Treatment of pulmonary hypertension associated with COPD: a systematic review

Recent Evidences of Epigenetic Alterations in Chronic Obstructive Pulmonary Disease (COPD): A Systematic Review

Chronic obstructive pulmonary disease (COPD) is a heterogeneous inflammatory condition characterized by progressive airflow limitation, which may be caused by genetic and environmental factors. Furthermore, epigenetic mechanisms could provide valuable insights into the complex interactions between environment and genes and subsequent development of the disease. The aim of this study is to provide a systematic review of the latest knowledge on epigenetic modifications that characterize COPD, summarizing epigenetic factors that could serve as potential novel biomarkers and therapeutic targets for the treatment of COPD patients. We queried the PubMed and Scopus electronic databases with specific keywords, in May 2024, according to the PRISMA guidelines, and articles were included if they met all the inclusion criteria and survived a quality assessment. We identified 5414 publications in our systematic search. Among them, only 51 articles met the criteria of COPD-associated epigenetic modifications in human patients compared to the control group. Eight studies described DNA methylation, one study histone modifications, and forty-two studies non-coding RNAs. Apoptosis and inflammatory pathways have been found to be the main mechanisms regulated by epigenetic elements in COPD patients. In addition, non-coding RNAs may be useful as biomarkers or therapeutic targets of pulmonary disease. Future studies will be needed to confirm the role of epigenetic elements associated with COPD.

Novel Therapies for Right Ventricular Failure

PURPOSE OF REVIEW

Traditionally viewed as a passive player in circulation, the right ventricle (RV) has become a pivotal force in hemodynamics. RV failure (RVF) is a recognized complication of primary cardiac and pulmonary vascular disorders and is associated with a poor prognosis. Unlike treatments for left ventricular failure (LVF), strategies such as adrenoceptor signaling inhibition and renin-angiotensin system modulation have shown limited success in RVF. This review aims to reassure about the progress in RVF treatment by exploring the potential of contemporary therapies for heart failure, including angiotensin receptor and neprilysin inhibitors, sodium-glucose co-transporter 2 inhibitors, and soluble guanylate cyclase stimulators, which may be beneficial for treating RV failure, particularly when associated with left heart failure. Additionally, it examines novel therapies currently in the pipeline.

RECENT FINDINGS

Over the past decade, a new wave of RVF therapies has emerged, both pharmacological and device-centered. Novel pharmacological interventions targeting metabolism, calcium homeostasis, oxidative stress, extracellular matrix remodeling, endothelial function, and inflammation have shown significant promise in preclinical studies. There is also a burgeoning interest in the potential of epigenetic modifications as therapeutic targets for RVF. Undoubtedly, a deeper understanding of the mechanisms underlying RV failure, both with and without pulmonary hypertension, is urgently needed. This knowledge is not just a theoretical pursuit, but a crucial step that could lead to the development of pharmacological and cell-based therapeutic options that directly target the RV and pulmonary vasculature, aligning with the principles of precision medicine.

The Saudi Thoracic Society Evidence-based guidelines for the diagnosis and management of chronic obstructive pulmonary disease

The Saudi Thoracic Society (STS) developed an updated evidence-based guideline for diagnosing and managing chronic obstructive pulmonary disease (COPD) in Saudi Arabia. This guideline aims to provide a comprehensive and unbiased review of current evidence for assessing, diagnosing, and treating COPD. While epidemiological data on COPD in Saudi Arabia are limited, the STS panel believes that the prevalence is increasing due to rising rates of tobacco smoking. The key objectives of the guidelines are to facilitate accurate diagnosis of COPD, identify the risk for COPD exacerbations, and provide recommendations for relieving and reducing COPD symptoms in stable patients and during exacerbations. A unique aspect of this guideline is its simplified, practical approach to classifying patients into three classes based on symptom severity using the COPD Assessment Test and the risk of exacerbations and hospitalizations. The guideline provides the reader with an executive summary of recommended COPD treatments based on the best available evidence and also addresses other major aspects of COPD management and comorbidities. This guideline is primarily intended for use by internists and general practitioners in Saudi Arabia.

Pulmonary hypertension associated to left heart disease: Phenotypes and treatment

Pulmonary hypertension associated to left heart disease (PH-LHD) refers to a clinical and haemodynamic condition of pulmonary hypertension associated with a heterogeneous group of diseases affecting any of the compartments that form the left ventricle and left atrium. PH-LHD is the most common cause of PH, accounting for 65-80 % of diagnoses. Based on the haemodynamic phase of the disease, PH-LDH is classified into three subgroups: postcapillary PH, isolated postcapillary PH and combined pre-postcapillary PH (CpcPH). Several signaling pathways involved in the regulation of vascular tone are dysfunctional in PH-LHD, including nitric oxide, MAP kinase and endothelin-1 pathways. These pathways are the same as those altered in PH group 1, however PH-LHD can heardly be treated by specific drugs that act on the pulmonary circulation. In this manuscript we provide a state of the art of the available clinical trials investigating the safety and efficacy of PAH-specific drugs, as well as drugs active in patients with heart failure and PH-LHD. We also discuss the different phenotypes of PH-LHD, as well as molecular targets and signaling pathways potentially involved in the pathophysiology of the disease. Finally we will mention some new emerging therapies that can be used to treat this form of PH.

Pulmonary Vascular Disease in Chronic Obstructive Pulmonary Disease

Pulmonary hypertension (PH) is a vascular disease characterized by pulmonary artery remodeling and right heart failure. PH related to COPD is a precapillary form of the disease, with hemodynamic measurements including a mean pulmonary artery pressure of greater than 20 mm Hg, a wedge pressure of less than 15 mm Hg, and a pulmonary vascular resistance of greater than 3 WU (Woods units), categorized under the World Health Organization classification as group 3. The presence of PH in COPD has been known to increase morbidity and mortality. Limited studies have evaluated treatment options for PH related to COPD.

Pulmonary hypertension associated with lung diseases

Pulmonary hypertension (PH) associated with chronic lung disease (CLD) is both common and underrecognised. The presence of PH in the setting of lung disease has been consistently shown to be associated with worse outcomes. Recent epidemiological studies have advanced understanding of the heterogeneity of this patient population and shown that defining both the specific type of CLD as well as the severity of PH (i.e. deeper phenotyping) is necessary to inform natural history and prognosis. A systematic diagnostic approach to screening and confirmation of suspected PH in CLD is recommended. Numerous uncontrolled studies and one phase 3 randomised, controlled trial have suggested a benefit in treating PH in some patients with CLD, specifically those with fibrotic interstitial lung disease (ILD). However, other studies in diseases such as COPD-PH showed adverse outcomes with some therapies. Given the expanding list of approved pharmacological treatments for pulmonary arterial hypertension, developing a treatment algorithm for specific phenotypes of CLD-PH is required. This article will summarise existing data in COPD, ILD and other chronic lung diseases, and provide recommendations for classification of CLD-PH and approach to the diagnosis and management of these challenging patients.

Phase 1 Study of MK-5475, an Inhaled Soluble Guanylate Cyclase Stimulator, in Participants with Pulmonary Hypertension Associated with Chronic Obstructive Pulmonary Disease

Purpose

This phase 1 study (NCT04370873) evaluated safety and pharmacokinetics/pharmacodynamics (PK/PD) of MK-5475 in participants with pulmonary hypertension associated with COPD (PH-COPD).

Methods

Eligible participants were 40-80 years old with COPD (FEV1/FVC <0.7; FEV1 >30% predicted) and PH (mean pulmonary arterial pressure ≥25 mmHg). Participants were randomized 2:1 to MK-5475 or placebo via dry-powder inhaler once daily for 7 days in Part 1 (360 µg) or 28 days in Part 2 (380 µg). Safety was assessed by adverse events (AEs) and arterial blood oxygenation. Part-2 participants had pulmonary vascular resistance (PVR; primary PD endpoint) and pulmonary blood volume (PBV; secondary PD endpoint) measured at baseline and Day 28. A non-informative prior was used to calculate posterior probability (PP) that the between-group difference (MK-5475 - placebo) in mean percent reduction from baseline in PVR was less than -15%.

Results

Nine participants were randomized in Part 1, and 14 participants in Part 2. Median age of participants (86.4% male) was 68.5 years (41-77 years); 95.5% had moderate-to-severe COPD. Incidences of AEs were comparable between MK-5475 and placebo: overall (5/14 [36%] versus 5/8 [63%]), drug-related (1/14 [7%] versus 2/8 [25%]), and serious (1/14 [7%] versus 1/8 [13%]). MK-5475 caused no meaningful changes in arterial blood oxygenation or PBV. MK-5475 versus placebo led to numerical improvements from baseline in PVR (-21.2% [95% CI: -35.4, -7.0] versus -5.4% [95% CI: -83.7, 72.9]), with between-group difference in PVR less than -15% and calculated PP of 51%.

Conclusion

The favorable safety profile and numerical reductions in PVR observed support further clinical development of inhaled MK-5475 for PH-COPD treatment.

Pulmonary hypertension in chronic obstructive pulmonary disease: current understanding, knowledge gaps and future directions

PURPOSE OF REVIEW

Despite the advent of effective and mechanistically diverse treatments for pulmonary arterial hypertension (PAH) and their positive impacts on the functional capacities and outcomes for PAH patients, the much larger population of patients with pulmonary hypertension (PH) in chronic lung diseases like chronic obstructive pulmonary disease (PH-COPD) remain without effective therapies.

RECENT FINDINGS

In this review, we will highlight advances in the understanding of PH-COPD pathobiology, the clinical impact comorbid PH has on COPD outcomes, and detail the spectrum of disease and clinical phenotypes that encompass the heterogenous disease manifestations of PH-COPD. Finally, we will examine recent studies exploring the effects of potential treatments for PH-COPD and highlight sub-populations and treatment options that warrant further study.

SUMMARY

As the PAH population-base ages and comorbid diseases become more frequently diagnosed in PAH patients, the need to clearly delineate subpopulations for clinical applications of PH therapies and research becomes even more urgent. Through an improved understanding of the clinical phenotypes of PH-COPD and the overlap with certain subpopulations of PAH, a framework for future research and potential for therapeutic impact is highlighted.

Effects of pulmonary rehabilitation on systemic inflammation in chronic obstructive pulmonary disease: a meta-analysis

Chronic obstructive pulmonary disease (COPD) is marked by both lung-related and systemic symptoms, notably chronic inflammation. Despite pulmonary rehabilitation (PR) being a critical treatment for COPD, its influence on systemic inflammation remains unclear. This meta-analysis was conducted to assess PR's effect on circulating inflammatory markers in COPD patients. We systematically reviewed databases like PubMed, EMBASE, and Web of Science to select randomized controlled trials and observational studies that investigated the impact of PR on systemic inflammation. We calculated the mean differences (MD) in inflammatory markers before and after PR using a random-effects model and assessed the risk of bias with established tools. Our study included six investigations (four RCTs, two observational) with 147 COPD patients. Our findings show notable increases in IL-6 (MD 0.44, 95% CI 0.17-0.70, P = 0.001), CRP (MD 0.56, 95% CI 0.31-0.81, P<0.00001), and TNF-alpha (MD 0.41, 95% CI 0.12-0.70, P = 0.005) following PR. However, sensitivity analysis pinpointed the study by El-Kader et al. as a key influence on these results. Excluding this study led to nonsignificant changes. Thus, our meta-analysis uncovers an unanticipated rise in inflammatory markers post-PR in COPD patients, questioning the assumed anti-inflammatory benefits of PR.

Analyzing the molecular mechanism of xuefuzhuyu decoction in the treatment of pulmonary hypertension with network pharmacology and bioinformatics and verifying molecular docking

BACKGROUND

XueFuZhuYu (XFZY), a typical Chinese herbal formula, has remarkable clinical effects for treating Pulmonary Hypertension (PH) with unclear mechanisms. Our research involved the utilization of network pharmacology to explore the traditional Chinese herbal monomers and their related targets within XFZY for PH treatment. Furthermore, molecular docking verification was performed.

METHODS

The XFZY's primary active compounds, along with their corresponding targets, were both obtained from the TCMSP, ChEMBL, and UniProt databases. The target proteins relevant to PH were sifted through OMIM, GeneCards and TTD databases. The common "XFZY-PH" targets were evaluated with Disease Ontology (DO), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses with the assistance of R software. The Protein-Protein Interaction (PPI) network and compound-target-pathway network were constructed and a systematic analysis of network parameters was performed by the powerful software Cytoscape. Molecular docking was employed for assessing and verifying the interactions between the core targets and the top Chinese herbal monomer.

RESULTS

The screening included 297 targets of active compounds in XFZY and 8400 PH-related targets. DO analysis of the above common 268 targets indicated that the treatment of the diseases by XFZY is mediated by genes related to Chronic Obstructive Pulmonary Disease (COPD), Obstructive Lung Disease (OLD), ischemia, and myocardial infarction. The findings from molecular docking indicated that the binding energies of 57 ligand-receptor pairs in PH and 20 ligand-receptor pairs in COPD-PH were lower than -7kJ•mol-1.

CONCLUSIONS

This study indicates that XFZY is a promising option within traditional Chinese medicine compound preparation for combating PH, particularly in cases associated with COPD. Our demonstration of the specific molecular mechanism of XFZY anti-PH and its effective active ingredients provides a theoretical basis for better clinical application of the compound.

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.

Management of Pulmonary Hypertension Associated with Chronic Lung Disease

Pulmonary hypertension (PH) is a common complication of chronic lung diseases, particularly in chronic obstructive pulmonary disease (COPD) and interstitial lung diseases (ILD) and especially in advanced disease. It is associated with greater mortality and worse clinical course. Given the high prevalence of some respiratory disorders and because lung parenchymal abnormalities might be present in other PH groups, the appropriate diagnosis of PH associated with respiratory disease represents a clinical challenge. Patients with chronic lung disease presenting symptoms that exceed those expected by the pulmonary disease should be further evaluated by echocardiography. Confirmatory right heart catheterization is indicated in candidates to surgical treatments, suspected severe PH potentially amenable with targeted therapy, and, in general, in those conditions where the result of the hemodynamic assessment will determine treatment options. The treatment of choice for these patients who are hypoxemic is long-term oxygen therapy and pulmonary rehabilitation to improve symptoms. Lung transplant is the only curative therapy and can be considered in appropriate cases. Conventional vasodilators or drugs approved for pulmonary arterial hypertension (PAH) are not recommended in patients with mild-to-moderate PH because they may impair gas exchange and their lack of efficacy shown in randomized controlled trials. Patients with severe PH (as defined by pulmonary vascular resistance >5 Wood units) should be referred to a center with expertise in PH and lung diseases and ideally included in randomized controlled trials. Targeted PAH therapy might be considered in this subset of patients, with careful monitoring of gas exchange. In patients with ILD, inhaled treprostinil has been shown to improve functional ability and to delay clinical worsening.

Burden of pulmonary hypertension due to chronic obstructive pulmonary disease: Analysis of exacerbations and healthcare resource utilization in the United States

BACKGROUND

The burden of pulmonary hypertension (PH) among patients with chronic obstructive pulmonary disease (COPD) is not well understood. The present retrospective cohort study aimed to quantify the clinical and economic burden of PH in patients with COPD.

METHODS

Adults with COPD were retrospectively identified in the Optum® Clinformatics® Data Mart between July 1, 2016 and June 30, 2021. Those diagnosed with PH were assigned to the PH-COPD cohort and those without a diagnosis of PH were assigned to the COPD cohort. Outcomes, including the number of visits for exacerbations and all-cause and COPD-related healthcare resource utilization (HCRU) and costs per patient per month (PPPM), were compared between cohorts. Baseline and study outcomes were analyzed descriptively. For significance testing, continuous variables were analyzed using Student's t-tests and categorical variables were analyzed using Chi-square tests.

RESULTS

A total of 1627 patients with PH-COPD were matched 1:1 to COPD patients without PH. A greater percentage of PH-COPD patients experienced COPD exacerbations vs. the COPD cohort (p < 0.001) and the PH-COPD cohort had more total (p < 0.001) and severe exacerbation-related visits PPPM (p < 0.001). All-cause and COPD-related HCRU PPPM estimates were higher among the PH-COPD cohort vs. the COPD cohort (p < 0.01). Total all-cause (p < 0.001) and COPD-related costs (p < 0.001) were higher among PH-COPD patients than COPD patients.

CONCLUSIONS

Patients with PH-COPD had higher rates of severe exacerbations, hospitalizations, and costs compared to COPD patients without PH, underscoring the need for targeted therapies to prevent and manage PH in patients with COPD.

Role of prostanoids, nitric oxide and endothelin pathways in pulmonary hypertension due to COPD

Pulmonary hypertension (PH) due to chronic obstructive pulmonary disease (COPD) is classified as Group 3 PH, with no current proven targeted therapies. Studies suggest that cigarette smoke, the most risk factor for COPD can cause vascular remodelling and eventually PH as a result of dysfunction and proliferation of pulmonary artery smooth muscle cells (PASMCs) and pulmonary artery endothelial cells (PAECs). In addition, hypoxia is a known driver of pulmonary vascular remodelling in COPD, and it is also thought that the presence of hypoxia in patients with COPD may further exaggerate cigarette smoke-induced vascular remodelling; however, the underlying cause is not fully understood. Three main pathways (prostanoids, nitric oxide and endothelin) are currently used as a therapeutic target for the treatment of patients with different groups of PH. However, drugs targeting these three pathways are not approved for patients with COPD-associated PH due to lack of evidence. Thus, this review aims to shed light on the role of impaired prostanoids, nitric oxide and endothelin pathways in cigarette smoke- and hypoxia-induced pulmonary vascular remodelling and also discusses the potential of using these pathways as therapeutic target for patients with PH secondary to COPD.

Efficacy of Sildenafil in Patients with Severe COVID-19 and Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is common in severe coronavirus disease 2019 (COVID-19) and worsens the prognosis. Sildenafil, a phosphodiesterase-5 inhibitor, is approved for PAH treatment but little is known about its efficacy in cases of severe COVID-19 with PAH. This study aimed to investigate the clinical efficacy of sildenafil in patients with severe COVID-19 and PAH. Intensive care unit (ICU) patients were randomly assigned to receive sildenafil or a placebo, with 75 participants in each group. Sildenafil was administered orally at 0.25 mg/kg t.i.d. for one week in a placebo-controlled, double-blind manner as an add-on therapy alongside the patient's routine treatment. The primary endpoint was one-week mortality, and the secondary endpoints were the one-week intubation rate and duration of ICU stay. The mortality rate was 4% vs. 13.3% (p = 0.078), the intubation rate was 8% and 18.7% (p = 0.09), and the length of ICU stay was 15 vs. 19 days (p < 0.001) for the sildenafil and placebo groups, respectively. If adjusted for PAH, sildenafil treatment significantly reduced mortality and intubation risks: OR = 0.21 (95% CI: 0.05-0.89) and OR = 0.26 (95% CI: 0.08-0.86), respectively. Sildenafil demonstrated some clinical efficacy in patients with severe COVID-19 and PAH and should be considered as an add-on therapy in these patients.

Inhibition of miR-4640-5p alleviates pulmonary hypertension in chronic obstructive pulmonary disease patients by regulating nitric oxide synthase 1

BACKGROUND

Pulmonary hypertension (PH) is a devastating disease characterized by vasoconstriction and vascular remodeling, leading to right ventricular failure and death. PH is a common complication of chronic obstructive pulmonary disease (COPD). Accumulating evidence demonstrate that microRNAs participate in the pathobiology of PH in COPD patients. In this study, we aimed to evaluate the expression and function of microRNA-4640-5p (miR-4640-5p) in PH.

METHODS

The mRNA and protein levels were determined by quantitative polymerase chain reaction (qPCR) and western blot, separately. Functional assays and western blot were performed to determine the effects of miR-4640-5p and NOS1 on cell growth, migration. Besides, the dual-luciferase reporter assays were used to validate miR-4640-5p and NOS1 interactions.

RESULTS

We found that miR-4640-5p expression was significantly higher in the lung tissues of COPD-PH patients than in the healthy controls while higher expression of miR-4640-5p was correlated with more severe COPD-PH. By using pulmonary artery smooth muscle cell (PASMC) in in vitro assays, we demonstrated that inhibition of miR-4640-5p suppressed cell proliferation and migration of PASMC via regulating mTOR/S6 signaling. Bioinformatics analysis and validation experiments revealed that nitric oxide synthase 1 (NOS1) was a direct downstream target of miR-4640-5p. Overexpression of NOS1 partially antagonized the effect of miR-4640-5p in regulating PASMC cell proliferation and migration. In addition, our findings suggested that miR-4640-5p/NOS1 axis regulated mitochondrial dynamics in PASMCs. Furthermore, in the hypoxia-induced PH rat model, inhibition of miR-4640-5p ameliorated PH with reduced right ventricular systolic pressure and Fulton index.

CONCLUSIONS

miR-4640-5p regulates PH via targeting NOS1, which provides a potential diagnostic biomarker and therapeutic target for COPD-PH patients.

The Potential Important Role of Mitochondrial Rieske Iron-Sulfur Protein as a Novel Therapeutic Target for Pulmonary Hypertension in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, which is often due to pulmonary hypertension (PH). The underlying molecular mechanisms are poorly understood, and current medications are neither specific nor always effective. In this review, we highlight the recent findings on the roles of altered mitochondrial bioenergetics in PH in COPD. We also discuss the central role of mitochondrial reactive oxygen species (ROS) generation mediated by Rieske iron-sulfur protein (RISP) and review the contributions of RISP-dependent DNA damage and NF-κB-associated inflammatory signaling. Finally, the potential importance of mitochondrial RISP and its associated molecules as novel therapeutic targets for PH in COPD are meticulously discussed.