Pulmonary hypertension in chronic lung diseases: comparison to other pulmonary hypertension groups

Efficacy, safety, and pharmacokinetics of inhaled treprostinil in Japanese patients with pulmonary hypertension associated with interstitial lung disease

BACKGROUND

The INCREASE trial, conducted in the United States, showed that inhaled treprostinil improved exercise capacity in pulmonary hypertension associated with interstitial lung disease (PH-ILD). However, hemodynamic and pharmacokinetic measurements were not performed in the trial. The objective of this trial was to evaluate the efficacy on hemodynamics and exercise capacity, safety, and pharmacokinetics (PK) of inhaled treprostinil in Japanese patients with PH-ILD.

METHODS

This trial was a multicenter, non-randomized, open-label, single-arm trial of patients with PH-ILD. Inhaled treprostinil was administered at 3 breaths (18 μg)/session four times daily, and the dose was gradually increased to a maximum of 12 breaths (72 μg)/session. The primary endpoints were the change of pulmonary vascular resistance index (PVRI) and peak 6-min walking distance (6MWD) from baseline to week 16. Endpoints also included other efficacy parameters, safety, and PK.

RESULTS

Twenty patients received inhaled treprostinil. At week 16, PVRI decreased from baseline by -40.1% (95% CI, -53.1 to -27.2) and peak 6MWD increased by 13.0 m (95% CI, -15.0 to 49.0). The most frequently reported adverse events related with treprostinil were cough, malaise and blood pressure decreased. PK was similar to those in pulmonary arterial hypertension (PAH) patients.

CONCLUSIONS

Treatment with inhaled treprostinil using the same dosing regimen as in the INCREASE trial resulted in improvements in hemodynamics and exercise capacity with a favorable tolerability and safety profile in Japanese patients with PH-ILD.

Health-Related Quality of Life Across the Spectrum of Pulmonary Hypertension

BACKGROUND

Health-related quality of life (HRQOL) is frequently impaired in pulmonary arterial hypertension. However, little is known about HRQOL in other forms of pulmonary hypertension (PH).

RESEARCH QUESTION

Does HRQOL vary across groups of the World Symposium on Pulmonary Hypertension (WSPH) classification system?

STUDY DESIGN AND METHODS

This cross-sectional study included patients with PH from the Pulmonary Vascular Disease Phenomics (PVDOMICS) cohort study. HRQOL was assessed by using emPHasis-10 (e-10), the 36-item Medical Outcomes Study Short Form survey (physical component score [PCS] and mental component score), and the Minnesota Living with Heart Failure Questionnaire. Pearson correlations between HRQOL and demographic, physiologic, and imaging characteristics within each WSPH group were tested. Multivariable linear regressions compared HRQOL across WSPH groups, adjusting for demographic characteristics, disease prevalence, functional class, and hemodynamics. Cox proportional hazards models were used to assess associations between HRQOL and survival across WSPH groups.

RESULTS

Among 691 patients with PH, HRQOL correlated with functional class and 6-min walk distance but not hemodynamics. HRQOL was severely depressed across WSPH groups for all measures except the 36-item Medical Outcomes Study Short Form survey mental component score. Compared with Group 1 participants, Group 2 participants had significantly worse HRQOL (e-10 score, 29 vs 24 [P = .001]; PCS, 32.9 ± 8 vs 38.4 ± 10 [P < .0001]; and Minnesota Living with Heart Failure Questionnaire score, 50 vs 38 [P = .003]). Group 3 participants similarly had a worse e-10 score (31 vs 24; P < .0001) and PCS (33.3 ± 9 vs 38.4 ± 10; P < .0001) compared with Group 1 participants, which persisted in multivariable models (P < .05). HRQOL was associated in adjusted models with survival across Groups 1, 2, and 3.

INTERPRETATION

HRQOL was depressed in PH and particularly in Groups 2 and 3 despite less severe hemodynamics. HRQOL is associated with functional capacity, but the severity of hemodynamic disease poorly estimates the impact of PH on patients' lives. Further studies are needed to better identify predictors and treatments to improve HRQOL across the spectrum of PH.

Exercise capacity-hemodynamics mismatch in elderly patients with pulmonary hypertension: A nationwide multicenter study from Taiwan Society of Cardiology Pulmonary Hypertension Registry (TAIPANS)

Background

Demographics of pulmonary hypertension (PH) has changed a lot over the past forty years. Several recent registries noted an increase in mean age of PH but only a few of them investigated the characteristics of elderly patients. Thus, we aimed to analyze the characteristics of PH in such a population in this study.

Methods

This multicenter study enrolled patients diagnosed with PH in group 1, 3, 4, and 5 consecutively from January 1, 2019 to December 31, 2020. A total of 490 patients was included, and patients were divided into three groups by age (≤45 years, 45-65 years, and >65 years).

Results

The mean age of PH patients diagnosed with PH was 55.3 ± 16.3 years of age. There was higher proportion of elderly patients classified as group 3 PH (≤45: 1.3, 45-65: 4.5, >65: 8.1 %; p = 0.0206) and group 4 PH (≤45: 8.4, 45-65: 14.5, >65: 31.6 %; p < 0.0001) than young patients. Elderly patients had shorter 6-min walking distance (6 MWD) (≤45 vs. >65, mean difference, 77.8 m [95% confidence interval (CI), 2.1-153.6 m]), lower mean pulmonary arterial pressure (mPAP) (≤45 vs. >65, mean difference, 10.8 mmHg [95% CI, 6.37-15.2 mmHg]), and higher pulmonary arterial wedge pressure (PAWP) (≤45 vs. 45-65, mean difference, -2.1 mmHg [95% CI, -3.9 to -0.3 mmHg]) compared to young patients. Elderly patients had a poorer exercise capacity despite lower mPAP level compared to young population, but they received combination therapy less frequently compared to young patients (triple therapy in group 1 PH, ≤45: 16.7, 45-65: 11.3, >65: 3.8 %; p = 0.0005). Age older than 65 years was an independent predictor of high mortality for PH patients.

Conclusions

Elderly PH patients possess unique hemodynamic profiles and epidemiologic patterns. They had higher PAWP, lower mPAP, and received combination therapy less frequently. Moreover, ageing is a predictor of high mortality for PH patients. Exercise capacity-hemodynamics mismatch and inadequate treatment are noteworthy in the approach of elderly population with PH.

Inhaled treprostinil in patients with pulmonary hypertension associated with interstitial lung disease with less severe haemodynamics: a post hoc analysis of the INCREASE study

BACKGROUND

Inhaled treprostinil (iTre) is the only treatment approved for pulmonary hypertension due to interstitial lung disease (PH-ILD) to improve exercise capacity. This post hoc analysis evaluated clinical worsening and PH-ILD exacerbations from the 16-week INCREASE study and change in 6-minute walking distance (6MWD) in the INCREASE open-label extension (OLE) in patients with less severe haemodynamics.

METHODS

Patients were stratified by baseline pulmonary vascular resistance (PVR) of <4 Wood units (WU) versus ≥4 WU and <5 WU versus ≥5 WU. Exacerbations of underlying lung disease, clinical worsening and change in N-terminal prohormone of brain natriuretic peptide (NT-proBNP) in INCREASE were evaluated. For the OLE, patients previously assigned to placebo were considered to have a 16-week treatment delay. 6MWD and clinical events in the OLE were evaluated by PVR subgroup.

RESULTS

Of the 326 patients enrolled in INCREASE, patients with less severe haemodynamics receiving iTre had fewer exacerbations of underlying lung disease and clinical worsening events. This was supported by the Bayesian analysis of the risk of disease progression (HR<1), and significant decreases in NT-proBNP levels. In the OLE, patients without a treatment delay had improved exercise capacity after 1-year compared with those with a 16-week treatment delay (22.1 m vs -10.3 m). Patients with a PVR of ≤5 WU without a treatment delay had a change of 5.5 m compared with -8.2 m for those with a treatment delay. Patients without a treatment delay had a prolonged time to hospitalisation, lung disease exacerbation and death.

CONCLUSION

Treatment with iTre led to consistent benefits in clinical outcomes in patients with PH-ILD and less severe haemodynamics. Earlier treatment in less severe PH-ILD may lead to better exercise capacity long-term, however, the subgroup analyses in this post hoc study were underpowered and confirmation of these findings is needed.

Survival analysis from the INCREASE study in PH-ILD: evaluating the impact of treatment crossover on overall mortality

OBJECTIVE

A post-hoc analysis of the INCREASE trial and its open-label extension (OLE) was performed to evaluate whether inhaled treprostinil has a long-term survival benefit in patients with pulmonary hypertension associated with interstitial lung disease (PH-ILD).

METHODS

Two different models of survival were employed; the inverse probability of censoring weighting (IPCW) and the rank-preserving structural failure time (RPSFT) models both allow construction of a pseudo-placebo group, thereby allowing for long-term survival evaluation of patients with PH-ILD receiving inhaled treprostinil. Time-varying stabilised weights were calculated by fitting Cox proportional hazards models based on the baseline and time-varying prognostic factors to generate weighted Cox regression models with associated adjusted HRs.

RESULTS

In the INCREASE trial, there were 10 and 12 deaths in the inhaled treprostinil and placebo arms, respectively, during the 16-week randomised trial. During the OLE, all patients received inhaled treprostinil and there were 29 and 33 deaths in the prior inhaled treprostinil arm and prior placebo arm, respectively. With a conventional analysis, the HR for death was 0.71 (95% CI 0.46 to 1.10; p=0.1227). Both models demonstrated significant reductions in death associated with inhaled treprostinil treatment with HRs of 0.62 (95% CI 0.39 to 0.99; p=0.0483) and 0.26 (95% CI 0.07 to 0.98; p=0.0473) for the IPCW and RPSFT methods, respectively.

CONCLUSION

Two independent modelling techniques that have been employed in the oncology literature both suggest a long-term survival benefit associated with inhaled treprostinil treatment in patients with PH-ILD.

Prognostic Factors of Mortality in Nonchronic Obstructive Pulmonary Disease Chronic Lung Disease: A Scoping Review

Introduction: Patients with chronic lung disease (CLD) experience a heavy symptom burden at the end of life, but their uptake of palliative care is notably low. Having an understanding of a patient's prognosis would facilitate shared decision making on treatment options and care planning between patients, families, and their clinicians, and complement clinicians' assessments of patients' unmet palliative needs. While literature on prognostication in patients with chronic obstructive pulmonary disease (COPD) has been established and summarized, information for other CLDs remains less consolidated. Summarizing the mortality risk factors for non-COPD CLDs would be a novel contribution to literature. Hence, we aimed to identify and summarize the prognostic factors associated with non-COPD CLDs from the literature. Methods: We conducted a scoping review following published guidelines. We searched MEDLINE, Embase, PubMed, CINAHL, Cochrane Library, and Web of Science for studies published between 2000 and 2020 that described non-COPD CLD populations with an all-cause mortality risk period of up to three years. Only primary studies which reported associations with mortality adjusted through multivariable analysis were included. Results: Fifty-five studies were reviewed, with 53 based on interstitial lung disease (ILD) or connective tissue disease-associated ILD populations and two in bronchiectasis populations. Prognostic factors were classified into 10 domains, with pulmonary function and disease being the largest. Older age, lower forced vital capacity, and lower carbon monoxide diffusing capacity were most commonly investigated and associated with statistically significant increases in mortality risks. Conclusions: This comprehensive overview of prognostic factors for patients with non-COPD CLDs would facilitate the identification and prioritization of candidate factors to predict short-term mortality, supporting tool development for decision making and to identify high-risk patients for palliative needs assessments. Literature focused on patients with ILDs, and more studies should be conducted on other CLDs to bridge the knowledge gap.

Evolution of pulmonary hypertension in interstitial lung disease: a journey through past, present, and future

Interstitial lung diseases (ILD) are a spectrum of disorders often complicated by pulmonary hypertension (PH) in its course. The pathophysiologic mechanism of WHO group 3 PH is different to other forms of PH. The advent of PH is a harbinger for adverse events like mortality and morbidity, implying that the PH component of disease expedites deteriorated clinical outcomes. In fact, WHO group 3 PH due to ILD has the worse prognosis among all groups of PH. Hence, early detection of PH by a comprehensive screening method is paramount. Given considerable overlap in clinical manifestations between ILD and PH, early detection of PH is often elusive. Despite, the treatment of PH due to ILD has been frustrating until recently. Clinical trials utilizing PAH-specific pulmonary vasodilators have been ongoing for years without desired results. Eventually, the INCREASE study (2018) demonstrated beneficial effect of inhaled Treprostinil to treat PH in ILD. In view of this pioneering development, a paradigm shift in clinical approach to this disease phenotype is happening. There is a renewed vigor to develop a well validated screening tool for early detection and management. Currently inhaled Treprostinil is the only FDA approved therapy to treat this phenotype, but emergence of a therapy has opened a plethora of research toward new drug developments. Regardless of all these recent developments, the overall outlook still remains grim in this condition. This review article dwells on the current state of knowledge of pre-capillary PH due to ILD, especially its diagnosis and management, the recent progresses, and future evolutions in this field.

Severe pulmonary hypertension-interstitial lung disease presenting as right ventricular failure: stabilisation with intravenous prostacyclin and maintenance with inhaled prostacyclin

Background

Pulmonary hypertension (PH) leads to increased morbidity and mortality in interstitial lung disease (ILD). While the INCREASE trial highlighted the use of inhaled prostacyclin in PH-ILD patients, such therapy may be inadequate when right ventricular failure (RVF) is also present. In this study, we report the use of intravenous prostacyclin in three PH-ILD patients to stabilise right ventricular (RV) function, with a subsequent transition to maintenance therapy with inhaled prostacyclin.

Methods

We evaluated three consecutive PH-ILD patients with RVF. RV afterload and pulmonary vascular resistance (PVR) were treated with intravenous prostacyclin during the induction phase of the therapy. Patients transitioned from intravenous prostacyclin to the maintenance phase of the treatment with inhaled prostacyclin once three transition criteria were met: cardiac index (CI) >2 L·min-1·m-2, PVR <7 Wood units (WU) and tricuspid annular plane systolic excursion (TAPSE) change >1 mm or TAPSE >1.6 cm.

Results

Pre-treatment parameters for the three patients were a mean PVR of 14.3 WU, a mean Fick CI of 1.8 L·min-1·m-2 and a mean TAPSE of 1.4 cm. The average intravenous prostacyclin dose at the time of transition to maintenance therapy was 20.7 ng·kg-1·m-2 of treprostinil. At 3-months follow-up, the mean PVR was 6.3 WU, Fick CI 2.2 L·min-1·m-2 and TAPSE 1.7 cm.

Conclusion

This case series of three PH-ILD patients with RVF introduces the concept of an initial intravenous prostacyclin induction phase, followed by a transition to maintenance therapy with inhaled prostacyclin. Further development of this treatment algorithm with a refinement of the transition criteria, potential testing in a clinical trial and a longer-term follow-up period is warranted to improve the outcomes of advanced PH-ILD patients with concomitant RVF.

NDRG1 promotes endothelial dysfunction and hypoxia-induced pulmonary hypertension by targeting TAF15

Background

Pulmonary hypertension (PH) represents a threatening pathophysiologic state that can be induced by chronic hypoxia and is characterized by extensive vascular remodeling. However, the mechanism underlying hypoxia-induced vascular remodeling is not fully elucidated.

Methods and Results

By using quantitative polymerase chain reactions, western blotting, and immunohistochemistry, we demonstrate that the expression of N-myc downstream regulated gene-1 (NDRG1) is markedly increased in hypoxia-stimulated endothelial cells in a time-dependent manner as well as in human and rat endothelium lesions. To determine the role of NDRG1 in endothelial dysfunction, we performed loss-of-function studies using NDRG1 short hairpin RNAs and NDRG1 over-expression plasmids. In vitro, silencing NDRG1 attenuated proliferation, migration, and tube formation of human pulmonary artery endothelial cells (HPAECs) under hypoxia, while NDRG1 over-expression promoted these behaviors of HPAECs. Mechanistically, NDRG1 can directly interact with TATA-box binding protein associated factor 15 (TAF15) and promote its nuclear localization. Knockdown of TAF15 abrogated the effect of NDRG1 on the proliferation, migration and tube formation capacity of HPAECs. Bioinformatics studies found that TAF15 was involved in regulating PI3K-Akt, p53, and hypoxia-inducible factor 1 (HIF-1) signaling pathways, which have been proved to be PH-related pathways. In addition, vascular remodeling and right ventricular hypertrophy induced by hypoxia were markedly alleviated in NDRG1 knock-down rats compared with their wild-type littermates.

Conclusions

Taken together, our results indicate that hypoxia-induced upregulation of NDRG1 contributes to endothelial dysfunction through targeting TAF15, which ultimately contributes to the development of hypoxia-induced PH.

Lung Transplantation for Pulmonary Arterial Hypertension

TOPIC IMPORTANCE

Even though patients with pulmonary arterial hypertension have multiple therapeutic options, the disease can be refractory despite appropriate management. In patients with end-stage pulmonary arterial hypertension, lung transplantation has the potential both to extend survival and improve health-related quality of life. Pulmonary arterial hypertension is the only major diagnostic indication for transplantation that is not a parenchymal pulmonary process, and thus the care of these patients is unique.

REVIEW FINDINGS

This review focuses on the complexities of lung transplantation for patients with pulmonary arterial hypertension, presents the updated referral and listing criteria, and discusses the inequities in the organ allocation process that impact this disease group and the strategies to optimize outcomes for patients with pulmonary arterial hypertension who require lung transplantation.

SUMMARY

Lung transplantation is an effective and lifesaving therapy for patients with end-stage lung disease. Sadly, patients with pulmonary arterial hypertension face many challenges as it relates to transplantation including higher perioperative risks, inequities in the allocation system, and less favorable long-term outcomes. This review covers the complexities of transplantation in patients with pulmonary vascular disease.

Assessing the optimal MAP target in pre-capillary PH patients with RV failure: A retrospective analysis

Right ventricular failure (RVF) in pre-capillary pulmonary hypertension (PH) is associated with high morbidity and mortality. While mean arterial pressure (MAP) goals have been well established in critical care literature, the optimal MAP target for patients with RVF secondary to pre-capillary PH remains unknown. The objective of this study was to evaluate the difference in outcomes between patients who were managed with different MAP targets. We retrospectively analyzed records of 60 patients who were admitted to the intensive care unit for decompensated RVF secondary to pre-capillary PH. The records were stratified into two groups: 30 patients who were treated with a static MAP goal of either 65 or 70 mmHg (MAP65/70) and 30 patients who received a dynamic MAP goal (MAPCVP) determined by invasively obtained central venous pressure or right atrial pressure. The dynamic MAP group had a statistically significant decrease in in-hospital mortality and incidence of acute kidney injury compared to the static MAP cohort.

Lung Imaging in COPD Part 1: Clinical Usefulness

COPD is a condition characterized by chronic airflow obstruction resulting from chronic bronchitis, emphysema, or both. The clinical picture is usually progressive with respiratory symptoms such as exertional dyspnea and chronic cough. For many years, spirometry was used to establish a diagnosis of COPD. Recent advancements in imaging techniques allow quantitative and qualitative analysis of the lung parenchyma as well as related airways and vascular and extrapulmonary manifestations of COPD. These imaging methods may allow prognostication of disease and shed light on the efficacy of pharmacologic and nonpharmacologic interventions. This is the first of a two-part series of articles on the usefulness of imaging methods in COPD, and it highlights useful information that clinicians can obtain from these imaging studies to make more accurate diagnosis and therapeutic decisions.

The PH-ILD Detection tool: External validation and use in patients with ILD

Pulmonary hypertension (PH) results in increased morbidity and mortality in patients with interstitial lung disease (ILD). Early recognition of PH in this population is essential for planning diagnostic testing, initiating therapy, and evaluating for lung transplantation. The previously developed PH-ILD Detection tool has significant potential in the evaluation and treatment of ILD patients; the aim of this study was to validate the tool in an independent, multicenter cohort of patients. We conducted a retrospective review of prospectively collected data from 161 ILD patients. Patients were stratified into low- (n = 78, 48.4%), intermediate- (n = 54, 33.5%), and high-risk (n = 29, 18.0%) groups based on the score obtained with the tool. Intermediate- and high-risk patients underwent follow-up echocardiogram (TTE); 49.4% (n = 41) had an abnormal TTE suggestive of underlying PH. These patients underwent right heart catheterization; PH-ILD was diagnosed in 73.2% (n = 30) of these cases. The PH-ILD Detection tool has a sensitivity of 93.3%, specificity of 90.9%, and area-under-the-curve of 0.921 for diagnosing PH in ILD patients, validating the findings from the original study and establishing the tool as a fundamental resource for early recognition of PH in ILD patients.

Combined Pulmonary Fibrosis and Emphysema: When Scylla and Charybdis Ally

Combined pulmonary fibrosis and emphysema (CPFE) is a recently recognized syndrome that, as its name indicates, involves the existence of both interstitial lung fibrosis and emphysema in one individual, and is often accompanied by pulmonary hypertension. This debilitating, progressive condition is most often encountered in males with an extensive smoking history, and is presented by dyspnea, preserved lung volumes, and contrastingly impaired gas exchange capacity. The diagnosis of the disease is based on computed tomography imaging, demonstrating the coexistence of emphysema and interstitial fibrosis in the lungs, which might be of various types and extents, in different areas of the lung and several relative positions to each other. CPFE bears high mortality and to date, specific and efficient treatment options do not exist. In this review, we will summarize current knowledge about the clinical attributes and manifestations of CPFE. Moreover, we will focus on pathophysiological and pathohistological lung phenomena and suspected etiological factors of this disease. Finally, since there is a paucity of preclinical research performed for this particular lung pathology, we will review existing animal studies and provide suggestions for the development of additional in vivo models of CPFE syndrome.

Bleomycin-induced lung injury: Revisiting an old tool to model group III PH associated with pulmonary fibrosis

Pulmonary hypertension (PH) is a chronic disorder of the pulmonary circulation that often associates with other respiratory diseases (i.e., group III PH), leading to worsened symptoms and prognosis, notably when combined with interstitial lung diseases such as pulmonary fibrosis (PF). PH may lead to right ventricular (RV) failure, which accounts for a substantial part of the mortality in chronic lung disease patients. The disappointing results of pulmonary arterial hypertension (PAH)-related therapies in patients with PF emphasize the need to better understand the pathophysiologic mechanisms that drive PH development and progression in this specific setting. In this work, we validated an animal model of group III PH associated with PF (PH-PF), by using bleomycin (BM) intratracheal instillation and characterizing the nature of induced lung and vascular remodeling, including the influence on RV structure and function. To our knowledge, this is the first work describing this dose of BM in Sprague Dawley rats and the effects upon the heart and lungs, using different techniques such as echocardiography, heart catheterization, and histology. Our data shows the successful implementation of a rat model that mimics combined PF-PH, with most features seen in the equivalent human disease, such as lung and arterial remodeling, increased mPAP and RV dysfunction.

Hub Genes and Immune Cell Infiltration in Hypoxia-Induced Pulmonary Hypertension: Bioinformatics Analysis and In Vivo Validation

BACKGROUND

Hypoxia-induced pulmonary hypertension (HPH) represents a severe pulmonary disorder with high morbidity and mortality, which necessitates identifying the critical molecular mechanisms underlying HPH pathogenesis.

METHODS

The mRNA expression microarray GSE15197 (containing 8 pulmonary tissues from HPH and 13 normal controls) was downloaded from Gene Expression Omnibus (GEO). Gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) were executed by RStudio software. The Protein-Protein Interaction (PPI) network was visualized and established using Cytoscape, and the cytoHubba app from Cytoscape was used to pick out the hub modules. The infiltration of immune cells in HPH was analyzed using the CIBERSORTx. To confirm the potential hub genes, real-time quantitative reverse transcription PCR (qRT-PCR) was conducted using lung tissues of rat HPH models and controls.

RESULTS

A total of 852 upregulated and 547 downregulated genes were identified. The top terms in biological processes were apoptosis, proliferation, and regulation of the MAPK cascade, including ERK1/2. Cytoplasm, cytosol, and membrane were enriched in cellular component groups. Molecular functions mainly focus on protein binding, protein serine/threonine kinase activity and identical protein binding. KEGG analysis identified pathways in cancer, regulation of actin cytoskeleton and rap1 signaling pathway. There was significantly different immune cell infiltration between HPH and normal control samples. High proportions of the memory subsets of B cells and CD4 cells, Macrophages M2 subtype, and resting Dendritic cells were found in HPH samples, while high proportions of naive CD4 cells and resting mast cells were found in normal control samples. The qRT-PCR results showed that among the ten identified hub modules, FBXL3, FBXL13 and XCL1 mRNA levels were upregulated, while NEDD4L, NPFFR2 and EDN3 were downregulated in HPH rats compared with control rats.

CONCLUSION

Our study revealed the key genes and the involvement of immune cell infiltration in HPH, thus providing new insight into the pathogenesis of HPH and potential treatment targets for patients with HPH.

Pulmonary hypertension in patients with interstitial lung disease: a tool for early detection

Pulmonary hypertension (PH) complicates the treatment of interstitial lung disease (ILD) patients resulting in poor functional status and worse outcomes. Early recognition of PH in ILD is important for initiating therapy and considering lung transplantation. However, no standard exists regarding which patients to screen for PH-ILD or the optimal method to do so. The aim of this study was to create a risk assessment tool that could reliably predict PH in ILD patients. We developed a PH-ILD Detection tool that incorporated history, exam, 6-min walk distance, diffusion capacity for carbon monoxide, chest imaging, and cardiac biomarkers to create an eight-component score. This tool was analyzed retrospectively in 154 ILD patients where each patient was given a score ranging from 0 to 12. The sensitivity (SN) and specificity (SP) of the PH-ILD Detection tool and an area-under-the-curve (AUC) were calculated. In this cohort, 74 patients (48.1%) had PH-ILD. A score of ≥6 on the PH-ILD Detection tool was associated with a diagnosis of PH-ILD (SN: 86.5%; SP: 86.3%; area-under-the-curve: 0.920, p < 0.001). The PH-ILD Detection tool provides high SN and SP for detecting PH in ILD patients. With confirmation in larger cohorts, this tool could improve the diagnosis of PH in ILD and may suggest further testing with right heart catheterization and earlier intervention with inhaled treprostinil and/or lung transplant evaluation.

Emerging phenotypes of pulmonary hypertension associated with COPD: a field guide

PURPOSE OF REVIEW

Pulmonary hypertension (PH) is a common complication of chronic obstructive lung disease (COPD), but clinical presentation is variable and not always 'proportional' to the severity of the obstructive disease. This review aims to analyze heterogeneity in clinical features of PH-COPD, providing a guide for diagnosis and management according to phenotypes.

RECENT FINDINGS

Recent works have focused on severe PH in COPD, providing insights into the characteristics of patients with predominantly vascular disease. The recently recognized 'pulmonary vascular phenotype', characterized by severe PH and mild airflow obstruction with severe hypoxemia, has markedly worse prognosis and may be a candidate for large trials with pulmonary vasodilators. In severe PH, which might be best described by a pulmonary vascular resistance threshold, there may also be a need to distinguish patients with mild COPD (pulmonary vascular phenotype) from those with severe COPD ('Severe COPD-Severe PH' phenotype).

SUMMARY

Correct phenotyping is key to appropriate management of PH associated with COPD. The lack of evidence regarding the use of pulmonary vasodilators in PH-COPD may be due to the existence of previously unrecognized phenotypes with different responses to therapy. This review offers the clinician caring for patients with COPD and PH a phenotype-focused approach to diagnosis and management, aimed at personalized care.

Haemodynamic effects of PAH-targeted therapies in pulmonary hypertension due to lung disease: A systematic review and meta-analysis

BACKGROUND

Pulmonary hypertension (PH) is a negative predictor in patients with lung disease and/or hypoxia (group 3 PH). Current guidelines do not endorse the use of targeted therapies for pulmonary arterial hypertension (PAH) in patients with group 3 PH, due to lack of strong evidence. However, a variety of studies have examined the effect of PAH-targeted therapies in group 3 PH with mixed methods and conflicting results.

OBJECTIVE

To evaluate the effect of PAH-targeted therapies on haemodynamic parameters as assessed by right heart catheterization in patients with group 3 PH.

METHODS

Search strategy included PubMed and CENTRAL databases for randomized controlled trials from inception until Jan 30, 2020. We hand searched review articles, clinical trial registries and reference lists of retrieved articles. The primary outcome was the effect of PAH-targeted therapies on haemodynamic parameters [mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), cardiac index (CI) and right atrial pressure (RAP)] in patients with group 3 PH, while secondary outcomes were 6-min walking distance (6MWD), brain natriuretic peptide (BNP) and quality of life (QoL).

RESULTS

Five studies with a total of 140 patients were included. PAH-targeted therapies improved significantly mPAP [mean difference (MD) -4.02 mmHg, 95% CI -7.95;-0.09], and PVR [standardized mean difference (SMD) -0.29, 95% CI -0.50;-0.07], but not CI (SMD 0.23, 95% CI -0.23; 0.70) or RAP (MD 0.26 mmHg, 95% CI -18.75; 19.27). PAH-targeted therapies significantly increased the 6MWD by 38.5 m (95% CI 17.6; 59.4), while they did not manage to improve QoL (SMD -3.42, 95% CI -14.74; 7.91) or BNP values. There was no effect of oxygenation by the PAH-targeted therapies compared to placebo.

CONCLUSION

PAH-targeted therapies slightly improved mPAP and PVR in group 3 PH, without affecting CI. Larger RCTs targeted in specific subpopulations are needed to extract more robust conclusions.

PROTOCOL REGISTRATION

Open Science Framework 10.17605/OSF.IO/56FDW.

Chronic Obstructive Pulmonary Disease and the Cardiovascular System: Vascular Repair and Regeneration as a Therapeutic Target

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and encompasses chronic bronchitis and emphysema. It has been shown that vascular wall remodeling and pulmonary hypertension (PH) can occur not only in patients with COPD but also in smokers with normal lung function, suggesting a causal role for vascular alterations in the development of emphysema. Mechanistically, abnormalities in the vasculature, such as inflammation, endothelial dysfunction, imbalances in cellular apoptosis/proliferation, and increased oxidative/nitrosative stress promote development of PH, cor pulmonale, and most probably pulmonary emphysema. Hypoxemia in the pulmonary chamber modulates the activation of key transcription factors and signaling cascades, which propagates inflammation and infiltration of neutrophils, resulting in vascular remodeling. Endothelial progenitor cells have angiogenesis capabilities, resulting in transdifferentiation of the smooth muscle cells via aberrant activation of several cytokines, growth factors, and chemokines. The vascular endothelium influences the balance between vaso-constriction and -dilation in the heart. Targeting key players affecting the vasculature might help in the development of new treatment strategies for both PH and COPD. The present review aims to summarize current knowledge about vascular alterations and production of reactive oxygen species in COPD. The present review emphasizes on the importance of the vasculature for the usually parenchyma-focused view of the pathobiology of COPD.

Pulmonary hypertension in fibrosing idiopathic interstitial pneumonia: Uncertainties, challenges and opportunities

Pulmonary hypertension is a serious complication of chronic fibrosing idiopathic interstitial pneumonia (PH-fIIP) leading to greater morbidity and mortality. The pathophysiologic basis for PH in fIIP is not completely understood, but microvascular rarefaction may play a key role. Severe hypoxemia and reduced diffusion capacity are characteristic. Doppler echocardiography has limited diagnostic utility and right heart catheterization is required to confirm the diagnosis. Lung volumes can be minimally affected, and radiographic findings can be subtle, making the distinction from pulmonary arterial hypertension challenging. Several randomized controlled trials of pulmonary arterial hypertension targeted therapies have recently been completed. Endothelin-receptor antagonists have shown either no benefit or harm. Sildenafil may have some favorable short-term effects but does not appear to impact long-term outcomes. Riociguat treatment increased hospitalizations and mortality. A recent trial of inhaled treprostinil demonstrated improved exercise capacity, but the impact on long-term morbidity and mortality are unknown. Currently, the only viable option for improved survival is lung transplantation. Early referral is imperative to optimize post-transplant outcomes.

Hypoxia and its preconditioning on cardiac and vascular remodelling in experimental animals

Since oxygen (O₂) is indispensable for mammalian life, every cell in the body is endowed with mechanisms to detect and to respond to changes in the O₂ levels in the microenvironment. The heart and the brain are the two most vital, life-supporting organs requiring a continuous supply of O₂ to sustain their high metabolic rate. On being challenged with hypoxia, maintenance of O₂ supply to these organs even at the cost of others becomes a priority. This review describes the cardiovascular, skeletal muscle vascular, pulmonary vascular and cerebrovascular remodelling in face of chronic mild hypoxia exposure and the underlying mechanisms, with special reference to the role of oxidative stress, hypoxia signalling, autonomic nervous mechanisms. The significance of the normalized wall index (NWI) in assessing the remodelling of the vessels particularly of the intramyocardial coronary artery has been underscored. The review also highlights the basic concepts of hypoxic preconditioning and the subsequent protection of the brain against an acute ischemic insult in preclinical studies hinting towards its possible therapeutic potential in the management of ischemic stroke.

Predictors of Mortality in Patients with Interstitial Lung Disease-Associated Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is a well-established complication in interstitial lung disease (ILD) patients. The aim of this study is to investigate the physiological and hemodynamic parameters that predict mortality in patients with ILD-PH.

METHODS

Consecutive ILD patients who underwent right heart catheterization (n = 340) were included. The information analyzed included demographics and physiological and hemodynamic parameters. Cox regression models were used to identify independent predictors of survival.

RESULTS

In total, 96 patients had PH and an additional 56 patients had severe PH. The overall survival of idiopathic pulmonary fibrosis (IPF) patients with PH was significantly worse than the survival of patients with other types of ILD with PH (p < 0.0001 by log-rank analysis). Patients with a reduced diffusing capacity of the lung for carbon monoxide (DLco) (<35% predicted), six-minute walk test final oxygen saturation by pulse oximetry (SpO2) <88% and pulmonary vascular resistance ≥4.5 Wood units in the ILD-PH cohort had significantly worse survival. IPF diagnosis, forced vital capacity, DLco, systolic pulmonary artery pressure and cardiac index were identified as independent predictors of survival among the ILD-PH cohort.

CONCLUSIONS

Patients with ILD-PH have poor prognosis. Physiological and hemodynamic parameters were important factors independently associated with outcome.

Diffusing Capacity Is an Independent Predictor of Outcomes in Pulmonary Hypertension Associated With COPD

BACKGROUND

Patients with COPD who experience pulmonary hypertension (PH) have worse mortality than those with COPD alone. Predictors of poor outcomes in COPD-PH are not well-described. Diffusing capacity of the lung (Dlco) assesses the integrity of the alveolar-capillary interface and thus may be a useful prognostic tool among those with COPD-PH.

RESEARCH QUESTION

Using a single center registry, we sought to evaluate Dlco as a predictor of mortality in a cohort of patients with COPD-PH.

STUDY DESIGN AND METHODS

This retrospective cohort study analyzed 71 COPD-PH patients from the Johns Hopkins Pulmonary Hypertension Registry with right-sided heart catheterization (RHC)-proven PH and pulmonary function testing data within one year of diagnostic RHC. Transplant-free survival was calculated from index RHC. Adjusted transplant-free survival was modelled using Cox proportional hazard methods; age, pulmonary vascular resistance, FEV1, oxygen use, and N-terminal pro-brain natriuretic peptide were included as covariates.

RESULTS

Overall unadjusted transplant-free 1-, 3-, and 5-year survivals were 87%, 60%, and 51%, respectively. Survival was associated with reduced Dlco across the observed range of pulmonary artery pressures and pulmonary vascular resistance. Severe Dlco impairment was associated with poorer survival (log-rank χ2 13.07) (P < .001); adjusting for covariates, for every percent predicted decrease in Dlco, mortality rates increased by 4% (hazard ratio, 1.04; 95% CI, 1.01-1.07).

INTERPRETATION

Among patients with COPD-PH, severe gas transfer impairment is associated with higher mortality, even with adjustment for airflow obstruction and hemodynamics, which suggests that Dlco may be a useful prognostic marker in this population. Future studies are needed to further investigate the association between Dlco and morbidity and to determine the utility of Dlco as a biomarker for disease risk and severity in COPD-PH.

Can a New Scoring System Improve Prediction of Pulmonary Hypertension in Newly Recognised Interstitial Lung Diseases?

INTRODUCTION

Pulmonary hypertension (PH) is a well-recognised complication of interstitial lung diseases (ILD), which worsens prognosis and impairs exercise capacity. Echocardiography is the most widely used, non-invasive method for PH assessment. The aim of our study was to identify the factors predictive for echocardiographic signs of PH in newly recognised ILD patients.

METHODS

Ninety-three consecutive patients (28F/65M) with different ILD were prospectively evaluated from January 2009 to March 2014. Pulmonary function testing, 6-min walk distance (6MWD), initial and sixth minute room air oxygen saturation, NT-proBNP and echocardiography were assessed in each patient. Echocardiographic PH probability was determined according to the 2009 ESC/ERS guidelines.

RESULTS

In 41 patients (Group B) increased PH possibility has been diagnosed on echocardiography, in 52 patients (Group A)-low PH probability. Most pronounced differences (p ≤ 0.0005) between groups B and A concerned: age, 6MWD, room air oxygen saturation at 6 min, DLCO and TLC/DLCO index (57.6 vs 43.8 years; 478 vs 583 m; 89.1% vs 93.4%; 54.8% predicted vs 70.5% predicted and 1.86 vs 1.44; respectively). Univariate analysis showed four-fold increased probability of PH when TLC/DLCO exceeded 1.67. A scoring system incorporating age, TLC/DLCO index, 6MWD and room air oxygen saturation at 6 min provided high diagnostic utility, AUC 0.867 (95% CI 0.792-0.867).

CONCLUSION

ILD patients with TLC/DLCO index > 1.67 have a high likelihood of PH and should undergo further evaluation. The composite model of PH prediction, including age, 6-min walk test and TLC/DLCO was highly specific for recognition of PH on echocardiography.

The Trouble With Group 3 Pulmonary Hypertension in Interstitial Lung Disease: Dilemmas in Diagnosis and the Conundrum of Treatment

Pulmonary hypertension (PH) due to interstitial lung disease (ILD; PH-ILD) can complicate a multitude of ILDs, including idiopathic pulmonary fibrosis, chronic hypersensitivity pneumonitis, and nonspecific interstitial pneumonia. Development of PH-ILD is associated with increased need for supplemental oxygen, reduced mobility, and decreased survival. A high index of suspicion is required to make the diagnosis, given the substantial overlap in symptoms with those of ILD without PH. Severely reduced diffusing capacity or 6-min walk test distance, prominent exertional desaturation, and impaired heart rate recovery after exercise are all suggestive of the development of PH-ILD. Traditional transthoracic echocardiography is the most commonly used screening test for PH-ILD, but it lacks sensitivity and specificity. Newer echocardiographic tools involving 3-dimensional assessment of the right ventricle may have a role in both prognosis and the monitoring of patients with PH-ILD. Right-sided heart catheterization remains the gold standard for confirming a diagnosis of PH-ILD. Although there is little debate about the use of supplemental oxygen and diuretic therapy in the treatment of PH-ILD, treatment with pulmonary vasodilator therapy remains controversial. Although several studies have been terminated prematurely for harm, the recently completed INCREASE trial of inhaled treprostinil appears to validate the concept of treating PH-ILD with pulmonary vasodilators and, we hope, will serve as a foundation from which future studies can be developed.

Pulmonary hypertension secondary to respiratory disease and/or hypoxia in dogs: Clinical features, diagnostic testing and survival

Pulmonary hypertension (PH) is associated with substantial morbidity and if untreated, mortality. The human classification of PH is based on pathological, hemodynamic characteristics, and therapeutic approaches. Despite being a leading cause of PH, little is known about dogs with respiratory disease and/or hypoxia (RD/H)-associated PH. Therefore, our objectives were to retrospectively describe clinical features, diagnostic evaluations, final diagnoses and identify prognostic variables in dogs with RD/H and PH. In 47 dogs identified with RD/H and PH, chronic airway obstructive disorders, bronchiectasis, bronchiolar disease, emphysema, pulmonary fibrosis, neoplasia and other parenchymal disorders were identified using thoracic radiography, computed tomography, fluoroscopy, tracheobronchoscopy, bronchoalveolar lavage, and histopathology. PH was diagnosed using transthoracic echocardiography. Overall median survival was 276.0 days (SE, 95% CI; 216, 0-699 days). Dogs with an estimated systolic pulmonary arterial pressure (sPAP) ≥47mmHg (n=21; 9 days; 95% CI, 0-85 days) had significantly shorter survival times than those <47mmHg (n=16; P=0.001). Estimated sPAP at a cutoff of ≥47mmHg was a fair predictor of non-survival with sensitivity of 0.78 (95% CI, 0.52-0.94) and specificity of 0.63 (95% CI, 0.38-0.84). Phosphodiesterase-5 (PDE5) inhibitor administration was the sole independent predictor of survival in a multivariable analysis (hazard ratio: 4.0, P=0.02). Canine PH is present in a diverse spectrum of respiratory diseases, most commonly obstructive disorders. Similar to people, severity of PH is prognostic in dogs with RD/H and PDE5 inhibition could be a viable therapy to improve outcome.