Pulmonary arterial enlargement and acute exacerbations of COPD

Computed Tomography Imaging for Novel Therapies of Chronic Obstructive Pulmonary Disease

Novel therapeutic options in chronic obstructive pulmonary disease (COPD) require delicate patient selection and thus demand for expert radiologists visually and quantitatively evaluating high-resolution computed tomography (CT) with additional functional acquisitions such as paired inspiratory-expiratory scans or dynamic airway CT. The differentiation between emphysema-dominant and airway-dominant COPD phenotypes by imaging has immediate clinical value for patient management. Assessment of emphysema severity, distribution patterns, and fissure integrity are essential for stratifying patients for different surgical and endoscopic lung volume reduction procedures. This is supported by quantitative software-based postprocessing of CT data sets, which delivers objective emphysema and airway remodelling metrics. However, the significant impact of scanning and reconstruction parameters, as well as intersoftware variability still hamper comparability between sites and studies. In earlier stage COPD imaging, it is less clear as to what extent quantitative CT might impact decision making and therapy follow-up, as emphysema progression is too slow to realistically be useful as a mid-term outcome measure in an individual, and longitudinal data on airway remodelling are still very limited.

Pulmonary Arterial Hypertension: a Pharmacotherapeutic Update

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) leads to progressive increases in pulmonary vascular resistance (PVR), right heart failure, and death if left untreated. This review will summarize and discuss recent updates in the classification and management of patients with PAH.

RECENT FINDINGS

PAH requires careful hemodynamic assessment and is defined by a mean pulmonary artery pressure > 20 mmHg with normal left-sided filling pressures and a PVR ≥ 3 Wood units. Most patients with PAH require targeted pharmacotherapy based on multiparametric risk stratification. Significant improvements in clinical outcome have been realized through the approval of 14 unique pharmacotherapeutic options. The latest clinical recommendations provide the updated hemodynamic definition and clinical classification as well as evidence-based treatment recommendations. An important change is the focus on initial upfront combination therapy for most patients with PAH. Structured follow-up and escalation of treatment for those not achieving low-risk status is paramount.

Rethinking Chronic Obstructive Pulmonary Disease. Chronic Pulmonary Insufficiency and Combined Cardiopulmonary Insufficiency

Almost 70 years ago, Drs. Baldwin, Cournand, and Richards defined chronic pulmonary insufficiency by the presence of respiratory symptoms, radiologic evidence of pulmonary emphysema on chest radiography, and physiologic gas trapping. A decade later, airflow obstruction on spirometry was added to the definition and insufficiency became a disease. Contemporary studies are reviving the diagnostic approach described by these early luminaries, with researchers finding that symptomatic smokers with preserved spirometry have increased exacerbations and that smokers and non-smokers with normal spirometry but emphysema on chest computed tomography have increased mortality. Hence, the Baldwin-Cournand-Richards concept of disease defined by respiratory symptoms, radiologic findings, and physiology-regardless of spirometric criteria-is being rediscovered. Baldwin, Cournand, and Richards also stated that "functionally, it is obvious that the pulmonary and circulatory apparatus are one unit," and they defined combined cardiopulmonary insufficiency as chronic pulmonary insufficiency with (left or right) cardiac and pulmonary artery enlargement. They appreciated the complexity of these interactions, which include the potential role of gas trapping in heart failure with reduced ejection fraction; the impact of emphysema on blood flow in heart failure with preserved ejection fraction; multiple contributions to cor pulmonale with increased pulmonary artery pressure; and cor pulmonale parvus in emphysema; all of which may be amenable to specific therapeutic interventions. Given the complexity of heart-lung interactions originally identified by Baldwin, Cournand, and Richards and the potentially large therapeutic opportunities, large-scale studies are still warranted to find specific therapies for subphenotypes of combined cardiopulmonary insufficiency.

Fifty Years of Progress in the Epidemiology of Chronic Obstructive Pulmonary Disease: A Review of National Heart, Lung, and Blood Institute-Sponsored Studies

Our understanding of the epidemiology of chronic obstructive pulmonary disease (COPD), including such metrics as incidence, prevalence, risk factors, outcome, and comorbidities has increased greatly over the past 50 years. Much of this increase is attributable to National Heart Blood and Lung Institute (NHLBI)-sponsored studies. This paper will review 13 of these key studies and their contribution to our understanding of COPD in the last half century.

Diameter of the dilated main pulmonary artery in patients with pulmonary hypertension decreases after lung transplantation

PURPOSE

The pulmonary artery (PA) in patients with pulmonary hypertension (PH) becomes dilated. We analyzed the postoperative changes of the main PA after lung transplantation (LuTx).

METHODS

The subjects of this retrospective study were 68 LuTx recipients, divided into a PH group (n = 36) and a non-PH group (n = 32), based on preoperative right heart catheterization findings. The PA diameter was measured on chest computed tomography. We evaluated the correlation between the mean pulmonary arterial pressure (mPAP) and the main PA diameter and compared the main PA diameters before and 3 months after LuTx.

RESULTS

The main PA diameter was significantly correlated with the mPAP (r = 0.423, P < 0.001). Preoperatively, the mean main PA diameter in the PH group was significantly greater than that in the non-PH group. However, by 3 months after LuTx, the main PA diameter in the PH group had decreased significantly from 32.4 ± 6.7 to 26.9 ± 4.8 mm (P < 0.001), while that in the non-PH group had decreased minimally from 28.3 ± 4.9 to 26.4 ± 4.6 mm (P < 0.001), resulting in no significant difference in postoperative main PA diameters between the two groups.

CONCLUSIONS

The main PA diameter in recipients with PH was enlarged and correlated with the mPAP. The dilated main PA diameter in PH patients decreased shortly after LuTx.

Increased pulmonary artery diameter is associated with reduced FEV1 in former World Trade Center workers

RATIONALE

Occupational exposures at the WTC site after September 11, 2001 have been associated with several presumably inflammatory lower airway diseases. Pulmonary arterial enlargement, as suggested by an increased ratio of the diameter of the pulmonary artery to the diameter of the aorta (PAAr) has been reported as a computed tomographic (CT) scan marker of adverse respiratory health outcomes, including WTC-related disease. In this study, we sought to utilize a novel quantitative CT (QCT) measurement of PAAr to test the hypothesis that an increased ratio is associated with FEV1 below each subject's statistically determined lower limit of normal (FEV1  < LLN).

METHODS

In a group of 1,180 WTC workers and volunteers, we examined whether FEV1  < LLN was associated with an increased QCT-measured PAAr, adjusting for previously identified important covariates.

RESULTS

Unadjusted analyses showed a statistically significant association of FEV1  < LLN with PAAr (35.3% vs 24.7%, P = 0.0001), as well as with height, body mass index, early arrival at the WTC disaster site, shorter WTC exposure duration, post-traumatic stress disorder checklist (PCL) score, wall area percent and evidence of bronchodilator response. The multivariate logistic regression model confirmed the association of FEV1  < LLN with PAAr (OR 1.63, 95% CI 1.21, 2.20, P = 0.0015) and all the unadjusted associations, except for PCL score.

CONCLUSIONS

In WTC workers, FEV1  < LLN is associated with elevated PAAr which, although likely multifactorial, may be related to distal vasculopathy, as has been hypothesized for chronic obstructive pulmonary disease.

Estimated Ventricular Size, Asthma Severity, and Exacerbations: The Severe Asthma Research Program III Cohort

BACKGROUND

Relative enlargement of the pulmonary artery (PA) on chest CT imaging is associated with respiratory exacerbations in patients with COPD or cystic fibrosis. We sought to determine whether similar findings were present in patients with asthma and whether these findings were explained by differences in ventricular size.

METHODS

We measured the PA and aorta diameters in 233 individuals from the Severe Asthma Research Program III cohort. We also estimated right, left, and total epicardial cardiac ventricular volume indices (eERVVI, eELVVI, and eETVVI, respectively). Associations between the cardiac and PA measures (PA-to-aorta [PA/A] ratio, eERVVI-to-eELVVI [eRV/eLV] ratio, eERVVI, eELVVI, eETVVI) and clinical measures of asthma severity were assessed by Pearson correlation, and associations with asthma severity and exacerbation rate were evaluated by multivariable linear and zero-inflated negative binomial regression.

RESULTS

Asthma severity was associated with smaller ventricular volumes. For example, those with severe asthma had 36.1 mL/m² smaller eETVVI than healthy control subjects (P = .003) and 14.1 mL/m² smaller eETVVI than those with mild/moderate disease (P = .011). Smaller ventricular volumes were also associated with a higher rate of asthma exacerbations, both retrospectively and prospectively. For example, those with an eETVVI less than the median had a 57% higher rate of exacerbations during follow-up than those with eETVVI greater than the median (P = .020). Neither PA/A nor eRV/eLV was associated with asthma severity or exacerbations.

CONCLUSIONS

In patients with asthma, smaller cardiac ventricular size may be associated with more severe disease and a higher rate of asthma exacerbations.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01761630; URL: www.clinicaltrials.gov.

Assessing pulmonary hypertension in COPD. Is there a role for computed tomography?

Pulmonary hypertension (PH) is a common complication of chronic obstructive pulmonary disease (COPD) and is associated with increased morbidity and mortality. Reference standard method to diagnose PH is right heart catheterization. Several non-invasive imaging techniques have been employed in the detection of PH. Among them, computed tomography (CT) is the most commonly used for phenotyping and detecting complications of COPD. Several CT findings have also been described in patients with severe PH. Nevertheless, CT analysis is currently based on visual findings which can lead to reproducibility failure. Therefore, there is a need for quantification in order to assess objective criteria. In this review, progresses in automated analyses of CT parameters and their values in predicting PH and COPD outcomes are presented.

Clinical relevance of chronic respiratory disease in Korean patients with pulmonary thromboembolism

Background

Data regarding clinical and radiological features of patients with pulmonary thromboembolism (PTE) and concomitant chronic respiratory disease (CRD) are limited. Accordingly, the aim of the present study was to investigate clinico-radiological features of this patient population.

Methods

Patients with PTE were retrospectively classified into one of two groups: those with and without CRD. Clinical characteristics, blood biomarkers, and computed tomographic (CT) findings were compared between the groups.

Results

Of 1,207 PTE patients included, CRD was detected in 128 (11%). The most common CRD was chronic obstructive pulmonary disease [41 (32%)], followed by bronchial anthracofibrosis [32 (25%)]. In multivariate analysis, unprovoked PTE [odds ratio (OR) 1.99, 95% confidence interval (CI): 1.29-3.05, P=0.002], dyspnea (OR 1.54, 95% CI: 1.11-2.34, P=0.041), lower respiratory tract infection (LRTI) (OR 3.90, 95% CI: 2.13-7.14, P<0.001), Pulmonary Embolism Severity Index (PESI) class IV-V (OR 5.24, 95% CI: 3.43-8.00, P<0.001), in-situ pulmonary artery thrombosis (OR 10.62, 95% CI: 3.71-30.45, P<0.001), and pulmonary artery enlargement (OR 1.65, 95% CI: 3.71-30.45, P<0.001) were found to be independent clinical factors related to CRD in patients with PTE. CRD was an independent predictor of PTE-related in-hospital mortality (OR 3.96, 95% CI: 1.32-11.88, P=0.014).

Conclusions

Patients with PTE and concomitant CRD were characterized by higher incidences of dyspnea, LRTI, PESI class IV-V, and in-situ pulmonary artery thrombosis, compared with non-CRD patients. In these patients, CRD was a predictor of PTE-related in-hospital mortality.

Pulmonary Hypertension in COPD: A Case Study and Review of the Literature

Pulmonary hypertension (PH) is a frequently encountered complication of chronic obstructive pulmonary disease (COPD) and is associated with worsened clinical symptoms and prognosis. The prevalence of PH-COPD is not concretely established as classification criteria vary historically, but the presence of severe disease out of proportion to underlying COPD is relatively rare. Right heart catheterization, the gold standard in diagnosis of PH, is infrequently performed in COPD, and the overlap in the clinical symptoms of PH and COPD presents diagnostic challenges. Proven treatments are limited. Trials exploring the use of vasodilator therapy in this patient group generally demonstrate improvements in hemodynamics accompanied by worsening gas exchange without clearly demonstrated improvements in clinically meaningful outcomes. In-depth workup of underlying pulmonary hypertension and use of pulmonary vasodilator medications may be appropriate on an individual basis. We present a case study and a review and discussion of the pertinent literature on this topic.

Clinical Epidemiology of COPD: Insights From 10 Years of the COPDGene Study

The Genetic Epidemiology of COPD (COPDGene) study is a noninterventional, multicenter, longitudinal analysis of > 10,000 subjects, including smokers with a ≥ 10 pack-year history with and without COPD and healthy never smokers. The goal was to characterize disease-related phenotypes and explore associations with susceptibility genes. The subjects were extensively phenotyped with the use of comprehensive symptom and comorbidity questionnaires, spirometry, CT scans of the chest, and genetic and biomarker profiling. The objective of this review was to summarize the major advances in the clinical epidemiology of COPD from the first 10 years of the COPDGene study. We highlight the influence of age, sex, and race on the natural history of COPD, and the impact of comorbid conditions, chronic bronchitis, exacerbations, and asthma/COPD overlap.

Multimodal noninvasive prediction of pulmonary hypertension in IPF

INTRODUCTION AND OBJECTIVE

Pulmonary hypertension (PH) complicating idiopathic pulmonary fibrosis (IPF) is challenging to diagnose given inaccuracy of transthoracic echocardiogram (TTE) measurements. However, it has significant prognostic implications and is therefore important to accurately identify.

METHODS

We conducted a cross-sectional study of patients with IPF who underwent RHC as part of their evaluation. A variety of commonly available noninvasive variables were evaluated for their ability to predict pulmonary arterial pressure in a linear regression model, including the traditionally used right ventricular systolic pressure (RVSP) estimated from TTE.

RESULTS

There were 105 eligible patients identified from January 2006 to July 2016. The average age was 62.7 ± 7.7 years, 35 had RHC proven PH and 43% ultimately underwent lung transplantation. A linear model including three terms: RVSP (ANOVA P < .01), the ratio of FVC/DLCO from PFTs (P = .05) and pulmonary artery to aorta diameter ratio from CT (P < .01) was found to predict the mean pulmonary artery pressure more reliably than RVSP alone (R² .39 vs .29, P < .05), with a lower rate of incorrect classification of PH status in these individuals (27.6 vs 35.2%, P = .05) and high negative predictive value (87.2%).

CONCLUSION

If used in conjunction with RVSP from TTE, parameters from PFTs and the CT scan more accurately predict the presence or absence of PH than any of the variables in isolation. Using these in concert may allow greater discrimination in deciding which patients to subject to diagnostic right heart catheterization.

Mild Elevation of Pulmonary Arterial Pressure as a Predictor of Mortality

RATIONALE

Normal mean pulmonary arterial pressure (mPAP) is 14.0 ± 3.3 mm Hg (mean ± SD). The prognostic relevance of mildly elevated mPAP not fulfilling the definition of pulmonary hypertension (PH; mPAP ≥ 25 mm Hg) has not been prospectively evaluated in a real-world setting.

OBJECTIVES

To assess the association of resting mPAP with all-cause mortality in a retrospective and a prospective cohort of patients with unexplained dyspnea and/or at risk of PH.

METHODS

Prognostic cutoffs were calculated by means of 1) classification and regression tree (CART) analysis without any preset thresholds, and 2) preset thresholds on the basis of literature data defining mPAP as lower-normal (≤mean + 1 SD), upper-normal (between mean + 1 SD and mean + 2 SD), borderline (between mean + 2 SD and 25 mm Hg), and manifest PH (≥25 mm Hg). We performed univariate and multivariate survival analysis adjusted for age and comorbidities.

MEASUREMENTS AND MAIN RESULTS

We enrolled 547 patients, of whom 137, 56, 64, and 290 presented with lower-normal, upper-normal, or borderline mPAP, and manifest PH, respectively. The CART analysis on mPAP discriminated three prognostic groups: mPAP less than 17 mm Hg, 17 to 26 mm Hg, and greater than 26 mm Hg, with significantly decreasing survival. The univariate analysis on the basis of preset thresholds showed that upper-normal mPAP, borderline mPAP, and manifest PH were significantly associated with poor survival compared with lower-normal mPAP. In the multivariate model, considering age and comorbidities, only borderline mPAP (hazard ratio, 2.37; 95% confidence interval, 1.14-4.97; P = 0.022) and manifest PH (hazard ratio, 5.05; 95% confidence interval, 2.79-9.12; P < 0.001) were significantly associated with poor survival.

CONCLUSIONS

In patients at risk for PH and/or with unexplained dyspnea, CART analysis detects prognostic thresholds at a resting mPAP of 17 mm Hg and 26 mm Hg, and values between 20 mm Hg and 25 mm Hg represent an independent predictor of poor survival. Clinical trial registered with www.clinicaltrials.gov (NCT 01607502).

COPD beyond proximal bronchial obstruction: phenotyping and related tools at the bedside

Chronic obstructive pulmonary disease (COPD) is characterised by nonreversible proximal bronchial obstruction leading to major respiratory disability. However, patient phenotypes better capture the heterogeneously reported complaints and symptoms of COPD. Recent studies provided evidence that classical bronchial obstruction does not properly reflect respiratory disability, and symptoms now form the new paradigm for assessment of disease severity and guidance of therapeutic strategies. The aim of this review was to explore pathways addressing COPD pathogenesis beyond proximal bronchial obstruction and to highlight innovative and promising tools for phenotyping and bedside assessment. Distal small airways imaging allows quantitative characterisation of emphysema and functional air trapping. Micro-computed tomography and parametric response mapping suggest small airways disease precedes emphysema destruction. Small airways can be assessed functionally using nitrogen washout, probing ventilation at conductive or acinar levels, and forced oscillation technique. These tests may better correlate with respiratory symptoms and may well capture bronchodilation effects beyond proximal obstruction.Knowledge of inflammation-based processes has not provided well-identified targets so far, and eosinophils probably play a minor role. Adaptative immunity or specific small airways secretory protein may provide new therapeutic targets. Pulmonary vasculature is involved in emphysema through capillary loss, microvascular lesions or hypoxia-induced remodelling, thereby impacting respiratory disability.

Pulmonary Hypertension

Pulmonary hypertension (PH) is a chronic and progressive disease that presents like many other lung diseases, often leading to a delay in diagnosis, and therefore a delay in optimal therapy. This article provides a review of PH for internists, covering clinical presentation, diagnostic algorithm, different types of PH, and overview of treatments. In addition, it emphasizes the importance of early referral to, and partnership between, PH specialists and physicians on the front lines to improve early diagnosis and optimize management of these complex patients.

Quantitative CT-derived vessel metrics in idiopathic pulmonary fibrosis: A structure-function study

BACKGROUND AND OBJECTIVE

This study aimed to investigate whether quantitative lung vessel morphology determined by a new fully automated algorithm is associated with functional indices in idiopathic pulmonary fibrosis (IPF).

METHODS

A total of 152 IPF patients had vessel volume, density, tortuosity and heterogeneity quantified from computed tomography (CT) images by a fully automated algorithm. Separate quantitation of vessel metrics in pulmonary arteries and veins was performed in 106 patients. Results were evaluated against readouts from lung function tests.

RESULTS

Normalized vessel volume expressed as a percentage of total lung volume was moderately correlated with functional indices on univariable linear regression analysis: forced vital capacity (R2 = 0.27, P < 1 × 10-6 ), diffusion capacity for carbon monoxide (DLCO ; R2 = 0.12, P = 3 × 10-5 ), total lung capacity (TLC; R2 = 0.45, P < 1 × 10-6 ) and composite physiologic index (CPI; R2 = 0.28, P < 1 × 10-6 ). Normalized vessel volume was correlated with vessel density but not with vessel heterogeneity. Quantitatively derived vessel metrics (and artery and vein subdivision scores) were not significantly linked with the transfer factor for carbon monoxide (KCO ), and only weakly with DLCO . On multivariable linear regression analysis, normalized vessel volume and vessel heterogeneity were independently linked with DLCO , TLC and CPI indicating that they capture different aspects of lung damage. Artery-vein separation provided no additional information beyond that captured in the whole vasculature.

CONCLUSION

Our study confirms previous observations of links between vessel volume and functional measures of disease severity in IPF using a new vessel quantitation tool. Additionally, the new tool shows independent linkages of normalized vessel volume and vessel heterogeneity with functional indices. Quantitative vessel metrics do not appear to reflect vasculopathic damage in IPF.

Prognostic impact of the ratio of the main pulmonary artery to that of the aorta on chest computed tomography in patients with idiopathic pulmonary fibrosis

Background

In many clinical disorders, there is a relationship between the ratio of the diameter of the main pulmonary artery (mPA) to that of the aorta (Ao) on chest computed tomography (CT). The aim of this study was to determine if the mPA/Ao ratio at diagnosis is associated with the clinical characteristics and outcomes in patients with idiopathic pulmonary fibrosis (IPF).

Methods

We retrospectively reviewed the diameters of the pulmonary artery and aorta on chest CT, clinical characteristics, and results of other examinations in 303 patients at the time of initial diagnosis of IPF at our tertiary care center between 2011 and 2015. The primary outcomes were death and lung transplantation. The patients were followed up until June 2017.

Results

One hundred and eight patients (35.6%) died and 58 (19.1%) underwent lung transplantation during follow-up. The mean mPA and Ao diameters were 28.3 mm and 34.0 mm, respectively, and the mean mPA/Ao ratio was 0.84. Thirty-one patients (10.2%) had an mPA/Ao ratio > 1.0 and 182 (60.1%) had an mPA/Ao ratio > 0.8. Patients with an mPA/Ao ratio > 0.8 had a lower DLco value than those with an mPA/Ao ratio ≤ 0.8. In Kaplan-Meier analysis, patients with an mPA/Ao ratio > 1.0 or > 0.8 had worse outcomes than those with an mPA/Ao ratio ≤ 1.0 and ≤ 0.8, respectively.

Conclusions

A higher mPA/Ao ratio based on 1.0 and 0.8 is associated with unfavorable prognosis in patients with IPF.

Role of medical and molecular imaging in COPD

Chronic obstructive pulmonary disease (COPD) is expected to climb on the podium of the leading causes of mortality worldwide in the upcoming decade. Clinical diagnosis of COPD has classically relied upon detecting irreversible airflow obstruction on pulmonary function testing as a global assessment of pulmonary physiology. However, the outcome is still not favorable to decrease mortality due to COPD. Progress made in both medical and molecular imaging fields are beginning to offer additional tools to address this clinical problem. This review aims to describe medical and molecular imaging modalities used to diagnose COPD and to select patients for appropriate treatments and to monitor response to therapy.

Mixed graphical models for integrative causal analysis with application to chronic lung disease diagnosis and prognosis

MOTIVATION

Integration of data from different modalities is a necessary step for multi-scale data analysis in many fields, including biomedical research and systems biology. Directed graphical models offer an attractive tool for this problem because they can represent both the complex, multivariate probability distributions and the causal pathways influencing the system. Graphical models learned from biomedical data can be used for classification, biomarker selection and functional analysis, while revealing the underlying network structure and thus allowing for arbitrary likelihood queries over the data.

RESULTS

In this paper, we present and test new methods for finding directed graphs over mixed data types (continuous and discrete variables). We used this new algorithm, CausalMGM, to identify variables directly linked to disease diagnosis and progression in various multi-modal datasets, including clinical datasets from chronic obstructive pulmonary disease (COPD). COPD is the third leading cause of death and a major cause of disability and thus determining the factors that cause longitudinal lung function decline is very important. Applied on a COPD dataset, mixed graphical models were able to confirm and extend previously described causal effects and provide new insights on the factors that potentially affect the longitudinal lung function decline of COPD patients.

AVAILABILITY AND IMPLEMENTATION

The CausalMGM package is available on http://www.causalmgm.org.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

The incremental shuttle walk test predicts mortality in non-group 1 pulmonary hypertension: results from the ASPIRE Registry

Pulmonary hypertension (PH) is classified into five groups based on disease etiology but there is only limited information on the prognostic value of exercise testing in non-group 1 PH. In group 1 PH, the incremental shuttle walking test (ISWT) distance has been shown to correlate with pulmonary hemodynamics and predict survival without a ceiling effect. This study assessed the ISWT in non-group 1 PH. Data were retrieved from the ASPIRE Registry (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre) for consecutive patients diagnosed with PH. Patients were required to have been systematically assessed as group 2-5 PH and to have a baseline ISWT within three months of cardiac catheterization. Patients were stratified according to incremental shuttle walk test distance (ISWD) and ISWT distance percent predicted (ISWD%pred). A total of 479 patients with non-group 1 PH were identified. ISWD and ISWD%pred correlated significantly with symptoms and hemodynamic severity. ISWD and ISWD%pred predicted survival with no ceiling effect. The test was prognostic in groups 2, 3, and 4. ISWD and ISWD%pred and change in ISWD and ISWD%pred at one year were all significant predictors of outcome. In patients with non-group 1 PH the ISWT is a simple non-invasive test that is easy to perform, is predictive of survival at baseline and follow-up, reflects change, and can be used in the assessment of PH of any etiology.

Bronchoscopic Lung Volume Reduction

Since the publication of the National Emphysema Treatment Trial study, lung volume reduction (LVR) has been considered a therapeutic alternative for patients with advanced obstructive lung disease. The high complication rate of surgical LVR has led to the development of bronchoscopic LVR (BLVR). Of the currently available BLVR alternatives, coils and unidirectional endobronchial valves lead the list. The choice of each device depends on emphysema characteristics and presence of collateral ventilation. Evaluation of these patients at centers with expertise in interventional pulmonology and management of BLVR is strongly recommended.

Exacerbations and health care resource use among patients with COPD in relation to blood eosinophil counts

Purpose

Current understanding of the relationship between COPD phenotype and health care resource utilization (HCRU) is limited. This real-world study evaluated disease burden and HCRU for COPD subgroups prone to exacerbation as defined by blood eosinophil (EOS) count and multiple inhaler triple therapy (MITT) use.

Methods

This was a large-scale, retrospective, longitudinal, observational cohort study using data from the US IBM Watson Explorys real-world database (GSK Study HO-17-18395). The population of interest comprised patients with COPD ≥40 years of age with ≥2 moderate or ≥1 severe exacerbations (prior year) while on inhaled maintenance therapy, with ≥1 blood EOS count. Data were analyzed during the year prior to index date (last COPD encounter between January 1, 2011 and December 31, 2016). Four subgroups were analyzed based on a combination of EOS counts (<150 and ≥150 cells/μL) and MITT use (receiving or not receiving). Among these groups, clinical characteristics, exacerbations, and HCRU were described. A sensitivity analysis that further stratified EOS into four categories (<150, ≥150-<300, ≥300-<500, and ≥500 cells/μL) was also performed.

Results

The COPD population of interest comprised 34,268 patients. Subgroups with EOS ≥150 cells/μL vs <150 cells/μL had more comorbidities and experienced significantly higher mean numbers of moderate exacerbations (not receiving MITT, ≥150 cells/μL vs <150 cells/μL: 1.93 vs 1.82, P<0.0001; receiving MITT 2.26 vs 2.16, P=0.0062) and COPD-related emergency visits (not receiving MITT, ≥150 cells/μL vs <150 cells/μL: 3.0 vs 2.5, P<0.001; receiving MITT 3.4 vs 3.1, P=0.0011). Increasing EOS category was associated with higher HCRU.

Conclusion

Blood EOS ≥150/μL cells were associated with increased HCRU and higher exacerbation rates compared with EOS <150 cells/μL, irrespective of MITT use. COPD phenotyping using blood EOS could help identify candidates for additional therapies that target eosinophilic inflammatory pathways.

Current Advances in COPD Imaging

OBJECTIVE

To review the recent advances in available technologies for imaging COPD and present the novel optical coherence tomography (OCT) airway imaging technology.

MATERIALS AND METHODS

This is an unstructured review of published evidence of available pulmonary imaging technologies along with a demonstration of state-of-the-art OCT imaging technology of in vivo human and animal airways.

RESULTS

Advanced imaging techniques such as Magnetic Resonance (MR) imaging using hyperoloarized noble gases, micro-Computed Tomography (micro-CT), and OCT aim to further our understanding of COPD. Lung densitometry can aid in identifying an exacerbation prone phenotype which may have implications for targeting specific therapies to these individuals. MR ventilation scans have the ability to provide a functional and regional distribution of airflow obstruction offering insight into the airway and parenchymal changes induced by COPD. Micro-CT gives a near microscopic view of the terminal bronchioles and alveoli permitting study of the microarchitecture of the lung ex vivo. Optical coherence tomography can visualize the microstructure of the airway walls (epithelium, smooth muscle, blood vessels, cartilage) permitting real time in vivo as well as longitudinal evaluation of airway changes in patients with COPD.

CONCLUSION

Advanced imaging techniques play a vital role in expanding our current understanding of COPD.

Imaging Advances in Chronic Obstructive Pulmonary Disease. Insights from the Genetic Epidemiology of Chronic Obstructive Pulmonary Disease (COPDGene) Study

The Genetic Epidemiology of Chronic Obstructive Pulmonary Disease (COPDGene) study, which began in 2007, is an ongoing multicenter observational cohort study of more than 10,000 current and former smokers. The study is aimed at understanding the etiology, progression, and heterogeneity of chronic obstructive pulmonary disease (COPD). In addition to genetic analysis, the participants have been extensively characterized by clinical questionnaires, spirometry, volumetric inspiratory and expiratory computed tomography, and longitudinal follow-up, including follow-up computed tomography at 5 years after enrollment. The purpose of this state-of-the-art review is to summarize the major advances in our understanding of COPD resulting from the imaging findings in the COPDGene study. Imaging features that are associated with adverse clinical outcomes include early interstitial lung abnormalities, visual presence and pattern of emphysema, the ratio of pulmonary artery to ascending aortic diameter, quantitative evaluation of emphysema, airway wall thickness, and expiratory gas trapping. COPD is characterized by the early involvement of the small conducting airways, and the addition of expiratory scans has enabled measurement of small airway disease. Computational advances have enabled indirect measurement of nonemphysematous gas trapping. These metrics have provided insights into the pathogenesis and prognosis of COPD and have aided early identification of disease. Important quantifiable extrapulmonary findings include coronary artery calcification, cardiac morphology, intrathoracic and extrathoracic fat, and osteoporosis. Current active research includes identification of novel quantitative measures for emphysema and airway disease, evaluation of dose reduction techniques, and use of deep learning for phenotyping COPD.

Pulmonary hypertension in chronic lung disease and hypoxia

Pulmonary hypertension (PH) frequently complicates the course of patients with various forms of chronic lung disease (CLD). CLD-associated PH (CLD-PH) is invariably associated with reduced functional ability, impaired quality of life, greater oxygen requirements and an increased risk of mortality. The aetiology of CLD-PH is complex and multifactorial, with differences in the pathogenic sequelae between the diverse forms of CLD. Haemodynamic evaluation of PH severity should be contextualised within the extent of the underlying lung disease, which is best gauged through a combination of physiological and imaging assessment. Who, when, if and how to screen for PH will be addressed in this article, as will the current state of knowledge with regard to the role of treatment with pulmonary vasoactive agents. Although such therapy cannot be endorsed given the current state of findings, future studies in this area are strongly encouraged.

State of the art and research perspectives in pulmonary hypertension in chronic lung disease and hypoxiahttp://ow.ly/XcW730meWxy

The pulmonary artery-aorta ratio: Is it related to quality of life in chronic obstructive pulmonary disease?

INTRODUCTION

Little is known about the relationship between health status and pulmonary artery diameter in chronic obstructive pulmonary disease (COPD) patients. The aim of this study was to evaluate correlation between pulmonary artery-aorta ratio (P-A ratio) and health status of the individuals, using COPD assessment test (CAT).

MATERIALS AND METHODS

In a cross-sectional study, 112 COPD patients were recruited. The severity of COPD was determined by global initiative for obstructive lung disease (GOLD). After digital chest CT scan, the P-A ratio was measured at the level of bifurcation and compared with CAT score, GOLD stage, exacerbation rate and Modified Medical Research Council (MMRC) score.

RESULTS

The average P-A ratio was 0.89 ± 0.16 and 62.5% of patients had ratio less than one. The P-A ratio correlates significantly with different GOLD stages, CAT score and MMRC score (P < .001, P < .001, P < .001, respectively). Compared patients with low P-A ratio (<1), those with high P-A ratio (≥ 1) showed higher CAT score [11.94 ± 5.94 vs 25.17 ± 5.84] (P < .001). The P-A ratio was significantly higher in frequent (≥2) comparing low (<2) exacerbations [1.07 ± 0.07 vs 0.77 ± 0.06] (P < .001).

CONCLUSION

Significant correlations were found between P-A ratio and GOLD, exacerbation rate and health status, using CAT of patients with COPD. These findings also may suggest the potential role of P-A ratio, in the management of COPD patients.

Airway fractal dimension predicts respiratory morbidity and mortality in COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by airway remodeling. Characterization of airway changes on computed tomography has been challenging due to the complexity of the recurring branching patterns, and this can be better measured using fractal dimensions.

METHODS

We analyzed segmented airway trees of 8,135 participants enrolled in the COPDGene cohort. The fractal complexity of the segmented airway tree was measured by the Airway Fractal Dimension (AFD) using the Minkowski-Bougliand box-counting dimension. We examined associations between AFD and lung function and respiratory morbidity using multivariable regression analyses. We further estimated the extent of peribronchial emphysema (%) within 5 mm of the airway tree, as this is likely to affect AFD. We classified participants into 4 groups based on median AFD, percentage of peribronchial emphysema, and estimated survival.

RESULTS

AFD was significantly associated with forced expiratory volume in one second (FEV1; P < 0.001) and FEV1/forced vital capacity (FEV1/FVC; P < 0.001) after adjusting for age, race, sex, smoking status, pack-years of smoking, BMI, CT emphysema, air trapping, airway thickness, and CT scanner type. On multivariable analysis, AFD was also associated with respiratory quality of life and 6-minute walk distance, as well as exacerbations, lung function decline, and mortality on longitudinal follow-up. We identified a subset of participants with AFD below the median and peribronchial emphysema above the median who had worse survival compared with participants with high AFD and low peribronchial emphysema (adjusted hazards ratio [HR]: 2.72; 95% CI: 2.20-3.35; P < 0.001), a substantial number of whom were not identified by traditional spirometry severity grades.

CONCLUSION

Airway fractal dimension as a measure of airway branching complexity and remodeling in smokers is associated with respiratory morbidity and lung function change, offers prognostic information additional to traditional CT measures of airway wall thickness, and can be used to estimate mortality risk.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00608764.

FUNDING

This study was supported by NIH K23 HL133438 (SPB) and the COPDGene study (NIH Grant Numbers R01 HL089897 and R01 HL089856). The COPDGene project is also supported by the COPD Foundation through contributions made to an Industry Advisory Board comprised of AstraZeneca, Boehringer Ingelheim, Novartis, Pfizer, Siemens, Sunovion and GlaxoSmithKline.

Impact of pulmonary emphysema on exercise capacity and its physiological determinants in chronic obstructive pulmonary disease

Exercise limitation is common in chronic obstructive pulmonary disease (COPD). We determined the impact of pulmonary emphysema on the physiological response to exercise independent of contemporary measures of COPD severity. Smokers 40–79 years old with COPD underwent computed tomography, pulmonary function tesing, and symptom-limited incremental exercise testing. COPD severity was quantified according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) by spirometry (GOLD 1–4); and symptom burden and exacerbation risk (GOLD A-D). Emphysema severity was quantified as the percent lung volume <−950 Hounsfield units. Regression models adjusted for age, gender, body size, smoking status, airflow limitation, symptom burden and exacerbation risk. Among 67 COPD subjects (age 67 ± 8 years; 75% male; GOLD 1–4: 11%, 43%, 30%, 16%), median percent emphysema was 11%, and peak power output (PPO) was 61 ± 32 W. Higher percent emphysema independently predicted lower PPO (−24 W per 10% increment in emphysema; 95%CI −41 to −7 W). Throughout exercise, higher percent emphysema predicted 1) higher minute ventilation, ventilatory equivalent for CO₂, and heart rate; and 2) lower oxy-hemoglobin saturation, and end-tidal PCO₂. Independent of contemporary measures of COPD severity, the extent of pulmonary emphysema predicts lower exercise capacity, ventilatory inefficiency, impaired gas-exchange and increased heart rate response to exercise.

Revised (2018) COPD Clinical Practice Guideline of the Korean Academy of Tuberculosis and Respiratory Disease: A Summary

Chronic obstructive pulmonary disease (COPD) results in high morbidity and mortality among patients nationally and globally. The Korean clinical practice guideline for COPD was revised in 2018. The guideline was drafted by the members of the Korean Academy of Tuberculosis and Respiratory Diseases as well as the participating members of the Health Insurance Review and Assessment Service, Korean Physicians' Association, and Korea Respiration Trouble Association. The revised guideline encompasses a wide range of topics, including the epidemiology, diagnosis, assessment, monitoring, management, exacerbation, and comorbidities of COPD in Korea. We performed systematic reviews assisted by an expert in meta-analysis to draft a guideline on COPD management. We expect this guideline to facilitate the treatment of patients with respiratory conditions by physicians as well other health care professionals and government personnel in South Korea.

Quantitative assessment of pulmonary vascular alterations in chronic obstructive lung disease: Associations with pulmonary function test and survival in the KOLD cohort

PURPOSE

Despite the high prevalence of pulmonary vascular alterations and their substantial impact on chronic obstructive pulmonary disease (COPD), tools for the direct in vivo assessment of pulmonary vascular alterations remain limited. Thus, the purpose of this study was to automatically extract pulmonary vessels from volumetric chest CT and evaluate the associations between the derived quantitative pulmonary vessel features and clinical parameters, including survival, in COPD patients.

METHODS

This study included 344 adult COPD patients. Pulmonary vessels were automatically extracted from volumetric chest CT data. Quantitative pulmonary vessel features were obtained from various lung surface areas (LSAs), which are theoretical surface areas drawn at different depths from the pleural borders. The total number of vessels (N_total) and number of vessels with vessel area (VA) less than 5 mm² (N_<5mm) were counted as both robust values and as values per 10 cm² of LSA (N_total/LSA; N_<5mm/LSA). The average VA (VA_mean) and percentage of measured VA in the corresponding LSA (%VA) were measured. Associations between quantitative pulmonary vessel features and clinical parameters, including survival and the pulmonary function test (PFT), were evaluated.

RESULTS

The pulmonary vessels were automatically extracted with 100% technical success. Cox regression analysis showed N_total/LSA, N_<5mm/LSA, VA_mean, and %VA to be significant predictors of survival (hazard ratio (HR), 0.80, 0.75, 0.70, 0.49, respectively). Patients classified into high-risk groups by %VA_18mm (cut-off = 3.258), chosen because it demonstrated the strongest statistical influence on survival in a univariate Cox analysis, were associated with worse overall survival before (HR, 4.83; p < 0.001) and after adjustment for patient age and BMI (HR, 2.18; p = 0.014). Of the quantitative pulmonary vessel features, N_total/LSA, N_<5mm/LSA, and %VA were correlated with FEV₁, FEV₁/FVC, and DLCO in all LSAs. The strongest correlation with PFTs was noted at LSA_9mm for both N_total (FEV₁, r = 0.33; FEV₁/FVC, r = 0.51) and N_<5mm (FEV₁, r = 0.35; FEV₁/FVC, r = 0.52). For %VA, the association was most evident at LSA_18mm (FEV₁, r = 0.27; FEV₁/FVC, r = 0.47). Significant moderate to strong correlations were consistently observed between the extent of emphysema and quantitative pulmonary vessel features (r = 0.44-0.66; all p < 0.001).

CONCLUSIONS

The automated extraction of pulmonary vessels and their quantitative assessment are technically feasible. Various quantitative pulmonary vessel features demonstrated significant relationships with survival and PFT in COPD patients. Of the various quantitative features, the percentage of total VA measured at 18 mm depth from the pleural surface (%VA_18mm) and the number of small vessels counted per 10 cm² of LSA at 9 mm depth from the pleural surface (N_<5mm/LSA_9mm) had the strongest predictability for the clinical parameters.

The influence of anemia on one-year exacerbation rate of patients with COPD-PH

BACKGROUND

Anemia is prevalent not only in COPD but also in pulmonary hypertension. We postulated that anemia may have certain prognostic value in COPD concomitant with PH due to COPD (COPD-PH).

METHODS

We performed a 12-month prospective investigation to follow up COPD patients with or without PH assessed by right heart catheterization. Eligible patients were enrolled, stratified into COPD-PH-anemia group (n = 40), COPD-PH group (n = 42), COPD-anemia group (n = 48), and COPD group(n = 50), and then followed up for 12 months.

RESULTS

After the follow-up, for both of the actual variation value and variation rate, the increase of NT-pro BNP (P<0.001; P = 0.03) and CAT score (P = 0.001; 0.002), as well as the decrease of PaO₂ (P = 0.03; 0.086) and Peak VO₂ (P = 0.021; 0.009) in COPD-PH-anemia group were highest among four groups. The cumulative one-year survival rates were similar among four groups (P = 0.434). The cumulative exacerbation-free rate was lowest in COPD-PH-anemia group among four groups (P<0.001). Hemoglobin was an independent promoting factor for the probability of hospitalization due to exacerbation ≧ 1/year in patients with COPD-PH-anemia [HR 3.121(2.325-5.981); P<0.001].

CONCLUSIONS

Anemia is a promoting factor for the worsening of exercise capacity, deterioration of hypoxemia, declining of life quality, and aggravation of exacerbations in patients with COPD-PH-anemia, by contrast with COPD-PH, COPD-anemia, and COPD.

Pulmonary hypertension in chronic obstructive pulmonary disease and emphysema patients: prevalence, therapeutic options and pulmonary circulatory effects of lung volume reduction surgery

The exact prevalence of pulmonary hypertension (PH) and cor pulmonale (CP) in chronic obstructive pulmonary disease (COPD) is unknown, and varies considerably from 20-91%. Usually, mean pulmonary artery pressure (mPAP) does not exceed 30 mmHg, and PH is not severe. However, PH and CP are important predictors of mortality in COPD and contribute to disability in this disease. Many factors contribute to the development of PH in chronic lung disease, including reduction of the pulmonary vascular cross-sectional area due to parenchymal loss and accompanying hypoxia, effects of abnormal pulmonary mechanics due to hyperinflation, but also vascular remodeling processes. So far, PH associated with chronic lung disease cannot be treated medically. Therefore, it is indicated to treat the underlying pulmonary disease. Patients with severe PH should be referred to centers experienced in the management of PH and enrollment in clinical trials should be considered. Lung volume reduction surgery (LVRS) theoretically further increases pulmonary vascular resistance (PVR) by reducing the vascular bed when resecting lung tissue, however, this might be compensated by better pulmonary mechanics through reduction of hyperinflation, which will be discussed in the present article.

Emphysema and lung volume reduction: the role of radiology

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death worldwide. One of the main findings is pulmonary emphysema in association with chronic bronchitis. Clinical signs, pulmonary function tests and imaging are the current used methods to diagnose and stage emphysema. Lung volume reduction (LVR) and endoscopic lung volume reduction (ELVR) are the current therapeutic options beside lung transplantation in cases of severe emphysema. Nowadays imaging is one of the key factors for the success of these therapies. Especially quantitative computed tomography (CT) with its increasing possibilities has become a viable tool, providing detailed information about distribution and heterogeneity of emphysema. Other imaging techniques like dual-energy CT (DECT) and functional magnetic resonance (MR) have shown to add functional information. These structural and functional information support thoracic surgeons and interventional pulmonologists in selecting patients and optimizing LVR procedures but also enables the development of new endobronchial therapies. Imaging will further improve the individual outcome by supporting the choice of optimal therapy.

Pruning of the Pulmonary Vasculature in Asthma. The Severe Asthma Research Program (SARP) Cohort

RATIONALE

Loss of the peripheral pulmonary vasculature, termed vascular pruning, is associated with disease severity in patients with chronic obstructive pulmonary disease.

OBJECTIVES

To determine if pulmonary vascular pruning is associated with asthma severity and exacerbations.

METHODS

We measured the total pulmonary blood vessel volume (TBV) and the blood vessel volume of vessels less than 5 mm2 in cross-sectional area (BV5) and of vessels less than 10 mm2 (BV10) in cross-sectional area on noncontrast computed tomographic scans of participants from the Severe Asthma Research Program. Lower values of the BV5 to TBV ratio (BV5/TBV) and the BV10 to TBV ratio (BV10/TBV) represented vascular pruning (loss of the peripheral pulmonary vasculature).

MEASUREMENTS AND MAIN RESULTS

Compared with healthy control subjects, patients with severe asthma had more pulmonary vascular pruning. Among those with asthma, those with poor asthma control had more pruning than those with well-controlled disease. Pruning of the pulmonary vasculature was also associated with lower percent predicted FEV1 and FVC, greater peripheral and sputum eosinophilia, and higher BAL serum amyloid A/lipoxin A4 ratio but not with low-attenuation area or with sputum neutrophilia. Compared with individuals with less pruning, individuals with the most vascular pruning had 150% greater odds of reporting an asthma exacerbation (odds ratio, 2.50; confidence interval, 1.05-5.98; P = 0.039 for BV10/TBV) and reported 45% more asthma exacerbations during follow-up (incidence rate ratio, 1.45; confidence interval, 1.02-2.06; P = 0.036 for BV10/TBV).

CONCLUSIONS

Pruning of the peripheral pulmonary vasculature is associated with asthma severity, control, and exacerbations, and with lung function and eosinophilia.

NT-proBNP in stable COPD and future exacerbation risk: Analysis of the SPIROMICS cohort

BACKGROUND

High N-terminal pro-brain natriuretic peptide (NT-proBNP) during COPD exacerbations is associated with worse clinical outcomes. The prognostic value of NT-proBNP measured during clinical stability has not been well characterized.

METHODS

We studied SPIROMICS participants 40-80 years of age with COPD GOLD spirometric stages 1-4. The association between baseline NT-proBNP and incident COPD exacerbations within one year of follow-up was tested using zero-inflated Poisson regression models adjusted for age, gender, race, body mass index, current smoking status, smoking history, FEV1 percent predicted, COPD Assessment Test score, exacerbation history, total lung capacity on chest CT and cardiovascular disease (any of coronary artery disease, myocardial infarction or congestive heart failure).

RESULTS

Among 1051 participants (mean age 66.1 years, 41.4% women), mean NT-proBNP was 608.9 pg/ml. Subjects in GOLD stage D had the highest mean NT-proBNP. After one year of follow-up, 268 participants experienced one or more COPD exacerbations. One standard deviation increase in baseline NT-proBNP was associated with a 13% increase in the risk of incident exacerbations (incident risk ratio 1.13; 95% CI 1.06-1.19; p < 0.0001). This association was maintained in participants with and without cardiovascular disease.

CONCLUSION

Baseline NT-proBNP in COPD is an independent predictor of respiratory exacerbations, even in individuals without overt cardiac disease. The impact of detection and treatment of early cardiovascular dysfunction on COPD exacerbation frequency warrants further investigation.

Pulmonary Embolism Among Patients With Acute Exacerbation Of Chronic Obstructive Pulmonary Disease: Implications For Emergency Medicine

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Common in COPD are acute exacerbations (AE-COPD) that cause acute dyspnea, cough, and bronchospasm. Symptoms of AE-COPD mimic pulmonary embolism (PE).

METHODS

We conducted a systematic review of the literature to assess the prevalence of PE in patients admitted to the hospital with a clinical diagnosis of AE-COPD. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, we queried PubMed and MEDLINE databases from 1990 to 2017. The search term "prevalence pulmonary embolism, COPD" was used, and Boolean operators were used to combine search terms. Data were extracted from each article, specifically the sample size, study setting, design, and the prevalence of PE.

RESULTS

A total of 5 articles were included that demonstrated a prevalence of PE among patients with a clinical diagnosis of AE-COPD that ranged from 3.3-29.1%. Sample sizes varied from 49-197 patients. Studies occurred in both emergency department and inpatient settings, including intensive care units. Among the studies that reported patient characteristics associated with PE in AE-COPD, both obesity and immobility were important.

CONCLUSION

Studies reporting the prevalence of PE during AE-COPD vary considerably in their methods and results. Because of the relatively high prevalence of PE during AE-COPD, it is important for providers to be aware of this linkage between the 2 conditions and to screen patients using clinical gestalt and validated screening tools until more emergency department data are available.

Reducing Readmissions in Patients With Both Heart Failure and COPD

Patients with both COPD and heart failure (HF) pose particularly high costs to the health-care system. These diseases arise from similar root causes, have overlapping symptoms, and share similar clinical courses. Because of these strong parallels, strategies to reduce readmissions in patients with both conditions share synergies. Here we present 10 practical tips to reduce readmissions in this challenging population: (1) diagnose the population accurately, (2) detect admissions for exacerbations early and consider risk stratification, (3) use specialist management in hospital, (4) modify the underlying disease substrate, (5) apply and intensify evidence-based therapies, (6) activate the patient and develop critical health behaviors, (7) setup feedback loops, (8) arrange an early follow-up appointment prior to discharge, (9) consider and address other comorbidities, and (10) consider ancillary support services at home. The multidisciplinary care teams needed to support these care models pose expense to the health-care system. Although these costs may more easily be recouped under financial models such as accountable care organizations and bundled payments, the opportunity cost of an admission for COPD or HF may represent an underrecognized financial lever.

Blood eosinophil count thresholds and exacerbations in patients with chronic obstructive pulmonary disease

BACKGROUND

Eosinophilic airway inflammation in patients with chronic obstructive pulmonary disease (COPD) is associated with exacerbations and responsivity to steroids, suggesting potential shared mechanisms with eosinophilic asthma. However, there is no consistent blood eosinophil count that has been used to define the increased exacerbation risk.

OBJECTIVE

We sought to investigate blood eosinophil counts associated with exacerbation risk in patients with COPD.

METHODS

Blood eosinophil counts and exacerbation risk were analyzed in patients with moderate-to-severe COPD by using 2 independent studies of former and current smokers with longitudinal data. The Genetic Epidemiology of COPD (COPDGene) study was analyzed for discovery (n = 1,553), and the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study was analyzed for validation (n = 1,895). A subset of the ECLIPSE study subjects were used to assess the stability of blood eosinophil counts over time.

RESULTS

COPD exacerbation risk increased with higher eosinophil counts. An eosinophil count threshold of 300 cells/μL or greater showed adjusted incidence rate ratios for exacerbations of 1.32 in the COPDGene study (95% CI, 1.10-1.63). The cutoff of 300 cells/μL or greater was validated for prospective risk of exacerbation in the ECLIPSE study, with adjusted incidence rate ratios of 1.22 (95% CI, 1.06-1.41) using 3-year follow-up data. Stratified analysis confirmed that the increased exacerbation risk associated with an eosinophil count of 300 cells/μL or greater was driven by subjects with a history of frequent exacerbations in both the COPDGene and ECLIPSE studies.

CONCLUSIONS

Patients with moderate-to-severe COPD and blood eosinophil counts of 300 cells/μL or greater had an increased risk exacerbations in the COPDGene study, which was prospectively validated in the ECLIPSE study.

SPIROMICS Protocol for Multicenter Quantitative Computed Tomography to Phenotype the Lungs

Multidetector row computed tomography (MDCT) is increasingly taking a central role in identifying subphenotypes within chronic obstructive pulmonary disease (COPD), asthma, and other lung-related disease populations, allowing for the quantification of the amount and distribution of altered parenchyma along with the characterization of airway and vascular anatomy. The embedding of quantitative CT (QCT) into a multicenter trial with a variety of scanner makes and models along with the variety of pressures within a clinical radiology setting has proven challenging, especially in the context of a longitudinal study. SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study), sponsored by the National Institutes of Health, has established a QCT lung assessment system (QCT-LAS), which includes scanner-specific imaging protocols for lung assessment at total lung capacity and residual volume. Also included are monthly scanning of a standardized test object and web-based tools for subject registration, protocol assignment, and data transmission coupled with automated image interrogation to assure protocol adherence. The SPIROMICS QCT-LAS has been adopted and contributed to by a growing number of other multicenter studies in which imaging is embedded. The key components of the SPIROMICS QCT-LAS along with evidence of implementation success are described herein. While imaging technologies continue to evolve, the required components of a QCT-LAS provide the framework for future studies, and the QCT results emanating from SPIROMICS and the growing number of other studies using the SPIROMICS QCT-LAS will provide a shared resource of image-derived pulmonary metrics.

Characterization of lymphangioleiomyomatosis patients with discordance between spirometric and diffusion measurements of pulmonary function

Background: A subset of lymphangioleiomyomatosis (LAM) patients present with normal FEV1 and FVC but with reduced DLCO. Patients with an isolated reduction in DLCO in other diseases appear to be at higher risk for pulmonary hypertension and worse survival but this has not been previously described in LAM patients. Objective: To characterize the prevalence and clinical progression of LAM patients who present with discordantly low DLCO. Methods: This was a retrospective cohort study of LAM patients in two centers in the United States and Brazil. Discordant DLCO was defined as FEV1 >80% predicted, FVC >80% predicted, and DLCO<80% predicted. We compared the rate of decline in pulmonary function, pulmonary artery to aorta (PA-A) ratio, and VEGF-D levels in patients with concordant and discordant DLCO. Results: The overall prevalence of discordant DLCO was 26.0%. Patients with discordant DLCO did not have a higher rate of yearly decline in FEV1 (-1.0±0.6 vs -1.0±0.6, p=0.50), FVC (-1.0±0.7 vs -0.3±0.8, p=0.54), or DLCO (-2.2±0.9 vs -1.6±0.6, p=0.79). They did not have higher rates of PA-A ratio>1 (23.3% vs 20.1%, p=1.00). Patients with discordant DLCO did not have higher levels of VEGF-D (1214±1256 pg/mL vs 1706±1214 pg/mL, p=0.07). Conclusions: LAM patients who present with a discordantly low DLCO do not appear to have different rates of decline in pulmonary function. Additional biological and radiographic markers are needed to more fully characterize this population. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 206-212).

Pulmonary arterial enlargement predicts long-term survival in COPD patients

Rationale

Pulmonary artery enlargement (PAE) is associated with exacerbations in Chronic Obstructive Pulmonary Disease (COPD) and with survival in moderate to severe patients. The potential role of PAE in survival prediction has not been compared with other clinical and physiological prognostic markers.

Methods

In 188 patients with COPD, PA diameter was measured on a chest CT and the following clinical and physiological parameters registered: age, gender, smoking status, pack-years history, dyspnea, lung function, exercise capacity, Body Mass Index, BODE index and history of exacerbations in year prior to enrolment. Proportional Cox regression analysis determined the best predictor of all cause survival.

Results

During 83 months (±42), 43 patients died. Age, pack-years history, smoking status, BMI, FEV1%, six minute walking distance, Modified Medical Research Council dyspnea scale, BODE index, exacerbation rate prior to enrollment, PA diameter and PAE (diameter≥30mm) were associated with survival. In the multivariable analysis, age (HR: 1.08; 95%CI: 1.03–1.12, p<0.001) and PAE (HR: 2.78; 95%CI: 1.35–5.75, p = 0.006) were the most powerful parameters associated with all-cause mortality.

Conclusions

In this prospective observational study of COPD patients with mild to moderate airflow limitation, PAE was the best predictor of long-term survival along with age.

Prophylactic function of excellent compliance with LTOT in the development of pulmonary hypertension due to COPD with hypoxemia

The long-term oxygen therapy (LTOT) for patients with chronic obstructive pulmonary disease (COPD) has been shown to increase survival in patients with severe resting hypoxemia. The adherence to LTOT may also simultaneously affect the development of concomitant pulmonary hypertension (PH) due to COPD with hypoxemia. We retrospectively reviewed 276 cases of COPD with or without PH assessed by right heart catheterization (RHC) to investigate whether adherence to continuous LTOT had a prophylactic effect on the development of PH in a time interval of two years. In contrast to the patients in the non-compliance group (PH prevalence 64.2%), patients with excellent compliance of adhering to continuous LTOT > 15 h per day in the compliance group (PH prevalence 37.6%) are more liable to postpone the development of PH due to hypoxic COPD for at least two years. Adherence to LTOT ≥ 15 h/day is strongly recommended in order to lower the risk and delay the development of consequent PH in COPD with hypoxemia.