Clinical Characterization and Treatment Patterns for the Frequent Exacerbator Phenotype in Chronic Obstructive Pulmonary Disease with Severe or Very Severe Airflow Limitation

Bronchodilator responsiveness in chronic obstructive pulmonary disease: prevalence, significance, and clinical implications

PURPOSE OF REVIEW

Bronchodilator responsiveness (BDR) is often considered a key feature distinguishing asthma from chronic obstructive pulmonary disease (COPD). However, recent evidence suggests that BDR alone may not be a reliable discriminator between these conditions. There is still no consensus on BDR definitions and testing protocols. Additionally, it remains unclear whether BDR is linked to a specific COPD phenotype or influences treatment responses. Our review of recent literature attempts to clarify some of these issues.

RECENT FINDINGS

A significant proportion of COPD patients demonstrate BDR, but the variability in testing procedures and definitions makes it challenging to draw any definite conclusion. There is no evident association between BDR and specific COPD characteristics. A few studies suggest that BDR may be associated with marginally better treatment response and disease outcomes in COPD. The impact of recent changes in BDR definitions on clinical practice remains to be fully understood.

SUMMARY

There is still no clear, clinically relevant threshold to define BDR. BDR is an unreliable discriminator to differentiate asthma from COPD and is not consistently linked to any specific COPD phenotype, treatment response, or disease outcomes. Further research is needed to refine the definitions and implications of BDR in COPD.

Ultra Long-Acting β-Agonists in Chronic Obstructive Pulmonary Disease

INTRODUCTION

Inhaled β-agonists have been foundational medications for maintenance COPD management for decades. Through activation of cyclic adenosine monophosphate pathways, these agents relax airway smooth muscle and improve expiratory airflow by relieving bronchospasm and alleviating air trapping and dynamic hyperinflation improving breathlessness, exertional capabilities, and quality of life. β-agonist drug development has discovered drugs with increasing longer durations of action: short acting (SABA) (4-6 h), long acting (LABA) (6-12 h), and ultra-long acting (ULABA) (24 h). Three ULABAs, indacaterol, olodaterol, and vilanterol, are approved for clinical treatment of COPD.

PURPOSE

This article reviews both clinically approved ULABAs and ULABAs in development.

CONCLUSION

Indacaterol and olodaterol were originally approved for clinical use as monotherapies for COPD. Vilanterol is the first ULABA to be approved only in combination with other respiratory medications. Although there are many other ULABA's in various stages of development, most clinical testing of these novel agents is suspended or proceeding slowly. The three approved ULABAs are being combined with antimuscarinic agents and corticosteroids as dual and triple agent treatments that are being tested for clinical use and efficacy. Increasingly, these clinical trials are using specific COPD clinical characteristics to define study populations and to begin to develop therapies that are trait-specific.

Impact of Non-alcoholic Fatty Liver Disease on long-term cardiovascular events and death in Chronic Obstructive Pulmonary Disease

Chronic Obstructive Pulmonary Disease (COPD) and Non-Alcoholic Fatty Liver Disease (NAFLD) both independently increase cardiovascular risk. We hypothesized that NAFLD might increase the incidence of cardiovascular disease and death in COPD patients. The relationship between NAFLD, incident cardiovascular events, and death was assessed in a prospective cohort of COPD patients with 5-year follow-up. Noninvasive algorithms combining biological parameters (FibroMax®) were used to evaluate steatosis, non-alcoholic steatohepatitis (NASH) and liver fibrosis. Univariate and multivariate Cox regression models were used to assess the hazard for composite outcome at the endpoint (death or cardiovascular event) for each liver pathology. In 111 COPD patients, 75% exhibited liver damage with a prevalence of steatosis, NASH and fibrosis of 41%, 37% and 61%, respectively. During 5-year follow-up, 31 experienced at least one cardiovascular event and 7 died. In univariate analysis, patients with liver fibrosis had more cardiovascular events and higher mortality (Hazard ratio [95% CI]: 2.75 [1.26; 6.03]) than those with no fibrosis; this remained significant in multivariate analysis (Hazard ratio [95% CI]: 2.94 [1.18; 7.33]). We also found that steatosis and NASH were not associated with increased cardiovascular events or mortality. To conclude, early assessment of liver damage might participate to improve cardiovascular outcomes in COPD patients.

Current Approaches for Phenotyping as a Target for Precision Medicine in COPD Management

The study of airway diseases continues to present several challenges for modern medicine. The different disease presentations with variables and overlapping features may result in a real challenge for the clinician. In this context, the concept of precision medicine has started to emerge in order to give answers to some of these challenges from a diagnostic and therapeutic point of view. The main reasons to target for precision medicine in chronic obstructive pulmonary disease (COPD) include that there is variability in the clinical presentation, there is no correlation between the different clinical variables at the patient level, there are a number of relevant clinical variables associated with outcomes, we do have specific therapies for specific patient types, and that there is variability in the clinical response to different therapies. To bring precision medicine into clinical practice several approaches have been used, including the use of independent variables to identify subjects, the use of multidimensional indexes, the so-called clinical phenotypes, and the approximation by the so-called treatable traits. All these approaches have their strengths and weaknesses which are reviewed in the present document. Although there is no universally accepted proposal, the available initiatives provide us with a framework on which to start working and move toward precision medicine in COPD, with the ultimate goal of bringing the best possible medicine to each patient in particular.

Metformin use and health care utilization in patients with coexisting chronic obstructive pulmonary disease and diabetes mellitus

Background

Chronic obstructive pulmonary disease (COPD) is associated with persistent systemic inflammation. Anti-inflammatory therapies have been shown to decrease acute exacerbations of COPD. The antidiabetic medication metformin decreases oxidative stress and inflammation and may benefit patients with COPD. We aimed at investigating the effect of metformin on health care utilizations in patients with coexisting COPD and diabetes mellitus (DM).

Methods

We studied 5% Medicare beneficiaries with coexisting COPD and DM prescribed metformin or other antidiabetics during the period 2007-2010. The primary outcome was COPD-specific emergency room (ER) visits and hospitalizations; the secondary outcome was all-cause ER visits and hospitalizations over the 2-year follow-up after the index antidiabetic prescription. The effects of metformin were examined by COPD complexity and compared with the effects of other antidiabetic medications.

Results

Among 11,260 patients, 3,193 were metformin users and 8,067 were nonusers. Metformin users were younger, were less sick, were less likely to be on oxygen, and had fewer hospitalizations in the prior year compared with the nonusers. Over a 2-year period, metformin users had lower COPD-specific and all-cause ER visits and hospitalizations (7.11% vs 9.61%, p<0.0001; and 61.63% vs 71.27%, p<0.0001, respectively). In a stratified multivariable analysis, the odds of COPD-specific ER visits and hospitalizations were lower in patients with low-complexity COPD (adjusted odds ratio =0.66, 95% confidence interval =0.52-0.85). However, patients with all COPD complexities get benefits of metformin on all-cause ER visits and hospitalizations.

Conclusion

The use of metformin in patients with coexisting COPD and DM was associated with fewer COPD-specific ER visits and hospitalizations, especially in low-complexity COPD.

Clinical characteristics of chronic bronchitic, emphysematous and ACOS phenotypes in COPD patients with frequent exacerbations

Purpose

Chronic bronchitis (CB), emphysematous (EM) and asthma–chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) phenotypes in COPD are well recognized. This study aimed to investigate distinguishing characteristics of these phenotypes in COPD patients with frequent exacerbations (FE).

Patients and methods

A retrospective study was carried out. COPD patients with acute exacerbations were consecutively reviewed from November 2015 to October 2016. Patients were divided into FE and infrequent exacerbations (iFE) subgroups.

Results

A total of 142 eligible COPD subjects were reviewed. In the CB phenotype subgroup, age, body mass index, forced expiratory volume in 1 second (FEV₁) % predicted, COPD assessment test (CAT), modified Medical Research Council breathlessness measurement (mMRC) dyspnea scale, emphysema scores and arterial carbon dioxide pressure (PaCO₂) were significantly different in subjects with FE when compared to those in subjects with iFE of CB. In the EM phenotype subgroup, age, CAT, mMRC scores and history of COPD were different in subjects with FE when compared to those in CB subjects with iFE. Multivariate analysis indicated that FEV₁% predicted (odds ratio [OR] =0.90, P=0.04) and PaCO₂ (OR =1.22, P=0.02) were independent risk factors for FE in COPD with CB phenotype, and CAT (OR =2.601, P=0.001) was the independent risk factor for FE in COPD with EM phenotype. No significant differences in characteristics were observed in ACOS phenotype subgroups with FE or iFE.

Conclusion

In CB or EM phenotypes, COPD patients with FE present several differential clinical characteristics compared to patients with iFE, while the characteristics of ACOS phenotype in patients with FE need more investigation.