Design of the Redefining Therapy in Early COPD Study

Mortality and readmission risk for hospitalised patients with acute exacerbation of COPD with and without spirometric obstruction: a longitudinal observational study in China

OBJECTIVE

To compare the clinical features and outcomes in patients with pre-chronic obstructive pulmonary disease (COPD) and COPD hospitalised for confirmed or suspected acute exacerbation of COPD (AECOPD).

DESIGN

A multicentre, longitudinal observational cohort study.

SETTING

Data were obtained from the AECOPD Inpatient Registry Study in China.

PARTICIPANTS

5896 patients hospitalised for AECOPD between 2017 and 2021.

OUTCOMES

Patients were divided into the COPD (n=5201) and pre-COPD (n=695) groups according to the lung function test results. The outcomes of interest included all-cause, respiratory disease-related and cardiovascular disease-related deaths as well as readmissions within 30 days and 12 months after discharge. Cumulative incidence functions were used to estimate the risk of cause-specific mortality and readmission. Multivariate hazard function models were used to determine the association between lung function and outcomes.

RESULTS

There were significant between-group differences in the symptoms at admission and medication use during hospitalisation. However, there was no significant between-group difference in the 30-day all-cause mortality (0.00 vs 2.23/1000 person-month (pm), p=0.6110) and readmission (33.52 vs 30.64/1000 pm, p=0.7175). Likewise, the 30-day and 12-month cause-specific outcomes were not significantly different between groups (30-day readmission with acute exacerbation (AE): 26.07 vs 25.11/1000 pm; 12-month all-cause mortality: 0.20 vs 0.93/1000 pm; all-cause readmission: 11.49 vs 13.75/1000 pm; readmission with AE: 9.15 vs 11.64/1000 pm, p>0.05 for all comparisons). Cumulative incidence curves revealed no significant between-group differences in the 30-day and 12-month prognosis (p>0.05). Multivariate analysis revealed no significant association of lung function categories with 30-day and 12-month mortality or readmission (p>0.05 for all effect estimations).

CONCLUSIONS

Patients with pre-COPD have mild symptoms and similar risks for mortality and readmission during follow-up as patients with COPD. Patients with pre-COPD should receive optimal therapies before the occurrence of irreversible damage.

Small airway function measured using forced expiratory flow between 25% and 75% of vital capacity and its relationship to airflow limitation in symptomatic ever-smokers: a cross-sectional study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is diagnosed and its severity graded by traditional spirometric parameters (forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) and FEV₁, respectively) but these parameters are considered insensitive for identifying early pathology. Measures of small airway function, including forced expiratory flow between 25% and 75% of vital capacity (FEF_25-75), may be more valuable in the earliest phases of COPD. This study aimed to determine the prevalence of low FEF_25-75 in ever-smokers with and without airflow limitation (AL) and to determine whether FEF_25-75 relates to AL severity.

METHOD

A retrospective analysis of lung function data of 1458 ever-smokers suspected clinically of having COPD. Low FEF_25-75 was defined by z-score<-0.8345 and AL was defined by FEV₁/FVC z-scores<-1.645. The severity of AL was evaluated using FEV₁ z-scores. Participants were placed into three groups: normal FEF_25-75/ no AL (normal FEF_25-75/AL-); low FEF_25-75/ no AL (low FEF_25-75/AL-) and low FEF_25-75/ AL (low FEF_25-75/AL+).

RESULTS

Low FEF_25-75 was present in 99.9% of patients with AL, and 50% of those without AL. Patients in the low FEF_25-75/AL- group had lower spirometric measures (including FEV₁ FEF_25-75/FVC and FEV₃/FVC) than those in the normal FEF_25-75/AL- group. FEF_25-75 decreased with AL severity. A logistic regression model demonstrated that in the absence of AL, the presence of low FEF_25-75 was associated with lower FEV₁ and FEV₁/FVC even when smoking history was accounted for.

CONCLUSIONS

Low FEF_25-75 is a physiological trait in patients with conventional spirometric AL and likely reflects early evidence of impairment in the small airways when spirometry is within the 'normal range'. FEF_25-75 likely identifies a group of patients with early evidence of pathological lung damage who warrant careful monitoring and reinforced early intervention to abrogate further lung injury.

Bronchodilators in Tobacco-Exposed Persons with Symptoms and Preserved Lung Function

BACKGROUND

Many persons with a history of smoking tobacco have clinically significant respiratory symptoms despite an absence of airflow obstruction as assessed by spirometry. They are often treated with medications for chronic obstructive pulmonary disease (COPD), but supporting evidence for this treatment is lacking.

METHODS

We randomly assigned persons who had a tobacco-smoking history of at least 10 pack-years, respiratory symptoms as defined by a COPD Assessment Test score of at least 10 (scores range from 0 to 40, with higher scores indicating worse symptoms), and preserved lung function on spirometry (ratio of forced expiratory volume in 1 second [FEV1] to forced vital capacity [FVC] ≥0.70 and FVC ≥70% of the predicted value after bronchodilator use) to receive either indacaterol (27.5 μg) plus glycopyrrolate (15.6 μg) or placebo twice daily for 12 weeks. The primary outcome was at least a 4-point decrease (i.e., improvement) in the St. George's Respiratory Questionnaire (SGRQ) score (scores range from 0 to 100, with higher scores indicating worse health status) after 12 weeks without treatment failure (defined as an increase in lower respiratory symptoms treated with a long-acting inhaled bronchodilator, glucocorticoid, or antibiotic agent).

RESULTS

A total of 535 participants underwent randomization. In the modified intention-to-treat population (471 participants), 128 of 227 participants (56.4%) in the treatment group and 144 of 244 (59.0%) in the placebo group had at least a 4-point decrease in the SGRQ score (difference, -2.6 percentage points; 95% confidence interval [CI], -11.6 to 6.3; adjusted odds ratio, 0.91; 95% CI, 0.60 to 1.37; P = 0.65). The mean change in the percent of predicted FEV1 was 2.48 percentage points (95% CI, 1.49 to 3.47) in the treatment group and -0.09 percentage points (95% CI, -1.06 to 0.89) in the placebo group, and the mean change in the inspiratory capacity was 0.12 liters (95% CI, 0.07 to 0.18) in the treatment group and 0.02 liters (95% CI, -0.03 to 0.08) in the placebo group. Four serious adverse events occurred in the treatment group, and 11 occurred in the placebo group; none were deemed potentially related to the treatment or placebo.

CONCLUSIONS

Inhaled dual bronchodilator therapy did not decrease respiratory symptoms in symptomatic, tobacco-exposed persons with preserved lung function as assessed by spirometry. (Funded by the National Heart, Lung, and Blood Institute and others; RETHINC ClinicalTrials.gov number, NCT02867761.).

Association Between Non-obstructive Chronic Bronchitis and Incident Chronic Obstructive Pulmonary Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis

Background

Chronic bronchitis in patients with chronic obstructive pulmonary disease (COPD) is associated with poor respiratory health outcomes. However, controversy exists around whether non-obstructive chronic bronchitis (NOCB) is associated with airflow obstruction, lung function decline, and all-cause mortality in ever smoker or never smoker.

Research Question

This systematic review and meta-analysis aimed to clarify the relationship between NOCB and incident COPD, lung function decline, and all-cause mortality, and to quantify the magnitude of these associations.

Study Design and Methods

We searched PubMed, Embase, and Web of Science for studies published up to October 1, 2021. Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted independently by two reviewers. Studies were included if they were original articles comparing incident COPD, lung function decline, and all-cause mortality in normal spirometry with and without chronic bronchitis. The primary outcomes were incident COPD and all-cause mortality. The secondary outcomes were respiratory disease-related mortality and lung function decline. Pooled effect sizes and 95% confidence intervals (CIs) were calculated using the random-effects model.

Results

We identified 17,323 related references and included 14 articles. Compared with individuals without NOCB, individuals with NOCB had an increased risk of incident COPD (odds ratio: 1.98, 95% CI: 1.21–3.22, I² = 76.3% and relative risk: 1.44, 95%CI: 1.13–1.85, I² = 56.1%), all-cause mortality (hazard ratio [HR]: 1.38, 95%CI: 1.26–1.51, I² = 29.4%), and respiratory disease-related mortality (HR: 1.88, 95%CI: 1.37–2.59, I² = 0.0%). Data on the decline in lung function could not be quantitatively synthesized, but the five articles that assessed the rate of decline in lung function showed that lung function declines faster in individuals with NOCB. The mean difference in the additional decline in forced expiratory volume in 1 s ranged from 3.6 to 23.2 mL/year.

Interpretation

Individuals with NOCB are at a higher risk of incident COPD and all-cause mortality than individuals without NOCB, highlighting the crucial need for strategies to screen for and reduce NOCB risk.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/ PROSPERO, identifier CRD42020202837

A rapidly changing understanding of COPD: World COPD Day from the COPD Foundation

World COPD Day raises awareness about chronic obstructive pulmonary disease (COPD). COPD accounts for over 150,000 US deaths per year. A major challenge is that COPD receives only a fraction of the research funding provided to other major diseases. Control of COPD is dependent on developing new approaches to diagnose the disease earlier with a recognition of either pre-COPD or established COPD based on symptoms, lung structural change and/or loss of lung function that occurs before meeting long established criteria for a population-based definition of obstruction. Optimization of current therapies improves lung function, exercise capacity, quality of life, and survival. New pathways of disease progression are being identified creating new opportunities for development of therapies that could stop or cure this disease.

Catching "Early" COPD - The Diagnostic Conundrum

Chronic obstructive pulmonary disease (COPD) remains a leading cause of morbidity and mortality worldwide. Despite this, there has been little progress so far in terms of disease-modifying therapies over the last few decades and this is in part due to poor understanding of the definition and mechanisms surrounding early disease before it becomes established and increasingly complex. In this review, the nuances and difficulty in defining early disease in COPD are discussed. There are clear benefits in identifying patients early; however, usually diagnosis is made in the presence of significant lung damage. We consider what can be learned of early disease from COPD studies and highlight the lack of inclusion of young smokers (who may be at risk of COPD) or those with mild disease. We discuss promising clinical measures that are being used in an effort to detect early disease. These include symptom assessment, lung physiology measures and computed tomography (CT) imaging modalities. There is emerging evidence for the role of neutrophils and their proteinases in early COPD. This may form an important biomarker to investigate the pathophysiological processes of early COPD. Given the importance of the early disease, it is recommended that future COPD studies focus on capturing the earliest manifestations of disease, to understand the initiating mechanisms and to identify novel treatment targets.