Which bronchodilator reversibility criteria can predict severe acute exacerbation in chronic obstructive pulmonary disease patients?

Clinical characterization and outcomes of impulse oscillometry-defined bronchodilator response: an ECOPD cohort-based study

BACKGROUND

The clinical significance of the impulse oscillometry-defined small airway bronchodilator response (IOS-BDR) is not well-known. Accordingly, this study investigated the clinical characteristics of IOS-BDR and explored the association between lung function decline, acute respiratory exacerbations, and IOS-BDR.

METHODS

Participants were recruited from an Early Chronic Obstructive Pulmonary Disease (ECOPD) cohort subset and were followed up for two years with visits at baseline, 12 months, and 24 months. Chronic obstructive pulmonary disease (COPD) was defined as a post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio < 0.70. IOS-BDR was defined as meeting any one of the following criteria: an absolute change in respiratory system resistance at 5 Hz ≤ - 0.137 kPa/L/s, an absolute change in respiratory system reactance at 5 Hz ≥ 0.055 kPa/L/s, or an absolute change in reactance area ≤ - 0.390 kPa/L. The association between IOS-BDR and a decline in lung function was explored with linear mixed-effects model. The association between IOS-BDR and the risk of acute respiratory exacerbations at the two-year follow-up was analyzed with the logistic regression model.

RESULTS

This study involved 466 participants (92 participants with IOS-BDR and 374 participants without IOS-BDR). Participants with IOS-BDR had higher COPD assessment test and modified Medical Research Council dyspnea scale scores, more severe emphysema, air trapping, and rapid decline in FVC than those without IOS-BDR over 2-year follow-up. IOS-BDR was not associated with the risk of acute respiratory exacerbations at the 2-year follow-up.

CONCLUSIONS

The participants with IOS-BDR had more respiratory symptoms, radiographic structural changes, and had an increase in decline in lung function than those without IOS-BDR.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1900024643. Registered on 19 July, 2019.

Prognostic risk factors for moderate-to-severe exacerbations in patients with chronic obstructive pulmonary disease: a systematic literature review

Background

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. COPD exacerbations are associated with a worsening of lung function, increased disease burden, and mortality, and, therefore, preventing their occurrence is an important goal of COPD management. This review was conducted to identify the evidence base regarding risk factors and predictors of moderate-to-severe exacerbations in patients with COPD.

Methods

A literature review was performed in Embase, MEDLINE, MEDLINE In-Process, and the Cochrane Central Register of Controlled Trials (CENTRAL). Searches were conducted from January 2015 to July 2019. Eligible publications were peer-reviewed journal articles, published in English, that reported risk factors or predictors for the occurrence of moderate-to-severe exacerbations in adults age ≥ 40 years with a diagnosis of COPD.

Results

The literature review identified 5112 references, of which 113 publications (reporting results for 76 studies) met the eligibility criteria and were included in the review. Among the 76 studies included, 61 were observational and 15 were randomized controlled clinical trials. Exacerbation history was the strongest predictor of future exacerbations, with 34 studies reporting a significant association between history of exacerbations and risk of future moderate or severe exacerbations. Other significant risk factors identified in multiple studies included disease severity or bronchodilator reversibility (39 studies), comorbidities (34 studies), higher symptom burden (17 studies), and higher blood eosinophil count (16 studies).

Conclusions

This systematic literature review identified several demographic and clinical characteristics that predict the future risk of COPD exacerbations. Prior exacerbation history was confirmed as the most important predictor of future exacerbations. These prognostic factors may help clinicians identify patients at high risk of exacerbations, which are a major driver of the global burden of COPD, including morbidity and mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02123-5.

Defining Asthma-Chronic Obstructive Pulmonary Disease Overlap

Much interest has been given to the asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) in the past 2 decades, but the condition is still ill-defined. There is general agreement that a patient with longstanding asthma who develops fixed airflow obstruction after years of smoking has ACO although defining asthma in the face of COPD can be challenging. Many features of asthma are also found in patients with COPD without indicating an overlap and no consensus exists on which characteristics should be included in the definition of ACO. Nevertheless, some guidance has been issued to help clinicians and researchers to make a diagnosis of ACO and these will be reviewed here.

Reduced bronchodilator reversibility correlates with non-type 2 high asthma and future exacerbations: A prospective cohort study

BACKGROUND

Given that airway obstruction in asthma is not always fully reversible, reduced bronchodilator reversibility (BDR) may be a special asthma phenotype.

OBJECTIVE

To explore the characteristics of BDR^high/low phenotypes (defined using two BDR criteria) and their associations with asthma exacerbations (AEs).

METHODS

After baseline assessments, all patients were classified into BDR^high or BDR^low phenotypes. This study consisted of 2 parts. Part I was a 12-month prospective observational cohort study designed to identify the clinical characteristics and associations with future AEs in BDR^high/low phenotypes (n = 456). Part II, designed as a post hoc analysis of the data obtained in Part I, was conducted to assess the association between BDR^high/low phenotypes and treatment responsiveness (n = 360).

RESULTS

Subjects with BDR^low phenotypes had better baseline asthma symptom control and was negatively associated with eosinophilic asthma and type 2 (T2) high asthma. During the 12-month follow-up, those with BDR^low phenotypes had a higher risk of severe AEs (SAEs) (guideline-based criterion: RR_adj = 2.24, 95% CI = [1.25, 3.68]; Ward's criterion: RR_adj = 2.46, 95% CI = [1.40, 4.00]) and moderate-to-severe AEs (MSAEs) (guideline-based criterion: RR_adj = 1.83, 95% CI = [1.22, 2.56]; Ward's criterion: RR_adj = 1.94, 95% CI = [1.32, 2.68]) in the following year according to logistic regression models. Similar findings were obtained with negative binominal regression models. BDR^low phenotype was a risk factor for an insensitive response to anti-asthma treatment (guideline-based criterion: OR_adj = 1.96, 95% CI = [1.05, 3.65]; Ward's criterion: OR_adj = 2.01, 95% CI = [1.12, 3.58]).

CONCLUSION

We identified that BDR^low phenotype was associated with non-T2 high asthma and future AEs. These findings have clinically relevant implications for asthma management.

Effect of TRPM8 and TRPA1 Polymorphisms on COPD Predisposition and Lung Function in COPD Patients

Certain transient receptor potential (TRP) channels including TRPM8 and TRPA1 are widely expressed in the respiratory tract and have been shown to be the receptors of cigarette smoke and particulate matter-the main causative factors of chronic obstructive pulmonary disease (COPD). The aim of the study was to investigate the effect of TRPM8 and TRPA1 polymorphisms on COPD predisposition and lung function in COPD patients. The study enrolled 143 COPD patients and 104 smokers with post-bronchodilator forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) > 70%. Lung function was measured by spirometry. TRPM8 and TRPA1 polymorphisms were genotyped by LATE-PCR. None of the polymorphisms significantly influenced COPD predisposition after correction for covariates and multiple testing. Among COPD patients, the TT genotype of TRPA1 rs7819749 was significantly associated with higher degree of bronchial obstruction. In addition, we established that carriers of the C allele of TRPM8 rs11562975 more commonly had post-bronchodilator FEV1 < 60% (OR 3.2, 95%CI (1.14-8.94), p = 0.03) and revealed the effect of TRPA1 rs959976 and TRPM8 rs17865682 on bronchodilator response in COPD. Thus, the obtained results suggest possible involvement of TRPM8 and TRPA1 in COPD pathogenesis, indicating the necessity to further investigate their functional role in this pathology.

The paradoxical response to short-acting bronchodilator administration in patients with chronic obstructive pulmonary disease

Background

There are a few studies about paradoxical bronchodilator response (BDR), which means a decrease in forced expiratory volume in 1 second (FEV₁) or forced vital capacity (FVC) after short-acting bronchodilator administration in patients with chronic obstructive pulmonary disease (COPD). We evaluated the effect of paradoxical BDR on the clinical outcomes of COPD patients in South Korea.

Methods

We analyzed the KOrea COpd Subgroup Study team (KOCOSS) cohort data in South Korea between January 2012 and December 2017. BDR was defined as at least a 12% and 200-mL reduction in FEV₁ or FVC after bronchodilator administration.

Results

A total of 1,991 patients were included in this study. A paradoxical BDR was noted in 57 (2.9%) patients and was independently associated with worse dyspnea and poor quality of life. High C-reactive protein (CRP) levels were associated with a paradoxical BDR (OR, 1.05; 95% CI, 1.01-1.09; P=0.003). However, paradoxical BDR was not associated with severe acute exacerbations. Pre-bronchodilator FEV₁ (L) showed a higher area under the curve (AUC) for predicting severe acute exacerbations than the post-bronchodilator FEV₁ (L) in the paradoxical BDR group (0.788 vs. 0.752).

Conclusion

A paradoxical reduction of FEV₁ or FVC after bronchodilator administration may be associated with chronic inflammation in the airway and independently associated with worse respiratory symptoms and poor quality of life.

Acute Exacerbation According to GOLD 2017 Categories in Patients with Chronic Obstructive Pulmonary Disease

INTRODUCTION

The association between GOLD categorizations and future exacerbations has not been fully investigated. This study elucidates whether the GOLD 2017 classification is associated with different future exacerbation risk in patients with chronic obstructive pulmonary disease (COPD) compared with the previous GOLD categorization. Another objective was to investigate the impacts of the symptoms and FEV1 on the predicted future exacerbation independently of previous exacerbation history.

METHODS

We analyzed patients from three prospective COPD cohorts (SNUH, KOCOSS, and KOLD) and evaluated the risk of moderate to severe exacerbation among different models, including GOLD grade (FEV1), GOLD 2011, and GOLD 2017.

RESULTS

In total, 611 COPD patients were included (36 from SNUH, 257 from KOCOSS, and 318 from KOLD). GOLD 2017 classification, excluding FEV1% for categorization criteria, showed no differences in future exacerbation risk compared with GOLD grade and GOLD 2011 based on c-statistics. Among those with no frequent exacerbation history and FEV1 ≥50%, the group with more symptoms was significantly associated with future exacerbations than the group with less symptoms. A lower FEV1 (FEV1 <50%) was not associated with a higher future exacerbation risk than a higher FEV1 (FEV1 ≥50%), regardless of prior exacerbation history and symptom group.

CONCLUSION

The GOLD 2017 classification was not different from GOLD grade and GOLD 2011 regarding the association with future exacerbation risk, and there were no significant differences in exacerbation risk according to FEV1%. This suggests that FEV1 might not be an important factor in future exacerbation risk. These results partly support the GOLD 2017 assessment tool.