Severe pulmonary hypertension associated with lung disease is characterised by a loss of small pulmonary vessels on quantitative computed tomography

A systematic review of the role of quantitative CT in the prognostication and disease monitoring of interstitial lung disease

BACKGROUND

The unpredictable trajectory and heterogeneity of interstitial lung disease (ILDs) make prognostication challenging. Current prognostic indices and outcome measures have several limitations. Quantitative computed tomography (qCT) provides automated numerical assessment of CT imaging and has shown promise when applied to the prognostication and disease monitoring of ILD. This systematic review aims to highlight the current evidence underpinning the prognostic value of qCT in predicting outcomes in ILD.

METHODS

A comprehensive search of four databases (Medline, EMCare, Embase and CINAHL (Cumulative Index to Nursing and Allied Health Literature)) was conducted for studies published up to and including 22 November 2024. A modified CHARMS (CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies) checklist was used for data extraction. The risk of bias was assessed using a Quality in Prognostic Studies template.

RESULTS

The search identified 1134 unique studies, of which 185 studies met inclusion and exclusion criteria. Commonly studied ILD subtypes included idiopathic pulmonary fibrosis (41%, n=75), mixed subtypes (26%, n=48) and systemic sclerosis ILD (16%, n=30). Numerous studies showed significant prognostic signals, even when adjusted for common covariates and/or significant correlation between serial qCT biomarkers and conventional outcome measures. Heterogenous and nonstandardised reporting methods meant that direct comparison or meta-analysis of studies was not possible. Studies were limited by the use of retrospective methodology without prospective validation and significant study attrition.

DISCUSSION

qCT has shown efficacy in the prognostication and disease monitoring of a range of ILDs. Hurdles exist to widespread adoption including governance concerns, appropriate algorithm anchoring and standardisation of image acquisition. International collaboration is underway to address these hurdles, paving the way for regulatory approval and ultimately patient benefit.

Review of the Diagnosis and Management of Pulmonary Hypertension Associated with Interstitial Lung Disease (ILD-PH)

Pulmonary hypertension associated with interstitial lung disease (ILD-PH) frequently complicates the course of patients with fibrotic ILD. In this narrative review, the authors assess current diagnostic tools and management considerations in ILD-PH patients. ILD-PH is associated with increased morbidity and mortality and may be suggested by the presence of symptoms out of proportion to the extent of the ILD. There are other clues to the presence of PH in the context of ILD including the need for supplemental oxygen, a reduced DLCO especially if accompanied by a disproportionately higher forced vital capacity, imaging demonstrating an enlarged pulmonary artery or a dilated right ventricle, or objective evidence of a reduced exercise capacity. While echocardiography is one screening tool, right heart catheterization remains the gold standard for the diagnosis of PH. When appropriate, treatment with inhaled treprostinil, or possibly other pulmonary vasodilators, may be indicated.

Artificial Intelligence Unveils the Unseen: Mapping Novel Lung Patterns in Bronchiectasis via Texture Analysis

Background and Objectives: Thin-section CT (TSCT) is currently the most sensitive imaging modality for detecting bronchiectasis. However, conventional TSCT or HRCT may overlook subtle lung involvement such as alveolar and interstitial changes. Artificial Intelligence (AI)-based analysis offers the potential to identify novel information on lung parenchymal involvement that is not easily detectable with traditional imaging techniques. This study aimed to assess lung involvement in patients with bronchiectasis using the Bronchiectasis Radiologically Indexed CT Score (BRICS) and AI-based quantitative lung texture analysis software (IMBIO, Version 2.2.0). Methods: A cross-sectional study was conducted on 45 subjects diagnosed with bronchiectasis. The BRICS severity score was used to classify the severity of bronchiectasis into four categories: Mild, Moderate, Severe, and tractional bronchiectasis. Lung texture mapping using the IMBIO AI software tool was performed to identify abnormal lung textures, specifically focusing on detecting alveolar and interstitial involvement. Results: Based on the Bronchiectasis Radiologically Indexed CT Score (BRICS), the severity of bronchiectasis was classified as Mild in 4 (8.9%) participants, Moderate in 14 (31.1%), Severe in 11 (24.4%), and tractional in 16 (35.6%). AI-based lung texture analysis using IMBIO identified significant alveolar and interstitial abnormalities, offering insights beyond conventional HRCT findings. This study revealed trends in lung hyperlucency, ground-glass opacity, reticular changes, and honeycombing across severity levels, with advanced disease stages showing more pronounced structural and vascular alterations. Elevated pulmonary vascular volume (PVV) was noted in cases with higher BRICSs, suggesting increased vascular remodeling in severe and tractional types. Conclusions: AI-based lung texture analysis provides valuable insights into lung parenchymal involvement in bronchiectasis that may not be detectable through conventional HRCT. Identifying significant alveolar and interstitial abnormalities underscores the potential impact of AI on improving the understanding of disease pathology and disease progression, and guiding future therapeutic strategies.

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.

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.

Chronic diesel exhaust exposure induced pulmonary vascular remodeling a potential trajectory for traffic related pulmonary hypertension

BACKGROUND

As one of the most common traffic-related pollutants, diesel exhaust (DE) confers high risk for cardiovascular and respiratory diseases. However, its impact on pulmonary vessels is still unclear.

METHODS

To explore the effects of DE exposure on pulmonary vascular remodeling, our study analyzed the number and volume of small pulmonary vessels in the diesel engine testers (the DET group) from Luoyang Diesel Engine Factory and the controls (the non-DET group) from the local water company, using spirometry and carbon content in airway macrophage (CCAM) in sputum. And then we constructed a rat model of chronic DE exposure, in which 12 rats were divided into the DE group (6 rats with 16-week DE exposure) and the control group (6 rats with 16-week clean air exposure). During right heart catheterization, right ventricular systolic pressure (RVSP) was assessed by manometry. Macrophage migration inhibitory factor (MIF) in lung tissues and bronchoalveolar lavage fluid (BALF) were measured by qRT-PCR and ELISA, respectively. Histopathological analysis for cardiovascular remodeling was also performed.

RESULTS

In DET cohort, the number and volume of small pulmonary vessels in CT were positively correlated with CCAM in sputum (P<0.05). Rat model revealed that chronic DE-exposed rats had elevated RVSP, along with increased wall thickness of pulmonary small vessels and right the ventricle. What's more, the MIF levels in BALF and lung tissues were higher in DE-exposed rats than the controls.

CONCLUSION

Apart from airway remodeling, DE also induces pulmonary vascular remodeling, which will lead to cardiopulmonary dysfunction.

Pulmonary vascular disease in chronic lung diseases: cause or comorbidity?

PURPOSE OF REVIEW

To provide timely and relevant insights into the complex relationship between pulmonary vascular disease (PVD) and chronic lung disease (CLD), focusing on the causative and consequential dynamics between these conditions.

RECENT FINDINGS

There are shared pathogenic mechanisms between pulmonary arterial hypertension (PAH) and group 3 pulmonary hypertension, including altered expression of mediators and growth factors implicated in both conditions. Factors such as hypoxia, hypoxemia, and hypercapnia also contribute to pulmonary vascular remodelling and endothelial dysfunction. However, the role of hypoxia as the sole driver of pulmonary hypertension in CLD is being reconsidered, particularly in chronic obstructive pulmonary disease (COPD), with evidence suggesting a potential role for cigarette smoke products in initiating pulmonary vascular impairment. On the other hand, interstitial lung disease (ILD) encompasses a group of heterogeneous lung disorders characterized by inflammation and fibrosis of the interstitium, leading to impaired gas exchange and progressive respiratory decline, which could also play a role as a cause of pulmonary hypertension.

SUMMARY

Understanding the intricate interplay between the pulmonary vascular compartment and the parenchymal and airway compartments in respiratory disease is crucial for developing effective diagnostic and therapeutic strategies for patients with PVD and CLD, with implications for both clinical practice and research.

Lung Fibrosis Is Linked to Increased Endothelial Cell Activation and Dysfunctional Vascular Barrier Integrity

Pulmonary fibrosis (PF) can be a fatal disease characterized by progressive lung scarring. It is still poorly understood how the pulmonary endothelium is involved in the disease pathogenesis. Differences of the pulmonary vasculature between patients and donors were analyzed using transmission electron microscopy, immunohistochemistry, and single-cell RNA sequencing. Vascular barrier resistance, endothelial-immune cell adhesion, and sensitivity to an inflammatory milieu were studied in vitro. Integrity and activation markers were measured by ELISA in human plasma. Transmission electron microscopy demonstrated abnormally swollen endothelial cells (ECs) in fibrotic lungs compared with donors. A more intense CD31 and von Willebrand Factor (vWF) and patchy vascular endothelial (VE)-Cadherin staining in fibrotic lungs supported the presence of a dysregulated endothelium. Integrity markers CD31, VE-Cadherin, Thrombomodulin, and VEGFR-2 (vascular endothelial growth factor receptor-2) and activation marker vWF gene expression was increased in different endothelial subpopulations (e.g., arterial, venous, general capillary, aerocytes) in PF. This was associated with a heightened sensitivity of fibrotic ECs to TNF-α or IFN-γ and elevated immune cell adhesion. The barrier strength was overall reduced in ECs from fibrotic lungs. vWF and IL-8 were increased in the plasma of patients, whereas VE-Cadherin, Thrombomodulin, and VEGFR-2 were decreased. VE-Cadherin staining was also patchy in biopsy tissue and was decreased in plasma samples of patients with PF 6 months after the initial diagnosis. Our data demonstrate highly abnormal ECs in PF. The vascular compartment is characterized by hyperactivation and increased immune cell adhesion, as well as dysfunctional endothelial barrier function. Reestablishing EC homeostasis and function might represent a new therapeutic option for fibrotic lung diseases.

Severe pulmonary hypertension in chronic obstructive pulmonary disease - From clinical perspective to histological evidence

Severe pulmonary hypertension (PH) in chronic obstructive pulmonary disease (COPD) is currently defined by an elevated mean pulmonary arterial pressure and strongly elevated pulmonary vascular resistance >5 wood units. Clinically, these patients show a male predominance, and usually present with very severe dyspnea, severe hypoxemia, strongly decreased exercise capacity and poor prognosis, even though the clinical picture is frequently associated with less severe airflow obstruction. Explanted lung samples of patients with COPD and severe PH show severe remodeling of small pulmonary arterioles, predominantly in the intima and media of the vessels. In this concise review, we discuss the clinical and histopathological evidence of severe PH in COPD.

Compartment-specific remodeling patterns in end-stage chronic obstructive pulmonary disease with and without severe pulmonary hypertension

BACKGROUND

In patients with end-stage chronic obstructive pulmonary disease (COPD), severe pulmonary hypertension (PH) is frequently associated with less severe airway obstruction as compared to mild or no PH. However, the histologic correlate of this finding is not clear. We aimed to quantify remodeling of pulmonary arteries, airways, and parenchyma in random samples of explanted end-stage COPD lungs.

METHODS

We quantified remodeling of small pulmonary arteries, small airways, and the degree of emphysema (mean interseptal distance [MID]) with dedicated software. As primary objective, we compared COPD patients with severe PH (SevPH-COPD) with age- and sex-matched MildPH-COPD. For comparison, we also investigated COPD lungs with no PH (NoPH-COPD), idiopathic PAH (IPAH), and healthy donors.

RESULTS

We included n = 17 SevPH-COPD (mPAP = 43 [39-45]mm Hg), n = 17 MildPH-COPD (mPAP = 28 [24-31]mm Hg), n = 5 NoPH-COPD (mPAP = 18 [16-19]mm Hg), n = 10 IPAH (mPAP = 72 [65-91]mm Hg), and n = 10 healthy donor lungs. SevPH-COPD versus MildPH-COPD was characterized by better preserved forced vital capacity (51% vs 40% predicted, p < 0.05), less emphysema (MID 169 µm vs 279 µm, p < 0.001), and less PAS-positive and CD45-positive mucosa cells (15% vs 22%, p = 0.063% and 5% vs 7%, p = 0.058) suggesting less airway inflammation. In COPD patients, intimal and medial thickening were strongly correlated with mPAP (r = 0.676, p < 0.001 and r = 0.595, p < 0.001). MID was negatively correlated with mPAP (r = -0.556, p < 0.001) and was highest in NoPH-COPD (mean 281 µm), suggesting that emphysema per se is not associated with PH.

CONCLUSIONS

End-stage COPD with severe PH is characterized by pronounced pulmonary vascular remodeling, less inflammation of small airways, and less emphysema as compared to COPD with mild PH or no PH, suggesting that COPD with severe PH may represent a unique phenotype of COPD.

Sarcoidosis-Associated Pulmonary Hypertension

Sarcoidosis-associated pulmonary hypertension (SAPH) is a very severe complication of the disease, largely impacting its morbidity and being one of its strongest predictors of mortality. With the recent modifications of the hemodynamic definition of pulmonary hypertension (mean arterial pulmonary pressure >20 instead of <25 mmHg,) its prevalence is presently not precisely known, but it affects from 3 to 20% of sarcoid patients; mostly, although not exclusively, those with an advanced, fibrotic pulmonary disease. Its gold-standard diagnostic tool remains right heart catheterization (RHC). The decision to perform it relies on an expert decision after a non-invasive work-up, in which echocardiography remains the screening tool of choice. The mechanisms underlying SAPH, very often entangled, are crucial to define, as appropriate and personalized therapeutic strategies will aim at targeting the most significant ones. There are no recommendations so far as to the indications and modalities of the medical treatment of SAPH, which is based upon the opinion of a multidisciplinary team of sarcoidosis, pulmonary hypertension and sometimes lung transplant experts.

Chronic obstructive pulmonary disease and cardiovascular disease: mechanistic links and implications for practice

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD) are both significant burdens on the healthcare system and often coexist. Mechanistic links between the two conditions and their clinical impact are increasingly understood.

RECENT FINDINGS

Recent studies demonstrate multiple mechanisms by which the pathobiology of COPD may have negative effects on the cardiovascular system. These include extrapulmonary consequences of the COPD inflammatory state, cardiac autonomic dysfunction, which has been recently implicated in worsening respiratory symptoms and exacerbation risk, and mechanical effects of lung hyperinflation on left ventricular diastolic function.Clinical studies have consistently shown a high prevalence of CVD in COPD patients and worsened outcomes (and vice versa ). Exacerbations of COPD have also been demonstrated to dramatically increase the risk of cardiovascular events. While some safety concerns exist, medications for COPD and cardiovascular disease should be used in accordance with respective guidelines. However, real-world data show suboptimal management for patients with COPD and CVD.

SUMMARY

COPD and cardiovascular disease have complicated interrelationships. Further mechanistic studies may lead to defining better targets for interventions. Education for medical professionals and implementation of novel screening protocols should be encouraged to fill in the gaps in clinical care for these patients.

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.

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.

Quantitative CT measures of pulmonary vascular volume distribution in pulmonary hypertension associated with COPD: Association with clinical characteristics and outcomes

To determine whether quantitative computed tomography (qCT)-derived metrics of pulmonary vascular volume distribution could distinguish chronic obstructive pulmonary disease (COPD) subjects with associated pulmonary hypertension (PH) from those without and to characterize associations of these measurements with clinical and physiological characteristics and outcomes. We collected retrospective CT, pulmonary hemodynamic, clinical, and outcomes data from subjects with COPD and right-heart catheterization-confirmed PH (PH-COPD) and control subjects with COPD but without PH. We measured the volumes of pulmonary vessels < 5 and >10 mm2 in cross-sectional area as a percentage of total pulmonary vascular volume (qCT-derived volume of pulmonary vessels < 5 mm2 in cross-sectional area as a volume fraction of total pulmonary blood volume [BV5%] and qCT-derived volume of pulmonary vessels > 10 mm2 in cross-sectional area [BV10] as a volume fraction of total pulmonary blood volume [BV10%], respectively) using Functional Respiratory Imaging (FRI), an automated qCT platform, and compared them between PH and control arms and between subjects with mild-moderate PH and those with severe disease. Correlations of hemodynamics with pulmonary function and associations with survival were tested. Forty-five PH-COPD and 42 control subjects were studied. BV5% was lower in PH subjects (32.2% vs. 37.7%, p = 0.003), and BV10% was higher (50.2% vs. 43.5, p = 0.001). Subjects with severe PH did not differ from those with mild-moderate PH in qCT. Pulmonary vascular volumes were not associated with pulmonary function. BV10 was associated with mean pulmonary artery pressure (r = 0.3, p = 0.05). Associations with survival were observed for BV5% (hazard ratio 0.63, p = 0.02) and BV10% (hazard ratio 1.43, p = 0.03) in the PH-COPD arm, but not for controls. qCT-derived measures of pulmonary vascular volume may have diagnostic and prognostic significance in PH-COPD and should be investigated further as screening and risk stratification tools.

Pulmonary hypertension associated with lung disease: new insights into pathomechanisms, diagnosis, and management

Patients with chronic lung diseases, particularly interstitial lung disease and chronic obstructive pulmonary disease, frequently develop pulmonary hypertension, which results in clinical deterioration, worsening of oxygen uptake, and an increased mortality risk. Pulmonary hypertension can develop and progress independently from the underlying lung disease. The pulmonary vasculopathy is distinct from that of other forms of pulmonary hypertension, with vascular ablation due to loss of small pulmonary vessels being a key feature. Long-term tobacco exposure might contribute to this type of pulmonary vascular remodelling. The distinct pathomechanisms together with the underlying lung disease might explain why treatment options for this condition remain scarce. Most drugs approved for pulmonary arterial hypertension have shown no or sometimes harmful effects in pulmonary hypertension associated with lung disease. An exception is inhaled treprostinil, which improves exercise capacity in patients with interstitial lung disease and pulmonary hypertension. There is a pressing need for safe, effective treatment options and for reliable, non-invasive diagnostic tools to detect and characterise pulmonary hypertension in patients with chronic lung disease.

The vascular perspective on acute and chronic lung disease

The pulmonary vasculature has been frequently overlooked in acute and chronic lung diseases, such as acute respiratory distress syndrome (ARDS), pulmonary fibrosis (PF), and chronic obstructive pulmonary disease (COPD). The primary emphasis in the management of these parenchymal disorders has largely revolved around the injury and aberrant repair of epithelial cells. However, there is increasing evidence that the vascular endothelium plays an active role in the development of acute and chronic lung diseases. The endothelial cell network in the capillary bed and the arterial and venous vessels provides a metabolically highly active barrier that controls the migration of immune cells, regulates vascular tone and permeability, and participates in the remodeling processes. Phenotypically and functionally altered endothelial cells, and remodeled vessels, can be found in acute and chronic lung diseases, although to different degrees, likely because of disease-specific mechanisms. Since vascular remodeling is associated with pulmonary hypertension, which worsens patient outcomes and survival, it is crucial to understand the underlying vascular alterations. In this Review, we describe the current knowledge regarding the role of the pulmonary vasculature in the development and progression of ARDS, PF, and COPD; we also outline future research directions with the hope of facilitating the development of mechanism-based therapies.

An increased risk of pulmonary hypertension in patients with combined pulmonary fibrosis and emphysema: a meta-analysis

BACKGROUND AND AIM

Pulmonary hypertension (PH) is a common complication of combined pulmonary fibrosis and emphysema (CPFE). Whether the incidence of PH is increased in CPFE compared with pure pulmonary fibrosis or emphysema remains unclear. This meta-analysis aimed to evaluate the risk of PH in patients with CPFE compared to those with IPF or COPD/emphysema.

METHODS

We searched the PubMed, Embase, Cochrane Library, and CNKI databases for relevant studies focusing on the incidence of PH in patients with CPFE and IPF or emphysema. Pooled odds ratios (ORs) and standard mean differences (SMD) with 95% confidence intervals (95% CIs) were used to evaluate the differences in the clinical characteristics presence and severity of PH between patients with CPFE, IPF, or emphysema. The survival impact of PH in patients with CPFE was assessed using hazard ratios (HRs).

RESULTS

A total of 13 eligible studies were included in the meta-analysis, involving 560, 720, and 316 patients with CPFE, IPF, and emphysema, respectively. Patients with CPFE had an increased PH risk with a higher frequency of pulmonary hypertension and higher estimated systolic pulmonary artery pressure (esPAP), compared with those with IPF (OR: 2.66; 95% CI: 1.55-4.57; P < 0.01; SMD: 0.86; 95% CI: 0.52-1.19; P < 0.01) or emphysema (OR: 3.19; 95% CI: 1.42-7.14; P < 0.01; SMD: 0.73; 95% CI: 0.50-0.96; P < 0.01). In addition, the patients with CPFE combined with PH had a poor prognosis than patients with CPFE without PH (HR: 6.16; 95% CI: 2.53-15.03; P < 0.01).

CONCLUSIONS

Our meta-analysis showed that patients with CPFE were associated with a significantly higher risk of PH compared with those with IPF or emphysema alone. The presence of PH was a poor predictor of mortality.