Pulmonary hypertension and chronic lung disease: where are we headed?

Temporal Dynamics of Cardiovascular Risk in Patients with Chronic Obstructive Pulmonary Disease During Stable Disease and Exacerbations: Review of the Mechanisms and Implications

Introduction

Exacerbations of chronic obstructive pulmonary disease (COPD) are risk factors for severe cardiovascular (CV) events, with the risk remaining significantly elevated long after the symptomatic phase of the exacerbation. The pathophysiology underpinning the relationship between acute events of both COPD and CV diseases has been understudied. Our objectives were to review the mechanisms by which COPD exacerbations increase the risk of CV events and understand the temporality of this risk.

Methods

A pragmatic and targeted literature review was conducted with a focus on identifying recent, high-impact papers up to June 2023, guided by insights from subject matter experts including pulmonologists and cardiologists.

Results

A substantial number of inter-related mechanisms underpin the spiral of anatomical and functional deterioration of lung and heart affecting COPD patients during stable state. In turn, an exacerbation of COPD may trigger a CV event, during and beyond the symptomatic phase, due to ventilation/perfusion mismatch, oxygen supply-demand imbalance, oxidative stress, systemic inflammation, hypercoagulable state, dynamic hyperinflation, pulmonary hypertension, and sympathetic activation. However, no study was identified that explored the mechanisms by which an exacerbation confers a sustained risk of CV event.

Conclusion

While our review identified multiple dynamic and interacting pathophysiological mechanisms during and after an exacerbation of COPD that contribute to increasing the risk of a wide range of cardiac events, little is known regarding the precise long-term mechanisms after acute exacerbation to explain the persistent increased CV event risk beyond the symptomatic phase. The temporal changes in static and dynamic substrates need further characterization to better understand the different risk factors and risk periods for a CV event following the onset of an exacerbation. Moreover, guideline-directed cardiopulmonary therapies should be implemented at every opportunity; preventing exacerbations and intensively treating traditional CV risk factors should be a focus in COPD management.

Noninvasive diagnostic modalities and prediction models for detecting pulmonary hypertension associated with interstitial lung disease: a narrative review

Pulmonary hypertension (PH) is highly prevalent in patients with interstitial lung disease (ILD) and is associated with increased morbidity and mortality. Widely available noninvasive screening tools are warranted to identify patients at risk for PH, especially severe PH, that could be managed at expert centres. This review summarises current evidence on noninvasive diagnostic modalities and prediction models for the timely detection of PH in patients with ILD. It critically evaluates these approaches and discusses future perspectives in the field. A comprehensive literature search was carried out in PubMed and Scopus, identifying 39 articles that fulfilled inclusion criteria. There is currently no single noninvasive test capable of accurately detecting and diagnosing PH in ILD patients. Estimated right ventricular pressure (RVSP) on Doppler echocardiography remains the single most predictive factor of PH, with other indirect echocardiographic markers increasing its diagnostic accuracy. However, RVSP can be difficult to estimate in patients due to suboptimal views from extensive lung disease. The majority of existing composite scores, including variables obtained from chest computed tomography, pulmonary function tests and cardiopulmonary exercise tests, were derived from retrospective studies, whilst lacking validation in external cohorts. Only two available scores, one based on a stepwise echocardiographic approach and the other on functional parameters, predicted the presence of PH with sufficient accuracy and used a validation cohort. Although several methodological limitations prohibit their generalisability, their use may help physicians to detect PH earlier. Further research on the potential of artificial intelligence may guide a more tailored approach, for timely PH diagnosis.

Risk of Death and Cardiovascular Events in Asian Patients With Atrial Fibrillation and Chronic Obstructive Pulmonary Disease: A Report From the Prospective APHRS Registry

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of adverse events in patients with atrial fibrillation (AF); however, few data are available on this topic in Asian populations.

METHODS AND RESULTS

Prospective observational study conducted on patients with AF enrolled in the Asia-Pacific Heart Rhythm Society (APHRS) AF Registry. The diagnosis of COPD was based on data reported in the case report form by the investigators. Cox-regression models were used to assess the 1-year risk of a primary composite outcome of all-cause death, thromboembolic events, acute coronary syndrome, and heart failure. Analysis on single outcomes and cardiovascular death was also performed. Interaction analysis was used to assess the risk of composite outcome and all-cause death in different subgroups. The study included 4094 patients with AF (mean±SD age 68.5±12 years, 34.6% female), of whom 112 (2.7%) had COPD. Patients with COPD showed a higher incidence of the primary composite outcome (25.1% versus 6.3%, P<0.001), all-cause death (14.9% versus 2.6%, P<0.001), cardiovascular death (2.0% versus 0.6%, P<0.001), and heart failure (8.3% versus 6.0%, P<0.001). On multiple Cox-regression analysis, COPD was associated with a higher risk of the primary composite outcome (hazard ratio [HR], 3.17 [95% CI, 2.05-4.90]), all-cause death (HR, 3.59 [95% CI, 2.04-6.30]), and heart failure (HR, 3.32 [95% CI, 1.56-7.03]); no statistically significant differences were found for other outcomes. The association between COPD and mortality was significantly modified by the use of beta blockers (Pint=0.018).

CONCLUSIONS

In Asian patients with AF, COPD is associated with worse prognosis. In patients with AF and COPD, the use of beta blockers was associated with a lower mortality.

REGISTRATION INFORMATION

clinicaltrials.gov Identifier: NCT04807049.

Prognostic analysis of pulmonary hypertension with lung parenchymal lesion: Comparison of mortality with and without connective tissue disease

BACKGROUND

The prognosis of pulmonary hypertension (PH) associated with connective tissue diseases related to interstitial pneumonia (CTD-IP PH) is relatively good among patients with PH and lung disease. However, the impact of pulmonary vasodilator treatment on the prognosis of CTD-IP PH compared with that of PH-induced chronic lung disease (group-3 PH) remains unclear.

METHODS

From 2012 to 2022, 50 patients with lung parenchymal lesions diagnosed with PH (mean pulmonary arterial pressure >20 mmHg) at Juntendo University Hospital were divided into two groups: CTD-IP PH (30 patients) and group 3-PH (20 patients). The impact of pulmonary vasodilator treatment and the use of long-term oxygen therapy (LTOT) on the prognosis of each group was examined retrospectively.

RESULTS

The prognosis of CTD-IP PH was significantly better compared to group-3 PH. While the treatment with pulmonary vasodilators did not affect the prognosis in group 3-PH, the prognosis of the patients treated with vasodilators in the CTD-IP PH group was significantly better than that of the non-treated patients. Treatment with multi-pulmonary vasodilators did not affect the prognosis in CTD-IP PH. Although the prognosis for the patients with LTOT was poor in all registered patients in the present study, treatment with pulmonary vasodilators improved the prognosis even under the use of LTOT in CTD-IP PH (P = 0.002). In a multivariate analysis of the CTD-IP PH group, pulmonary vasodilator treatment was an independent factor for better prognosis.

CONCLUSION

Treatment with a pulmonary vasodilator for CTD-IP PH may improve the prognosis, even in patients requiring LTOT.

Cryoballoon ablation for paroxysmal atrial fibrillation mildly improves lung function: An observational study

Atrial fibrillation (AF) is the most common arrhythmia and a major public health burden. Catheter ablation (CA) is an effective treatment of AF. Although radiofrequency catheter ablation (RFCA) is the standard practice, cryoballoon ablation (CBA) has become increasingly popular. Pulmonary dysfunction is also associated with AF. As CA targets the pulmonary vasculature, it poses a risk to lung function. However, the effect of CA on respiration in patients with paroxysmal atrial fibrillation (PAF) post-ablation has not yet been assessed. We assessed pulmonary function after CA in a cohort of patients with AF. This prospective, single-center study included 26 patients with symptomatic PAF and 18 patients without PAF. CA techniques include RFCA, CBA, hot balloon ablation, and laser balloon-mediated ablation. Spirometry parameters included vital capacity (VC), forced vital capacity (FVC), forced expiratory volume (FEV1), and peak expiratory flow, which were all measured 6 months post-ablation. AF ablation significantly improved VC (P = .04), FVC (P = .01), and peak expiratory flow (P = .006) in all the patients. In the patients with PAF, we observed a significant increase in FEV1 (P = .04). CBA significantly improved VC (P = .012) and FVC (P = .013). A significant improvement in these pulmonary parameters was achieved, specifically in patients with PAF treated with an ablation protocol with CBA, but not with RFCA or hot balloon ablation. A significant decrease in FEV1 was observed with hot balloon ablation (P = .035). Significant improvement in pulmonary parameters was observed specifically in patients with PAF who underwent CBA. CBA may be a more suitable treatment strategy for patients with PAF, particularly those with compromised pulmonary function.

Spirometry in atrial fibrillation: what's the catch?

INTRODUCTION

People with COPD rarely have COPD alone, and the commonest co-morbidities occurring with COPD are cardiovascular. Whilst multiple studies have explored the association between major cardiovascular events and COPD, less attention has been paid to arrhythmias, specifically atrial fibrillation (AF). AF and COPD frequently occur together, posing challenges in diagnosis and management. In this review, we describe the relationship between AF and COPD epidemiologically and physiologically, demonstrating the role of spirometry as a diagnostic and disease management tool.

AREAS COVERED

We provide epidemiological evidence that COPD and AF are independent risk factors for one another, that either disease is highly prevalent amongst people with the other, and that they have shared risk factors; all of which contribute to adverse prognostic. We elucidated common pathophysiological mechanisms implicated in AF-COPD. We ultimately present the epidemiological and physiological evidence with a view to highlight specific areas where we feel spirometry is of value in the management of AF-COPD.

EXPERT OPINION

AF and COPD commonly co-occur, there is often diagnostic delay, increased risk of reduced cardioversion success, and missed opportunity to intervene to reduce stroke risk. Greater awareness and timelier diagnosis and guideline directed management may improve outcomes for people with both diseases.

Incident atrial fibrillation in relation to ventilatory parameters: a prospective cohort study

BACKGROUND

There is a paucity of data on the association between respiratory function and atrial fibrillation (AF). This study aimed to assess the relationship between forced expiratory volume (FEV1), forced vital capacity (FVC), and FEV1/FVC and incident AF.

METHODS

We performed an analysis of prospectively collected data from the UK Biobank. We included all participants with available spirometry and excluded those with a prior AF. Incident AF was ascertained through hospitalization and death records, and dose-response associations were assessed using multivariable Cox regression analysis with adjustment for known AF risk factors.

RESULTS

We studied 348,219 white individuals (54.1% female) with a median age of 58.1 (IQR 50.8-63.5) years. Over a median follow-up time of 11.5 years (IQR: 11.0-12.6 years), a total of 18,188 incident AF events occurred. After standardization to sex, age, and height, the risk of AF consistently increased with decreasing FEV1 percentage predicted, FEV1 z-score, and FVC z-score. The risk of AF linearly increased with decreasing FEV1/FVC ratio, and those that had airway obstruction as defined by an FEV1/FVC ratio < 0.70 had a 23% greater risk of incident AF (aHR 1.23, 95% CI 1.19-1.28) compared to those without airway obstruction. Patients with known chronic obstructive pulmonary disease and asthma were at 40% (aHR 1.40, 95% CI 1.29-1.51) and 17% (aHR 1.17, 95% CI 1.12-1.22) increased risk of incident AF.

CONCLUSION

These findings indicate that reduced ventilatory function is associated with increased risk of AF independently of age, sex, smoking, and other known AF risk factors.

Association between lung function and the risk of atrial fibrillation in a nationwide population cohort study

We investigated the association between lung function and atrial fibrillation (AF) in 21,349 adults without AF aged ≥ 40 years who underwent spirometry. The study participants were enrolled from the Korean National Health and Nutritional Examination Survey between 2008 and 2016. The primary outcome was new-onset non-valvular AF identified from the National Health Insurance Service database. During the median follow-up of 6.5 years, 2.15% of participants developed new-onset AF. The incidence rate of AF per 1000 person-years was inversely related to the forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and FEV₁/FVC quartile. After adjustment for multiple variables, the AF risk in the lowest FEV₁ quartile was 1.64-fold higher than that in the highest quartile (hazard ratio (HR) 1.64 (95% confidence interval (CI) 1.26–2.12) for lowest FEV₁ quartile). The lowest quartile of FVC had 1.56-fold higher AF risk than the highest quartile (HR 1.56 (95% CI 1.18–2.08) for lowest FVC quartile). Although the lowest FEV₁/FVC quartile was associated with an increased risk of AF in the unadjusted model, this increased risk was not statistically significant in the multivariable analysis. Compared to those with normal lung function, participants with restrictive or obstructive lung function had 1.49 and 1.42-fold higher AF risks, respectively. In this large nationwide cohort study, both obstructive and restrictive patterns of reduced lung function were significantly associated with increased AF risk.

Expression of the microRNA-30 family in pulmonary arterial hypertension and the role of microRNA-30d-5p in the regulation of pulmonary arterial smooth muscle cell toxicity and apoptosis

The biological processes of pulmonary artery vascular smooth muscle cells (PA-SMCs) and pulmonary artery endothelial cells in pulmonary arterial hypertension (PAH) are generally abnormal, with increased levels of proliferation and reduced levels of apoptosis. Although microRNAs (miRNAs/miRs) participate in a number of biological processes in a variety of diseases, such as tumors and infections, studies on the association between miRNAs and PAH are limited. In the present study, blood samples were collected from 6 patients with patent ductus arteriosus. The experimental group included 3 patients with severe PAH, while the control group included 3 patients without PAH. Microarray technology was used to detect the presence of any associated miRNAs. Moreover, a rat PAH model was established via left lung resection followed by monocrotaline injection, involving a total of 8 rats in the PAH group and 8 untreated rat in the control group. Reverse transcription-quantitative PCR was performed to verify the expression levels of the miR-30 family in the animal model. miR-30d-5p mimics and anti-miR-30d-5p were transfected into primary cultured PA-SMCs. Levels of cytotoxicity and cell apoptosis were examined, and Notch-3 expression levels were studied using western blotting. The results of the present study demonstrated that miR-30d-5p expression was downregulated in both patient blood and animal models of the PAH group compared with control groups. In primary cultured PA-SMCs, overexpression of miR-30d-5p attenuated the platelet-derived growth factor-induced toxicity of PA-SMCs, while knockdown of miR-30d-5p resulted in the increased toxicity of PA-SMCs compared with control group. The apoptosis rate of PA-SMCs increased with the overexpression of miR-30d-5p compared with control group. Moreover, the expression levels of Notch-3 in the miR-30d-5p group were significantly reduced compared with the anti-miR-30d-5p and miR-NC groups. In total, 10 circulating miRNAs that may be associated with PAH were discovered in the present study. Moreover, the expression of the miR-30 family was verified in animal models in vivo, and seven miRNAs in this family were discovered that may be associated with PAH. Additionally, miR-30d-5p was downregulated in both patients with PAH and animal models compared with control groups. Thus, the results of the present study demonstrated that the regulatory mechanism underlying PA-SMCs may be via the Notch-3 signaling pathway.

Computed tomography lung parenchymal descriptions in routine radiological reporting have diagnostic and prognostic utility in patients with idiopathic pulmonary arterial hypertension and pulmonary hypertension associated with lung disease

BACKGROUND

Patients with pulmonary hypertension (PH) and lung disease may pose a diagnostic dilemma between idiopathic pulmonary arterial hypertension (IPAH) and PH associated with lung disease (PH-CLD). The prognostic impact of common computed tomography (CT) parenchymal features is unknown.

METHODS

660 IPAH and PH-CLD patients assessed between 2001 and 2019 were included. Reports for all CT scans 1 year prior to diagnosis were analysed for common lung parenchymal patterns. Cox regression and Kaplan-Meier analysis were performed.

RESULTS

At univariate analysis of the whole cohort, centrilobular ground-glass (CGG) changes (hazard ratio, HR 0.29) and ground-glass opacification (HR 0.53) predicted improved survival, while honeycombing (HR 2.79), emphysema (HR 2.09) and fibrosis (HR 2.38) predicted worse survival (all p<0.001). Fibrosis was an independent predictor after adjusting for baseline demographics, PH severity and diffusing capacity of the lung for carbon monoxide (HR 1.37, p<0.05). Patients with a clinical diagnosis of IPAH who had an absence of reported parenchymal lung disease (IPAH-noLD) demonstrated superior survival to patients diagnosed with either IPAH who had coexistent CT lung disease or PH-CLD (2-year survival of 85%, 60% and 46%, respectively, p<0.05). CGG changes were present in 23.3% of IPAH-noLD and 5.8% of PH-CLD patients. There was no significant difference in survival between IPAH-noLD patients with or without CGG changes. PH-CLD patients with fibrosis had worse survival than those with emphysema.

INTERPRETATION

Routine clinical reports of CT lung parenchymal disease identify groups of patients with IPAH and PH-CLD with significantly different prognoses. Isolated CGG changes are not uncommon in IPAH but are not associated with worse survival.

[Chronic exposure to altitude. Clinical characteristics and diagnosis]

La exposición crónica a la altitud se ha asociado a hipoxia hipobárica en quienes la experimentan. Dos entidades se han asociado a la hipoxia hipobárica: la hipertensión pulmonar de la alta altitud y el mal de montaña crónico. Se describen sus características fisiológicas y de la circulación pulmonar, así como su perfil clínico y el diagnóstico.

SPECT imaging of pulmonary vascular disease in bleomycin-induced lung fibrosis using a vascular endothelium tracer

Background

Pulmonary hypertension (PH) complicating idiopathic pulmonary fibrosis (IPF) is associated to worse outcome. There is a great need for a non-invasive diagnostic modality to detect and evaluate the severity of pulmonary vascular disease (PVD). ^99mTc-PulmoBind is a novel imaging agent that binds to the adrenomedullin (AM) receptor on the pulmonary microvascular endothelium. SPECT imaging employing the endothelial cell tracer ^99mTc-PulmoBind was used to assess PVD associated with lung fibrosis.

Methods

Rats with selective right lung bleomycin-induced fibrosis were compared to control rats. SPECT imaging was performed after three weeks with ^99mTc-PulmoBind and ^99mTc-macroaggregates of albumin (MAA). PH and right ventricular (RV) function were assessed by echocardiography. Lung perfusion was evaluated by fluorescent microangiography. Lung AM receptor expression was measured by qPCR and by immunohistology. Relevance to human IPF was explored by measuring AM receptor expression in lung biopsies from IPF patients and healthy controls.

Results

The bleomycin group developed preferential right lung fibrosis with remodeling and reduced perfusion as assessed with fluorescent microangiography. These rats developed PH with RV hypertrophy and dysfunction. ^99mTc-PulmoBind uptake was selectively reduced by 50% in the right lung and associated with reduced AM receptor expression, PH and RV hypertrophy. AM receptor was co-expressed with the endothelial cell protein CD31 in alveolar capillaries, and markedly reduced after bleomycin. Quantitative dynamic analysis of ^99mTc-PulmoBind uptake in comparison to ^99mTc-MAA revealed that the latter distributed only according to flow, with about 60% increased left lung uptake while left lung uptake of ^99mTc-PulmoBind was not affected. Lung from human IPF patients showed important reduction in AM receptor expression closely associated with CD31.

Conclusions

SPECT imaging with ^99mTc-PulmoBind detects PVD and its severity in bleomycin-induced lung fibrosis. Reduced AM receptor expression in human IPF supports further clinical development of this imaging approach.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01836-3.

Chronic obstructive pulmonary disease and atrial fibrillation: an interdisciplinary perspective

Chronic obstructive pulmonary disease (COPD) is highly prevalent among patients with atrial fibrillation (AF), shares common risk factors, and adds to the overall morbidity and mortality in this population. Additionally, it may promote AF and impair treatment efficacy. The prevalence of COPD in AF patients is high and is estimated to be ∼25%. Diagnosis and treatment of COPD in AF patients requires a close interdisciplinary collaboration between the electrophysiologist/cardiologist and pulmonologist. Differential diagnosis may be challenging, especially in elderly and smoking patients complaining of unspecific symptoms such as dyspnoea and fatigue. Routine evaluation of lung function and determination of natriuretic peptides and echocardiography may be reasonable to detect COPD and heart failure as contributing causes of dyspnoea. Acute exacerbation of COPD transiently increases AF risk due to hypoxia-mediated mechanisms, inflammation, increased use of beta-2 agonists, and autonomic changes. Observational data suggest that COPD promotes AF progression, increases AF recurrence after cardioversion, and reduces the efficacy of catheter-based antiarrhythmic therapy. However, it remains unclear whether treatment of COPD improves AF outcomes and which metric should be used to determine COPD severity and guide treatment in AF patients. Data from non-randomized studies suggest that COPD is associated with increased AF recurrence after electrical cardioversion and catheter ablation. Future prospective cohort studies in AF patients are needed to confirm the relationship between COPD and AF, the benefits of treatment of either COPD or AF in this population, and to clarify the need and cost-effectiveness of routine COPD screening.

Pulmonary Hypertension in Association with Lung Disease: Quantitative CT and Artificial Intelligence to the Rescue? State-of-the-Art Review

Accurate phenotyping of patients with pulmonary hypertension (PH) is an integral part of informing disease classification, treatment, and prognosis. The impact of lung disease on PH outcomes and response to treatment remains a challenging area with limited progress. Imaging with computed tomography (CT) plays an important role in patients with suspected PH when assessing for parenchymal lung disease, however, current assessments are limited by their semi-qualitative nature. Quantitative chest-CT (QCT) allows numerical quantification of lung parenchymal disease beyond subjective visual assessment. This has facilitated advances in radiological assessment and clinical correlation of a range of lung diseases including emphysema, interstitial lung disease, and coronavirus disease 2019 (COVID-19). Artificial Intelligence approaches have the potential to facilitate rapid quantitative assessments. Benefits of cross-sectional imaging include ease and speed of scan acquisition, repeatability and the potential for novel insights beyond visual assessment alone. Potential clinical benefits include improved phenotyping and prediction of treatment response and survival. Artificial intelligence approaches also have the potential to aid more focused study of pulmonary arterial hypertension (PAH) therapies by identifying more homogeneous subgroups of patients with lung disease. This state-of-the-art review summarizes recent QCT developments and potential applications in patients with PH with a focus on lung disease.

Redox Regulation, Oxidative Stress, and Inflammation in Group 3 Pulmonary Hypertension

Group 3 pulmonary hypertension (PH), which occurs secondary to hypoxia lung diseases, is one of the most common causes of PH worldwide and has a high unmet clinical need. A deeper understanding of the integrative pathological and adaptive molecular mechanisms within this group is required to inform the development of novel drug targets and effective treatments. The production of oxidants is increased in PH Group 3, and their pleiotropic roles include contributing to disease progression by promoting prolonged hypoxic pulmonary vasoconstriction and pathological pulmonary vascular remodeling, but also stimulating adaptation to pathological stress that limits the severity of this disease. Inflammation, which is increasingly being viewed as a key pathological feature of Group 3 PH, is subject to complex regulation by redox mechanisms and is exacerbated by, but also augments oxidative stress. In this review, we investigate aspects of this complex crosstalk between inflammation and oxidative stress in Group 3 PH, focusing on the redox-regulated transcription factor NF-κB and its upstream regulators toll-like receptor 4 and high mobility group box protein 1. Ultimately, we propose that the development of specific therapeutic interventions targeting redox-regulated signaling pathways related to inflammation could be explored as novel treatments for Group 3 PH.

In-Hospital Outcomes of Patients With Pulmonary Hypertension and Cirrhosis: A 6-Year Population Cohort Study of Over One Million Patients

INTRODUCTION

There is a paucity of data on the influence of sex, race, insurance, pulmonary hypertension-related complications, and cirrhosis-related complications on mortality, hospital length of stay (LOS), and total hospital charges. The aim of this study was to identify risk factors in a national population cohort (in the USA) admitted to hospital between 2012 and 2017.

METHODS

All patients aged > 18 years with pulmonary hypertension and cirrhosis, who had been admitted to hospital between 2012 and 2017, were identified from the US Nationwide Inpatient Sample (NIS), a large publicly available all-payer inpatient care database in the USA. Multivariate regression analysis was used to estimate the odds ratios of in-hospital mortality, average length of hospital stay, and hospital charges, after adjusting for age, gender, race, primary insurance payer status, hospital type and size (number of beds), hospital region, hospital teaching status, and other demographic characteristics.

RESULTS

Our study identified 1,111,594 patients who had been discharged from hospital from 2012 to 2017. Of these patients, 355,455 were admitted with pulmonary hypertension, with 9.8% having cirrhosis as a complication (n = 34,986). The analysis revealed that patients with both pulmonary hypertension and cirrhosis compared to patients with only pulmonary hypertension experience increased mortality, hospital LOS, total hospital charges, and pulmonary hypertension-related and cirrhosis-related complications. Independent positive predictors of mortality were Asian/Pacific Islander race and "other" insurance status (worker's compensation; other US health benefits plans [CHAMPUS/TRICARE, CHAMPVA, Title V]). Independent positive predictors of increased hospital LOS were black race and "other" patients (more than one race/mixed). Independent positive predictors of increased total hospital charges were male gender, Hispanic ethnicity, Asian/Pacific Islander race, and other insurance status. Pulmonary hypertension-related complications (cor pulmonale, pulmonary embolism, hemoptysis, cardiac arrest, atrial fibrillation, ventricular tachycardia) and cirrhosis-related complications (ascites, hepatorenal syndrome, hepatic encephalopathy, variceal bleeding, portal hypertension) were independent positive predictors of mortality, hospital LOS, and total hospital charges.

CONCLUSIONS

Patients with pulmonary hypertension and cirrhosis have increased mortality and hospital utilization compared to patients with only pulmonary hypertension. We identified key drivers for these outcomes. Targeted interventions, such as novel medications, right-to-left shunts, more evaluations for lung transplantation, and reversal of pulmonary vacular remodeling, are needed for the subgroups identified in this study in order to improve outcomes.

Dysregulation of BMP9/BMPR2/SMAD signalling pathway contributes to pulmonary fibrosis and pulmonary hypertension induced by bleomycin in rats

BACKGROUND AND PURPOSE

Pulmonary hypertension related to pulmonary fibrosis is classed as WHO Group III, one of the most common groups which lacks effective treatment options. In this study, we aimed to uncover the underlying mechanisms, particularly the involvement of the BMP9/BMPR2/SMAD signalling pathway, in this subtype of pulmonary hypertension.

EXPERIMENTAL APPROACH

Male Sprague Dawley rats were used to establish a model of pulmonary hypertension with pulmonary fibrosis, induced by bleomycin. Haemodynamic and lung functions were measured, along with histological and immunohistochemical examinations. Primary cultures of rat pulmonary microvascular endothelial cells (PMVECs) were analysed with western blots, apoptosis assays and immunohistochemistry.

KEY RESULTS

Early (7 days) after bleomycin treatment of rats, pulmonary arterial thickening and severe loss of pulmonary arterial endothelium were observed, followed (14 days) by increased right ventricular systolic pressure and right ventricular hypertrophy. Marked down-regulation of the BMP9/BMPR2/SMAD signalling pathway was markedly down-regulated in lung tissues from bleomycin-treated rats (throughout the 7- to 35-day treatment period) and bleomycin-treated rat PMVECs, along with excessive cell apoptosis and loss of pulmonary arterial endothelium. Treatment with recombinant human bone morphogenetic protein 9 (rhBMP9) attenuated these aspects of bleomycin-induced pulmonary hypertension, by restoring disrupted BMP9/BMPR2/SMAD signalling.

CONCLUSION AND IMPLICATIONS

In bleomycin-treated rats, early and persisting suppression of the BMP9/BMPR2/SMAD signalling pathway triggered severe loss of pulmonary arterial endothelium and subsequent pulmonary arterial vascular remodelling, contributing to the development of pulmonary hypertension. Therapeutic approaches reinforcing BMP9/BMPR2/SMAD signalling might be ideal strategies for this subtype of pulmonary hypertension.

LINKED ARTICLES

This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

Pro-inflammatory effects of crystalline- and nano-sized non-crystalline silica particles in a 3D alveolar model

BACKGROUND

Silica nanoparticles (SiNPs) are among the most widely manufactured and used nanoparticles. Concerns about potential health effects of SiNPs have therefore risen. Using a 3D tri-culture model of the alveolar lung barrier we examined effects of exposure to SiNPs (Si10) and crystalline silica (quartz; Min-U-Sil) in the apical compartment consisting of human alveolar epithelial A549 cells and THP-1-derived macrophages, as well as in the basolateral compartment with Ea.hy926 endothelial cells. Inflammation-related responses were measured by ELISA and gene expression.

RESULTS

Exposure to both Si10 and Min-U-Sil induced gene expression and release of CXCL8, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α) and interleukin-1β (IL-1β) in a concentration-dependent manner. Cytokine/chemokine expression and protein levels were highest in the apical compartment. Si10 and Min-U-Sil also induced expression of adhesion molecules ICAM-1 and E-selectin in the apical compartment. In the basolateral endothelial compartment we observed marked, but postponed effects on expression of all these genes, but only at the highest particle concentrations. Geneexpressions of heme oxygenase-1 (HO-1) and the metalloproteases (MMP-1 and MMP-9) were less affected. The IL-1 receptor antagonist (IL-1RA), markedly reduced effects of Si10 and Min-U-Sil exposures on gene expression of cytokines and adhesion molecules, as well as cytokine-release in both compartments.

CONCLUSIONS

Si10 and Min-U-Sil induced gene expression and release of pro-inflammatory cytokines/adhesion molecules at both the epithelial/macrophage and endothelial side of a 3D tri-culture. Responses in the basolateral endothelial cells were only induced at high concentrations, and seemed to be mediated by IL-1α/β released from the apical epithelial cells and macrophages.