The Use of Bronchial Rheoplasty in Emphysema Patients Previously Treated with Endoscopic Lung Volume Reduction: A Case Series.

Endoscopic lung volume reduction (ELVR) is an established treatment option for patients with severe emphysema. Not all patients are candidates for this type of intervention, and in the context of significant airway secretions, they may be excluded from treatment. Bronchial Rheoplasty (BR) was developed to treat mucus hypersecretion by delivering nonthermal pulsed electric fields to the airway epithelium and submucosa. The literature to date demonstrates that patients treated with BR in clinical studies have a reduction in airway goblet cell hyperplasia as well as substantive clinical improvement in the setting of chronic bronchitis (CB). In this case series, we present four patients treated at three different institutions who had previously undergone ELVR with beneficial outcome. However, over time, these patients subsequently developed worsening clinical issues, including complaints of increased and thickened mucus, along with exacerbations in the setting of a loss of some ELVR-associated benefits. These patients then underwent exploratory treatment with BR with the intent of reducing their secretion burden and potentially restoring the efficacy associated with the initial placement of the airway valves. All BR procedures were well tolerated, and three of the four patients showed substantial improvement in their symptom burden. Airway examinations during the second of the two BR procedures also revealed what appeared to be less airway mucosal inflammation and a decrease in the quantity of airway secretions. Therefore, treatment with BR may have the potential to improve and restore the initial benefits associated with ELVR, thus enhancing long-term outcomes. Further clinical studies with sufficient follow-up are warranted to assess this in a larger cohort of patients, and to determine whether treatment with BR prior to ELVR may make more patients eligible for this treatment through reduction in their secretions and/or symptoms.

Differences in the Quantitative HRCT Characteristics of Patients with Asthma, COPD and Asthma-COPD Overlap and Their Relationships with Pulmonary Function.

Purpose: We compared pulmonary function indices and quantitative CT parameters of airway remodeling, air trapping, and emphysema in asthmatic patients and patients with COPD and asthma-COPD overlap (ACO) and explored their relationships with airflow limitation. Patients and Methods: Patients with asthma (n=48), COPD (n=52), and ACO (n=30) and controls (n=54) who completed pulmonary function tests and HRCT scans were retrospectively enrolled in our study. Quantitative CT analysis software was used to assess emphysema (LAA%), airway wall dimensions (wall area (WA), luminal area (LA), and wall area percentage (WA%)), and air trapping ((relative volume change of -860 HU to -950 HU (RVC-860 to-950) and the expiration-to-inspiration ratio of the mean lung density (MLDE/I))). Differences in pulmonary function and HRCT parameters were compared among the groups. Spearman correlation analysis and regression analysis were utilized to explore structure‒function relationships. Results: The LAA% in COPD and ACO patients was significantly greater than that in asthmatic patients and controls. The WA% and WA in COPD and ACO patients were greater than those in controls, whereas the WA% and LA between asthmatic patients and controls reached statistical significance. The RVC-860 to -950 levels decreased in the following order: ACO, COPD, and asthma. RVC-860 to -950 independently predicted FEV1% in asthmatic patients; LAA% and MLDE/I in COPD patients; and LAA%, WA% and RVC-860 to -950 in ACO patients. Conclusion: Comparable emphysema was observed in patients with COPD and ACO but not in asthmatic patients. All patients exhibited proximal airway remodeling. The bronchi were thickened outward in COPD and ACO patients but are thickened inward in asthmatic patients. Furthermore, air trapping in ACO patients was the most severe among all the groups. Indirect lung densitometry measurements might be more predictive of the degree of airflow limitation than direct airway measurements in obstructive airway diseases.

Personalised indication of augmentation therapy for emphysema associated with severe alpha-1 antitrypsin deficiency: a case series.

Severe alpha-1 antitrypsin deficiency (AATD) is associated with an increased risk of emphysema. However, the clinical manifestations are very heterogeneous, and an individual prognosis is very difficult to establish. Intravenous augmentation therapy with alpha-1 antitrypsin (AAT) from pooled blood donors is the only specific treatment available, but it requires weekly or biweekly administration for life. Several guidelines provide the indication criteria for the initiation of AAT augmentation therapy. However, in clinical practice, there are situations in which the decision as to when to start treatment becomes uncertain and some studies have shown great variability in the indication of this treatment even among specialists. The usual dilemma is between initiating augmentation therapy in individuals who may not develop significant lung disease or in whom disease will not progress or delaying it in patients who may otherwise rapidly and irreversibly progress. We illustrate this dilemma with five clinical cases: from the case of a patient with normal lung function who requests initiation of therapy to a moderately stable patient without augmentation or a mild patient who, after several years of remaining stable without treatment, deterioration in lung function initiated and, consequently, augmentation therapy was begun. All the nuances associated with the indication of augmentation justify a personalised approach and the decision about initiating augmentation therapy must be made after careful consideration of the pros and cons with the patient in reference centres with experience in treatment. These reference centres can work in collaboration with local hospitals where patients can be closely followed and augmentation therapy can be administered to avoid unnecessary travelling, making periodical administrations more comfortable for the patient.

CT Chest Imaging Using Normalized Join-Count: Predicting Emphysema Progression in the CanCOLD Study.

Background Pre-existing emphysema is recognized as an indicator of future worsening in patients with chronic obstructive pulmonary disease (COPD) when observed through CT imaging. However, it remains uncertain whether additional factors, such as the spatial compactness of CT emphysema, might also serve as predictors of disease progression. Purpose To evaluate the relationship between the compactness of CT emphysema voxels and emphysema progression. Materials and Methods This secondary analysis uses data from the prospective Canadian Cohort Obstructive Lung Disease (CanCOLD) study, examining CT images obtained in participants with and without COPD at baseline and a 3-year follow-up time point (November 2009 to November 2018). Measurements of forced expiratory volume in first second of expiration (FEV1) and diffusing capacity of lung for carbon monoxide (DLco) were collected. The normalized join-count (NJC) measurement from baseline CT images and lung density (LD) changes were analyzed. Emphysema progression was defined as an annualized LD change of less than half an SD below the mean of the participants without COPD with no smoking history. Multivariable linear and logistic regression models were used to assess the association between baseline CT NJC measurements and the annualized change in LD, FEV1, DLco, and emphysema progression versus nonprogression. Results A total of 524 participants (mean age, 66 years ± 10 [SD]; 293 male) (FEV1 percent predicted, 88% ± 19; FEV1/FVC, 67% ± 9; DLco percent predicted, 105% ± 25) were analyzed, 187 (36%) of whom had COPD. CT NJC was associated with the annualized change in LD (P < .001), FEV1 (P = .02), and DLco (P = .01). Additionally, CT NJC predicted emphysema progression versus nonprogression (odds ratio, 2.24; 95% CI: 1.37, 3.50; P < .001). Conclusion The spatial distribution, or "compactness," of CT emphysema voxels predicted emphysema progression in individuals with and without COPD. ClinicalTrials.gov Identifier: NCT00920348 © RSNA, 2024 Supplemental material is available for this article.

Obesity Impact on Dyspnea in COPD Patients.

Background: The role of obesity on dyspnea in chronic obstructive pulmonary disease (COPD) patients remains unclear. We aimed to provide an assessment of dyspnea in COPD patients according to their Body Mass Index (BMI) and to investigate the impact of obesity on dyspnea according to COPD severity. Methods: One hundred and twenty seven COPD patients with BMI ≥ 18.5 kg/m² (63% male, median (interquartile range) post bronchodilator forced expiratory volume of 1 second (post BD FEV1) at 51 (34-66) % pred) were consecutively included. Dyspnea was assessed by mMRC (Modified medical research council) scale. Lung function tests were recorded, and emphysema was quantified on CT-scan (computed tomography-scan). Results: Twenty-five percent of the patients were obese (BMI ≥ 30kg/m²), 66% of patients experienced disabling dyspnea (mMRC ≥ 2). mMRC scores did not differ depending on BMI categories (2 (1-3) for normal weight, 2 (1-3) 1 for overweight and 2 (1-3) for obese patients; p = 0.71). Increased mMRC scores (0-1 versus 2-3 versus 4) were associated with decreased post BD-FEV1 (p < 0.01), higher static lung hyperinflation (inspiratory capacity/total lung capacity (IC/TLC), p < 0.01), reduced DLCO (p < 0.01) and higher emphysema scores (p < 0.01). Obese patients had reduced static lung hyperinflation (IC/TLC p < 0.01) and lower emphysema scores (p < 0.01) than non-obese patients. mMRC score increased with GOLD grades (1-2 versus 3-4) in non-obese patients but not in obese patients, in association with a trend towards reduced static lung hyperinflation and lower emphysema scores. Conclusion: By contrast with non-obese patients, dyspnea did not increase with spirometric GOLD grades in obese patients. This might be explained by a reduced lung hyperinflation related to the mechanical effects of obesity and a less severe emphysema in severe COPD patients with obesity.

Clustering analysis of HRCT parameters measured using a texture-based automated system: relationship with clinical outcomes of IPF.

PURPOSE: The extent of honeycombing and reticulation predict the clinical prognosis of IPF. Emphysema, consolidation, and ground glass opacity are visible in HRCT scans. To date, there have been few comprehensive studies that have used these parameters. We conducted automated quantitative analysis to identify predictive parameters for clinical outcomes and then grouped the subjects accordingly. METHODS: CT images were obtained while patients held their breath at full inspiration. Parameters were analyzed using an automated lung texture quantification system. Cluster analysis was conducted on 159 IPF patients and clinical profiles were compared between clusters in terms of survival. RESULTS: Kaplan-Meier analysis revealed that survival rates declined as fibrosis, reticulation, honeycombing, consolidation, and emphysema scores increased. Cox regression analysis revealed that reticulation had the most significant impact on survival rate, followed by honeycombing, consolidation, and emphysema scores. Hierarchical and K-means cluster analyses revealed 3 clusters. Cluster 1 (n = 126) with the lowest values for all parameters had the longest survival duration, and relatively-well preserved FVC and DLCO. Cluster 2 (n = 15) with high reticulation and consolidation scores had the lowest FVC and DLCO values with a predominance of female, while cluster 3 (n = 18) with high honeycombing and emphysema scores predominantly consisted of male smokers. Kaplan-Meier analysis revealed that cluster 2 had the lowest survival rate, followed by cluster 3 and cluster 1. CONCLUSION: Automated quantitative CT analysis provides valuable information for predicting clinical outcomes, and clustering based on these parameters may help identify the high-risk group for management.

[Fibrophysematous lung changes and microbiota changes in senile persons.]

Research on the condition of the lungs in senile people is an urgent task. This is due to the fact that degenerative or age-associated changes in the respiratory system play an important role in the formation of senile asthenia syndrome and a decrease in the age-related viability of the body as a whole. CT-scans of patients aged 80-90 years were analyzed (n=31). Age-associated changes were evaluated: the presence of linear fibrosis, increased pulmonary pattern by the type of reticular (reticular) changes, the presence of gross fibrous reticular changes with cystic cavities and air bullae (by the type of «cellular lung¼), as well as the presence of pulmonary emphysema. Most naturally, senile people show changes characteristic of linear pulmonary fibrosis and emphysema. The progression of the process leads to diffuse reticular changes in the interalveolar and intersegmental septa and, in adverse cases, to the formation of gross changes in the type of «cellular lung¼. Fibro-emphysematous changes are significantly more common in men. A microbiological study of the microbiota of the lower respiratory tract in elderly people was also carried out (n=16). When studying the microbiocenosis of the lower respiratory tract in elderly people, the following data were obtained: resident microflora was found in 71% and clinically significant microorganisms were found in 29%.

Improvements of the shape and strength of the diaphragm after endoscopic lung volume reduction.

RATIONALE: Endoscopic lung volume reduction improves lung function, quality of life and exercise capacity in severe emphysema patients. However, its effect on the diaphragm function is not well understood. We hypothesised that endoscopic lung volume reduction increases its strength by modifying its shape. OBJECTIVES: To investigate changes in both diaphragm shape and strength induced by the insertion of endobronchial valves. METHODS: In 19 patients, both the diaphragm shape and strength were investigated respectively by 3D Slicer software applied on CT scans acquired at functional residual capacity and by transdiaphragmatic pressure measurements by bilateral magnetic stimulation of the phrenic nerves before and 3 months after unilateral valves insertion. MEASUREMENTS AND MAIN RESULTS: After lung volume reduction (median (IQR), 434 mL (-597 to -156], p<0.0001), diaphragm strength increased (transdiaphragmatic pressure: 3 cmH2O (2.3 to 4.2), p<0.0001). On the treated side, this increase was associated with an increase in the coronal (16 mm (13 to 24), p<0.0001) and sagittal (26 mm (21 to 30), p<0.0001) lengths as well as in the area of the zone of apposition (62 cm2 (3 to 100), p<0.0001) with a decrease in the coronal (8 mm (-12 to -4), p<0.0001) and sagittal (9 mm (-18 to -2), p=0.0029) radii of curvature. CONCLUSIONS: Endoscopic lung volume reduction modifies the diaphragm shape by increasing its length and its zone of apposition and by decreasing its radius of curvature on the treated side, resulting in an increase in its strength. TRIAL REGISTRATION NUMBER: NCT05799352.

Altered skeletal muscle function and beneficial effects of exercise training in a rat model of induced pulmonary emphysema.

AIM: Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow obstruction and development of emphysema. Among the comorbidities associated with COPD, skeletal muscle dysfunction is known to affect exercise capacity and the survival rate of patients. Pulmonary rehabilitation (PR), via exercise training, is essential for COPD patients. However, the response to PR is most often moderate. An animal model that recapitulates critical features of chronic human disease and provides access to muscle function should therefore be useful to improve PR benefits. METHODS: We used a rat model of induced emphysema based on pulmonary instillations of elastase (ELA) and lipopolysaccharides (LPS). We assessed the long-term effects of ELA/LPS and the potential effectiveness of endurance training on the skeletal muscle function. In vivo strength of the animals, and ex vivo contractility, endurance, type 1 fiber proportion, fiber cross-sectional area, and capillarization of both soleus and extensor digitorum longus (EDL) were assessed. RESULTS: An impaired overall muscle strength with decreased force, reduced capillarization, and atrophy of type 1 fiber of EDL was observed in ELA/LPS rats. Soleus was not affected. Endurance training was able to reduce fatigability, and increase type 1 fiber proportion and capillarization of soleus, and improve force, endurance, and capillarization of EDL in control and ELA/LPS rats. CONCLUSION: Our rat model of induced emphysema, which shares some features with the phenotype present in patients with COPD, could represent a suitable model to study skeletal muscle dysfunction and the effects of exercise training on muscle function in patients.

Design of the multicentre randomised controlled BENTO trial to demonstrate patient-relevant benefit of bronchoscopic lung volume reduction using thermal vapour ablation in the German healthcare system for patients with upper lobe emphysema: a study protocol.

INTRODUCTION: Application of vapour ablation as a novel approach to lung volume reduction has positive effects in patients with severe emphysema. The BENTO study is a randomised, controlled, open, multicentre trial, to assess the effects of bronchoscopic thermal vapour ablation (BTVA) in the German healthcare system. METHODS AND ANALYSIS: Patients with bilateral heterogeneous emphysema of the upper lobes in Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 3/4 will be enrolled in this trial and will receive either standard medical management alone (according to GOLD guidelines) or BTVA treatment with the InterVapor system together with standard medical management. Patients will be randomised in a 2:1 ratio (treatment group:control group). A total of 224 patients will be enrolled at 15 study sites. The primary endpoint is the change in patient-reported disease-specific quality of life, as measured by the St George's Respiratory Questionnaire for chronic obstructive pulmonary disease patients between randomisation and the 9-month follow-up visit. Secondary endpoints include adverse events, mortality, vital status, changes in lung function parameters, exercise capacity and other efficacy measures at 3, 9 and 12 months.The BENTO trial was commissioned by the German Federal Joint Committee, to demonstrate that this approach is an efficient and safe treatment option in the German healthcare system. ETHICS AND DISSEMINATION: The protocol has been approved by the lead ethics committee in Germany (Ethics Committee of the Medical Faculty of Heidelberg) and until present also by the following ethics committees: Ethics Committee of the Medical Faculty of Duisburg-Essen, Ethics Committee of the Medical Faculty of Martin-Luther-University Halle-Wittenberg, Ethics Committee of the State Medical Association of Hessen, Ethics Commission of the State Office for Health and Social Affairs of the State of Berlin, Ethics Committee of the Medical Faculty of Greifswald. The results will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT05717192.

Impact and timing of pulmonary rehabilitation in patients undergoing bronchoscopic lung volume reduction with endobronchial valves: A multicentre randomized controlled trial in patients with severe emphysema.

BACKGROUND AND OBJECTIVE: Both bronchoscopic lung volume reduction with endobronchial valves (BLVR-EBV) and pulmonary rehabilitation (PR) are effective treatments for improving exercise capacity and patient-reported outcomes in patients with severe Chronic Obstructive Pulmonary Disease (COPD). According to current recommendations, all BLVR-EBV patients should have undergone PR first. Our aim was to study the effects of PR both before and after BLVR-EBV compared to BLVR-EBV alone. METHODS: We included patients with severe COPD who were eligible for BLVR-EBV and PR. Participants were randomized into three groups: PR before BLVR-EBV, PR after BLVR-EBV or BLVR-EBV without PR. The primary outcome was change in constant work rate cycle test (CWRT) endurance time at 6-month follow-up of the PR groups compared to BLVR-EBV alone. Secondary endpoints included changes in 6-minute walking test, daily step count, dyspnoea and health-related quality of life. RESULTS: Ninety-seven participants were included. At 6-month follow-up, there was no difference in change in CWRT endurance time between the PR before BLVR-EBV and BLVR-EBV alone groups (median: 421 [IQR: 44; 1304] vs. 787 [123; 1024] seconds, p = 0.82) or in any of the secondary endpoints, but the PR after BLVR-EBV group exhibited a smaller improvement in CWRT endurance time (median: 107 [IQR: 2; 573], p = 0.04) and health-related quality of life compared to BLVR-EBV alone. CONCLUSION: The addition of PR to BLVR-EBV did not result in increased exercise capacity, daily step count or improved patient-reported outcomes compared to BLVR-EBV alone, neither when PR was administered before BLVR-EBV nor when PR was administered after BLVR-EBV.

Twenty four-month follow-up after bullectomy, unilateral and bilateral lung volume reduction surgery: a single-center retrospective analysis of consecutive cases.

PURPOSE: While pharmacologic therapy remains the cornerstone of lung emphysema treatment, surgery is an additional therapeutic option in selected patient groups with advanced emphysema. The aim of lung volume reduction surgery (LVRS) is to improve lung function, exercise capacity, quality of life and survival. We sought to determine the therapeutic value of surgical resection in specific patients with lung emphysema. PATIENTS AND METHODS: A retrospective study was performed consisting of 58 patients with lung emphysema who underwent surgical intervention over a 10-year period and were followed for 2 years postoperatively. The clinical characteristics recorded were FEV1 (forced expiratory volume in 1 s), the 6-min walk test (6-MWT), the Modified Medical Research Council (mMRC), body mass index (BMI) and quality of life prior to and 6, 12 and 24 months after surgical intervention. Moreover, all peri- and post-operative complications were noted. RESULTS: Out of 58 emphysema patients (72% male, FEV1 (L) 2.21 ± 0.17, RV (L) 3.39 ± 0.55), 19 underwent surgical bullectomy, 31 unilateral LVRS and 8 sequential bilateral LVRS. Six months after surgery, there was a statistically significant improvement in FEV1, RV, TLC, 6-MWT and mMRC. Over a period of 12 to 24 months postoperatively, clinical benefit gradually declines most likely due to COPD progression but patients still experienced a significant improvement in FEV1. The most common postoperative complications were persistent air leakage (> 7 days), arrhythmia and subcutaneous emphysema in 60%, 51.6% and 22.4%, respectively. No deaths were observed after surgical intervention. CONCLUSION: In a selected patient population, surgery led to significant improvement of lung function parameters, exercise capacity and quality of life. Over a period of 12 to 24 months postoperatively, clinical benefit gradually decreased most likely due to COPD progression.

Mechanical and morphological characterization of the emphysematous lung tissue.

Irreversible alveolar airspace enlargement is the main characteristic of pulmonary emphysema, which has been extensively studied using animal models. While the alterations in lung mechanics associated with these morphological changes have been documented in the literature, the study of the mechanical behavior of parenchymal tissue from emphysematous lungs has been poorly investigated. In this work, we characterize the mechanical and morphological properties of lung tissue in elastase-induced emphysema rat models under varying severity conditions. We analyze the non-linear tissue behavior using suitable hyperelastic constitutive models that enable to compare different non-linear responses in terms of hyperelastic material parameters. We further analyze the effect of the elastase dose on alveolar morphology and tissue material parameters and study their connection with respiratory-system mechanical parameters. Our results show that while the lung mechanical function is not significantly influenced by the elastase treatment, the tissue mechanical behavior and alveolar morphology are markedly affected by it. We further show a strong association between alveolar enlargement and tissue softening, not evidenced by respiratory-system compliance. Our findings highlight the importance of understanding tissue mechanics in emphysematous lungs, as changes in tissue properties could detect the early stages of emphysema remodeling. STATEMENT OF SIGNIFICANCE: Gas exchange is vital for life and strongly relies on the mechanical function of the lungs. Pulmonary emphysema is a prevalent respiratory disease where alveolar walls are damaged, causing alveolar enlargement that induces harmful changes in the mechanical response of the lungs. In this work, we study how the mechanical properties of lung tissue change during emphysema. Our results from animal models show that tissue properties are more sensitive to alveolar enlargement due to emphysema than other mechanical properties that describe the function of the whole respiratory system.

Bronchoscopic Lung Volume Reduction as the Treatment of Choice versus Robotic-Assisted Lung Volume Reduction Surgery in Similar Patients with Emphysema - An Initial Experience of the Benefits and Complications.

Objective: There is an assumption that because EBLVR requires less use of hospital resources, offsetting the higher cost of endobronchial valves, it should therefore be the treatment of choice wherever possible. We have tested this hypothesis in a retrospective analysis of the two in similar groups of patients. Methods: In a 4-year experience, we performed 177 consecutive LVR procedures: 83 patients underwent Robot Assisted Thoracoscopic (RATS) LVRS and 94 EBLVR. EBLVR was intentionally precluded by evidence of incomplete fissure integrity or intra-operative assessment of collateral ventilation. Unilateral RATS LVRS was performed in these cases together with those with unsuitable targets for EBLVR. Results: EBLVR was uncomplicated in 37 (39%) cases; complicated by post-procedure spontaneous pneumothorax (SP) in 28(30%) and required revision in 29 (31%). In the LVRS group, 7 (8%) patients were readmitted with treatment-related complications, but no revisional procedure was needed. When compared with uncomplicated EBLVR, LVRS had a significantly longer operating time: 85 (14-82) vs 40 (15-151) minutes (p<0.001) and hospital stay: 7.5 (2-80) vs 2 (1-14) days (p<0.01). However, LVRS had a similar total operating time to both EBLVR requiring revision: 78 (38-292) minutes and hospital stay to EBLVR complicated by pneumothorax of 11.5 (6.5-24.25) days. Use of critical care was significantly longer in RATS group, and it was also significantly longer in EBV with SP group than in uncomplicated EBV group. Conclusion: Endobronchial LVR does use less hospital resources than RATS LVRS in comparable groups if the recovery is uncomplicated. However, this advantage is lost if one includes the resources needed for the treatment of complications and revisional procedures. Any decision to favour EBLVR over LVRS should not be based on the assumption of a smoother, faster perioperative course.

Optimizing clinical outcomes for bronchoscopic lung volume reduction with Zephyr® valves.

Bronchoscopic lung volume reduction treatment with Zephyr one-way valves is an effective guideline-based treatment option for patients with severe emphysema and hyperinflation. However, in some cases the treatment response is less than anticipated or there might be a loss of initial treatment effect. Reasons for the lack of response can include incorrect assessment of collateral ventilation, improper valve placement, or patient related factors. Loss of initial benefit can be due to granulation tissue formation and subsequent valve dysfunction, or there may be side effects such as excessive coughing or infectious problems. Careful follow-up after treatment with valves is important and evaluation with a CT scan and/or bronchoscopy is helpful if there is no improvement after treatment or loss of initial benefit. This paper aims to describe the most important causes and provide a strategy of how to approach and manage these patients.

Vessel and Airway Characteristics in One-Year Computed Tomography-defined Rapid Emphysema Progression: SPIROMICS.

Rationale: Rates of emphysema progression vary in chronic obstructive pulmonary disease (COPD), and the relationships with vascular and airway pathophysiology remain unclear. Objectives: We sought to determine if indices of peripheral (segmental and beyond) pulmonary arterial dilation measured on computed tomography (CT) are associated with a 1-year index of emphysema (EI; percentage of voxels <-950 Hounsfield units) progression. Methods: Five hundred ninety-nine former and never-smokers (Global Initiative for Chronic Obstructive Lung Disease stages 0-3) were evaluated from the SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study) cohort: rapid emphysema progressors (RPs; n = 188, 1-year ΔEI > 1%), nonprogressors (n = 301, 1-year ΔEI ± 0.5%), and never-smokers (n = 110). Segmental pulmonary arterial cross-sectional areas were standardized to associated airway luminal areas (segmental pulmonary artery-to-airway ratio [PAARseg]). Full-inspiratory CT scan-derived total (arteries and veins) pulmonary vascular volume (TPVV) was compared with small vessel volume (radius smaller than 0.75 mm). Ratios of airway to lung volume (an index of dysanapsis and COPD risk) were compared with ratios of TPVV to lung volume. Results: Compared with nonprogressors, RPs exhibited significantly larger PAARseg (0.73 ± 0.29 vs. 0.67 ± 0.23; P = 0.001), lower ratios of TPVV to lung volume (3.21 ± 0.42% vs. 3.48 ± 0.38%; P = 5.0 × 10-12), lower ratios of airway to lung volume (0.031 ± 0.003 vs. 0.034 ± 0.004; P = 6.1 × 10-13), and larger ratios of small vessel volume to TPVV (37.91 ± 4.26% vs. 35.53 ± 4.89%; P = 1.9 × 10-7). In adjusted analyses, an increment of 1 standard deviation in PAARseg was associated with a 98.4% higher rate of severe exacerbations (95% confidence interval, 29-206%; P = 0.002) and 79.3% higher odds of being in the RP group (95% confidence interval, 24-157%; P = 0.001). At 2-year follow-up, the CT-defined RP group demonstrated a significant decline in postbronchodilator percentage predicted forced expiratory volume in 1 second. Conclusions: Rapid one-year progression of emphysema was associated with indices indicative of higher peripheral pulmonary vascular resistance and a possible role played by pulmonary vascular-airway dysanapsis.

A 6-year experience of Zephyr endobronchial valves for severe emphysema in an Australian single-centre cohort.

BACKGROUND: Endobronchial valve (EBV) insertion for lung volume reduction is a management option for patients with severe emphysema. One-way valves cause lobar deflation and improve lung function, exercise capacity and quality of life. AIMS: To retrospectively analyse and compare the outcomes of the first 57 patients treated with EBVs between 2015 and 2021 at the Royal Adelaide Hospital to international standards. METHODS: Clinical outcomes of forced expiratory volume in 1 s (FEV1), residual volume (RV), treated lobe volume reduction (TLVR) and 6-min walk distance (6MWD) at 3, 6 and 12 months after valve insertion were reviewed against established minimally clinically important differences (MCIDs). Complications and subjective breathlessness measured by Borg scores were also reviewed. RESULTS: Fifty-seven patients were included. At 12 months, 77.2% achieved TLVR. FEV1 improved by 170 mL (95% confidence interval (CI): 100-250, P < 0.001), 80 mL (95% CI: 10-150, P = 0.019) and 40 mL (95% CI: -60 to 130, P 0.66) at 3, 6 and 12 months respectively. RV improved by -610 mL (95% CI: -330 to -900, P < 0.0001) at 3 months, -640 mL (95% CI: -360 to -920, P < 0.0001) at 6 months and -360 mL (95% CI: -60 to -680, P = 0.017) at 12 months. 6MWD improved by 57.34 m (95% CI: 36.23-78.45, P < 0.0001) and 44.93 m (95% CI: 7.19-82.67, P = 0.02) at 3 and 6 months. Borg score improved by -0.53 (95% CI: 0.11 to -1.2, P = 0.11) and -0.49 (95% CI: 0.17 to -1.15, P = 0.16) at 3 and 6 months. Complication rates aligned with international standards with mucous/infection (26.3%) and pneumothorax (17.5%) as the most common. Subgroup analysis signalled improved outcomes in patients with heterogeneous emphysema. CONCLUSION: Our study represents the first publicly funded Australian analysis of EBVs. The results align with international prospective trials demonstrating improved lung function and exercise capacity. Australians with severe emphysema and gas trapping should be referred to a multidisciplinary centre for consideration of EBVs.

Artificial Intelligence-Based Emphysema Quantification in Routine Chest Computed Tomography: Correlation With Spirometry and Visual Emphysema Grading.

OBJECTIVE: The aim of the study is to assess the correlation between artificial intelligence (AI)-based low attenuation volume percentage (LAV%) with forced expiratory volume in the first second to forced vital capacity (FEV1/FVC) and visual emphysema grades in routine chest computed tomography (CT). Furthermore, optimal LAV% cutoff values for predicting a FEV1/FVC < 70% or moderate to more extensive visual emphysema grades were calculated. METHODS: In a retrospective study of 298 consecutive patients who underwent routine chest CT and spirometry examinations, LAV% was quantified using an AI-based software with a threshold < -950 HU. The FEV1/FVC was derived from spirometry, with FEV1/FVC < 70% indicating airway obstruction. The mean time interval of CT from spirometry was 3.87 ± 4.78 days. Severity of emphysema was visually graded by an experienced chest radiologist using an established 5-grade ordinal scale (Fleischner Society classification system). Spearman correlation coefficient between LAV% and FEV1/FVC was calculated. Receiver operating characteristic determined the optimal LAV% cutoff values for predicting a FEV1/FVC < 70% or a visual emphysema grade of moderate or higher (Fleischner grade 3-5). RESULTS: Significant correlation between LAV% and FEV1/FVC was found (ϱ = -0.477, P < 0.001). Increasing LAV% corresponded to higher visual emphysema grades. For patients with absent visual emphysema, mean LAV% was 2.98 ± 3.30, for patients with trace emphysema 3.22 ± 2.75, for patients with mild emphysema 3.90 ± 3.33, for patients with moderate emphysema 6.41 ± 3.46, for patients with confluent emphysema 9.02 ± 5.45, and for patients with destructive emphysema 16.90 ± 8.19. Optimal LAV% cutoff value for predicting a FEV1/FVC < 70 was 6.1 (area under the curve = 0.764, sensitivity = 0.773, specificity = 0.665), while for predicting a visual emphysema grade of moderate or higher, it was 4.7 (area under the curve = 0.802, sensitivity = 0.766, specificity = 0.742). Furthermore, correlation between visual emphysema grading and FEV1/FVC was found. In patients with FEV1/FVC < 70% a high proportion of subjects had emphysema grade 3 (moderate) or higher, whereas in patients with FEV1/FVC ≥ 70%, a larger proportion had emphysema grade 3 (moderate) or lower. The sensitivity for visual emphysema grading predicting a FEV1/FVC < 70% was 56.3% with an optimal cutoff point at a visual grade of 4 (confluent), demonstrating a lower sensitivity compared with LAV% (77.3%). CONCLUSIONS: A significant correlation between AI-based LAV% and FEV1/FVC as well as visual CT emphysema grades can be found in routine chest CT suggesting that AI-based LAV% measurement might be integrated as an add-on functional parameter in the evaluation of chest CT in the future.

Machine Learning and CT Texture Features in Ex-smokers with no CT Evidence of Emphysema and Mildly Abnormal Diffusing Capacity.

RATIONALE AND OBJECTIVES: Ex-smokers without spirometry or CT evidence of chronic obstructive pulmonary disease (COPD) but with mildly abnormal diffusing capacity of the lungs for carbon monoxide (DLCO) are at higher risk of developing COPD. It remains difficult to make clinical management decisions for such ex-smokers without other objective assessments consistent with COPD. Hence, our objective was to develop a machine-learning and CT texture-analysis pipeline to dichotomize ex-smokers with normal and abnormal DLCO (DLCO≥75%pred and DLCO<75%pred). MATERIALS AND METHODS: In this retrospective study, 71 ex-smokers (50-85yrs) without COPD underwent spirometry, plethysmography, thoracic CT, and 3He MRI to generate ventilation defect percent (VDP) and apparent diffusion coefficients (ADC). PyRadiomics was utilized to extract 496 CT texture-features; Boruta and principal component analysis were used for feature selection and various models were investigated for classification. Machine-learning classifiers were evaluated using area under the receiver operator characteristic curve (AUC), sensitivity, specificity, and F1-measure. RESULTS: Of 71 ex-smokers without COPD, 29 with mildly abnormal DLCO had significantly different MRI ADC (p < .001), residual-volume to total-lung-capacity ratio (p = .003), St. George's Respiratory Questionnaire (p = .029), and six-minute-walk distance (6MWD) (p < .001), but similar relative area of the lung < -950 Hounsfield-units (RA950) (p = .9) compared to 42 ex-smokers with normal DLCO. Logistic-regression machine-learning mixed-model trained on selected texture-features achieved the best classification accuracy of 87%. All clinical and imaging measurements were outperformed by high-high-pass filter high-gray-level-run-emphasis texture-feature (AUC=0.81), which correlated with DLCO (ρ = -0.29, p = .02), MRI ADC (ρ = 0.23, p = .048), and 6MWD (ρ = -0.25, p = .02). CONCLUSION: In ex-smokers with no CT evidence of emphysema, machine-learning models exclusively trained on CT texture-features accurately classified ex-smokers with abnormal diffusing capacity, outperforming conventional quantitative CT measurements.