Blood Eosinophil Count and Hospital Readmission in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Moderate-High Blood Eosinophilia Is Associated with Increased Hospitalization and Other Asthma Comorbidities

(1) Background: Eosinophilia has traditionally been linked to eosinophilic asthma, for which it is the gold-standard prognostic biomarker. However, the association between eosinophilia and the presence of other diseases and comorbidities is yet unclear. (2) Methods: For this retrospective study, we reviewed the electronic medical records of 49,909 subjects with blood eosinophilia to gather data on the presence of asthma, COPD, sleep apnea, tuberculosis, dyslipidemia, hypertension, and other cardiovascular diseases and severe CRSwNP among these subjects. Demographic features including age, sex, and smoking habits were collected, as well as the number of hospitalizations and emergency department visits. T-tests, ANOVA, Fisher test, and logistic regression models were used. (3) Results: For all age groups studied, eosinophilia was significantly more prevalent among asthmatic subjects than nonasthmatics, especially in patients also presenting CRSwNP, hypertension, and dyslipidemia. The likelihood of developing asthma, COPD, and CRSwNP, and hospitalization, was increased when BEC was above 600 eosinophils/μL. The association between asthma, CRSwNP, and BEC was corroborated by multiple logistic regressions models. (4) Conclusions: We demonstrated the association of having over 600 blood eosinophils/μL with a higher number of hospitalizations and comorbidities (CRSwNP and COPD), which proves that BEC is a highly useful parameter to consider in subjects who present blood eosinophilia.

A predictive model for frequent exacerbator phenotype of acute exacerbations of chronic obstructive pulmonary disease

Background

The frequent exacerbator phenotype of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is characterized by experiencing at least two exacerbations per year, leading to a significant economic burden on healthcare systems worldwide. Although several biomarkers have been shown to be effective in assessing AECOPD severity in recent years, there is a lack of studies on markers to predict the frequent exacerbator phenotype of AECOPD. The current study aimed to develop a new predictive model for the frequent exacerbator phenotype of AECOPD based on rapid, inexpensive, and easily obtained routine markers.

Methods

This was a single-center, retrospective study that enrolled a total of 2,236 AECOPD patients. The participants were divided into two groups based on the frequency of exacerbations: infrequent group (n=1,827) and frequent group (n=409). They underwent a complete blood count, as well as blood biochemistry, blood lipid and coagulation testing, and general characteristics were also recorded. Univariate analysis and binary multivariate logistic regression analyses were used to explore independent risk factors for the frequent exacerbator phenotype of AECOPD, which could be used as components of a new predictive model. The receiver operator characteristic (ROC) curve was used to assess the predictive value of the new model, which consisted of all significant risk factors predicting the primary outcome. The nomogram risk prediction model was established using R software.

Results

Age, gender, length of stay (LOS), neutrophils, monocytes, eosinophils, direct bilirubin (DBil), gamma-glutamyl transferase (GGT), and the glucose-to-lymphocyte ratio (GLR) were independent risk factors for the frequent exacerbator phenotype of AECOPD. The area under the curve (AUC) of the new predictive model was 0.681 [95% confidence interval (CI): 0.653-0.708], and the sensitivity was 63.6% (95% CI: 58.9-68.2%) and the specificity was 65.0% (95% CI: 60.3-69.6%).

Conclusions

A new predictive model based on demographic characteristics and blood parameters can be used to predict the frequency of acute exacerbations in the management of chronic obstructive pulmonary disease (COPD).

Predictors of Readmission, for Patients with Chronic Obstructive Pulmonary Disease (COPD) - A Systematic Review

Introduction

Chronic obstructive pulmonary disease (COPD) is the third-leading cause of death globally and is responsible for over 3 million deaths annually. One of the factors contributing to the significant healthcare burden for these patients is readmission. The aim of this review is to describe significant predictors and prediction scores for all-cause and COPD-related readmission among patients with COPD.

Methods

A search was conducted in Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials, from database inception to June 7, 2022. Studies were included if they reported on patients at least 40 years old with COPD, readmission data within 1 year, and predictors of readmission. Study quality was assessed. Significant predictors of readmission and the degree of significance, as noted by the p-value, were extracted for each study. This review was registered on PROSPERO (CRD42022337035).

Results

In total, 242 articles reporting on 16,471,096 patients were included. There was a low risk of bias across the literature. Of these, 153 studies were observational, reporting on predictors; 57 studies were observational studies reporting on interventions; and 32 were randomized controlled trials of interventions. Sixty-four significant predictors for all-cause readmission and 23 for COPD-related readmission were reported across the literature. Significant predictors included 1) pre-admission patient characteristics, such as male sex, prior hospitalization, poor performance status, number and type of comorbidities, and use of long-term oxygen; 2) hospitalization details, such as length of stay, use of corticosteroids, and use of ventilatory support; 3) results of investigations, including anemia, lower FEV1, and higher eosinophil count; and 4) discharge characteristics, including use of home oxygen and discharge to long-term care or a skilled nursing facility.

Conclusion

The findings from this review may enable better predictive modeling and can be used by clinicians to better inform their clinical gestalt of readmission risk.

The Prognostic Value of Blood Eosinophil Level in AECOPD is Influenced by Corticosteroid Treatment During Hospitalization

PURPOSE

Blood eosinophil is a promising biomarker for phenotyping patients with acute exacerbation of COPD (AECOPD). We aimed to evaluate the prognostic value of eosinophil on short- and long-term outcomes stratified by corticosteroid treatment among AECOPD inpatients.

PATIENTS AND METHODS

In this retrospective cohort study, we included patients hospitalized for AECOPD from July 2013 to June 2021 in Beijing, China. Clinical data were collected from electronic medical records. The blood eosinophil count was measured within 24h after admission. Eosinophilic AECOPD was defined as having an eosinophil percentage ≥ 2%. The study outcomes were length of stay (LOS), treatment failure, and AECOPD readmission risk within 3 years of discharge. Multivariable models were used to analyze the associations between blood eosinophil count and outcomes stratified by corticosteroid treatment during hospitalization.

RESULTS

A total of 2406 AECOPD patients were included. The median LOS of AECOPD patients was 10 (interquartile range: 8-14) days. The eosinophil percentage was negatively associated with LOS (P-trend=0.014). Compared with the non-eosinophilic AECOPD group, the eosinophilic group had a 58% lower risk of treatment failure (OR=0.42, 95% CI: 0.20-0.89) in patients treated with systemic corticosteroids, but no association was observed in those treated with inhaled corticosteroids (ICS) only (OR=0.95, 95% CI: 0.60-1.52). The eosinophilic group had an increased risk of 90-day re-admission in patients treated with ICS only (HR=1.51, 95% CI: 1.00-2.29), but not in patients treated with systemic corticosteroids during hospitalization (HR=0.67, 95% CI: 0.39-1.15). No statistically significant results were found for 180-day, 1-year, or 3-year readmission risk.

CONCLUSION

Elevated blood eosinophils in AECOPD were associated with shorter length of stay and improved response to treatment with systemic corticosteroids, but not inhaled corticosteroids. Our study suggested that a therapeutic approach of using systemic corticosteroid may benefit patients present with eosinophilic AECOPD.

Readmission rate for acute exacerbation of chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

The readmission rate following hospitalization for chronic obstructive pulmonary disease (COPD) exacerbations is extremely high and has become a common and challenging clinical problem. This study aimed to systematically summarize COPD readmission rates for acute exacerbations and their underlying risk factors.

METHODS

A comprehensive search was performed using PubMed, Embase, Cochrane Library, and Web of Science, published from database inception to April 2, 2022. Methodological quality was evaluated using the Newcastle-Ottawa Scale (NOS). We used a random-effects model or a fixed-effects model to estimate the pooled COPD readmission rate for acute exacerbations and underlying risk factors.

RESULTS

A total of 46 studies were included, of which 24, 7, 17, 7, and 20 summarized the COPD readmission rates for acute exacerbations within 30, 60, 90, 180, and 365 days, respectively. The pooled 30-, 60-, 90-, 180-, and 365-day readmission rates were 11%, 17%, 17%, 30%, and 37%, respectively. The study design type, age stage, WHO region, and length of stay (LOS) were initially considered to be sources of heterogeneity. We also identified potential risk factors for COPD readmission, including male sex, number of hospitalizations in the previous year, LOS, and comorbidities such as heart failure, tumor or cancer, and diabetes, whereas obesity was a protective factor.

CONCLUSIONS

Patients with COPD had a high readmission rate for acute exacerbations, and potential risk factors were identified. Therefore, we should propose clinical interventions and adjust or targeted the control of avoidable risk factors to prevent and reduce the negative impact of COPD readmission.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42022333581.

COPD Exacerbation Syndrome: The Spanish Perspective on an Old Dilemma

The definition of exacerbation of COPD as a syndrome, as proposed by the Spanish COPD guidelines (GesEPOC) 2021 update, and the consequences that this implies, have direct implications on patient care. This review analyzes this novel vision of the COPD exacerbation syndrome, its rationale, and its clinical implications, as opposed to the traditional symptoms-based or event-based definitions. An exacerbation conceived as a syndrome provides us with an umbrella term to include a set of diverse alterations, which, either in isolation or more frequently in combination, are clinically expressed in a similar way in patients with COPD. In patients with COPD, this occurs as a consequence of worsening expiratory airflow limitation or the underlying inflammatory process, producing a worsening in symptoms with respect to the baseline situation. This definition therefore assumes a worsening in at least one of the two key physiopathological markers, lung function and inflammation. The main features of this new physiopathological proposal include a syndromic approach with narrower differential diagnosis, the use of several biomarkers, treatable traits to better guide treatment, and a new severity classification. Further research is needed to examine the role of eosinophils in this context, but currently, the early results are promising. The evaluation of severity is key in the multidimensional characterization of exacerbation and the GesEPOC 2021 proposes new approaches and also recommends the use of multidisciplinary scores for severity categorization in patients. Finally, another innovation in the GesEPOC 2021 refers to the recurrence of exacerbations, which has implications for disease prognosis or long-term clinical impact which need to be elucidated in further studies.

Low Eosinophil Phenotype Predicts Noninvasive Mechanical Ventilation Use in Patients with Hospitalized Exacerbations of COPD

Rationale

Objective

Methods

Results

Conclusion

Assessing Treatment Success or Failure as an Outcome in Randomised Clinical Trials of COPD Exacerbations. A Meta-Epidemiological Study

A recently published ERS core outcome set recommends that all trials of COPD exacerbation management should assess the treatment success (or “cure” of the exacerbation), defined as a dichotomous measure of the overall outcome of an exacerbation. This methodological systematic review describes and compares the instruments that were used to assess treatment success or failure in 54 such RCTs, published between 2006–2020. Twenty-three RCTs used composite measures consisting of several undesirable outcomes of an exacerbation, together defining an overall unfavourable outcome, to define treatment failure. Thirty-four RCTs used descriptive instruments that used qualitative or semi-quantitative descriptions to define cure, marked improvement, improvement of the exacerbation, or treatment failure. Treatment success and failure rates among patients receiving guidelines-directed treatments at different settings and timepoints are described and could be used to inform power calculations in future trials. Descriptive instruments appeared more sensitive to treatment effects compared to composite instruments. Further methodological studies are needed to optimise the evaluation of treatment success/failure. In the meantime, based on the findings of this systematic review, the ERS core outcome set recommends that cure should be defined as sufficient improvement of the signs and symptoms of the exacerbation such that no additional systemic treatments are required.

Blood eosinophils in COPD: friend or foe?

INTRODUCTION

The pathogenesis of chronic obstructive pulmonary disease (COPD) is highly complex and the underlying cellular and molecular mechanisms remain poorly understood.

AREAS COVERED

COPD has been traditionally associated with neutrophilic inflammation of the bronchi, but in the last decade, studies have demonstrated that eosinophils may also migrate into the lower airways of patients with COPD and their increased numbers can be noticed during exacerbations as well as stable disease. In this review, we present clinical characteristics of eosinophilic COPD, as well as the role of eosinophils as a biomarker-guided therapy in COPD. A systematic research using the database of Pubmed up to February 2021 was performed. The terms we searched were eosinophilic inflammation, COPD, COPD phenotypes, COPD exacerbations, corticosteroids in COPD, and monoclonal antibodies in COPD.

EXPERT OPINION

Blood eosinophil levels show strong potential as a prognostic and theragnostic biomarker in the clinical management of COPD being at the moment the most reliable biomarker. The lack of a certain cutoff value of blood eosinophils as guidance for treatment with ICS and biologic therapies and the uncertainty regarding the stability of eosinophilia and eosinophilic phenotype through the course of COPD remain as unmet dilemmas and problems.

Stability of blood eosinophils in acute exacerbation of chronic obstructive pulmonary disease and its relationship to clinical outcomes: a prospective cohort study

BACKGROUND

The clinical value of blood eosinophils and their stability in chronic obstructive pulmonary disease (COPD) remains controversial. There are limited studies on association between the stability of blood eosinophils in acute exacerbation of COPD (AECOPD) and clinical outcomes. This study aimed to evaluate the stability of blood eosinophils in hospitalized AECOPD and its relationship to clinical outcomes.

METHODS

This prospective observational study recruited patients hospitalized with AECOPD from November 2016 to July 2020. The eligible patients were divided into four groups according to their blood eosinophil counts at admission and discharge: persistently < 300 cells/μl (LL), < 300 cells/μl at admission but ≥ 300 cells/µl at discharge (LH), ≥ 300 cells/μl at admission but < 300 cells/µl at discharge (HL), and persistently ≥ 300 cells/μl (HH). Cox hazard analyses were used to study the association between eosinophil changes and exacerbations or mortality.

RESULTS

In 530 patients included, 90 (17.0%) had a high blood eosinophil count (BEC) ≥ 300 cells/µl at admission but 32 (35.6%) of them showed a decreased BEC at discharge. The proportions and distribution for group LL, LH, HL, and HH were 381 (71.9%), 59 (11.1%), 32 (6.0%), and 58 (10.9%), respectively. During hospitalization, the LH group had a higher C-reactive protein level, higher rate of intensive care unit (ICU) admission, and higher total cost. The length of hospital stay of the LH group was longer compared with group LL, HL, or HH (P = 0.002, 0.017, and 0.001, respectively). During a follow-up of 12 months, the HH group was associated with a higher risk of moderate-to-severe exacerbations compared to the LL group (hazard ratio 2.00, 95% confidence interval 1.30-3.08, P = 0.002). Eosinophil changes had no significant association with mortality at 12 months. Sensitivity analyses in patients without asthma and without use of systemic corticosteroids prior to admission did not alter the results.

CONCLUSIONS

More attention should be paid to the LH group when evaluating the short-term prognosis of AECOPD. A persistently high BEC was a risk factor for long-term exacerbations. Eosinophil changes during hospitalization could help to predict outcomes.

US Hospitalizations and 60-Day Readmission Rates Associated with Herpes simplex virus Encephalitis: Analysis of All Cause Readmissions and Encephalopathy Associated Readmissions

BACKGROUND

Herpes simplex encephalitis (HSE) is the most common cause of encephalitis hospitalizations. We sought to describe and analyze features associated with all cause readmissions and encephalopathy associated readmissions amongst HSE cases.

METHODS

HSE hospitalizations and 60-day rehospitalizations were assessed in a retrospective cohort using linked hospitalizations from the Healthcare Utilization Project (HCUP) National Readmission Database (NRD) from 2010 through 2017. Risk factors for all-cause readmissions and encephalopathy associated readmissions were assessed with a weighted logistic regression model.

RESULTS

There were 10,272 HSE cases in the US between 2010 and 2017, resulting in a national rate of 4.95 per 100,000 hospitalizations. A total of 23.7% were readmitted at least once within 60-days. Patients that were readmitted were older (mean age 62.4 vs. 57.9, p<0.001), had a greater number of procedures at the index hospitalization (aOR 1.03, p<0.001) and have a higher Charlson comorbidity score (aOR 1.11, p<0.001). Amongst those readmitted, 465 (16.5%) had an encephalopathy related diagnosis. Over eight years, the rate of encephalopathy associated readmissions increased from 0.12 to 0.20. Encephalopathy specific readmissions were found to be associated with greater age (mean age 65.9 vs. 61.7, p = 0.004) and findings of cerebral edema at index hospitalization (aOR 2.16, p <0.001).

CONCLUSIONS

HSE readmissions are relatively common, particularly among older and sicker individuals. However, early signs and symptoms of neurological disease at index were correlated with encephalopathic specific readmissions.

Blood eosinophil count-guided corticosteroid therapy and as a prognostic biomarker of exacerbations of chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by persistent respiratory symptoms and dyspnea, as well as an increase in the number of leukocytes in the airways, lungs, and pulmonary vessels. A 'One size fits all' approach to COPD patients with different clinical features may be considered outdated. The following are the two major objectives of this meta-analysis: the first is to determine if blood eosinophil counts (BEC) can serve as a prognostic biomarker of COPD outcomes, and the second is to determine which level of BEC is effective for inhaled corticosteroid (ICS) treatment.

METHODS

We searched articles published before 15 May 2021 in the following four electronic databases: Web of Science, Cochrane Library, EMBASE, and PubMed.

RESULTS

A total of 42 studies, comprising a sampling of 188,710 subjects, were summarized and compared in this meta-analysis. The rate ratio (RR) of exacerbations of COPD (ECOPD) between ICS and non-ICS treatment was statistically significant for the COPD patients with a baseline BEC ⩾ 2% or ⩾ 200 cells/μl, RR = 0.82 (0.73, 0.93) or 0.79 (0.70, 0.89) respectively, while the RR of ECOPD between ICS and non-ICS treatment was statistically insignificant for the COPD patients with baseline BEC < 2% or <200 cells/μl, RR = 0.97 (0.87, 1.08) or 0.97 (0.86, 1.08), suggested that ICS therapy was beneficial to the improvement of ECOPD in patients with a baseline BEC ⩾ 2% or BEC ⩾ 200 cells/μl.

CONCLUSION

Our research shows that a BEC ⩾ 200 cells/μl or ⩾2% is likely to become the cutoff value of ICS treatment for ECOPD. Moreover, we believe that the baseline BEC can be used as a biomarker for predicting ECOPD. The stability of BEC requires special attention.

Blood Eosinophils and Clinical Outcomes in Patients With Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Propensity Score Matching Analysis of Real-World Data in China

Background and Objective: Elevated eosinophils in chronic obstructive pulmonary disease (COPD) are recognized as a biomarker to guide inhaled corticosteroids use, but the value of blood eosinophils in hospitalized exacerbations of COPD remains controversial. This study aimed to evaluate the accuracy of eosinophils in predicting clinical outcomes in acute exacerbation of COPD (AECOPD).

Methods: We analyzed data from the acute exacerbation of chronic obstructive pulmonary disease inpatient registry (ACURE) study, which is an ongoing nationwide multicenter, observational real-world study in patients admitted for AECOPD. Data collected between January 2018 and December 2019 in 163 centers were first reviewed. The eligible patients were divided into eosinophilic and non-eosinophilic groups, according to blood eosinophil with 2% of the total leukocyte count as the threshold. Propensity score (PS) matching was performed to adjust for confounders.

Results: A total of 1,566 patients (median age: 69 years; 80.3% male) were included and 42.7% had an eosinophilic AECOPD. Eosinophil count <2% was associated with the development of respiratory failure and pneumonia. After PS matching, 650 pairs in overall patients, 468 pairs in patients with smoking history and 177 pairs in patients without smoking were selected, respectively. Only in patients with smoking history, the non-eosinophilic AECOPD was associated with longer median hospital stays (9 vs. 8 days, P = 0.034), higher dosage of corticosteroid use, higher economic burden of hospitalization, and poorer response to corticosteroid therapy compared to the eosinophilic AECOPD. No significant difference was found in patients without smoking. Eosinophil levels had no relationship with the change of COPD Assessment Test scores and readmissions or death after 30 days.

Conclusion: Elevated eosinophils were associated with better short-term outcomes only in patients with a smoking history. Eosinophil levels cannot be confidently used as a predictor alone for estimating prognosis.