Prognostication of co-morbidity clusters on hospitalisation and mortality in advanced COPD

RATIONALE

As the prevalence of multimorbidity increases, understanding the impact of isolated comorbidities in people COPD becomes increasingly challenging. A simplified model of common comorbidity patterns may improve outcome prediction and allow targeted therapy.

OBJECTIVES

To assess whether comorbidity phenotypes derived from routinely collected clinical data in people with COPD show differences in risk of hospitalisation and mortality.

METHODS

Twelve clinical measures related to common comorbidities were collected during annual reviews for people with advanced COPD and k-means cluster analysis performed. Cox proportional hazards with adjustment for covariates was used to determine hospitalisation and mortality risk between clusters.

MEASUREMENTS AND MAIN RESULTS

In 203 participants (age 66 ± 9 years, 60 % male, FEV1%predicted 31 ± 10 %) no comorbidity in isolation was predictive of worse admission or mortality risk. Four clusters were described: cluster A (cardiometabolic and anaemia), cluster B (malnourished and low mood), cluster C (obese, metabolic and mood disturbance) and cluster D (less comorbid). FEV1%predicted did not significantly differ between clusters. Mortality risk was higher in cluster A (HR 3.73 [95%CI 1.09-12.82] p = 0.036) and B (HR 3.91 [95%CI 1.17-13.14] p = 0.027) compared to cluster D. Time to admission was highest in cluster A (HR 2.01 [95%CI 1.11-3.63] p = 0.020). Cluster C was not associated with increased risk of mortality or hospitalisation.

CONCLUSIONS

Despite presence of advanced COPD, we report striking differences in prognosis for both mortality and hospital admissions for different co-morbidity phenotypes. Objectively assessing the multi-system nature of COPD could lead to improved prognostication and targeted therapy for patients.

Effect of aerobic exercise training on pulse wave velocity in adults with and without long-term conditions: a systematic review and meta-analysis

RATIONALE

There is conflicting evidence whether aerobic exercise training (AET) reduces pulse wave velocity (PWV) in adults with and without long-term conditions (LTCs).

OBJECTIVE

To explore whether PWV improves with AET in adults with and without LTC, to quantify the magnitude of any effect and understand the influence of the exercise prescription.

DATA SOURCES

CENTRAL, MEDLINE and EMBASE were among the databases searched.

ELIGIBILITY CRITERIA

We included studies with a PWV measurement before and after supervised AET of at least 3 weeks duration. Exclusion criteria included resistance exercise and alternative measures of arterial stiffness.

DESIGN

Controlled trials were included in a random effects meta-analysis to explore the effect of AET on PWV. Uncontrolled studies were included in a secondary meta-analysis and meta-regression exploring the effect of patient and programme factors on change in PWV. The relevant risk of bias tool was used for each study design.

RESULTS

79 studies (n=3729) were included: 35 controlled studies (21 randomised control trials (RCT) (n=1240) and 12 non-RCT (n=463)) and 44 uncontrolled (n=2026). In the controlled meta- analysis, PWV was significantly reduced following AET (mean (SD) 11 (7) weeks) in adults with and without LTC (mean difference -0.63; 95% CI -0.82 to -0.44; p<0.0001). PWV was similarly reduced between adults with and without LTC (p<0.001). Age, but not specific programme factors, was inversely associated with a reduction in PWV -0.010 (-0.020 to -0.010) m/s, p<0.001.

DISCUSSION

Short-term AET similarly reduces PWV in adults with and without LTC. Whether this effect is sustained and the clinical implications require further investigation.

Understanding the effectiveness of different exercise training programme designs on V̇O2peak in COPD: a component network meta-analysis

Pulmonary rehabilitation programmes including aerobic training improve cardiorespiratory fitness in patients with COPD, but the optimal programme design is unclear. We used random effects additive component network meta-analysis to investigate the relative effectiveness of different programme components on fitness measured by V̇O2peak in COPD. The included 59 studies involving 2191 participants demonstrated that V̇O2peak increased after aerobic training of at least moderate intensity with the greatest improvement seen following high intensity training. Lower limb aerobic training (SMD 0.56 95% CI 0.32;0.81, intervention arms=86) and the addition of non-invasive ventilation (SMD 0.55 95% CI 0.04;1.06, intervention arms=4) appeared to offer additional benefit but there was limited evidence for effectiveness of other exercise and non-exercise components.

The role of diet and nutrition in the management of COPD

In 2014, the European Respiratory Society published a statement on nutritional assessment and therapy in COPD. Since then, increasing research has been performed on the role of diet and nutrition in the prevention and management of COPD. Here, we provide an overview of recent scientific advances and clinical implications. Evidence for a potential role of diet and nutrition as a risk factor in the development of COPD has been accumulating and is reflected in the dietary patterns of patients with COPD. Consuming a healthy diet should, therefore, be promoted in patients with COPD. Distinct COPD phenotypes have been identified incorporating nutritional status, ranging from cachexia and frailty to obesity. The importance of body composition assessment and the need for tailored nutritional screening instruments is further highlighted. Dietary interventions and targeted single or multi-nutrient supplementation can be beneficial when optimal timing is considered. The therapeutic window of opportunity for nutritional interventions during and recovering from an acute exacerbation and hospitalisation is underexplored.

Collaboration between explainable artificial intelligence and pulmonologists improves the accuracy of pulmonary function test interpretation

RATIONALE

Few studies have investigated the collaborative potential between artificial intelligence (AI) and pulmonologists for diagnosing pulmonary disease. We hypothesized that the collaboration between pulmonologist and AI with explanations (explainable AI, XAI) is superior in diagnostic interpretation of pulmonary function tests (PFTs) than a pulmonologist without support.

MATERIALS AND METHODS

The study was conducted in two phases, a mono-centre (P1) and a multi-centre intervention study (P2). Each phase utilized two different sets of 24 PFT reports of patients with a clinically validated gold-standard diagnosis. Each PFT was interpreted without (control) and with XAI's suggestions (intervention). Pulmonologists provided a differential diagnosis consisting of a preferential diagnosis and optionally up to three additional diagnoses. Primary endpoint compared accuracy of preferential and additional diagnoses between control and intervention. Secondary endpoints were number of diagnoses in differential diagnosis, diagnostic confidence and inter-rater agreement. We also analysed how XAI influenced pulmonologists' decisions.

RESULTS

In P1 (N=16 pulmonologists), mean preferential and differential diagnostic accuracy significantly increased by 10.4% and 9.4%, respectively between control and intervention (p<0.001). Improvements were somewhat lower but highly significant (p<0.0001) in P2 (5.4% and 8.7% respectively, N=62 pulmonologists). In both phases, the number of diagnoses in differential diagnosis did not reduce, but diagnostic confidence and inter-rater agreement significantly increased during intervention. Pulmonologists updated their decisions with XAI's feedback and consistently improved their baseline performance if AI provided correct predictions.

CONCLUSION

A collaboration between pulmonologist and XAI is better at interpreting PFTs than individual pulmonologists reading without XAI support or XAI alone.

Lung volume reduction surgery versus endobronchial valves: a randomised controlled trial

BACKGROUND

Lung volume reduction surgery (LVRS) and bronchoscopic lung volume reduction (BLVR) with endobronchial valves (EBVs) can improve outcomes in appropriately selected patients with emphysema. However, no direct comparison data exist to inform clinical decision-making in people who appear suitable for both procedures. Our aim was to investigate whether LVRS produces superior health outcomes when compared to BLVR at 12 months.

METHODS

this multi-centre, single-blind parallel-group trial randomised patients from five UK hospitals, who were suitable for a targeted lung volume reduction procedure, to either LVRS or BLVR, and compared outcomes at 1 year using the i-BODE score. This composite disease severity measure includes body mass index, airflow obstruction, dyspnoea and exercise capacity (incremental shuttle walk test). The researchers responsible for collecting outcomes were masked to treatment allocation. All outcomes were assessed in the intention-to-treat population.

FINDINGS

88 participants (48% female, mean (sd) age 64.6 (7.7), FEV₁%predicted 31.0 (7.9) were recruited at five specialist centres across the UK and randomised to either LVRS (n=41) or BLVR (n=47). At 12 months follow up, the complete i-BODE was available in 49 participants (21 LVRS/28 BLVR). Neither improvement in the i-BODE score (LVRS: -1.10 (1.44), BLVR: -0.82 (1.61) p=0.54) nor in its individual components differed between groups. Both treatments produced similar improvements in gas trapping; RV% predicted (LVRS -36.1 (-54.1, -10), BLVR: -30.1 (-53.7, -9) p=0.81). There was one death in each treatment arm.

INTERPRETATION

Our findings do not support the hypothesis that LVRS is a substantially superior treatment to BLVR in individuals who are suitable for both treatments.

COPD: Providing the right treatment for the right patient at the right time

Chronic Obstructive Pulmonary Disease (COPD) is a common disease associated with significant morbidity and mortality that is both preventable and treatable. However, a major challenge in recognizing, preventing, and treating COPD is understanding its complexity. While COPD has historically been characterized as a disease defined by airflow limitation, we now understand it as a multi-component disease with many clinical phenotypes, systemic manifestations, and associated co-morbidities. Evidence is rapidly emerging in our understanding of the many factors that contribute to the pathogenesis of COPD and the identification of "early" or "pre-COPD" which should provide exciting opportunities for early treatment and disease modification. In addition to breakthroughs in our understanding of the origins of COPD, we are optimizing treatment strategies and delivery of care that are showing impressive benefits in patient-centered outcomes and healthcare utilization. This special issue of Respiratory Medicine, "COPD: Providing the Right Treatment for the Right Patient at the Right Time" is a summary of the proceedings of a conference held in Stresa, Italy in April 2022 that brought together international experts to discuss emerging evidence in COPD and Pulmonary Rehabilitation in honor of a distinguished friend and colleague, Claudio Ferdinando Donor (1948-2021). Claudio was a true pioneer in the field of pulmonary rehabilitation and the comprehensive care of individuals with COPD. He held numerous leadership roles in in the field, provide editorial stewardship of several respiratory journals, authored numerous papers, statement and guidelines in COPD and Pulmonary Rehabilitation, and provided mentorship to many in our field. Claudio's most impressive talent was his ability to organize spectacular conferences and symposia that highlighted cutting edge science and clinical medicine. It is in this spirit that this conference was conceived and planned. These proceedings are divided into 4 sections which highlight crucial areas in the field of COPD: (1) New concepts in COPD pathogenesis; (2) Enhancing outcomes in COPD; (3) Non-pharmacologic management of COPD; and (4) Optimizing delivery of care for COPD. These presentations summarize the newest evidence in the field and capture lively discussion on the exciting future of treating this prevalent and impactful disease. We thank each of the authors for their participation and applaud their efforts toward pushing the envelope in our understanding of COPD and optimizing care for these patients. We believe that this edition is a most fitting tribute to a dear colleague and friend and will prove useful to students, clinicians, and researchers as they continually strive to provide the right treatment for the right patient at the right time. It has been our pleasure and a distinct honor to serve as editors and oversee such wonderful scholarly work.

Comparing research recruitment strategies to prospectively identify patients presenting with breathlessness in primary care

Two recruitment strategies for research were compared to prospectively identify patients with breathlessness who are awaiting a diagnosis in primary care. The first method utilised searches of the electronic patient record (EPR), the second method involved an electronic template triggered during a consultation. Using an electronic template triggered at the point of consultation increased recruitment to prospective research approximately nine-fold compared with searching for symptom codes and study mailouts.

Exercise rehabilitation in COPD and heart failure: comparison of two national audits

Pulmonary (PR) and cardiac rehabilitation (CR) are recommended in the management of chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF); the impact of co-existing COPD and CHF on completion and outcomes of rehabilitation programmes is unknown. We examined enrolment, completion and clinical outcomes of CR and PR in adults with COPD, CHF and co-existing COPD and CHF. The National Audit of CR and National COPD Audit Programme: Clinical audit of PR were analysed (211 PR and 237 CR programmes); adults with a diagnosis of CHF, COPD or co-existing COPD and CHF were identified (COPD+CHF or CHF+COPD according to database). Propensity matching was conducted (age, sex, body mass index and functional status) between COPD+CHF and COPD, and CHF+COPD and CHF. Group by time interaction was examined using a mixed 2×2 ANOVA. Those with CHF+COPD had lower enrolment and completion of CR compared to those with CHF; there were no differences in PR enrolment or completion between the two groups. Adults with COPD made a significantly larger gain in the incremental shuttle walk test compared to adults with COPD+CHF following PR (59.3 mversus37.4 m); the improvements following CR were similar (CHF 77.3 mversusCHF+COPD 58.3 m). Similar improvements were made in the six minute walk test following CR (CHF 45.1 mversusCHF+COPD 38.8 m) and PR (COPD 48.2 mversusCOPD+CHF 44.0 m). Comparable improvements in quality of life and mood state were made following CR and PR, regardless of diagnosis. We have demonstrated multi-morbid adults benefit from exercise- based rehabilitation, yet efforts are needed to promote completion. These findings support group based, tailored, multi-morbid exercise rehabilitation.

A More Intense Examination of the Intensity of Physical Activity in People Living with Chronic Obstructive Pulmonary Disease: Insights from Threshold-Free Markers of Activity Intensity

Physical activity (PA) intensity of people living with chronic obstructive pulmonary disease (COPD) is typically evaluated using intensity thresholds developed in younger, healthier populations with greater exercise capacity and free from respiratory symptoms. This study therefore compared (i) PA differences between COPD and non-COPD controls using both traditional intensity thresholds and threshold-free metrics that represent the volume and intensity of the whole PA profile, and (ii) explored the influence of exercise capacity on observed differences. Moderate-to-vigorous physical activity (MVPA), average acceleration (proxy for volume, mg) and intensity distribution of activity were calculated for 76 individuals with COPD and 154 non-COPD controls from wrist-worn ActiGraph accelerometry. PA profiles representing the minimum intensity (acceleration, mg) during the most active accumulated 5-960 min were plotted. Estimated VO_2peak and relative intensity were derived from the incremental shuttle walk test distance. Compared to the non-COPD control group, individuals with COPD recorded fewer MVPA minutes (59 vs. 83 min/day), lower overall waking activity (29.1 vs. 36.4 mg) and a poorer waking intensity distribution (-2.73 vs. -2.57). Individuals with COPD also recorded a lower absolute intensity (acceleration, mg) for their most active 5-960 min, but higher intensity relative to their estimated exercise capacity derived from the ISWT. People with COPD have a lower volume and absolute intensity of PA than controls but perform PA at a higher relative intensity. There is a need to move away from absolute intensity thresholds, and towards personalised or relative-intensity thresholds, to reflect reduced exercise capacity in COPD populations.

Mortality associated with Metabolic Syndrome in people with COPD managed in primary care

Objective

The prevalence of metabolic syndrome (MetS) has been reported to be higher in selected populations of people with COPD. The impact of MetS on mortality in COPD is unknown. We used routinely collected healthcare data to estimate the prevalence of MetS in people with COPD managed in primary care and determine its impact on 5-year mortality.

Methods

Records from 103 955 patients with COPD from the Clinical Practice Research Datalink (CPRD-GOLD) between 2009 to 2017 were scrutinised. MetS was defined as the presence of three or more of: obesity, hypertension, lowered high-density lipoprotein cholesterol, elevated triglycerides or type 2 diabetes mellitus (T2DM). Univariate and multivariable Cox regression models were constructed to determine the prognostic impact of MetS on 5-year mortality. Similar univariate models were constructed for individual components of the definition of MetS.

Results

The prevalence of MetS in the COPD cohort was 10.1%. Univariate analyses showed the presence of MetS increased mortality (hazard ratio (HR) 1.19, 95% CI: 1.12–1.27, p<0.001), but this risk was substantially attenuated in the multivariable analysis (HR 1.06, 95% CI: 0.99–1.13, p=0.085). The presence of hypertension (HR 1.70, 95% CI: 1.63–1.77, p<0.001) and T2DM (HR 1.41, 95% CI: 1.34–1.48, p<0.001) increased and obesity (HR 0.74, 95% CI: 0.71–0.78, p<0.001) reduced mortality risk.

Conclusion

MetS in patients with COPD is associated with higher 5-year mortality, but this impact was minimal when adjusted for indices of COPD disease severity and other comorbidities. Individual components of the MetS definition exerted differential impacts on mortality suggesting limitation to the use of MetS as a multicomponent condition in predicting outcome in COPD.

The presence of MetS in COPD is not significantly associated with increased mortality over 5 years. The individual components of MetS exert differential effects on mortality, limiting the utility of the syndrome in predicting outcome.https://bit.ly/3PooGQd

Whole-body and muscle responses to aerobic exercise training and withdrawal in ageing and COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) patients exhibit lower peak oxygen uptake (V'_{O2 peak}), altered muscle metabolism and impaired exercise tolerance compared with age-matched controls. Whether these traits reflect muscle-level deconditioning (impacted by ventilatory constraints) and/or dysfunction in mitochondrial ATP production capacity is debated. By studying aerobic exercise training (AET) at a matched relative intensity and subsequent exercise withdrawal period we aimed to elucidate the whole-body and muscle mitochondrial responsiveness of healthy young (HY), healthy older (HO) and COPD volunteers to whole-body exercise.

METHODS

HY (n=10), HO (n=10) and COPD (n=20) volunteers were studied before and after 8 weeks of AET (65% V'_{O2 peak}) and after 4 weeks of exercise withdrawal. V'_{O2 peak}, muscle maximal mitochondrial ATP production rate (MAPR), mitochondrial content, mitochondrial DNA (mtDNA) copy number and abundance of 59 targeted fuel metabolism mRNAs were determined at all time-points.

RESULTS

Muscle MAPR (normalised for mitochondrial content) was not different for any substrate combination in HO, HY and COPD at baseline, but mtDNA copy number relative to a nuclear-encoded housekeeping gene (mean±sd) was greater in HY (804±67) than in HO (631±69; p=0.041). AET increased V'_{O2 peak} in HO (17%; p=0.002) and HY (21%; p<0.001), but not COPD (p=0.603). Muscle MAPR for palmitate increased with training in HO (57%; p=0.041) and HY (56%; p=0.003), and decreased with exercise withdrawal in HO (-45%; p=0.036) and HY (-30%; p=0.016), but was unchanged in COPD (p=0.594). mtDNA copy number increased with AET in HY (66%; p=0.001), but not HO (p=0.081) or COPD (p=0.132). The observed changes in muscle mRNA abundance were similar in all groups after AET and exercise withdrawal.

CONCLUSIONS

Intrinsic mitochondrial function was not impaired by ageing or COPD in the untrained state. Whole-body and muscle mitochondrial responses to AET were robust in HY, evident in HO, but deficient in COPD. All groups showed robust muscle mRNA responses. Higher relative exercise intensities during whole-body training may be needed to maximise whole-body and muscle mitochondrial adaptation in COPD.

A proof of concept for continuous, non-invasive, free-living vital signs monitoring to predict readmission following an acute exacerbation of COPD: a prospective cohort study

Background

The use of vital signs monitoring in the early recognition of an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) post-hospital discharge is limited. This study investigated whether continuous vital signs monitoring could predict an AECOPD and readmission.

Methods

35 people were recruited at discharge following hospitalisation for an AECOPD. Participants were asked to wear an Equivital LifeMonitor during waking hours for 6 weeks and to complete the Exacerbations of Chronic Pulmonary Disease Tool (EXACT), a 14-item symptom diary, daily. The Equivital LifeMonitor recorded respiratory rate (RR), heart rate (HR), skin temperature (ST) and physical activity (PA) every 15-s. An AECOPD was classified as mild (by EXACT score), moderate (prescribed oral steroids/antibiotics) or severe (hospitalisation).

Results

Over the 6-week period, 31 participants provided vital signs and symptom data and 14 participants experienced an exacerbation, of which, 11 had sufficient data to predict an AECOPD. HR and PA were associated with EXACT score (p < 0.001). Three days prior to an exacerbation, RR increased by mean ± SD 2.0 ± 0.2 breaths/min for seven out of 11 exacerbations and HR increased by 8.1 ± 0.7 bpm for nine of these 11 exacerbations.

Conclusions

Increased heart rate and reduced physical activity were associated with worsening symptoms. Even with high-resolution data, the variation in vital signs data remains a challenge for predicting AECOPDs. Respiratory rate and heart rate should be further explored as potential predictors of an impending AECOPD.

Trial registration: ISRCTN registry; ISRCTN12855961. Registered 07 November 2018—Retrospectively registered, https://www.isrctn.com/ISRCTN12855961

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02018-5.

Developing Appropriate Pulmonary Rehabilitation Services in Sri Lanka: Assessment of People Living with COPD and Healthcare Providers in Urban and Semi Urban Areas in Sri Lanka

Introduction

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, corresponding to 5% of all deaths globally, with more than 90% occurring in low- and middle-income countries (LMIC). Pulmonary Rehabilitation (PR) is a routine clinical service for COPD management, often used in western countries. At present, there is no formal PR in Sri Lanka; a culturally appropriate programme is required that considers the views of adults living with COPD and healthcare providers (HCPs) who would be involved in the referral or delivery of PR.

Purpose

The study assessed the attitudes and preferences of Sri Lankan adults living with COPD and attitudes and barriers of HCPs making PR referrals to inform an appropriate PR programme.

Methodology

A descriptive cross-sectional study was conducted with the ethical clearance of Colombo south teaching hospital ERC committee (ERC Application No. 674), among adults living with COPD and HCPs in Colombo district, Sri Lanka. Adults living with COPD were enrolled August 2018–December 2018 using systematic random sampling from Colombo South Teaching Hospital and were assessed using a pre-tested interviewer administered questionnaire. HCPs were recruited from Colombo South Teaching Hospital and Jaffna Teaching Hospital between August 2018 and November 2018 and assessed using self-administered questionnaire.

Results

Responses from 138 adults living with COPD (53% male, 52% aged ≥60 years) and 277 HCPs were collected. The majority of adults living with COPD were interested in participating in PR (80%) and would prefer PR to be delivered in a supervised, group-based, setting with hospital-based (49%). Adults living with COPD were mostly (73%) willing to spend between 30 minutes and 2 hours per day for PR-related activities. Among HCPs, 234 (83%) were nurses, 29 (11%) were hospital doctors and 14 (4%) were family physicians. The majority of HCPs stated that they were unsure about referring adults with COPD for PR (86%) and 61% stated considerable uncertainty regarding the availability of resources for PR. Nearly half of the HCPs (45%) felt they were not adequately prepared to refer adults living with COPD to PR programmes. Most HCPs (92%) reported that PR is worthwhile for COPD management.

Conclusion

Adults living with COPD in Sri Lanka are willing to attend PR and would prefer group-based programmes delivered in hospitals, under the supervision of qualified personnel. Awareness about PR is poor and there is a lack of readiness to refer to PR amongst HCPs. There is an urgent need to train HCPs on PR and develop effective referral strategies to support PR uptake and delivery for adults living with COPD in Sri Lanka.

Culturally adapted pulmonary rehabilitation for adults living with post-tuberculosis lung disease in Kyrgyzstan: protocol for a randomised controlled trial with blinded outcome measures

INTRODUCTION

Pulmonary rehabilitation (PR) is a programme of individually prescribed physical exercise, education and self-management activities. PR is recommended in international guidelines for managing chronic obstructive pulmonary disease (COPD) and other chronic respiratory diseases. PR is still under-recognised in tuberculosis (TB) guidelines and PR is not available in many low and middle-income countries and for people with post-TB lung disease (PTBLD). The main aims of the study are to adapt and define a culturally appropriate PR programme in Kyrgyzstan for people living with PTBLD and to test, in a fully powered randomised controlled trial (RCT), the effectiveness of PR in improving exercise capacity for people living with PTBLD.

METHODS AND ANALYSIS

The study will be divided into three stages: stage 1: focus group discussions with patients living with PTBLD and interviews with PR referrers will be conducted to explore initial perceptions and inform the cultural adaptation, structure and content of PR. Stage 2a: a single-blind RCT evaluating the effectiveness of a culturally adapted 6-week PR programme on maximal exercise capacity, assessed by the incremental shuttle walking test, before and after PR. Participants will be additionally followed-up 12 weeks postbaseline. Additional outcomes will include health-related quality of life, respiratory symptoms, psychological well-being and physical function. Stage 2b: participants' experience of PR will be collected through interviews and using a log book and a patient evaluation form. Staff delivering PR will be interviewed to explore their experience of delivering the intervention and refining the delivery for future implementation.

ETHICS AND DISSEMINATION

The study was approved 22/07/2019 by Ethics Committee National Center for Cardiology and Internal Medicine (reference number 17) and by University of Leicester ethics committee (reference number 22293). Study results will be disseminated through appropriate peer-reviewed journals, national and international respiratory/physiotherapy conferences, social media, and through patient and public involvement events in Kyrgyzstan and in the UK.

TRIAL REGISTRATION NUMBER

ISRCTN11122503.

Usability of Wearable Multiparameter Technology to Continuously Monitor Free-Living Vital Signs in People Living With Chronic Obstructive Pulmonary Disease: Prospective Observational Study

Background

Vital signs monitoring (VSM) is routine for inpatients, but monitoring during free-living conditions is largely untested in chronic obstructive pulmonary disease (COPD).

Objective

This study investigated the usability and acceptability of continuous VSM for people with COPD using wearable multiparameter technology.

Methods

In total, 50 people following hospitalization for an acute exacerbation of COPD (AECOPD) and 50 people with stable COPD symptoms were asked to wear an Equivital LifeMonitor during waking hours for 6 weeks (42 days). The device recorded heart rate (HR), respiratory rate (RR), skin temperature, and physical activity. Adherence was defined by the number of days the vest was worn and daily wear time. Signal quality was examined, with thresholds of ≥85% for HR and ≥80% for RR, based on the device’s proprietary confidence algorithm. Data quality was calculated as the percentage of wear time with acceptable signal quality. Participant feedback was assessed during follow-up phone calls.

Results

In total, 84% of participants provided data, with average daily wear time of 11.8 (SD 2.2) hours for 32 (SD 11) days (average of study duration 76%, SD 26%). There was greater adherence in the stable group than in the post-AECOPD group (≥5 weeks wear: 71.4% vs 45.7%; P=.02). For all 84 participants, the median HR signal quality was 90% (IQR 80%-94%) and the median RR signal quality was 93% (IQR 92%-95%). The median HR data quality was 81% (IQR 58%-91%), and the median RR data quality was 85% (IQR 77%-91%). Stable group BMI was associated with HR signal quality (r_s=0.45, P=.008) and HR data quality (r_s=0.44, P=.008). For the AECOPD group, RR data quality was associated with waist circumference and BMI (r_s=–0.49, P=.009; r_s=–0.44, P=.02). In total, 36 (74%) participants in the Stable group and 21 (60%) participants in the AECOPD group accepted the technology, but 10 participants (12%) expressed concerns with wearing a device around their chest.

Conclusions

This wearable multiparametric technology showed good user acceptance and was able to measure vital signs in a COPD population. Data quality was generally high but was influenced by body composition. Overall, it was feasible to continuously measure vital signs during free-living conditions in people with COPD symptoms but with additional challenges in the post-AECOPD context.

Body mass index across adulthood and the development of airflow obstruction and emphysema

Background

Low body mass index (BMI) is associated with COPD, but temporal relationships between airflow obstruction (AO) development and emphysematous change are unclear. We investigated longitudinal changes in BMI, AO, and lung density throughout adulthood using data from the Framingham Offspring Cohort (FOC).

Methods

BMI trajectories were modelled throughout adulthood in 4587 FOC participants from Exam 2 (mean age = 44), through Exam 9 (mean age = 71), in AO participants and non-AO participants (AO n = 1036), determined by spirometry, using fractional polynomial growth curves. This process was repeated for low lung density (LLD) and non LLD participants (LLD n = 225) determined by Computed Tomography. Spirometry decline was compared separately between tertiles of BMI in those aged <40 years and associations between fat and lean mass (measured using Dual Energy X-ray Absorptiometry, DEXA) and development of AO and LLD were also assessed. Additional analyses were performed with adjustment for smoking volume.

Results

The BMI trajectory from 30 years of age was visually lower in the AO group than both non-AO smokers (non-<AO-S) and non-AO non-smokers (non-AO-N). Similarly, BMI trajectories were visually lower in participants with LLD throughout adulthood compared to normal lung density smokers and non-smokers. Differences remained after adjustment for smoking volume. The lowest BMI tertile in ages <40 years was associated with the steepest subsequent decline in FEV1/FVC ratio in both sexes.

Conclusion

Mean BMI is lower throughout adulthood in AO and LLD participants. Lower BMI is associated with a steeper decline in the ratio of FEV1/FVC. These findings suggest body mass may precede and potentially have a role in the development of COPD lung pathophysiology.

Identifying Appropriate Delivery of and Referral to Pulmonary Rehabilitation in Uganda: A Survey Study of People Living with Chronic Respiratory Disease and Health Care Workers

Introduction

Pulmonary rehabilitation (PR) is a low cost, high impact intervention that ameliorates the disability associated with chronic respiratory diseases (CRD). PR is becoming increasingly recognized in low resource settings where the burden of CRD is rapidly increasing. To aid the implementation of PR in Uganda, we conducted a study to assess the attitudes and opinions towards PR among patients with CRD in Uganda and explore barriers faced by health care workers (HCWs) in referring to PR.

Methods

A cross-sectional study comprising two survey populations: people living with CRD and HCWs regarded as potential PR referrers and PR deliverers. This exploratory study sought initial opinions and thoughts regarding PR, as well as baseline knowledge and potential barriers faced in the referral process.

Results

Overall, 30 HCWs (53% female, 43% doctors) and 51 adults with CRD (63% female) participated in the survey. Among those with CRD, the majority reported breathlessness as a major problem (86%) and breathlessness affected their ability to do paid and unpaid work (70%). Interest in PR was high amongst adults with CRD (92%) with preference for a hospital-based programme (67%) as opposed to community-based (16%) or home-based (17%). All HCWs considered PR important in lung disease management, but 77% do not refer patients due to a lack of information about PR. HCWs' free-text responses identified the need for training in PR, patient education and streamlining the referral process as key elements to develop successful PR referral services.

Conclusion

To successfully set up a PR service for people with CRD in Uganda, there is a great need for appropriately tailored training and education of prospective referrers about CRD and PR programs. Educating patients about the benefits of PR as well as streamlining the referral process is critical in expanding PR services across Uganda to fulfill this unmet need.

Study protocol for a randomised controlled trial assessing the impact of pulmonary rehabilitation on maximal exercise capacity for adults living with post-TB lung disease: Global RECHARGE Uganda

INTRODUCTION

The burden of post-tuberculosis (TB) lung disease (PTBLD) is steadily increasing in sub-Saharan Africa, causing disability among TB survivors. Without effective medicines, the mainstay of PTBLD treatment evolves around disease prevention and supportive treatment. Pulmonary rehabilitation (PR), a low-cost, non-pharmacological intervention has shown effectiveness in a group of PTBLD individuals but has not been tested in a clinical trial. This study aims to assess the impact of a 6-week PR programme on maximal exercise capacity and other outcomes among adults in Uganda living with PTBLD.

METHODS AND ANALYSIS

This is a randomised waiting-list controlled trial with blinded outcome measures, comparing PR versus usual care for patients with PTBLD. A total of 114 participants will be randomised (1:1) to receive either usual care (on the waiting list) or PR, with follow-up assessments at 6 weeks and 12 weeks postintervention. The primary outcome is change in walking distance measured by the Incremental Shuttle Walk Test from baseline to the end of 6 weeks of PR. All secondary outcomes will be compared between the PR and usual care arms from baseline to 6-week and 12-week follow-ups. Secondary outcomes include self-reported respiratory symptoms, physical activity, psychological well-being, health-related quality of life and cost-benefit analysis. All randomised participants will be included in the intention-to-treat analysis population. The primary efficacy analysis will be based on both per-protocol and modified intention-to-treat populations.

ETHICS AND DISSEMINATION

The trial has received ethical clearance from the Mulago Hospital Research and Ethics Committee (MHREC 1478), Kampala, Uganda as well as the Uganda National Council for Science and Technology (SS 5105). Ethical approval has been obtained from the University of Leicester, UK research ethics committee (Ref No. 22349). Study findings will be published in appropriate peer-reviewed journals and disseminated at appropriate local, regional and international scientific meetings and conferences.

TRIAL REGISTRATION NUMBER

ISRCTN18256843.

PROTOCOL VERSION

Version 1.0 July 2019.

Predicting Future Health Risk in COPD: Differential Impact of Disease-Specific and Multi-Morbidity-Based Risk Stratification

Objective

Multi-morbidity contributes to mortality and hospitalisation in COPD, but it is uncertain how this interacts with disease severity in risk prediction. We compared contributions of multi-morbidity and disease severity factors in modelling future health risk using UK primary care healthcare data.

Methods

Health records from 103,955 patients with COPD identified from the Clinical Practice Research Datalink were analysed. We compared area under the curve (AUC) statistics for logistic regression (LR) models incorporating disease indices with models incorporating categorised comorbidities. We also compared these models with performance of The John Hopkins Adjusted Clinical Groups^® System (ACG) risk prediction algorithm.

Results

LR models predicting all-cause mortality outperformed models predicting hospitalisation. Mortality was best predicted by disease severity (AUC & 95% CI: 0.816 (0.805–0.827)) and prediction was enhanced only marginally by the addition of multi-morbidity indices (AUC & 95% CI: 0.829 (0.818–0.839)). The model combining disease severity and multi-morbidity indices was a better predictor of hospitalisation (AUC & 95% CI: 0.679 (0.672–0.686)). ACG-derived LR models outperformed conventional regression models for hospitalisation (AUC & 95% CI: 0.697 (0.690–0.704)) but not for mortality (AUC & 95% CI: 0.816 (0.805–0.827)).

Conclusion

Stratification of future health risk in COPD can be undertaken using clinical and demographic data recorded in primary care, but the impact of disease severity and multi-morbidity varies depending on the choice of health outcome. A more comprehensive risk modelling algorithm such as ACG offers enhanced prediction for hospitalisation by incorporating a wider range of coded diagnoses.

Breathless and awaiting diagnosis in UK lockdown for COVID-19…We're stuck

During the COVID-19 pandemic, semi-structured interviews were undertaken with 20 adults awaiting a diagnosis for their chronic breathlessness. Three key themes were identified using thematic analysis: (1) de-prioritisation of diagnosis, (2) following UK 'lockdown' guidance for the general population but patients fearful they were more at risk, and (3) the impact of lockdown on coping strategies for managing breathlessness. The existing unpredictable pathway to diagnosis for those with chronic breathlessness has been further interrupted during the COVID-19 pandemic.

Predictors of pulmonary rehabilitation completion in the UK

Introduction

Pulmonary rehabilitation has been shown to improve dyspnoea, fatigue, quality of life and exercise capacity in individuals with chronic obstructive pulmonary disease (COPD). Our aim was to determine the characteristics of people with COPD associated with completion of pulmonary rehabilitation.

Methods

This was a cross-sectional analysis of 7060 people with COPD enrolled in pulmonary rehabilitation between January 1, 2017 and March 31, 2017. Data were from a UK national audit of COPD care. Factors associated with pulmonary rehabilitation completion were determined using mixed effects logistic regression with a random intercept for pulmonary rehabilitation service. Factors chosen for assessment based on clinical judgement and data availability were age, sex, country, socioeconomic status, body mass index, referral location, programme type, start within 90 days, smoking status, oxygen therapy, Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage, Medical Research Council (MRC) dyspnoea grade, any exercise test and any health status questionnaire.

Results

4635 (66%) people with COPD completed a pulmonary rehabilitation programme. People that were aged ≥60 years, resident in Wales, referred within 90 days, an ex- or never-smoker, received an exercise test, or received a health status questionnaire had significantly greater odds of completing pulmonary rehabilitation. People that were in the most deprived quintile, underweight or very severely obese, enrolled in a rolling rather than a cohort programme, had a higher GOLD stage and had a higher MRC grade had significantly lower odds of completing pulmonary rehabilitation.

Conclusions

People with COPD were more likely to complete pulmonary rehabilitation when best practice guidelines were followed. People with more severe COPD symptoms and those enrolled in rolling rather than cohort programmes were less likely to complete pulmonary rehabilitation. Referring people with COPD in the earlier stages of disease, ensuring programmes follow best practice guidelines and favouring cohort over rolling programmes could improve rates of pulmonary rehabilitation completion.

COPD in the time of COVID-19: an analysis of acute exacerbations and reported behavioural changes in patients with COPD

Introduction

The impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and associated “lockdown” measures on acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is unknown. We aimed to evaluate the change in AECOPD treatment frequency during the first 6 weeks of lockdown in the UK compared with 2019 and assess changes in self-reported behaviour and wellbeing.

Methods

In this observational study in Leicestershire, UK, patients with COPD under a secondary care clinic were recruited. Exacerbation frequency in the first 6 weeks of COVID-19 lockdown was compared with the same period in 2019 using electronic health records. A telephone survey was used to assess changes in anxiety, inhaler adherence, physical activity and behaviour during the pre-lockdown and lockdown periods compared with normal.

Results

160 participants were recruited (mean±sd age 67.3±8.1 years, 88 (55%) males, mean±sd forced expiratory volume in 1 s 34±13% pred). 140 (88%) reported at least one AECOPD in the previous year. Significantly more community managed exacerbations were observed in 2020 compared with 2019 (126 versus 99; p=0.026). The increase was a result of multiple courses of treatment, with a similar proportion of patients receiving at least one course (34.4% versus 33.8%).

Discussion

During lockdown participants reported significantly increased anxiety, adherence to their preventative inhalers and good adherence to shielding advice (all p<0.001). A significant reduction in self-reported physical activity and visitors was reported (both p<0.001).

Conclusions

Treatment for AECOPD events increased during the first 6 weeks of the SARS-CoV-2 pandemic in the UK compared with 2019. This was associated with increased symptoms of anxiety and significant behavioural change.

The #COVID19 pandemic has changed healthcare provision and access. This study shows a 38% increase in the number of community treated #AECOPD in 2020 compared with 2019, alongside increased anxiety and inhaler adherence with reduced physical activity.https://bit.ly/3lV17Q6

Longitudinal changes to quadriceps thickness demonstrate acute sarcopenia following admission to hospital for an exacerbation of chronic respiratory disease

Acute admission to hospital for an exacerbation of chronic respiratory disease (CRD) may impair skeletal muscle mass and function. We measured quadriceps thickness (Q_thick), as a surrogate marker of muscle mass, at hospital admission, discharge, 6 weeks and 3 months in 55 patients with CRD. Q_thick fell by 8.3% during the period of hospitalisation, which was sustained at 6 weeks, and only partially recovered at 3 months. Sustained loss was most marked in patients readmitted during the follow-up period. Acute reduction in quadriceps muscle mass occurs during hospitalisation, with prolonged and variable recovery, which is prevented with subsequent hospital readmission.

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.

Protocol for the cultural adaptation of pulmonary rehabilitation and subsequent testing in a randomised controlled feasibility trial for adults with chronic obstructive pulmonary disease in Sri Lanka

INTRODUCTION

International guidelines recommend pulmonary rehabilitation (PR) should be offered to adults living with chronic obstructive pulmonary disease (COPD), but PR availability is limited in Sri Lanka. Culturally appropriate PR needs to be designed and implemented in Sri Lanka. The study aims to adapt PR to the Sri Lankan context and determine the feasibility of conducting a future trial of the adapted PR in Sri Lanka.

METHODS AND ANALYSIS

Eligible participants will be identified and will be invited to take part in the randomised controlled feasibility trial, which will be conducted in Central Chest Clinic, Colombo, Sri Lanka. A total of 50 participants will be recruited (anticipated from April 2021) to the trial and randomised (1:1) into one of two groups; control group receiving usual care or the intervention group receiving adapted PR. The trial intervention is a Sri Lankan-specific PR programme, which will consist of 12 sessions of exercise and health education, delivered over 6 weeks. Focus groups with adults living with COPD, caregivers and nurses and in-depth interviews with doctors and physiotherapist will be conducted to inform the Sri Lankan specific PR adaptations. After completion of PR, routine measures in both groups will be assessed by a blinded assessor. The primary outcome measure is feasibility, including assessing eligibility, uptake and completion. Qualitative evaluation of the trial using focus groups with participants and in-depth interviews with PR deliverers will be conducted to further determine feasibility and acceptability of PR, as well as the ability to run a larger future trial.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the ethics review committee of Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka and University of Leicester, UK. The results of the trial will be disseminated through patient and public involvement events, local and international conference proceedings, and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN13367735.

Predictors of Referral to Pulmonary Rehabilitation from UK Primary Care

Background

A large proportion of people with COPD are not referred to pulmonary rehabilitation (PR) despite its proven benefits. No previous studies have examined predictors of referral to PR.

Objective

To determine the characteristics of people with COPD associated with referral to PR.

Methods

Cross-sectional analysis of a primary care cohort of 82,696 Welsh people with COPD generated as part of a UK national audit of COPD care. Data represent care received by patients as of 31/03/2017. Referral to PR was defined as any code in the patient record indicating referral to PR in the last 3 years. Potential predictors of referral to PR were chosen based on clinical judgement and data availability. Independent predictors of PR referral were determined using backward stepwise mixed-effects logistic regression with a random effect for practice. Variables assessed were: age, gender, deprivation, MRC recorded in past year, MRC grade, smoking status recorded in past year, smoking status, number of exacerbations in past year, inhaled therapy prescription, influenza vaccination, and comorbidities of diabetes, hypertension, coronary heart disease, stroke, heart failure, lung cancer, asthma, bronchiectasis, depression, anxiety, severe mental illness, osteoporosis, and painful condition.

Results

A total of 13,297 people (16%) with COPD were referred from primary care for PR. Patients with a comorbidity of bronchiectasis or depression, MRC recorded in the last year, higher MRC grade, more exacerbations in the last year, a greater level of inhaled therapy, an influenza vaccination, or were an ex-smoker had significantly higher odds of referral to PR. Patients that were older, female, more deprived, or had a comorbidity of diabetes, asthma, or painful condition had significantly lower odds of referral to PR.

Conclusion

Generally appropriate patients are being prioritised for PR referral; however, it is concerning that women, current smokers, and more deprived patients appear to have lower odds of referral.

Submaximal Eccentric Cycling in People With COPD: Acute Whole-Body Cardiopulmonary and Muscle Metabolic Responses

BACKGROUND

Eccentric cycling (ECC) may be an attractive exercise method in COPD because of both low cardiorespiratory demand and perception of effort compared with conventional concentric cycling (CON) at matched mechanical loads. However, it is unknown whether ECC can be performed by individuals with COPD at an intensity able to cause sufficient metabolic stress to improve aerobic capacity.

RESEARCH QUESTION

What are the cardiopulmonary and metabolic responses to ECC in people with COPD and healthy volunteers when compared with CON at matched mechanical loads?

STUDY DESIGN AND METHODS

Thirteen people with COPD (mean ± SD age, 64 ± 9 years; FEV₁, 45 ± 19% predicted; BMI, 24 ± 4 kg/m²; oxygen uptake at peak exercise [V̇O_2peak], 15 ± 3 mL/kg/min) and 9 age-matched control participants (FEV₁, 102 ± 13% predicted; BMI, 28 ± 5 kg/m²; V̇O_2peak, 23 ± 5 mL/kg/min), performed up to six 4-min bouts of ECC and CON at matched mechanical loads of increasing intensity. In addition, 12 individuals with COPD underwent quadriceps muscle biopsies before and after 20 min of ECC and CON at 65% peak power.

RESULTS

At matched mechanical loads, oxygen uptake, minute ventilation, heart rate, systolic BP, respiratory exchange ratio (all P < .001), capillary lactate, perceived breathlessness, and leg fatigue (P < .05) were lower in both groups during ECC than CON. Muscle lactate content increased (P = .008) and muscle phosphocreatine decreased (P = .012) during CON in COPD, which was not evident during ECC.

INTERPRETATION

Cardiopulmonary and blood lactate responses during submaximal ECC were less compared with during CON at equivalent mechanical workloads in healthy participants and COPD patients, and this was confirmed at a muscle level in COPD patients. Submaximal ECC was well tolerated and allowed greater mechanical work at lower ventilatory cost. However, in people with COPD, a training intervention based on ECC is unlikely to stimulate cardiovascular and metabolic adaptation to the same extent as CON.

Are the measurement properties of incremental exercise tests similar between patients with COPD and CHF?

We investigated whether the differences in exercise limitation between patients with chronic obstructive pulmonary disease (COPD) or chronic heart failure (CHF) affect the repeatability or responsiveness of incremental exercise tests. Patients with COPD (Medical Research Council dyspnoea grade 2-5) and patients with CHF (New York Heart Association class II-IV) performed two incremental shuttle walk tests (ISWT) following familiarisation and two incremental cycle ergometer tests (ICE) within 2 weeks. Both tests were repeated on completion of a pulmonary rehabilitation (PR) programme. One hundred and twelve patients were recruited. In response to exercise, patients with COPD were more likely than patients with CHF to have a ventilatory limitation (p < 0.001) and less likely to have a cardiovascular limitation (p < 0.001). The ISWT distance and ICE peak volume of oxygen uptake (VO₂Peak) were similarly repeatable (p = 0.11 and p = 0.47 for time and disease effect) and responsive to PR (p = 0.44 and p = 0.67) between diseases. There was no difference in repeatability or responsiveness with either a ventilatory or cardiovascular limitation to exercise (p > 0.20 for all comparisons). The coefficient of repeatability across the cohort was 60 m for the ISWT and 0.270 L/minute for ICE VO₂Peak. The minimum important difference (MID) for the ISWT in both diseases for PR was 30 m. The repeatability and responsiveness of the ISWT distance and ICE VO₂Peak are similar between patients with COPD and CHF and are unaffected by differences in exercise limitation. A change of 60 m in the ISWT or 0.270 L/minute in ICE VO₂Peak is required to be 95% certain that a true change has occurred within an individual patient. For a group of patients with either COPD or CHF, the MID for the ISWT distance is estimated to be 30 m.

Change in V˙O2peak in Response to Aerobic Exercise Training and the Relationship With Exercise Prescription in People With COPD: A Systematic Review and Meta-analysis

BACKGROUND

Despite the wide-ranging benefits of pulmonary rehabilitation, conflicting results remain regarding whether people with COPD can improve their peak oxygen uptake (V˙O_2peak) with aerobic training.

RESEARCH QUESTION

The goal of this study was to investigate the effect of aerobic training and exercise prescription on V˙O_2peak in COPD.

STUDY DESIGN AND METHODS

A systematic review was performed by using MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, and Cochrane databases for all studies measuring V˙O_2peak prior to and following supervised lower-limb aerobic training in COPD. A random effects meta-analysis limited to randomized controlled trials comparing aerobic training vs usual care was conducted. Other study designs were included in a secondary meta-analysis and meta-regression to investigate the influence of program and patient factors on outcome.

RESULTS

A total of 112 studies were included (participants, N = 3,484): 21 controlled trials (n = 489), of which 13 were randomized (n = 288) and 91 were uncontrolled (n = 2,995) studies. Meta-analysis found a moderate positive change in V˙O_2peak (standardized mean difference, 0.52; 95% CI, 0.34-0.69) with the intervention. The change in V˙O_2peak was positively associated with target duration of exercise session (P = .01) and, when studies > 1 year duration were excluded, greater total volume of exercise training (P = .01). Similarly, the change in V˙O_2peak was greater for programs > 12 weeks compared with those 6 to 12 weeks when adjusted for age and sex. However, reported prescribed exercise intensity (P = .77), training modality (P > .35), and mode (P = .29) did not affect V˙O_2peak. Cohorts with more severe airflow obstruction exhibited smaller improvements in V˙O_2peak (P < .001).

INTERPRETATION

Overall, people with COPD achieved moderate improvements in V˙O_2peak through supervised aerobic training. There is sufficient evidence to show that programs with greater total exercise volume, including duration of exercise session and program duration, are more effective. Reduced effects in severe disease suggest alternative aerobic training methods may be needed in this population.

CLINICAL TRIAL REGISTRATION

PROSPERO; No.: CRD42018099300; URL: https://www.crd.york.ac.uk/prospero/.

Findings of a feasibility study of pre-operative pulmonary rehabilitation to reduce post-operative pulmonary complications in people with chronic obstructive pulmonary disease scheduled for major abdominal surgery

Background: Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of complications and death following surgery. Pulmonary complications are particularly prominent.  Pulmonary rehabilitation is a course of physical exercise and education that helps people with COPD manage their condition.  Although proven to improve health outcomes in patients with stable COPD, it has never been formally tested as a pre-surgical intervention in patients scheduled for non-cardiothoracic surgery.  If a beneficial effect were to be demonstrated, pulmonary rehabilitation for pre-surgical patients with COPD might be rapidly implemented across the National Health Service, as pulmonary rehabilitation courses are already well established across much of the United Kingdom (UK). Methods: We performed a feasibility study to test study procedures and barriers to identification and recruitment to a randomised controlled trial testing whether pulmonary rehabilitation, delivered before major abdominal surgery in a population of people with COPD, would reduce the incidence of post-operative pulmonary complications.  This study was run in two UK centres (Oxford and Newcastle upon Tyne). Results:  We determined that a full randomised controlled trial would not be feasible, due to failure to identify and recruit participants.  We identified an unmet need to identify more effectively patients with COPD earlier in the surgical pathway.  Service evaluations suggested that barriers to identification and recruitment would likely be the same across other UK hospitals. Conclusions:  Although pulmonary rehabilitation is a potentially beneficial intervention to prevent post-operative pulmonary complications, a randomised controlled trial is unlikely to recruit sufficient participants to answer our study question conclusively at the present time, when spirometry is not automatically conducted in all patients planned for surgery.  As pulmonary rehabilitation is a recommended treatment for all people with COPD, alternative study methods combined with earlier identification of candidate patients in the surgical pathway should be considered. Trial registration: ISRCTN29696295, 31/08/2017.

Activin Type II Receptor Blockade for Treatment of Muscle Depletion in Chronic Obstructive Pulmonary Disease. A Randomized Trial

RATIONALE

Bimagrumab is a fully human monoclonal antibody that blocks the activin type II receptors, preventing the activity of myostatin and other negative skeletal muscle regulators.

OBJECTIVES

To assess the effects of bimagrumab on skeletal muscle mass and function in patients with chronic obstructive pulmonary disease (COPD) and reduced skeletal muscle mass.

METHODS

Sixty-seven patients with COPD (mean FEV₁, 1.05 L [41.6% predicted]; aged 40-80 yr; body mass index < 20 kg/m² or appendicular skeletal muscle mass index ≤ 7.25 [men] and ≤ 5.67 [women] kg/m²), received two doses of either bimagrumab 30 mg/kg intravenously (n = 33) or placebo (n = 34) (Weeks 0 and 8) over 24 weeks.

MEASUREMENTS AND MAIN RESULTS

We assessed changes in thigh muscle volume (cubic centimeters) as the primary endpoint along with 6-minute-walk distance (meters), safety, and tolerability. Fifty-five (82.1%) patients completed the study. Thigh muscle volume increased by Week 4 and remained increased at Week 24 in bimagrumab-treated patients, whereas no changes were observed with placebo (Week 4: +5.9% [SD, 3.4%] vs. 0.0% [3.3%], P < 0.001; Week 8: +7.0% [3.7%] vs. -0.7% [2.8%], P < 0.001; Week 16: +7.8% [5.1%] vs. -0.9% [4.5%], P < 0.001; Week 24: +5.0% [4.9%] vs. -1.3% [4.3%], P < 0.001). Over 24 weeks, 6-minute-walk distance did not increase significantly in either group. Adverse events in the bimagrumab group included muscle-related symptoms, diarrhea, and acne, most of which were mild in severity.

CONCLUSIONS

Blocking the action of negative muscle regulators through the activin type II receptors with bimagrumab treatment safely increased skeletal muscle mass but did not improve functional capacity in patients with COPD and low muscle mass. Clinical trial registered with www.clinicaltrials.gov (NCT01669174).

Anaemia and iron dysregulation: untapped therapeutic targets in chronic lung disease?

Hypoxia is common in many chronic lung diseases. Beyond pulmonary considerations, delivery of oxygen (O₂) to the tissues and subsequent O₂ utilisation is also determined by other factors including red blood cell mass and iron status; consequently, disruption to these mechanisms provides further physiological strains on an already stressed system. O₂ availability influences ventilation, regulates pulmonary blood flow and impacts gene expression throughout the body. Deleterious effects of poor tissue oxygenation include decreased exercise tolerance, increased cardiac strain and pulmonary hypertension in addition to pathophysiological involvement of multiple other organs resulting in progressive frailty. Increasing inspired O₂ is expensive, disliked by patients and does not normalise tissue oxygenation; thus, other strategies that improve O₂ delivery and utilisation may provide novel therapeutic opportunities in patients with lung disease. In this review, we focus on the rationale and possibilities for doing this by increasing haemoglobin availability or improving iron regulation.

A specific proteinase 3 activity footprint in α1-antitrypsin deficiency

α₁-Antitrypsin (α₁-AT) deficiency is a risk factor for emphysema due to tissue damage by serine proteases. Neutrophil elastase (NE) has long been considered the enzyme responsible. However, proteinase 3 (PR3) also produces the pathological features of chronic obstructive pulmonary disease (COPD), is present in the same granules in the neutrophil and is inhibited after NE. We developed a specific footprint assay for PR3 activity and assessed its relationship to an NE footprint in α₁-AT deficiency.

An ELISA was developed for the specific PR3 fibrinogen cleavage site Aα-Val⁵⁴¹. Levels were measured in plasma from 239 PiZZ patients, 94 PiSZ patients, 53 nondeficient healthy smokers and 78 individuals with usual COPD. Subjects underwent extensive demographic characterisation including full lung function and lung computed tomography scanning.

Aα-Val⁵⁴¹ was greater than the NE footprint in all cohorts, consistent with differential activity. Values were highest in the PiZZ α₁-AT-deficient patients and correlated with the NE marker Aα-Val³⁶⁰, but were ∼17 times higher than for the NE footprint, consistent with a greater potential contribution to lung damage. Aα-Val⁵⁴¹ was related cross-sectionally to the severity of lung disease (forced expiratory volume in 1 s % pred: r_s= −0.284; p<0.001) and was sensitive to augmentation therapy, falling from 287.2 to 48.6 nM (p<0.001).

An in vivo plasma footprint of PR3 activity is present in greater quantities than an NE footprint in patients with α₁-AT deficiency, is sensitive to augmentation therapy and represents a likely biomarker for dose-ranging studies.

This novel assay provides evidence of proteinase 3 activity in α₁-antitrypsin deficiency, suggesting it may play a significant role in lung tissue damage and act as a specific biomarker for augmentation therapyhttp://bit.ly/32dnx66

Time to NIV and mortality in AECOPD hospital admissions: an observational study into real world insights from National COPD Audits

Background

Randomised control trial (RCT)-derived survival figures for acute exacerbation of chronic obstructive pulmonary disease admissions managed with non-invasive ventilation (NIV) have not been replicated in UK clinical audits. Subsequent guidelines have emphasised the need for timely NIV application.

Methods

Data from the 2008 and 2014 national chronic obstructive pulmonary disease audits was used to analyse the association between time to NIV and mortality.

Results

1032 patients received NIV in 2008, and 1612 in 2014. Overall mortality rates reduced between the audits from 24.9% in 2008 to 16.8% in 2014 but time to NIV lengthened. In 2014, 20.9% of patients received NIV within 60 min versus 24.9% in 2008 (p=0.001). The proportion of patients receiving NIV between 3 and 24 hours increased from 31.3% in 2008 to 39% in 2014 (p=0.001). Patients admitted with hypercapnic acidotic respiratory failure who received NIV within 3 hours had lower in-patient mortality than those who received NIV between 3 and 24 hours, 15.9% versus 18.4%, but this did not reach statistical significance (p=0.425), but acidotic patients receiving NIV >24 hours after admission had significantly higher mortality (28.9%, p=0.002). A second cohort admitted with hypercapnia but normal range pH, who developed later acidosis, had higher mortality (24.6%), compared with those acidotic on admission (18% p≤0.001) and an extremely high mortality when NIV was given >24 hours after admission (42.6%).

Conclusion

Survival rates for those treated with NIV has improved between the two audits but remains lower than reported in RCTs. Patients who developed acidosis after admission and received NIV later in the hospital stay have even higher mortality and deserve further study and clinical attention.

Impact of transcutaneous neuromuscular electrical stimulation or resistance exercise on skeletal muscle mRNA expression in COPD

Background: Voluntary resistance exercise (RE) training increases muscle mass and strength in patients with chronic obstructive pulmonary disease (COPD). Nonvolitional transcutaneous neuromuscular electrical stimulation (NMES) may be an alternative strategy for reducing ambulatory muscle weakness in patients unable to perform RE training, but little comparative data are available. This study, therefore, investigated changes in muscle mRNA abundance of a number of gene targets in response to a single bout of NMES compared with RE. Methods: Twenty-six patients with stable COPD (15 male; FEV₁, 43±18% predicted; age, 64±8 years; fat free mass index, 16.6±1.8 kg/m²) undertook 30 minutes of quadriceps NMES (50 Hz, current at the limit of tolerance) or 5×30 maximal voluntary isokinetic knee extensions. Vastus lateralis muscle biopsies were obtained at rest immediately before and 24 hours after intervention. Expression of 384 targeted mRNA transcripts was assessed by real time TaqMan PCR. Significant change in expression from baseline was determined using the ΔΔC_T method with a false discovery rate (FDR) of <5%. Results: NMES and RE altered mRNA abundance of 18 and 68 genes, respectively (FDR <5%), of which 14 genes were common to both interventions and of the same magnitude of fold change. Biological functions of upregulated genes included inflammation, hypertrophy, muscle protein turnover, and muscle growth, whilst downregulated genes included mitochondrial and cell signaling functions. Conclusions: Compared with NMES, RE had a broader impact on mRNA abundance and, therefore, appears to be the superior intervention for maximizing transcriptional responses in the quadriceps of patients with COPD. However, if voluntary RE is not feasible in a clinical setting, NMES by modifying expression of genes known to impact upon muscle mass and strength may have a positive influence on muscle function.

Changes in physical activity during hospital admission for chronic respiratory disease

BACKGROUND AND OBJECTIVE

Establishing the amount of inpatient physical activity (PA) undertaken by individuals hospitalized for chronic respiratory disease is needed to inform interventions. This observational study investigated whether PA changes when a person is an inpatient, how long is required to obtain representative PA measures and whether PA varies within a day and between patients of differing lengths of stay.

METHODS

A total of 389 participants were recruited as early as possible into their hospitalization. Patients wore a PA monitor from recruitment until discharge. Step count was extracted for a range of wear time criteria. Single-day intraclass correlation coefficients (ICC) were calculated, with an ICC ≥ 0.80 deemed acceptable.

RESULTS

PA data were available for 259 participants. No changes in daily step count were observed during the inpatient stay (586 (95% CI: 427-744) vs 652 (95% CI: 493-812) steps/day for day 2 and 7, respectively). ICC across all wear time criteria were > 0.80. The most stringent wear time criterion, retaining 80% of the sample, was ≥11 h on ≥1 day. More steps were taken during the morning and afternoon than overnight and evening. After controlling for the Medical Research Council (MRC) grade or oxygen use, there was no difference in step count between patients admitted for 2-3 days (short stay) and those admitted for 7-14 days (long stay).

CONCLUSION

Patients move little during their hospitalization, and inpatient PA did not increase during their stay. A wear time criterion of 11 waking hours on any single day was representative of the entire admission whilst retaining an acceptable proportion of the initial sample size. Patients may need encouragement to move more during their hospital stay.

Use, utility and methods of telehealth for patients with COPD in England and Wales: a healthcare provider survey

Introduction

Although the effectiveness of domiciliary monitoring (telehealth) to improve outcomes in chronic obstructive pulmonary disease (COPD) is controversial, it is being used in the National Health Service (NHS).

Aim

To explore the use of teleheath for COPD across England and Wales, to assess the perceptions of clinicians employing telehealth in COPD and to summarise the techniques that have been used by healthcare providers to personalise alarm limits for patients with COPD enrolled in telehealth programmes.

Methods

A cross-sectional survey consisting of 14 questions was sent to 230 COPD community services in England and Wales. Questions were designed to cover five aspects of telehealth in COPD: purpose of use, equipment type, clinician perceptions, variables monitored and personalisation of alarm limits.

Results

65 participants completed the survey from 52 different NHS Trusts. 46% of Trusts had used telehealth for COPD, and currently, 31% still provided telehealth services to patients with COPD. Telehealth is most commonly used for baseline monitoring and to allow early detection of exacerbations, with 54% believing it to be effective. The three most commonly monitored variables were oxygen saturation, heart rate and breathlessness. A variety of methods were used to set alarm limits with the majority of respondents believing that at least 40% of alarms were false.

Conclusion

Around one-third of responded community COPD services are using telehealth, believing it to be effective without robust evidence, with a variety of variables monitored, a variety of hardware and varying techniques to set alarm limits with high false alarm frequencies.

24-hour accelerometry in COPD: Exploring physical activity, sedentary behavior, sleep and clinical characteristics

Background

The constructs and interdependency of physical behaviors are not well described and the complexity of physical activity (PA) data analysis remains unexplored in COPD. This study examined the interrelationships of 24-hour physical behaviors and investigated their associations with participant characteristics for individuals with mild–moderate airflow obstruction and healthy control subjects.

Patients and methods

Vigorous PA (VPA), moderate-to-vigorous PA (MVPA), light PA (LPA), stationary time (ST), average movement intensity (vector magnitude counts per minute), and sleep duration for 109 individuals with COPD and 135 healthy controls were obtained by wrist-worn accelerometry. Principal components analysis (PCA) examined interrelationships of physical behaviors to identify distinct behavioral constructs. Using the PCA component loadings, linear regressions examined associations with participant (+, positive correlation; -, negative correlation), and were compared between COPD and healthy control groups.

Results

For both groups PCA revealed ST, LPA, and average movement intensity as distinct behavioral constructs to MVPA and VPA, labeled “low-intensity movement” and “high-intensity movement,” respectively. Sleep was also found to be its own distinct behavioral construct. Results from linear regressions supported the identification of distinct behavioral constructs from PCA. In COPD, low-intensity movement was associated with limitations with mobility (−), daily activities (−), health status (+), and body mass index (BMI) (−) independent of high-intensity movement and sleep. High-intensity movement was associated with age (−) and self-care limitations (−) independent of low-intensity movement and sleep. Sleep was associated with gender (0= female, 1= male; [−]), lung function (−), and percentage body fat (+) independent of low-intensity and high-intensity movement.

Conclusion

Distinct behavioral constructs comprising the 24-hour day were identified as “low-intensity movement,” “high-intensity movement,” and “sleep” with each construct independently associated with different participant characteristics. Future research should determine whether modifying these behaviors improves health outcomes in COPD.

CELEB trial: Comparative Effectiveness of Lung volume reduction surgery for Emphysema and Bronchoscopic lung volume reduction with valve placement: a protocol for a randomised controlled trial

INTRODUCTION

Although lung volume reduction surgery and bronchoscopic lung volume reduction with endobronchial valves have both been shown to improve lung function, exercise capacity and quality of life in appropriately selected patients with emphysema, there are no direct comparison data between the two procedures to inform clinical decision-making.

METHODS AND ANALYSIS

We describe the protocol of the CELEB study, a randomised controlled trial which will compare outcomes at 1 year between the two procedures, using a composite disease severity measure, the iBODE score, which includes body mass index, airflow obstruction, dyspnoeaand exercise capacity (incremental shuttle walk test).

ETHICS AND DISSEMINATION

Ethical approval to conduct the study has been obtained from the Fulham Research Ethics Committee, London (16/LO/0286). The outcome of this trial will provide information to guide treatment choices in this population and will be presented at national and international meetings and published in peer-reviewed journals. We will also disseminate the main results to all participants in a letter.

TRIAL REGISTRATION NUMBER

ISRCTN19684749; Pre-results.

Metabolic phenotype of skeletal muscle in early critical illness

OBJECTIVES

To characterise the sketetal muscle metabolic phenotype during early critical illness.

METHODS

Vastus lateralis muscle biopsies and serum samples (days 1 and 7) were obtained from 63 intensive care patients (59% male, 54.7±18.0 years, Acute Physiology and Chronic Health Evaluation II score 23.5±6.5).

MEASUREMENTS AND MAIN RESULTS

From day 1 to 7, there was a reduction in mitochondrial beta-oxidation enzyme concentrations, mitochondrial biogenesis markers (PGC1α messenger mRNA expression (-27.4CN (95% CI -123.9 to 14.3); n=23; p=0.025) and mitochondrial DNA copy number (-1859CN (IQR -5557-1325); n=35; p=0.032). Intramuscular ATP content was reduced compared tocompared with controls on day 1 (17.7mmol/kg /dry weight (dw) (95% CI 15.3 to 20.0) vs. 21.7 mmol/kg /dw (95% CI 20.4 to 22.9); p<0.001) and decreased over 7 days (-4.8 mmol/kg dw (IQR -8.0-1.2); n=33; p=0.001). In addition, the ratio of phosphorylated:total AMP-K (the bioenergetic sensor) increased (0.52 (IQR -0.09-2.6); n=31; p<0.001). There was an increase in intramuscular phosphocholine (847.2AU (IQR 232.5-1672); n=15; p=0.022), intramuscular tumour necrosis factor receptor 1 (0.66 µg (IQR -0.44-3.33); n=29; p=0.041) and IL-10 (13.6 ng (IQR 3.4-39.0); n=29; p=0.004). Serum adiponectin (10.3 µg (95% CI 6.8 to 13.7); p<0.001) and ghrelin (16.0 ng/mL (IQR -7-100); p=0.028) increased. Network analysis revealed a close and direct relationship between bioenergetic impairment and reduction in muscle mass and between intramuscular inflammation and impaired anabolic signaling. ATP content and muscle mass were unrelated to lipids delivered.

CONCLUSIONS

Decreased mitochondrial biogenesis and dysregulated lipid oxidation contribute to compromised skeletal muscle bioenergetic status. In addition, intramuscular inflammation was associated with impaired anabolic recovery with lipid delivery observed as bioenergetically inert. Future clinical work will focus on these key areas to ameliorate acute skeletal muscle wasting.

TRIAL REGISTRATION NUMBER

NCT01106300.