Poor Survival of Patients With Idiopathic Pulmonary Arterial Hypertension

Runt-related transcription factor 2 (RUNX2) plays a pivotal role in the pathogenesis of pulmonary arterial hypertension (PAH); yet, whether circulating levels of RUNX2 can predict survival of patients with idiopathic PAH (IPAH) is still unclear. The present study aimed to investigate the correlation between circulating levels of RUNX2 and survival of patients with IPAH. Blood samples were collected from 46 incident patients with IPAH and 30 healthy controls in Shanghai Pulmonary Hospital. Levels of RUNX2 were measured using ELISA. Linear regression and cox proportional hazards analysis were performed to assess the prognostic value of RUNX2 levels in predicting survival using the Kaplan-Meier method. Nonsurvivors had significantly shorter 6MWD, higher levels of NT-proBNP, increased mRAP, mPAP, mPAWP, PVR, and decreased CO as well as CI, compared with survivors (p < .05). Plasma levels of RUNX2 were significantly higher in nonsurvival and survival patients with IPAH compared with controls (p ≤ .001), and higher in nonsurvivors than in survivors (p = .001). RUNX2 levels served as an independent predictor of survival in these patients (p < .001). RUNX2 levels ≥41.5 ng/ml had a sensitivity of 80.0% and a specificity of 74.2% by ROC analysis. Patients with a RUNX2 level <41.5 ng/ml and/or mRAP <3.5 mmHg had a significantly better prognosis than those with a higher RUNX2 level in all subjects as well as in male or female patients (p < .05). The level of circulating RUNX2 is an independent predictor for survival and it is correlated with the clinical severity of IPAH.

Overexpression of PD-1 on Peripheral Blood Lymphocytes in Patients with Idiopathic Pulmonary Arterial Hypertension and Its Association with High Viral Loads of Epstein-Barr Virus and Poor Clinical Parameters

Idiopathic pulmonary arterial hypertension (IPAH) is a rare but severe disease with the elevated blood pressure in the pulmonary arteries without a known trigger of vascular remodelling. It leads to the right heart failure with reduced survival. Changes in the immunological landscape of the lungs and the periphery are common in IPAH patients, suggesting an immune system dysfunction. A cohort of 25 IPAH patients was enrolled in our study to investigate a link between the patient’s clinical status, immune parameters of the blood, and the Epstein–Barr virus (EBV) infection. We found significant alterations of the patients’ peripheral blood parameters. Therein, T lymphocytes and NK cell counts were decreased in the IPAH patients’ blood, while the proportion of regulatory T cells was increased. Additionally, levels of proinflammatory cytokines interleukin-6 (IL-6), IL-2, and interferon-gamma (IFN-γ) were elevated. We identified a weak correlation between EBV loads and IPAH patients’ clinical state (r = 0.54) and between EBV loads and overexpression of PD-1 on helper T cells (r = 0.56). We speculate that a significant dysregulation of the immune system homeostasis observed in IPAH patients may contribute to increased susceptibility of those patients to EBV infection, yet further longitudinal studies are required to characterize this relation in detail.

Integrative analysis reveals key mRNA and long non-coding RNA interaction in idiopathic pulmonary arterial hypertension

Introduction

Idiopathic pulmonary arterial hypertension (IPAH) is a rare and sporadic form of pulmonary arterial hypertension (PAH), characterized by elevated pulmonary arterial resistance leading to right heart failure. However, molecular mechanisms of PAH development are still not completely understood.

Material and methods

In this study, we aimed to uncover key mRNAs and long non-coding RNA (lncRNAs), functional modules and pathways. Moreover, to detect the dysregulated pathway or biological function, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. PPI and co-expression networks were constructed to reveal the potential roles of PAH-related mRNAs and lncRNAs.

Results

A total of 3,134 genes, including 945 up-regulated and 2,189 down-regulated genes, were identified to be differentially expressed in IPAH by differential expression analysis. We identified T cell differentiation and the T cell receptor signaling pathway as up-regulated in IPAH by using GO and KEGG analysis. Based on the PPI module analysis, we identified that the pro-inflammatory genes, such as OAS1, CXCL10, STAT1 and TLR4, were the hub genes in the PPI modules. To link the lncRNAs to the PPI modules, we calculated the Spearman correlation coefficient for lncRNA-DE-mRNA pairs to identify the modules with high correlation with each lncRNA.

Conclusions

Notably, 6 of these lncRNAs were associated with modules characterized by the NOD-like receptor signaling pathway and chemokine signaling pathway, suggesting that these lncRNAs may promote the occurrence of IPAH via participating in the pro-inflammatory pathways. In conclusion, our systematic analysis not only improved our understanding of the molecular mechanism, but also provided potential lncRNA biomarkers for further research.

Systemic Arterial Stiffness in New Diagnosed Idiopathic Pulmonary Arterial Hypertension Patients

Objective

We suggested: 1) patients with idiopathic pulmonary hypertension (IPAH) have active factors which could damage not only the pulmonary but systemic arteries too as in arterial hypertensive patients; 2) if these changes were present, they might correlate with other parameters influencing on the prognosis. This study is the first attempt to use cardio-ankle vascular index (CAVI) for the evaluation of systemic arterial stiffness in patients with IPAH.

Methods

A total of 112 patients were included in the study: group 1 consisted of 45 patients with new diagnosed IPAH, group 2 included 32 patients with arterial hypertension, and in the control group were 35 healthy persons adjusted by age. Right heart catheterization, ECG, a 6-minute walk test (6MWT), echocardiography, blood pressure (BP) measurement and ambulatory BP monitoring, pulse wave elastic artery stiffness (PWVe; segment carotid-femoral arteries) and muscular artery stiffness (PWVm; segment carotid-radial arteries), CAVI, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) level were provided. The Spearman correlation, a linear regression and multivariable binary logistic analysis were performed to indicate the predictors associated with PWV and CAVI.

Results

The groups were adjusted for principal characteristics influenced on arterial stiffness. IPAH patients had significantly (P<0.001 for all) shorter 6MWT distance and higher Borg dyspnea score than the patients with arterial hypertension (systolic/diastolic BP = 146.1±10.7/94.2±9.8 mmHg) and the control group = 330.2±14.6 vs 523.8±35.3 and 560.9±30.2 m respectively and 6.2±1.8 vs 1.2±2.1 and 0.9±2.8 points. The PWVm and PWVe were the highest in hypertensive patients (10.3±1.5 and 11.42±1.70 m/s). The control group and IPAH did not have significant differences in aorta BP, but PWVm/PWVe values were significantly (P<0.003/0.008) higher in IPAH patients than in the control group (8.1±1.9/8.49±1.92 vs 6.63±1.34/7.29±0.87 m/s). The CAVIs on both sides were significantly lower in the healthy subjects (5.91±0.99/5.98±0.87 right/left side). Patients with IPAH did not differ from the arterial hypertension patients by CAVIs in comparison with the control group (7.40±1.32/7.22±1.32 vs 7.19±0.78/7.2±1.1 PWVe) did not correlate with any parameters except uric acid. PWVm correlated with uric acid (r=0.58, P<0.001), NT-proBNP (r=0.33, P=0.03) and male gender (r=0.37, P=0.013) at Spearman analysis, but not at multifactorial linear regression analysis. The CAVI correlated with age and parameters characterized functional capacity (6MWT distance) and right ventricle function (NT-proBNP, TAPSE) at Spearman analysis and with age and TAPSE at multifactorial linear regression analysis. At binary logistic regression analysis CAVI > 8.0 at right and/or left side had a correlation with age, 6MWT distance, TAPSE, but an independent correlation was only with age (β=1.104, P=0.008, CI 1.026–1.189) and TAPSE (β=0.66, P=0.016, CI 0.474–0.925).

Conclusion

In spite of equal and at normal range BP level, the age-adjusted patients with IPAH had significantly stiffer arteries than the healthy persons and they were comparable with the arterial hypertensive patients. Arterial stiffness evaluated by CAVI correlated with age and TAPSE in IPAH patients. Based on our results it is impossible to conclude the pathogenesis of arterial stiffening in IPAH patients, but the discovered changes and correlations suggest new directions for further studies, including pathogenesis and prognosis researches.

Association Between High FSH, Low Progesterone, and Idiopathic Pulmonary Arterial Hypertension in Women of Reproductive Age

BACKGROUND

While sex differences characterize susceptibility and severity of idiopathic pulmonary arterial hypertension (IPAH), our understanding of the relationship between levels of gonadotropins and sex hormones in fertile women and the disease is limited. We aimed to investigate whether gonadotropin and sex hormone levels in women of reproductive age were associated with risk and mortality of IPAH.

METHODS

We did a matched case-control study. Cases were reproductive female patients with idiopathic pulmonary arterial hypertension admitted in Shanghai Pulmonary Hospital (Tongji University School of Medicine, Shanghai, China) during 2008-2014. Healthy controls were matched on age and body mass index. We also did a prospective cohort study to assess the effects of hormone levels on mortality in IPAH fertile female patients.

RESULTS

One hundred sixty-four cases and 133 controls were included. After adjustment for age and body mass index, the odds ratios of having IPAH for follicle-stimulating hormone, testosterone, and progesterone as expressed on natural log scale were 1.51 (95% confidence interval: 1.06, 2.16), 0.42 (0.31-0.57), and 0.52 (0.43-0.63), respectively. In the cohort study with a median follow-up of 77 months, the hazard ratios for dying after adjustment for baseline characteristics and treatments among IPAH patients were 2.01 (95% confidence interval: 1.22-3.30) and 0.78 (95% confidence interval: 0.62-0.98) for follicle-stimulating hormone and progesterone in natural log scale, respectively.

CONCLUSIONS

In reproductive women with IPAH, high follicle-stimulating hormone and low progesterone tended to be associated with high risk of IPAH and mortality among patients.

[Features of clinical, functional and hemodynamics profile, medical treatment and prognosis evaluation in patients with inoperable chronic thromboembolic pulmonary hypertension and idiopathic pulmonary arterial hypertension according to the Russian registry]

AIM

to perform the complex analysis of clinical, functional, hemodynamics profile in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) compared to the idiopathic pulmonary arterial hypertension (IPAH) group at the time of diagnosis verification according to the Russian registry, and to evaluate the features of medical therapy and it's influence on prognosis in these patients.

MATERIALS AND METHODS

In the retrospective study 193 patients with IPAH and 130 patients with inoperable CTEPH older than 18 years were included. All included patients were the participants of Russian registry (www.medibase.pro) in 15 Russian expert centers during the period from 01.01.2012 to 31.12.2018 year. The diagnosis was verified according to the algorithm, reflected in the Russian guidelines on diagnosis and treatment of PH and CTEPH (2016 year). The comparison analysis of clinical, functional, hemodynamics parameters in patients with IPAH and inoperable CTEPH was made.

RESULTS

The status of 193 patients with IPAH (32 male and 162 female) and 130 patients with inoperable CTEPH - (40 male and 90 female) was analyzed during the study. The CTEPH patients were older compared to the IPAH patients: 52.2 [41.1; 60.6] and 36.5 [26.8; 36.5] years, respectively. The median period since symptom occurrence till CTEPH verification was 1.08 [0.2; 3.1] years, in IPAH patients - 2.01 [0.6; 4.2] years. More than 80% of inoperable CTEPH patients had III and IV functional class (FC) according to the World Health Organization classification at the time of diagnosis verification versus 61% of IPAH patients. According to echocardiography the level of mean pulmonary arterial pressure was comparable in two groups of PH patients. However in inoperable CTEPH patients the right atrial area was larger. The significantly higher value of mean pulmonary arterial pressure and lower value oxygen saturation of arterial blood according to the right heart catheterization were revealed. The 5-year survival in CTEPH patients, receiving initial dual combination therapy in 75% cases (in 40% - combination of riociguat and iloprost ) was 93% versus 86.5% in patients with IPAH.

CONCLUSION

It was revealed, that inoperable CTEPH patients were significantly older with severe functional and hemodynamics status at the time of diagnosis verification, although with higher level of 5-year survival compared to the IPAH patients according to the Russian registry.

EXPRESS: Acute Vasoreactivity Testing in Pediatric Idiopathic Pulmonary Arterial Hypertension: an international Survey on Current Practice

The aim of this study was to determine practice patterns and inter-institutional variability in how acute vasoreactivity testing (AVT) is performed and interpreted in pediatrics throughout the world. A survey was offered to physicians affiliated with the Pediatric & Congenital Heart Disease Taskforce of the Pulmonary Vascular Research Institute (PVRI), the Pediatric Pulmonary Hypertension Network (PPHNET), or the Spanish Registry for Pediatric Pulmonary Hypertension (REHIPED), from February to December 2016. The survey requested data about the site-specific protocol for AVT and subsequent management of pediatric patients with idiopathic pulmonary arterial hypertension (IPAH) or heritable PAH (HPAH). Twenty-eight centers from 13 countries answered the survey. AVT is performed in most centers using inhaled nitric oxide (iNO). Sitbon criteria was used in 39% of the centers, Barst criteria in 43%, and other criteria in 18%. First-line therapy for positive AVT responders in functional class (FC) I/II was calcium channel blocker (CCB) in 89%, but only in 68% as monotherapy. Most centers (71%) re-evaluated AVT-positive patients hemodynamics after 6–12 months; 29% of centers re-evaluated based only on clinical criteria. Most centers (64%) considered a good response as remaining in FC I or II, with near normalization of pulmonary arterial pressure and pulmonary vascular resistance, but a stable FC I/II alone was sufficient criteria in 25% of sites. Protocols and diagnostic criteria for AVT, and therapeutic approaches during follow-up, were highly variable across the world. Reported clinical practice is not fully congruent with current guidelines, suggesting the need for additional studies that better define the prognostic value of AVT for pediatric IPAH patients.

Advanced interstitial lung fibrosis with emphysema and pulmonary hypertension with no evidence for interstitial lung disease on high resolution CT

The diagnosis of idiopathic pulmonary arterial hypertension (iPAH) is complex and, besides invasive hemodynamic evaluation, includes several diagnostic steps to exclude any underlying diseases. The role of a decreased diffusion capacity of the lung for carbon monoxide (DLCO) is a matter of discussion. Here, we present a 76-year-old man with a smoking history of 30 pack-years who was diagnosed with iPAH after chronic thromboembolic pulmonary hypertension was excluded based on a negative perfusion scan, an underlying heart disease was excluded based on echocardiography and right heart catheterization, and a significant lung disease was excluded based on lung function test (FVC = 101% predicted, FEV1 = 104% predicted, FEV1/FVC = 77, TLC = 97% predicted) and thin-slice computed tomography (CT) scan. Just DLCO was reduced to 40% predicted, suggesting a possible structural lung disease. Postmortem examination demonstrated severe interstitial lung fibrosis combined with microscopic emphysema. This indicates that both CT imaging and pulmonary function test may be insensitive to a diffuse peripheral combined pattern of fibrosis and emphysema and that DLCO may be the only sensitive marker of this significant lung pathology.

Dendritic Cell Subsets and Effector Function in Idiopathic and Connective Tissue Disease-Associated Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a cardiopulmonary disease characterized by an incurable condition of the pulmonary vasculature, leading to increased pulmonary vascular resistance, elevated pulmonary arterial pressure resulting in progressive right ventricular failure and ultimately death. PAH has different underlying causes. In approximately 30–40% of the patients no underlying risk factor or cause can be found, so-called idiopathic PAH (IPAH). Patients with an autoimmune connective tissue disease (CTD) can develop PAH [CTD-associated PAH (CTD-PAH)], suggesting a prominent role of immune cell activation in PAH pathophysiology. This is further supported by the presence of tertiary lymphoid organs (TLOs) near pulmonary blood vessels in IPAH and CTD-PAH. TLOs consist of myeloid cells, like monocytes and dendritic cells (DCs), T-cells, and B-cells. Next to their T-cell activating function, DCs are crucial for the preservation of TLOs. Multiple DC subsets can be found in steady state, such as conventional DCs (cDCs), including type 1 cDCs (cDC1s), and type 2 cDCs (cDC2s), AXL⁺Siglec6⁺ DCs (AS-DCs), and plasmacytoid DCs (pDCs). Under inflammatory conditions monocytes can differentiate into monocyte-derived-DCs (mo-DCs). DC subset distribution and activation status play an important role in the pathobiology of autoimmune diseases and most likely in the development of IPAH and CTD-PAH. DCs can contribute to pathology by activating T-cells (production of pro-inflammatory cytokines) and B-cells (pathogenic antibody secretion). In this review we therefore describe the latest knowledge about DC subset distribution, activation status, and effector functions, and polymorphisms involved in DC function in IPAH and CTD-PAH to gain a better understanding of PAH pathology.

Value of lung perfusion scintigraphy in patients with idiopathic pulmonary arterial hypertension: a patchy pattern to consider

The ventilation/perfusion lung scan is recommended to exclude chronic thromboembolic pulmonary hypertension in the diagnostic algorithm of pulmonary hypertension, but its role in pulmonary arterial hypertension (PAH) has not been well explored. We characterized the lung perfusion pattern assessed by lung perfusion scintigraphy in idiopathic PAH (IPAH) patients and evaluate the potential prognostic significance of the patchy pattern perfusion defect. A total of 318 patients with IPAH confirmed by right heart catheterization who performed lung perfusion scintigraphy were included. On lung perfusion scintigraphy, 134 patients had normal lung perfusion and 184 patients showed patchy perfusion defects. In comparison to patients with normal lung perfusion, patients with patchy perfusion defects experienced significantly higher mean pulmonary arterial pressure (58.0 ± 15.4 mmHg vs. 54.1 ± 16.2 mmHg, P = 0.027) and total pulmonary resistance (1192.6 ± 533.7 dyn·s·cm⁻⁵ vs. 1067.2 ± 549.3 dyn·s·cm⁻⁵, P = 0.042). During a median follow-up period of 884.0 days, 53 patients reached the primary endpoint of all-cause mortality. On univariate Cox analysis, the patchy pattern of perfusion defect was significantly associated with the all-cause mortality (hazard ratio [HR] = 2.47, 95% confidence interval [CI] = 1.32–4.63, P = 0.005). Patients with patchy perfusion defects had a worse outcome (log-rank = 8.605, P = 0.003). On multivariate analysis, the patchy pattern remained as a significant independent predictor of the endpoint (HR = 2.30, 95% CI = 1.22–4.31, P = 0.010). IPAH patients presented with heterogeneity in lung perfusion and the patchy pattern of lung perfusion defect commonly existed. Patients with patchy pattern identified by lung perfusion scintigraphy were associated with more severe disease and worse outcome.

Lung transplantation as a viable option of treatment for pulmonary veno-occlusive disease

Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary hypertension caused by alteration of pulmonary veins. Many clinical and hemodynamic similarities to idiopathic pulmonary arterial hypertension (IPAH) may cause diagnostic and therapeutic difficulties. This case report is about a patient with PVOD, whose first symptoms of the disease occurred after infectious mononucleosis. Patient was administered with prostacycline (PGI2) mimetic (Treprostinil), what made qualification process and lung transplantation possible. Despite more and more knowledge about causes, ethiopathogenesis and changes in pulmonary veins on molecular level, lung transplantation is the only successful therapeutic option for patients suffering from PVOD.

Integrated bioinformatic analysis reveals YWHAB as a novel diagnostic biomarker for idiopathic pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is a severe cardiovascular disease that is a serious threat to human life. However, the specific diagnostic biomarkers have not been fully clarified and candidate regulatory targets for IPAH have not been identified. The aim of this study was to explore the potential diagnostic biomarkers and possible regulatory targets of IPAH. We performed a weighted gene coexpression network analysis and calculated module-trait correlations based on a public microarray data set (GSE703) and six modules were found to be related to IPAH. Two modules which have the strongest correlation with IPAH were further analyzed and the top 10 hub genes in the two modules were identified. Furthermore, we validated the data by quantitative real-time polymerase chain reaction (qRT-PCR) in an independent sample set originated from our study center. Overall, the qRT-PCR results were consistent with most of the results of the microarray analysis. Intriguingly, the highest change was found for YWHAB, a gene encodes a protein belonging to the 14-3-3 family of proteins, members of which mediate signal transduction by binding to phosphoserine-containing proteins. Thus, YWHAB was subsequently selected for validation. In congruent with the gene expression analysis, plasma 14-3-3β concentrations were significantly increased in patients with IPAH compared with healthy controls, and 14-3-3β expression was also positively correlated with mean pulmonary artery pressure ( R ²  = 0.8783; p < 0.001). Taken together, using weighted gene coexpression analysis, YWHAB was identified and validated in association with IPAH progression, which might serve as a biomarker and/or therapeutic target for IPAH.

High levels of healthcare utilization prior to diagnosis in idiopathic pulmonary arterial hypertension support the feasibility of an early diagnosis algorithm: the SPHInX project

Idiopathic pulmonary arterial hypertension (iPAH) is a rare progressive, life-shortening disease, usually diagnosed at an advanced stage. We hypothesize that patients with iPAH exhibit patterns of health-seeking behavior before diagnosis that will allow the development of earlier identification tools. The Sheffield Pulmonary Hypertension IndeX (SPHInX) project aims to develop a predictive algorithm based on routinely collected healthcare resource utilization (HCRU) data. This report focuses on the initial feasibility of the project, examining whether Hospital Episode Statistics (HES) data from the National Health Service in England have sufficient richness to support the development of an early diagnosis algorithm. This is a two-stage study. First, hospital interactions during 2009–2014 captured in HES data identified 127,815 adult patients with pulmonary hypertension (PH) ICD-10 codes, containing a probable iPAH cohort with incidence and demographics similar to the reported literature. HCRU was high in the three years before diagnosis. Second, to examine HCRU in patients with a confirmed iPAH diagnosis, we built the SPHInX dataset incorporating all patients investigated for suspected PH in the Sheffield Pulmonary Vascular Disease Unit during 2008–2016 (n = 6674). For the SPHInX dataset, data could be linked to HES in 98.6% of cases and patients with confirmed iPAH had similar levels of pre-diagnosis HCRU. In conclusion, patients with probable iPAH identified using HES and patients with confirmed iPAH have high levels of HCRU for several years before diagnosis. Artificial intelligence models will now be used to develop the SPHInX algorithm to screen for undiagnosed iPAH in the general population.

ACR Appropriateness Criteria® Suspected Pulmonary Hypertension

Pulmonary hypertension may be idiopathic or related to a large variety of diseases. Various imaging examinations that may be helpful in diagnosing and determining the etiology of pulmonary hypertension are discussed. Imaging examinations that may aid in the diagnosis of pulmonary hypertension include chest radiography, ultrasound echocardiography, ventilation/perfusion scans, CT, MRI, right heart catheterization, pulmonary angiography, and fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Differences in Right Ventricular Functional Changes during Treatment between Systemic Sclerosis-associated Pulmonary Arterial Hypertension and Idiopathic Pulmonary Arterial Hypertension

RATIONALE

Patients with systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) continue to have an unacceptably high mortality rate despite the progress achieved with pulmonary arterial vasodilator therapies.

OBJECTIVES

We sought to determine whether SSc-PAH is a clinically distinct pulmonary vascular disease phenotype when compared with idiopathic pulmonary arterial hypertension (IPAH) on the basis of progression of echocardiographic right ventricular (RV) dysfunction.

METHODS

Retrospective analysis of echocardiographic data in 13 patients with SSc-PAH and 11 patients with IPAH was used to delineate the progression of RV dysfunction during single or combination pulmonary arterial vasodilator therapy. All patients had right heart catheterization-confirmed pulmonary arterial hypertension as well as complete baseline (at the time of diagnosis) and follow-up (most recent) echocardiograms. We excluded patients with significant scleroderma-associated interstitial lung disease. Adjusting for time of follow-up and disease duration, we performed mixed model regression analyses comparing the changes between the two groups for different echocardiographic variables: tricuspid annular plane systolic excursion, tricuspid regurgitation jet velocity, right atrial area, and RV diameter.

RESULTS

The mean ages for the SSc-PAH and IPAH groups were 60.8 and 48.2 years, respectively. The mean follow-up periods for the two groups were 3.8 and 1.95 years, respectively. Tricuspid annular plane systolic excursion did not improve in patients with SSc-PAH, whereas it increased in the patients with IPAH (-0.38 mm, P = 0.87; vs. +5.6 mm, P = 0.02). The other echocardiographic variables showed a trend toward worsening in the SSc-PAH group and improvement in the IPAH group.

CONCLUSIONS

Our results indicate that, in patients with SSc-PAH, echocardiographic RV function does not improve over time compared with that of patients with IPAH, despite institution of pulmonary artery vasodilator therapies.

Validation of claims-based algorithms for pulmonary arterial hypertension

Administrative claims studies do not adequately distinguish pulmonary arterial hypertension (PAH) from other forms of pulmonary hypertension (PH). Our aim is to develop and validate a set of algorithms using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes and electronic medical records (EMR), to identify patients with PAH. From January 2012 to August 2015, the EMRs of patients with ICD-9-CM codes for PH with an outpatient visit at the University of Texas Medical Branch were reviewed. Patients were divided into PAH or non-PAH groups according to EMR encounter diagnosis. Patient demographics, echocardiography, right heart catheterization (RHC) results, and PAH-specific therapies were assessed. RHC measurements were reviewed to categorize cases as hemodynamically determined PAH or not PAH. Weighted sensitivity, specificity, and positive and negative predictive values were calculated for the developed algorithms. A logistic regression analysis was conducted to determine how well the algorithms performed. External validation was performed at the University of Virginia Health System. The cohort for the development algorithms consisted of 683 patients with PH, PAH group (n = 191) and non-PAH group (n = 492). A hemodynamic diagnosis of PAH determined by RHC was recorded in the PAH (26%) and non-PAH (3%) groups. The positive predictive value for the algorithm that included ICD-9-CM and PAH-specific medications was 66.9% and sensitivity was 28.2% with a c-statistic of 0.66. The positive predictive value for the EMR-based algorithm that included ICD-9-CM, EMR encounter diagnosis, echocardiography, RHC, and PAH-specific medication was 69.4% and a c-statistic of 0.87. A validation cohort of 177 patients with PH examined from August 2015 to August 2016 using EMR-based algorithms yielded a similar positive predictive value of 62.5%. In conclusion, claims-based algorithms that included ICD-9-CM codes, EMR encounter diagnosis, echocardiography, RHC, and PAH-specific medications better-identified patients with PAH than ICD-9-CM codes alone.