Effective Bronchoscopic Lung Volume Reduction Accelerates Exercise Oxygen Uptake Kinetics in Emphysema

Efficacy and safety of bronchoscopic lung volume reduction for chronic obstructive pulmonary disease: a systematic review and network meta-analysis

BACKGROUND

Various bronchoscopic lung volume reduction (BLVR) methods have been developed to treat chronic obstructive pulmonary disease (COPD). The efficacy and safety of these interventions remain unclear. This study assessed the efficacy and safety of various BLVR interventions in COPD patients.

METHODS

PubMed and Embase were searched from inception to 21 October 2023. The primary outcomes assessed included the 6-min walking distance (6MWD), St. George Respiratory Questionnaire (SGRQ) score, lung function, and adverse events (AE). A frequentist approach with a random-effects model was used for a network meta-analysis.

RESULTS

Twelve randomized controlled trials (RCTs) with 1646 patients were included in this meta-analysis. Patients treated with an endobronchial valve (EBV) achieved a minimum clinically important difference (MCID) in 6MWD and SGRQ at 6 months. Patients treated with coils achieved MCID in the SGRQ score at 12 months. Patients with aspiration valve system and bronchoscopic thermal vapor ablation (BTVA) achieved MCID in the SGRQ score at 6 months.

CONCLUSIONS

In COPD patients, EBV should be considered first, while being wary of pneumothorax. Coil and BTVA are potential therapeutic alternatives. Although BTVA demonstrates a safer procedural profile than coils, additional studies are imperative to clarify its efficacy.

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.

Survival following lung volume reduction procedures: results from the UK Lung Volume Reduction (UKLVR) registry

INTRODUCTION

Lung volume reduction surgery (LVRS) and endobronchial valve (EBV) placement can produce substantial benefits in appropriately selected people with emphysema. The UK Lung Volume Reduction (UKLVR) registry is a national multicentre observational study set up to support quality standards and assess outcomes from LVR procedures at specialist centres across the UK.

METHODS

Data were analysed for all patients undergoing an LVR procedure (LVRS/EBV) who were recruited into the study at participating centres between January 2017 and June 2022, including; disease severity and risk assessment, compliance with guidelines for selection, procedural complications and survival to February 2023.

RESULTS

Data on 541 patients from 14 participating centres were analysed. Baseline disease severity was similar in patients who had surgery n=244 (44.9%), or EBV placement n=219 (40.9%), for example, forced expiratory volume in 1 s (FEV1) 32.1 (12.1)% vs 31.2 (11.6)%. 89% of cases had discussion at a multidisciplinary meeting recorded. Median (IQR) length of stay postprocedure for LVRS and EBVs was 12 (13) vs 4 (4) days(p=0.01). Increasing age, male gender and lower FEV1%predicted were associated with mortality risk, but survival did not differ between the two procedures, with 50 (10.8%) deaths during follow-up in the LVRS group vs 45 (9.7%) following EBVs (adjusted HR 1.10 (95% CI 0.72 to 1.67) p=0.661) CONCLUSION: Based on data entered in the UKLVR registry, LVRS and EBV procedures for emphysema are being performed in people with similar disease severity and long-term survival is similar in both groups.

Dual-energy Computed Tomographic Pulmonary Angiography Accurately Estimates Lobar Perfusion Before Lung Volume Reduction for Severe Emphysema

PURPOSE

To assess if dual-energy computed tomographic pulmonary angiography (DECTPA) derived lobar iodine quantification can provide an accurate estimate of lobar perfusion in patients with severe emphysema, and offer an adjunct to single-photon emission CT perfusion scintigraphy (SPECT-PS) in assessing suitability for lung volume reduction (LVR).

MATERIALS AND METHODS

Patients with severe emphysema (forced expiratory volume in 1 s <49% predicted) undergoing evaluation for LVR between May 2018 and April 2020 imaged with both SPECT-PS and DECTPA were included in this retrospective study. DECTPA perfused blood volume maps were automatically segmented and lobar iodine mass was estimated and compared with lobar technetium (Tc99m) distribution acquired with SPECT-PS. Pearson correlation and Bland-Altman analysis were used for intermodality comparison between DECTPA and SPECT-PS. Univariate and adjusted multivariate linear regression were modelled to ascertain the effect sizes of possible confounders of disease severity, sex, age, and body mass index on the relationship between lobar iodine and Tc99m values. Effective radiation dose and adverse reactions were recorded.

RESULTS

In all, 123 patients (64.5±8.8 y, 71 men; mean predicted forced expiratory volume in 1 s 32.1 ±12.7%,) were eligible for inclusion. There was a linear relationship between lobar perfusion values acquired using DECTPA and SPECT-PS with statistical significance ( P <0.001). Lobar relative perfusion values acquired using DECTPA and SPECT-PS had a consistent relationship both by linear regression and Bland-Altman analysis (mean bias, -0.01, mean r2 0.64; P <0.0001). Individual lobar comparisons demonstrated moderate correlation ( r =0.79, 0.78, 0.84, 0.78, 0.8 for the right upper, middle, lower, left upper, and lower lobes, respectively, P <0.0001). The relationship between lobar iodine and Tc99m values was not significantly altered after controlling for confounders including symptom and disease severity, age, sex, and body mass index.

CONCLUSIONS

DECTPA provides an accurate estimation of lobar perfusion, showing good agreement with SPECT-PS and could potentially streamline preoperative assessment for LVR.

Heart rate and oxygen uptake kinetics obtained from continuous measurements with wearable devices during outdoor walks of patients with COPD

Objective

Continuous physiological measurements during a laboratory-based exercise test can provide physiological biomarkers, such as heart rate (HR) and oxygen uptake (V̇O₂) kinetics, that carry clinically relevant information. In contrast, it is not clear how continuous data generated by wearable devices during daily-life routines could provide meaningful biomarkers. We aimed to determine whether valid HR and V̇O₂ kinetics can be obtained from measurements with wearable devices during outdoor walks in patients with chronic obstructive pulmonary disease (COPD).

Methods

HR (Polar Belt) and V̇O₂(METAMAX3B) were measured during 93 physical activity transitions performed by eight patients with COPD during three different outdoor walks (n_tr= 77) and a 6-minute walk test (n_tr= 16). HR and V̇O₂ kinetics were calculated every time a participant started a walk, finished a walk or walked upstairs. HR and V̇O₂ kinetics were considered valid if the response magnitude and model fit were adequate, and model parameters were reliable.

Results

Continuous measurements with wearable devices provided valid HR kinetics when COPD patients started or finished (range 63%-100%) the different outdoor walks and valid V̇O₂ kinetics when they finished (range 63%-100%) an outdoor walk. The amount of valid kinetics and kinetic model performance was comparable between outdoor walks and a laboratory-based exercise test (p > .05).

Conclusion

We envision that the presented approach could improve telemonitoring applications of patients with COPD by providing regular, unsupervised assessments of HR kinetics during daily-life routines. This could allow to early identify a decline in the patients' dynamic physiological functioning, physical fitness and/or health status.

Physiological Changes Differ between Responders and Nonresponders to Pulmonary Rehabilitation in COPD

PURPOSE

Not all patients with chronic obstructive pulmonary disease (COPD) experience similar benefits after pulmonary rehabilitation (PR). This pre-post PR study used a large sample of patients with COPD to determine whether PR-induced changes of oxygen uptake (V˙O2) kinetics and exercise responses of V˙O2, carbon dioxide output (V˙CO2), minute ventilation (V˙E), V˙E/V˙CO2, breathing frequency, and tidal volume differed between responders and nonresponders to PR.

METHODS

Responders to PR were defined as patients with a minimal clinically important increase in endurance time of 105 s. Isotime (=180 s) values of V˙O2, V˙CO2, V˙E, V˙E/V˙CO2, breathing frequency, and tidal volume; gains of V˙O2, V˙CO2, and V˙E; and V˙O2 mean response time of 183 patients with COPD (forced expiratory volume in 1 s: 56% ± 19% predicted) were compared between pre- and post-PR constant work rate tests.

RESULTS

After PR, only the group of responders significantly decreased V˙O2 mean response time (P < 0.05), V˙CO2 gain, V˙E gain, and isotime values of V˙CO2, V˙E, and V˙E/V˙CO2 (all, P < 0.001), while also improving their breathing pattern (e.g., decreased breathing frequency isotime value; P < 0.0001). These changes were not observed in the group of nonresponders. Changes in physiological exercise responses were correlated with changes in physical performance (e.g., correlation between changes in V˙O2 mean response time and endurance time: P = 0.0002, r = -0.32).

CONCLUSIONS

PR-induced changes in physiological exercise responses differed between responders and nonresponders. Physiological changes are relevant to explain the variable improvements of physical performance after PR in patients with COPD.

Interventional Pulmonology: Diagnostic and Therapeutic Advances in Bronchoscopy

BACKGROUND

Interventional pulmonology is a rapidly evolving subspecialty of pulmonary medicine that offers advanced consultative and procedural services to patients with airway diseases, pleural diseases, as well as in the diagnosis and management of patients with thoracic malignancy.

AREAS OF UNCERTAINTY

The institution of lung cancer screening modalities as well as the search of additional minimally invasive diagnostic and treatment modalities for lung cancer and other chronic lung diseases has led to an increased focus on the field of interventional pulmonology. Rapid advancements in the field over the last 2 decades has led to development of various new minimally invasive bronchoscopic approaches and techniques for patients with cancer as well as for patients with chronic lung diseases.

DATA SOURCES

A review of literature was performed using PubMed database to identify all articles published up till October 2020 relevant to the field of interventional pulmonology and bronchoscopy. The reference list of each article was searched to look for additional articles, and all relevant articles were included in the article.

THERAPEUTIC ADVANCES

Newer technologies are now available such navigation platforms to diagnose and possibly treat peripheral pulmonary nodules, endobronchial ultrasound in diagnosis of mediastinal and hilar adenopathy as well as cryobiopsy in the diagnosis of diffuse lung diseases. In addition, flexible and rigid bronchoscopy continues to provide new and expanding ability to manage patients with benign and malignant central airway obstruction. Interventions are also available for diseases such as asthma, chronic bronchitis, chronic obstructive pulmonary disease, and emphysema that were traditionally treated with medical management alone.

CONCLUSIONS

With continued high quality research and an increasing body of evidence, interventional bronchoscopy has enormous potential to provide both safe and effective options for patients with a variety of lung diseases.

Cardiorespiratory coupling is associated with exercise capacity in patients with chronic obstructive pulmonary disease

Background

The interaction between the pulmonary function and cardiovascular mechanics is a crucial issue, particularly when treating patients with chronic obstructive pulmonary disease (COPD). Synchrogram index is a new parameter that can quantify this interaction and has the potential to apply in COPD patients. Our objective in this study was to characterize cardiorespiratory interactions in terms of cardiorespiratory coupling (CRC) using the synchrogram index of the heart rate and respiratory flow signals in patients with chronic obstructive pulmonary disease.

Methods

This is a cross-sectional and preliminary data from a prospective study, which examines 55 COPD patients. K-means clustering analysis was applied to cluster COPD patients based on the synchrogram index. Linear regression and multivariable regression analysis were used to determine the correlation between the synchrogram index and the exercise capacity assessed by a six-minute walking test (6MWT).

Results

The 55 COPD patients were separated into a synchronized group (median 0.89 (0.64–0.97), n = 43) and a desynchronized group (median 0.23 (0.02–0.51), n = 12) based on K-means clustering analysis. Synchrogram index was correlated significantly with six minutes walking distance (r = 0.42, p = 0.001) and distance saturation product (r = 0.41, p = 0.001) assessed by 6MWT, and still was an independent variable by multivariable regression analysis.

Conclusion

This is the first result studying the heart–lung interaction in terms of cardiorespiratory coupling in COPD patients by the synchrogram index, and COPD patients are clustered into synchronized and desynchronized groups. Cardiorespiratory coupling is associated with exercise capacity in patients with COPD.

Lung volume reduction eligibility in patients with COPD completing pulmonary rehabilitation: results from the UK National Asthma and COPD Audit Programme

OBJECTIVES

To establish what proportion of patients completing a UK pulmonary rehabilitation (PR) programme meet the 2018 National Institute for Health and Care Excellence (NICE) chronic obstructive pulmonary disease (COPD) guideline (NG115) criteria to have a respiratory review to establish whether referral to a lung volume reduction multidisciplinary team would be appropriate. This respiratory review would include evaluation of the presence of hyperinflation and the presence of emphysema on CT scan. The NICE criteria include measures of breathlessness and exercise capacity but these parameters are not completely defined.

DESIGN

Observational study.

SETTING

PR programmes across the UK in 2015 (210 centres) and 2017 (184 centres) entering data into the Royal College of Physicians' National Asthma and COPD Audit Programme.

PARTICIPANTS

8295 (55.7%) of 14 889 patients in programmes using incremental shuttle walk test (ISWT) or 6-minute walk test (6MWT) as an outcome measure completed PR, and 4856 (32.6%) had complete data recorded (6MWT/ISWT, baseline spirometry, Medical Research Council (MRC) dyspnoea score).

RESULTS

Depending on the walking test safety threshold adopted for the ISWT (≥140 m or ≥ 80 m) and the MRC dyspnoea score threshold used (MRC score ≥3 or ≥4 at the end of PR), between 4.9% and 18.1% of PR completers met the NICE criteria for a lung volume reduction-focused respiratory review.

CONCLUSIONS

Lung volume reduction therapies are beneficial in appropriately selected patients with COPD, but few procedures are performed, and treatment pathways are unclear. These data help to inform the feasibility of the approach recommended by NICE and highlight the need for future systematic pathways to reduce inequalities in patients being considered for effective treatments.

The Effects of Endobronchial Coil Therapy on Right Ventricular Functions

Lung hyperinflation is an important therapeutic target in symptomatic emphysema patients. Endobronchial therapies that reduce end-expiratory lung volume are increasingly being used in advanced cases. However, there is paucity of data regarding the effects of these therapies on the heart functions. The aim of this study is to evaluate the right ventricular functions before and after the procedure in patients who underwent endobronchial coil therapy (EBCT).Patients who were between 18 and 80 years of age and scheduled for EBCT with GOLD 3-4 were enrolled in the study. Right heart functions were evaluated using MPI, TAS, TAPSE. Right atrium area and maximum velocity of tricuspid regurgitation were also noted.A total of 23 patients were enrolled in the study. 21 patients underwent bilateral intervention, while only 2 patients received unilateral treatment. There was an improvement in MPI (0.49 ± 0.15 vs 0.39 ± 0.11, p < 0.001) and TAS (11.6 (9 - 15) vs 13.2 (9.80 - 17.0), p = 0.001). Peak TRV (2.52 ± 0.6, 2.38 ± 0.6, p = 0.02) and PASP values were lower in the post-operative period (41.15 ± 5.94 vs 36.83 ± 8.01 p = 0.019).In this current study, we found improved echocardiographic RtV parameters in patients who received EBCT treatment.

Bronchoscopic interventions for severe emphysema: Where are we now?

Patients with severe emphysema have limited treatment options and only derive a small benefit from optimal medical treatment. The only other therapy to have significant clinical beneficial effect in emphysema is LVRS but the perceived risk and invasiveness of surgery has fuelled bronchoscopic approaches to induce lung volume reduction. There are multiple bronchoscopic methods for achieving volume reduction in severe emphysema: EBV, airway bypass procedure, endobronchial coils, thermal (vapour) sclerosis and chemical sclerosis (sealants). Optimal patient selection is key to successful patient outcomes. This review discusses bronchoscopic approaches for emphysema treatment which has progressed through clinical trials to clinical practice.

Kinetic analyses as a tool to examine physiological exercise responses in a large sample of patients with COPD

Kinetic features such as oxygen uptake (V̇o₂) mean response time (MRT), and gains of V̇o₂, carbon dioxide output (V̇co₂), and minute ventilation (V̇e) can describe physiological exercise responses during a constant work rate test of patients with chronic obstructive pulmonary disease (COPD). This study aimed to establish simple guidelines that can identify COPD patients for whom kinetic analyses are (un)likely to be reliable and examined whether slow V̇o₂ responses and gains of V̇o₂, V̇co₂, and V̇e are associated with ventilatory, cardiovascular, and/or physical impairments. Kinetic features were examined for 265 COPD patients [forced expiratory volume in 1 s (FEV₁): 54 ± 19%predicted] who performed a constant work rate test (duration > 180 s) with breath-by-breath measurements of V̇o₂, V̇co₂, and V̇e. Negative/positive predictive values were used to define cutoff values of relevant clinical variables below/above which kinetic analyses are (un)likely to be reliable. Kinetic feature values were unreliable for 21% (= 56/265) of the patients and for 79% (= 19/24) of the patients with a peak work rate (WR_peak)< 45 W. Kinetic feature values were considered reliable for 94% (= 133/142) of the patients with an FEV₁ > 1.3 L. For patients exhibiting reliable kinetic feature values, V̇o₂ MRT was associated with ventilatory (e.g., FEV₁ %predicted: P < 0.001; r = -0.35) and physical (e.g., V̇o_2peak %predicted: P = 0.009; r = -0.18) impairments. Gains were mainly associated with cardiac function and ventilatory constraints, representing both response efficiency and limitation. Kinetic analyses are likely to be unreliable for patients with a WR_peak < 45 W. Whereas gains enrich analyses of physiological exercise responses, V̇o₂ MRT shows potential to serve as a motivation-independent, physiological indicator of physical performance.NEW & NOTEWORTHY A constant work rate test that is standardly performed during a prerehabilitation assessment is unable to provide reliable kinetic feature values for chronic obstructive pulmonary disease (COPD) patients with a peak work rate below 45 W. For patients suffering from less severe impairments, kinetic analyses are a powerful tool to examine physiological exercise responses. Especially oxygen uptake mean response time can serve as a motivation-independent, physiological indicator of physical performance in patients with COPD.

Effects of lung deflation induced by tiotropium/olodaterol on the cardiocirculatory responses to exertion in COPD

BACKGROUND

Hyperinflation has been associated with negative cardiocirculatory consequences in patients with chronic obstructive pulmonary disease (COPD). These abnormalities are likely to worsen when the demands for O₂ increase, e.g., under the stress of exercise. Thus, pharmacologically-induced lung deflation may improve cardiopulmonary interactions and exertional cardiac output leading to higher limb muscle blood flow and oxygenation in hyperinflated patients with COPD.

METHODS

20 patients (residual volume = 201.6 ± 63.6% predicted) performed endurance cardiopulmonary exercise tests (75% peak) 1 h after placebo or tiotropium/olodaterol 5/5 μg via the Respimat® inhaler (Boehringer Ingelheim, Ingelheim am Rhein, Germany). Cardiac output was assessed by signal-morphology impedance cardiography. Near-infrared spectroscopy determined quadriceps blood flow (indocyanine green dye) and intra-muscular oxygenation.

RESULTS

Tiotropium/olodaterol was associated with marked lung deflation (p < 0.01): residual volume decreased by at least 0.4 L in 14/20 patients (70%). The downward shift in the resting static lung volumes was associated with less exertional inspiratory constraints and dyspnoea thereby increasing exercise endurance by ~50%. Contrary to our premises, however, neither central and peripheral hemodynamics nor muscle oxygenation improved after active intervention compared to placebo. These results were consistent with those found in a subgroup of patients showing the largest decrements in residual volume (p < 0.05).

CONCLUSIONS

The beneficial effects of tiotropium/olodaterol on resting and operating lung volumes are not translated into enhanced cardiocirculatory responses to exertion in hyperinflated patients with COPD. Improvement in exercise tolerance after dual bronchodilation is unlikely to be mechanistically linked to higher muscle blood flow and/or O₂ delivery.

Box-Jenkins Transfer Function Modelling for Reliable Determination of VO2 Kinetics in Patients with COPD

Oxygen uptake (VO2) kinetics provide information about the ability to respond to the increased physical load during a constant work rate test (CWRT). Box-Jenkins transfer function (BJ-TF) models can extract kinetic features from the phase II VO2 response during a CWRT, without being affected by unwanted noise contributions (e.g., phase I contribution or measurement noise). CWRT data of 18 COPD patients were used to compare model fits and kinetic feature values between BJ-TF models and three typically applied exponential modelling methods. Autocorrelation tests and normalised root-mean-squared error values (BJ-TF: 2.8 ± 1.3%; exponential methods A, B and C: 10.5 ± 5.8%, 11.3 ± 5.2% and 12.1 ± 7.0%; p < 0.05) showed that BJ-TF models, in contrast to exponential models, could account for the most important noise contributions. This led to more reliable kinetic feature values compared to methods A and B (e.g., mean response time (MRT), BJ-TF: 74 ± 20 s; methods A-B: 100 ± 56 s–88 ± 52 s; p < 0.05). Only exponential modelling method C provided kinetic feature values comparable to BJ-TF features values (e.g., MRT: 75 ± 20 s). Based on theoretical considerations, we recommend using BJ-TF models, rather than exponential models, for reliable determinations of VO2 kinetics.

Surgical and endoscopic interventions that reduce lung volume for emphysema: a systemic review and meta-analysis

BACKGROUND

Severe emphysema is a debilitating condition with few treatment options. Lung volume reduction procedures in the treatment of severe emphysema have shown excellent results in selected patients but their exact role remains unclear with studies reporting a wide variation in outcomes. We therefore aimed to evaluate the effects of volume reduction.

METHODS

We did a systematic review and meta-analysis. We searched MEDLINE on Sept 29, 2016, for trials of lung volume reduction in patients with emphysema, and we did an updated search on Embase and PubMed on June 18, 2018. We only included randomised controlled studies published in English evaluating the intervention with either sham or standard of care. Inclusion was limited to trials of techniques in which there was sustainable volume reduction. Primary outcomes were residual volume, FEV₁, St George's Respiratory Questionnaire (SGRQ), and 6-min walk distance (6MWT). Secondary outcomes were severe adverse events (including mortality), short-term mortality, and overall mortality. We extracted summary level data from the trial publications and where necessary we obtained unpublished data. A random-effects model with the I² statistic was used to determine heterogeneity and trial weight in each analysis. The study is registered with the PROSPERO database, number CRD42016045705.

FINDINGS

We identified 4747 references in the search, and included 20 randomised controlled trials of lung volume reduction involving 2794 participants with emphysema. Following lung volume reduction from any of the interventions in pooled analyses (ie, surgery, endobronchial valve, endobronchial coil, or sclerosing agents), the mean differences compared with the control were reduction in residual volume of 0·58 L (95% CI -0·80 to -0·37), increase in FEV₁ of 15·87% (95% CI 12·27 to 19·47), improvement in 6MWT of 43·28 m (31·36 to 55·21), and reduction in the SGRQ of 9·39 points (-10·92 to -7·86). The odds ratio for a severe adverse event, which included mortality, was 6·21 (95% CI 4·02 to 9·58) following intervention. Regression analysis showed improvements relative to the degree of volume reduction: FEV₁ (r²=0·86; p<0·0001), 6MWT (r²=0·77; p<0·0001), and SGRQ (r²=0·70; p<0·0001). Most studies were at high risk of bias for lack of blinding, and heterogeneity was high for some outcomes when pooled across all interventions, but was generally lower in the subgroups by intervention type.

INTERPRETATION

Despite limitations of high risk of bias and heterogeneity for some analyses, our results provide support that lung volume reduction in patients with severe emphysema on maximal medical treatment has clinically meaningful benefits. These benefits should be considered alongside potential adverse events.

FUNDING

None.

Vascular inflammation and aortic stiffness: potential mechanisms of increased vascular risk in chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is a complex inflammatory condition in which an important extra-pulmonary manifestation is cardiovascular disease. We hypothesized that COPD patients would have increased aortic inflammation and stiffness, as candidate mechanisms mediating increased cardiovascular risk, compared to two negative control groups: healthy never-smokers and smokers without COPD. We also studied patients with COPD due to alpha_− 1 antitrypsin deficiency (α₁ATD) as a comparator lung disease group.

Methods

Participants underwent ¹⁸F-Fluorodeoxyglucose (FDG) positron emission tomography imaging to quantify aortic inflammation as the tissue-to-blood-ratio (TBR) of FDG uptake. Aortic stiffness was measured by carotid-femoral aortic pulse wave velocity (aPWV).

Results

Eighty-five usual COPD (COPD due to smoking), 12 α₁ATD-COPD patients and 12 each smokers and never-smokers were studied. There was no difference in pack years smoked between COPD patients and smokers (45 ± 25 vs 37 ± 19, p = 0.36), but α₁ATD patients smoked significantly less (19 ± 11, p < 0.001 for both). By design, spirometry measures were lower in COPD and α₁ATD-COPD patients compared to smokers and never-smokers. Aortic inflammation and stiffness were increased in COPD (TBR: 1.90 ± 0.38, aPWV: 9.9 ± 2.6 m/s) and α₁ATD patients (TBR: 1.94 ± 0.43, aPWV: 9.5 ± 1.8 m/s) compared with smokers (TBR: 1.74 ± 0.30, aPWV: 7.8 ± 1.8 m/s, p < 0.05 all) and never-smokers (TBR: 1.71 ± 0.34, aPWV: 7.9 ± 1.7 m/s, p ≤ 0.05 all).

Conclusions

In this cross-sectional prospective study, novel findings were that both usual COPD and α1ATD-COPD patients have increased aortic inflammation and stiffness compared to smoking and never-smoking controls, regardless of smoking history. These findings suggest that the presence of COPD lung disease per se may be associated with adverse aortic wall changes, and aortic inflammation and stiffening are potential mechanisms mediating increased vascular risk observed in COPD patients.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0792-1) contains supplementary material, which is available to authorized users.

The Link between Reduced Inspiratory Capacity and Exercise Intolerance in Chronic Obstructive Pulmonary Disease

Low inspiratory capacity (IC), chronic dyspnea, and reduced exercise capacity are inextricably linked and are independent predictors of increased mortality in chronic obstructive pulmonary disease. It is no surprise, therefore, that a major goal of management is to improve IC by reducing lung hyperinflation to improve respiratory symptoms and health-related quality of life. The negative effects of lung hyperinflation on respiratory muscle and cardiocirculatory function during exercise are now well established. Moreover, there is growing appreciation that a key mechanism of exertional dyspnea in chronic obstructive pulmonary disease is critical mechanical constraints on tidal volume expansion during exercise when resting IC is reduced. Further evidence for the importance of lung hyperinflation comes from multiple studies, which have reported the clinical benefits of therapeutic interventions that reduce lung hyperinflation and increase IC. A reduced IC in obstructive pulmonary disease is further eroded by exercise and contributes to ventilatory limitation and dyspnea. It is an important outcome for both clinical and research studies.

Endobronchial Coils Versus Lung Volume Reduction Surgery or Medical Therapy for Treatment of Advanced Homogenous Emphysema

Rationale: Bronchoscopic lung volume reduction utilizing shape-memory nitinol endobronchial coils (EBC) may be safer and more effective in severely hyperinflated homogeneous emphysema compared to medical therapy or lung volume reduction surgery (LVRS). Methods: The effect of bilateral EBC in patients with homogeneous emphysema on spirometry, lung volumes and survival was compared to patients with homogeneous emphysema randomized in the National Emphysema Treatment Trial (NETT) to LVRS or medical therapy. NETT participants were selected to match EBC participants in age, baseline spirometry, and gender. Outcomes were compared from baseline, at 6 and 12 months. Results: There were no significant baseline differences in gender in the EBC, NETT-LVRS or medical treatment patients. At baseline no differences existed between EBC and NETT-LVRS patients in forced expiratory volume in 1 second ( FEV₁) or total lung capacity (TLC) %-predicted; residual volume (RV) and diffusing capacity of the lung for carbon monoxide (DLco) %-predicted were higher in the EBC group compared to NETT-LVRS (p < 0.001). Compared to the medical treatment group, EBC produced greater improvements in FEV₁ and RV but not TLC at 6 months. FEV₁ and RV in the EBC group remained significantly improved at 12-months compared to the medical treatment group. While all 3 therapies improved quality of life, survival at 12 months with EBC or medical therapy was greater than NETT-LVRS. Conclusion: EBC may be a potential therapeutic option in patients with severe homogeneous emphysema and hyperinflation who are already receiving optimal medical treatment.

Endobronchial valves for emphysema: an individual patient-level reanalysis of randomised controlled trials

Introduction

Endobronchial valve placement has potential as a treatment for patients with chronic obstructive pulmonary disease (COPD). However, a robust evidence base will be needed to convince commissioners of healthcare that it is a high-value treatment. We sought to develop the evidence base by performing an individual patient-level analysis of randomised controlled trials in people with heterogeneous emphysema and an absence of collateral ventilation.

Methods

A literature search (PROSPERO register CRD42016048127) identified two trials meeting these criteria, the BelieVeR-HIFi and STELVIO studies. Anonymised individual patient data were obtained from investigators and analysed. The primary outcome measure was a comparison of change in forced expiratory volume in 1 s (FEV₁) from baseline between the treatment and control groups. Secondary end points were change from baseline in 6 min walk distance (6MWD), Medical Research Council dyspnoea score and St George’s Respiratory Questionnaire (SGRQ).

Results

114 individuals were treated with 3-month to 6-month follow-up data available for 101 individuals. FEV₁ improved by 23.1 (±28.3)% in patients treated with valves with a mean (95% CI) difference in response between groups of 17.8 (26.5, 9.2)% (p<0.0001). Relative to controls valve placement was associated with a fall in residual volume of 0.64 (0.43, 0.86) L (p<0.0001), a 9.5 (3.5, 15.6) unit fall in SGRQ (p=0.0022) and a 64.2 (94.0, 34.5) m increase in 6MWD. There were three deaths in the treatment arm and the pneumothorax rate was 15%.

Conclusions

These data strengthen the evidence that endobronchial valve treatment can produce clinically meaningful improvements in appropriately selected COPD patients.

Patient experience of lung volume reduction procedures for emphysema: a qualitative service improvement project

The aim of this service improvement project was to gain understanding of the patient experience of lung volume reduction surgery (LVRS) and endobronchial valve (EBV) placement, from referral through to post-discharge care.

Focus group interviews were carried out in two tertiary centres in London and Leicester, UK. Sixteen patients who had undergone lung volume reduction surgery (LVRS), endobronchial valve (EBV) placement, or both, were recruited. Prior to participation in each focus group, participants completed a questionnaire to guide and focus discussion. Thematic analysis identified common themes to the participant experience of receiving lung volume reduction interventions.

Themes included patient focus on declining health and the need to “fight” for a referral; consequences of having procedures and potential unexpected complications; and vulnerability post discharge and limited continuity of care. Participants were clear that the benefits of having had either LVRS or EBV procedures outweighed any difficulties experienced. Participants were keen to have further similar interventions if appropriate.

These data confirm the need to develop more systematic lung volume reduction pathways, provide appropriate information, and ensure that post-discharge care is optimal.

Patients feel they have to fight to get a lung volume reduction procedure; a more systematic approach is neededhttp://ow.ly/82Oy30cLORk

Endobronchial Valve Therapy in Patients with Homogeneous Emphysema. Results from the IMPACT Study

RATIONALE

Endobronchial valves (EBVs) have been successfully used in patients with severe heterogeneous emphysema to improve lung physiology. Limited available data suggest that EBVs are also effective in homogeneous emphysema.

OBJECTIVES

To evaluate the efficacy and safety of EBVs in patients with homogeneous emphysema with absence of collateral ventilation assessed with the Chartis system.

METHODS

Prospective, multicenter, 1:1 randomized controlled trial of EBV plus standard of care (SoC) or SoC alone. Primary outcome was the percentage change in FEV₁ (liters) at 3 months relative to baseline in the EBV group versus the SoC group. Secondary outcomes included changes in FEV₁, St. George's Respiratory Questionnaire (SGRQ), 6-minute-walk distance (6MWD), and target lobe volume reduction.

MEASUREMENTS AND MAIN RESULTS

Ninety-three subjects (age, 63.7 ± 6.1 yr [mean ± SD]; FEV₁, % predicted, 29.3 ± 6.5; residual volume, % predicted, 275.4 ± 59.4) were allocated to either the EBV group (n = 43) or the SoC group (n = 50). In the intention-to-treat population, at 3 months postprocedure, improvement in FEV₁ from baseline was 13.7 ± 28.2% in the EBV group and -3.2 ± 13.0% in the SoC group (mean between-group difference, 17.0%; P = 0.0002). Other variables demonstrated statistically and clinically significant changes from baseline to 3 months (EBV vs. SoC, respectively: SGRQ, -8.63 ± 11.25 vs. 1.01 ± 9.36; and 6MWD, 22.63 ± 66.63 m vs. -17.34 ± 52.8 m). Target lobe volume reduction at 3 months was -1,195 ± 683 ml (P < 0.0001). Of the EBV subjects, 97.2% achieved volume reduction in the target lobe (P < 0.0001). Procedure-related pneumothoraces occurred in 11 subjects (25.6%). Five subjects required removal/replacement of one or more valves. One subject experienced two valve migration events requiring removal/replacement of valves.

CONCLUSIONS

EBV in patients with homogeneous emphysema without collateral ventilation results in clinically meaningful benefits of improved lung function, exercise tolerance, and quality of life.

Oral N-acetylcysteine and exercise tolerance in mild chronic obstructive pulmonary disease

Heightened oxidative stress is implicated in the progressive impairment of skeletal muscle vascular and mitochondrial function in chronic obstructive pulmonary disease (COPD). Whether accumulation of reactive oxygen species contributes to exercise intolerance in the early stages of COPD is unknown. The purpose of the present study was to determine the effects of oral antioxidant treatment with N-acetylcysteine (NAC) on respiratory, cardiovascular, and locomotor muscle function and exercise tolerance in patients with mild COPD. Thirteen patients [forced expiratory volume in 1 s (FEV₁)-to-forced vital capacity ratio < lower limit of normal (LLN) and FEV₁ ≥ LLN) were enrolled in a double-blind, randomized crossover study to receive NAC (1,800 mg/day) or placebo for 4 days. Severe-intensity constant-load exercise tests were performed with noninvasive measurements of central hemodynamics (stroke volume, heart rate, and cardiac output via impedance cardiography), arterial blood pressure, pulmonary ventilation and gas exchange, quadriceps muscle oxygenation (near-infrared spectroscopy), and estimated capillary blood flow. Nine patients completed the study with no major adverse clinical effects. Although NAC elevated plasma glutathione by ~27% compared with placebo (P < 0.05), there were no differences in exercise tolerance (placebo: 325 ± 47 s, NAC: 336 ± 51 s), central hemodynamics, arterial blood pressure, pulmonary ventilation or gas exchange, locomotor muscle oxygenation, or capillary blood flow from rest to exercise between conditions (P > 0.05 for all). In conclusion, modulation of plasma redox status with oral NAC treatment was not translated into beneficial effects on central or peripheral components of the oxygen transport pathway, thereby failing to improve exercise tolerance in nonhypoxemic patients with mild COPD.NEW & NOTEWORTHY Acute antioxidant treatment with N-acetylcysteine (NAC) elevated plasma glutathione but did not modulate central or peripheral components of the O₂ transport pathway, thereby failing to improve exercise tolerance in patients with mild chronic obstructive pulmonary disease (COPD).

Bronchoscopic lung volume reduction procedures for chronic obstructive pulmonary disease

BACKGROUND

In the recent years, a variety of bronchoscopic lung volume reduction (BLVR) procedures have emerged that may provide a treatment option to participants suffering from moderate to severe chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To assess the effects of BLVR on the short- and long-term health outcomes in participants with moderate to severe COPD and determine the effectiveness and cost-effectiveness of each individual technique.

SEARCH METHODS

Studies were identified from the Cochrane Airways Group Specialised Register (CAGR) and by handsearching of respiratory journals and meeting abstracts. All searches are current until 07 December 2016.

SELECTION CRITERIA

We included randomized controlled trials (RCTs). We included studies reported as full text, those published as abstract only and unpublished data, if available.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed studies for inclusion and extracted data. Where possible, data from more than one study were combined in a meta-analysis using RevMan 5 software.

MAIN RESULTS

AeriSealOne RCT of 95 participants found that AeriSeal compared to control led to a significant median improvement in forced expiratory volume in one second (FEV₁) (18.9%, interquartile range (IQR) -0.7% to 41.9% versus 1.3%, IQR -8.2% to 12.9%), and higher quality of life, as measured by the St Georges Respiratory Questionnaire (SGRQ) (-12 units, IQR -22 units to -5 units, versus -3 units, IQR -5 units to 1 units), P = 0.043 and P = 0.0072 respectively. Although there was no significant difference in mortality (Odds Ratio (OR) 2.90, 95% CI 0.14 to 62.15), adverse events were more common for participants treated with AeriSeal (OR 3.71, 95% CI 1.34 to 10.24). The quality of evidence found in this prematurely terminated study was rated low to moderate. Airway bypass stentsTreatment with airway bypass stents compared to control did not lead to significant between-group changes in FEV₁ (0.95%, 95% CI -0.16% to 2.06%) or SGRQ scores (-2.00 units, 95% CI -5.58 units to 1.58 units), as found by one study comprising 315 participants. There was no significant difference in mortality (OR 0.76, 95% CI 0.21 to 2.77), nor were there significant differences in adverse events (OR 1.33, 95% CI 0.65 to 2.73) between the two groups. The quality of evidence was rated moderate to high. Endobronchial coilsThree studies comprising 461 participants showed that treatment with endobronchial coils compared to control led to a significant between-group mean difference in FEV₁ (10.88%, 95% CI 5.20% to 16.55%) and SGRQ (-9.14 units, 95% CI -11.59 units to -6.70 units). There were no significant differences in mortality (OR 1.49, 95% CI 0.67 to 3.29), but adverse events were significantly more common for participants treated with coils (OR 2.14, 95% CI 1.41 to 3.23). The quality of evidence ranged from low to high. Endobronchial valvesFive studies comprising 703 participants found that endobronchial valves versus control led to significant improvements in FEV₁ (standardized mean difference (SMD) 0.48, 95% CI 0.32 to 0.64) and scores on the SGRQ (-7.29 units, 95% CI -11.12 units to -3.45 units). There were no significant differences in mortality between the two groups (OR 1.07, 95% CI 0.47 to 2.43) but adverse events were more common in the endobronchial valve group (OR 5.85, 95% CI 2.16 to 15.84). Participant selection plays an important role as absence of collateral ventilation was associated with superior clinically significant improvements in health outcomes. The quality of evidence ranged from low to high. Intrabronchial valvesIn the comparison of partial bilateral placement of intrabronchial valves to control, one trial favoured control in FEV₁ (-2.11% versus 0.04%, P = 0.001) and one trial found no difference between the groups (0.9 L versus 0.87 L, P = 0.065). There were no significant differences in SGRQ scores (MD 2.64 units, 95% CI -0.28 units to 5.56 units) or mortality rates (OR 4.95, 95% CI 0.85 to 28.94), but adverse events were more frequent (OR 3.41, 95% CI 1.48 to 7.84) in participants treated with intrabronchial valves. The lack of functional benefits may be explained by the procedural strategy used, as another study (22 participants) compared unilateral versus partial bilateral placement, finding significant improvements in FEV₁ and SGRQ when using the unilateral approach. The quality of evidence ranged between moderate to high. Vapour ablationOne study of 69 participants found significant mean between-group differences in FEV₁ (14.70%, 95% CI 7.98% to 21.42%) and SGRQ (-9.70 units, 95% CI -15.62 units to -3.78 units), favouring vapour ablation over control. There was no significant between-group difference in mortality (OR 2.82, 95% CI 0.13 to 61.06), but vapour ablation led to significantly more adverse events (OR 3.86, 95% CI 1.00 to 14.97). The quality of evidence ranged from low to moderate.

AUTHORS' CONCLUSIONS

Results for selected BLVR procedures indicate they can provide significant and clinically meaningful short-term (up to one year) improvements in health outcomes, but this was at the expense of increased adverse events. The currently available evidence is not sufficient to assess the effect of BLVR procedures on mortality. These findings are limited by the lack of long-term follow-up data, limited availability of cost-effectiveness data, significant heterogeneity in results, presence of skew and high CIs, and the open-label character of a number of the studies.

Breathing SPACE-a practical approach to the breathless patient

Breathlessness is a common symptom that may have multiple causes in any one individual and causes that may change over time. Breathlessness campaigns encourage people to see their General Practitioner if they are unduly breathless. Members of the London Respiratory Network collaborated to develop a tool that would encourage a holistic approach to breathlessness, which was applicable both at the time of diagnosis and during ongoing management. This has led to the development of the aide memoire “Breathing SPACE”, which encompasses five key themes—smoking, pulmonary disease, anxiety/psychosocial factors, cardiac disease, and exercise/fitness. A particular concern was to ensure that high-value interventions (smoking cessation and exercise interventions) are prioritised across the life-course and throughout the course of disease management. The approach is relevant both to well people and in those with an underling diagnosis or diagnoses. The inclusion of anxiety draws attention to the importance of mental health issues. Parity of esteem requires the physical health problems of people with mental illness to be addressed. The SPACE mnemonic also addresses the problem of underdiagnosis of heart disease in people with lung disease and vice versa, as well as the systematic undertreatment of these conditions where they do co-occur.

Fissure Integrity and Volume Reduction in Emphysema: A Retrospective Study

BACKGROUND

One-way endobronchial valves (EBVs) relieve symptoms of emphysema, particularly in patients without collateral ventilation between the target and adjacent lobes. Pretreatment knowledge of fissure integrity could serve as an aid in indicating EBV interventions.

OBJECTIVE

This study aimed to investigate the relationship between software-measured lung fissure integrity and clinically relevant lung volume reduction (≥350 ml) in emphysema patients treated with one-way EBVs using a lobar exclusion strategy.

METHODS

Of 108 patients treated between March 2008 and July 2014, 38 had both baseline and follow-up computed tomography (CT) scans acquired following a specific protocol for quantitative CT analysis and were included in the study (total of 39 treatments, two lungs treated in 1 patient). Outcome measures were fissure integrity measured on baseline CT scans, difference between pre- and postoperative lung volume (considering the lowest measured postoperative volume), and correlation between fissure integrity and volume change.

RESULTS

Fissure integrity ≥75% correlated with volume reduction ≥350 ml (Spearman coefficient: -0.65; p < 0.01). The mean and median volume reductions were 1,223.96 ± 907.5 ml and 663 ml, respectively, for lungs with fissure integrity ≥75% (n = 31). The accuracy of fissure integrity ≥75% in predicting a volume reduction was 87.2%. The positive predictive value of fissure integrity ≥75% to predict a volume reduction ≥350 ml was 83.9%, and it was 70% for fissure integrity 75-90% and 90.5% for fissure integrity >90%.

CONCLUSIONS

A target lobe volume reduction using EBVs is possible with lung fissure integrity ≥75%. For patients with fissure integrity between 75 and 90%, a further evaluation of interlobar ventilation should be performed. A clinically relevant volume reduction following treatment with EBVs is likely with any level of fissure integrity >90%.

An update on the efficacy of endobronchial valve therapy in the management of hyperinflation in patients with chronic obstructive pulmonary disease

Lung volume reduction surgery has been shown to be effective in patients with heterogeneous emphysema, but is also associated with a relatively high perioperative morbidity and mortality. Accordingly, several novel and potentially less invasive methods for bronchoscopic lung volume reduction have been developed. Endobronchial valve (EBV) therapy is one such therapeutic approach in patients with advanced emphysema. It has been the most widely studied technique over the past years and represents an effective treatment option for patients with severe heterogeneous upper- or lower-lobe-predominant emphysema. The choice of EBV therapy largely depends on the distribution of emphysema and the presence or absence of interlobar collateral ventilation. Adequate patient selection and technical success of valve implantation with the intention of lobar exclusion are predictive factors for positive outcomes. This review attempts to highlight the milestones in the development of bronchoscopic lung volume reduction with one-way valve implantation over the past few years.