Multidimensional outcome assessment of pulmonary rehabilitation in traits-based clusters of COPD patients

Predicting Response to In-Hospital Pulmonary Rehabilitation in Individuals Recovering From Exacerbations of Chronic Obstructive Pulmonary Disease

BACKGROUND

Predicting the response to pulmonary rehabilitation (PR) could be valuable in defining admission priorities. We aimed to investigate whether the response of individuals recovering from a COPD exacerbation (ECOPD) could be forecasted using machine learning approaches.

METHOD

This multicenter, retrospective study recorded data on anthropometrics, demographics, physiological characteristics, post-PR changes in six-minute walking distance test (6MWT), Medical Research Council scale for dyspnea (MRC), Barthel Index dyspnea (BId), COPD assessment test (CAT) and proportion of participants reaching the minimal clinically important difference (MCID). The ability of multivariate approaches (linear regression, quantile regression, regression trees, and conditional inference trees) in predicting changes in each outcome measure has been assessed.

RESULTS

Individuals with lower baseline 6MWT, as well as those with less severe airway obstruction or admitted from acute care hospitals, exhibited greater improvements in 6MWT, whereas older as well as more dyspnoeic individuals had a lower forecasted improvement. Individuals with more severe CAT and dyspnea, and lower 6MWT had a greater potential improvement in CAT. More dyspnoeic individuals were also more likely to show improvement in BId and MRC. The Mean Absolute Error estimates of change prediction were 44.70m, 3.22 points, 5.35 points, and 0.32 points for 6MWT, CAT, BId, and MRC respectively. Sensitivity and specificity in discriminating individuals reaching the MCID of outcomes ranged from 61.78% to 98.99% and from 14.00% to 71.20%, respectively.

CONCLUSION

While the assessed models were not entirely satisfactory, predictive equations derived from clinical practice data might help in forecasting the response to PR in individuals recovering from an ECOPD. Future larger studies will be essential to confirm the methodology, variables, and utility.

Baseline dependent minimally important differences for clinical outcomes of pulmonary rehabilitation in people with COPD

INTRODUCTION

Minimally important differences (MIDs) for common outcomes of pulmonary rehabilitation are well documented for people with chronic obstructive pulmonary disease (COPD). It is not known whether MIDs differ based on COPD disease characteristics. This study aimed to estimate MIDs for clinical outcomes of pulmonary rehabilitation dependent upon baseline characteristics.

METHODS

A database containing 2791 people with COPD was split into derivation (n=2245; age 66±9 years; 50% males; FEV1 47±20% predicted) and comparator (n=546; age 66±9 years; 47% males; FEV1 46±21% predicted) cohorts. MIDs were estimated using 0.5 x SD (symmetrically distributed) or 0.5 x IQR (non-symmetrically distributed) for: 6-minute walk test (6MWT), constant work rate test (CWRT), COPD assessment test (CAT), St. George's respiratory questionnaire (SGRQ), hospital anxiety and depression scale (HADS), and fat-free mass index (FFMI). MIDs were estimated based on baseline outcome scores, lung function, modified medical research council (mMRC) grade and FFMI.

RESULTS

MID estimates were comparable to previously reported values. MIDs for SGRQ domains (Symptom=8.7 points, Activity=7.1 points, Impact=8.1 points) and FFMI were produced (0.36kg/m2). There was greater variation of change in 6MWT, SGRQ-activity, SGRQ-impact, HADS and FFMI on which the MIDs were determined when categorising for baseline values (all, p<0.05). Greater variation of change in 6MWT on which the MIDs were determined was evident with COPD disease severity grouping (p<0.05). The magnitude of change in 6MWT, CAT, CWRT, SGRQ-activity, and FFMI with baseline mMRC score categorisation resulted in greater variation on which the MIDs were determined (all, p<0.05). Baseline stratification for FFMI resulted in greater variation of change in CWRT (p<0.001) and HADS-depression (p = 0.043) on which MIDs were determined.

DISCUSSION

Findings suggest that baseline presentation should be considered for people with COPD when assessing the efficacy of pulmonary rehabilitation. However, clinical significance of the variation underpinning MIDs is yet to be determined.

Acoustic Lung Imaging Utilized in Continual Assessment of Patients with Obstructed Airway: A Systematic Review

Smart respiratory therapy is enabled by continual assessment of lung functions. This systematic review provides an overview of the suitability of equipment-to-patient acoustic imaging in continual assessment of lung conditions. The literature search was conducted using Scopus, PubMed, ScienceDirect, Web of Science, SciELO Preprints, and Google Scholar. Fifteen studies remained for additional examination after the screening process. Two imaging modalities, lung ultrasound (LUS) and vibration imaging response (VRI), were identified. The most common outcome obtained from eleven studies was positive observations of changes to the geographical lung area, sound energy, or both, while positive observation of lung consolidation was reported in the remaining four studies. Two different modalities of lung assessment were used in eight studies, with one study comparing VRI against chest X-ray, one study comparing VRI with LUS, two studies comparing LUS to chest X-ray, and four studies comparing LUS in contrast to computed tomography. Our findings indicate that the acoustic imaging approach could assess and provide regional information on lung function. No technology has been shown to be better than another for measuring obstructed airways; hence, more research is required on acoustic imaging in detecting obstructed airways regionally in the application of enabling smart therapy.

Gene polymorphisms associated with heterogeneity and senescence characteristics of sarcopenia in chronic obstructive pulmonary disease

BACKGROUND

Sarcopenia, or loss of skeletal muscle mass and decreased contractile strength, contributes to morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD). The severity of sarcopenia in COPD is variable, and there are limited data to explain phenotype heterogeneity. Others have shown that COPD patients with sarcopenia have several hallmarks of cellular senescence, a potential mechanism of primary (age-related) sarcopenia. We tested if genetic contributors explain the variability in sarcopenic phenotype and accelerated senescence in COPD.

METHODS

To identify gene variants [single nucleotide polymorphisms (SNPs)] associated with sarcopenia in COPD, we performed a genome-wide association study (GWAS) of fat free mass index (FFMI) in 32 426 non-Hispanic White (NHW) UK Biobank participants with COPD. Several SNPs within the fat mass and obesity-associated (FTO) gene were associated with sarcopenia that were validated in an independent COPDGene cohort (n = 3656). Leucocyte telomere length quantified in the UK Biobank cohort was used as a marker of senescence. Experimental validation was done by genetic depletion of FTO in murine skeletal myotubes exposed to prolonged intermittent hypoxia or chronic hypoxia because hypoxia contributes to sarcopenia in COPD. Molecular biomarkers for senescence were also quantified with FTO depletion in murine myotubes.

RESULTS

Multiple SNPs located in the FTO gene were associated with sarcopenia in addition to novel SNPs both within and in proximity to the gene AC090771.2, which transcribes long non-coding RNA (lncRNA). To replicate our findings, we performed a GWAS of FFMI in NHW subjects from COPDGene. The SNP most significantly associated with FFMI was on chromosome (chr) 16, rs1558902A > T in the FTO gene (β = 0.151, SE = 0.021, P = 1.40 × 10-12 for UK Biobank |β= 0.220, SE = 0.041, P = 9.99 × 10-8 for COPDGene) and chr 18 SNP rs11664369C > T nearest to the AC090771.2 gene (β = 0.129, SE = 0.024, P = 4.64 × 10-8 for UK Biobank |β = 0.203, SE = 0.045, P = 6.38 × 10-6 for COPDGene). Lower handgrip strength, a measure of muscle strength, but not FFMI was associated with reduced telomere length in the UK Biobank. Experimentally, in vitro knockdown of FTO lowered myotube diameter and induced a senescence-associated molecular phenotype, which was worsened by prolonged intermittent hypoxia and chronic hypoxia.

CONCLUSIONS

Genetic polymorphisms of FTO and AC090771.2 were associated with sarcopenia in COPD in independent cohorts. Knockdown of FTO in murine myotubes caused a molecular phenotype consistent with senescence that was exacerbated by hypoxia, a common condition in COPD. Genetic variation may interact with hypoxia and contribute to variable severity of sarcopenia and skeletal muscle molecular senescence phenotype in COPD.

Nonpharmacological management of psychological distress in people with COPD

Psychological distress is prevalent in people with COPD and relates to a worse course of disease. It often remains unrecognised and untreated, intensifying the burden on patients, carers and healthcare systems. Nonpharmacological management strategies have been suggested as important elements to manage psychological distress in COPD. Therefore, this review presents instruments for detecting psychological distress in COPD and provides an overview of available nonpharmacological management strategies together with available scientific evidence for their presumed benefits in COPD. Several instruments are available for detecting psychological distress in COPD, including simple questions, questionnaires and clinical diagnostic interviews, but their implementation in clinical practice is limited and heterogeneous. Moreover, various nonpharmacological management options are available for COPD, ranging from specific cognitive behavioural therapy (CBT) to multi-component pulmonary rehabilitation (PR) programmes. These interventions vary substantially in their specific content, intensity and duration across studies. Similarly, available evidence regarding their efficacy varies significantly, with the strongest evidence currently for CBT or PR. Further randomised controlled trials are needed with larger, culturally diverse samples and long-term follow-ups. Moreover, effective nonpharmacological interventions should be implemented more in the clinical routine. Respective barriers for patients, caregivers, clinicians, healthcare systems and research need to be overcome.

Responsiveness to pulmonary rehabilitation in COPD is associated with changes in microbiota

BACKGROUND

Pulmonary Rehabilitation (PR) is one of the most cost-effective therapies for chronic obstructive pulmonary disease (COPD) management. There are, however, people who do not respond to PR and reasons for non-response are mostly unknown. PR is likely to change the airway microbiota and this could play a role in its responsiveness. In this study we have explored the association between PR effectiveness and specific alterations in oral microbiota and inflammation.

METHODS

A prospective longitudinal study was conducted. Data on exercise capacity, dyspnoea, impact of disease and 418 saliva samples were collected from 76 patients, half of whom participated in a 12-weeks PR programme. Responders and non-responders to PR (dyspnoea, exercise-capacity and impact of disease) were defined based on minimal clinically important differences.

RESULTS

Changes in microbiota, including Prevotella melaninogenica and Streptococcus were observed upon PR. Prevotella, previously found to be depleted in severe COPD, increased during the first month of PR in responders. This increase was negatively correlated with Streptococcus and Lautropia, known to be enriched in severe cases of COPD. Simultaneously, an anti-inflammatory commensal of the respiratory tract, Rothia, correlated strongly and negatively with several pro-inflammatory markers, whose levels were generally boosted by PR. Conversely, in non-responders, the observed decline in Prevotella correlated negatively with Streptococcus and Lautropia whose fluctuations co-occurred with several pro-inflammatory markers.

CONCLUSIONS

PR is associated with changes in oral microbiota. Specifically, PR increases salivary Prevotella melaninogenica and avoids the decline in Rothia and the increase in Streptococcus and Lautropia in responders, which may contribute to the benefits of PR.

Airflow grades, outcome measures and response to pulmonary rehabilitation in individuals after an exacerbation of severe chronic obstructive pulmonary disease

BACKGROUND

Individuals with COPD may be staged according to symptoms and exacerbation history (GOLD groups: A-D) and on airflow obstruction (GOLD grades: 1-4). Guidelines recommend pulmonary rehabilitation (PR) for these individuals, including those recovering from an exacerbation (ECOPD) OBJECTIVE: To evaluate whether in individuals with clinically severe COPD, recovering from an ECOPD, the effect size of an in-hospital PR program would be affected by airflow severity grades and assessed outcome measures.

METHODS

Retrospective, multicentre study. Participants were compared according to different GOLD airflow grades. In addition to the MRC dyspnoea scale, six-minute walking distance test and COPD assessment test (CAT), Barthel dyspnoea index (Bid), and Short Physical Performance Battery (SPPB) were assessed, evaluating the proportion of individuals reaching the minimum clinically important difference (MCID) (responders).

RESULTS

Data of 479 individuals, completing the program were evaluated. Most of the participants were allocated in GOLD grades 4, (57.6%) and 3 (22.1%). All outcome measures significantly improved after PR (p < 0.05), without any significant difference in the proportion of responders in any measure.

CONCLUSIONS

in individuals with severe COPD, recovering from ECOPD the success rate of PR does not depend on airflow severity, or outcome measure assessed. In addition to the most used outcome measures, also Bid and SPPB are sensitive to PR.

The presence of extra-pulmonary treatable traits increases the likelihood of responding to pulmonary rehabilitation

INTRODUCTION

Studies suggest that people with chronic obstructive pulmonary disease (COPD) who are worse at baseline respond better to pulmonary rehabilitation (PR). Identifying treatable traits (TTs) may help to distinguish responders from non-responders. We explored the impact of PR on extra-pulmonary traits of people with COPD and whether the presence of TT influences the type of response to PR.

METHODS

A comprehensive assessment of 9 TT including symptoms (dyspnoea, fatigue, anxiety and depression), functional capacity, deconditioning, balance, impact of the disease and health-related quality of life was conducted before and after a 12-week community-based PR programme. Pre-post differences between people with or without each TT at baseline were compared with independent samples t-tests or Mann-Whitney U tests. Proportion of responders between groups were explored with chi-square tests and odds ratio.

RESULTS

102 people with COPD were included (70 [65; 75] years old, 78% male, FEV₁ 47 [36; 60] %predicted). They had a median of 3 (out of 9) TTs per person and each patient responded on average to 5 (out of 9) outcomes of PR. People with TT were more responsive than those without them in all outcomes (p < 0.05) except for the 1-min sit-to-stand test. The presence of TT increased 4 to 20 times the likelihood of being a good responder.

CONCLUSIONS

Identification of baseline extra-pulmonary TT in people with COPD showed the potential to inform on PR responsiveness and might therefore be an important strategy for patient prioritization, treatment personalisation (i.e., activation of the most suitable components) and optimisation.