Hana Müllerova

Susceptibility to Exacerbation in Chronic Obstructive Pulmonary Disease

BACKGROUND Although we know that exacerbations are key events in chronic obstructive pulmonary disease (COPD), our understanding of their frequency, determinants, and effects is incomplete. In a large observational cohort, we tested the hypothesis that there is a frequent-exacerbation phenotype of COPD that is independent of disease severity. METHODS We analyzed the frequency and associations of exacerbation in 2138 patients enrolled in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study. Exacerbations were defined as events that led a care provider to prescribe antibiotics or corticosteroids (or both) or that led to hospitalization (severe exacerbations). Exacerbation frequency was observed over a period of 3 years. RESULTS Exacerbations became more frequent (and more severe) as the severity of COPD increased; exacerbation rates in the first year of follow-up were 0.85 per person for patients with stage 2 COPD (with stage defined in accordance with Global Initiative for Chronic Obstructive Lung Disease [GOLD] stages), 1.34 for patients with stage 3, and 2.00 for patients with stage 4. Overall, 22% of patients with stage 2 disease, 33% with stage 3, and 47% with stage 4 had frequent exacerbations (two or more in the first year of follow-up). The single best predictor of exacerbations, across all GOLD stages, was a history of exacerbations. The frequent-exacerbation phenotype appeared to be relatively stable over a period of 3 years and could be predicted on the basis of the patients recall of previous treated events. In addition to its association with more severe disease and prior exacerbations, the phenotype was independently associated with a history of gastroesophageal reflux or heartburn, poorer quality of life, and elevated white-cell count. CONCLUSIONS Although exacerbations become more frequent and more severe as COPD progresses, the rate at which they occur appears to reflect an independent susceptibility phenotype. This has implications for the targeting of exacerbation-prevention strategies across the spectrum of disease severity. (Funded by GlaxoSmithKline; ClinicalTrials.gov number, NCT00292552.)

C-reactive protein in patients with COPD, control smokers and non-smokers

Background: Patients with chronic obstructive pulmonary disease (COPD) have raised serum levels of C reactive protein (CRP). This may be related directly to COPD and its associated systemic inflammation or secondary to other factors such as concomitant ischaemic heart disease (IHD) or smoking status. The aim of this study was to evaluate IHD and smoking as potential causes of raised CRP levels in COPD and to test the association between inhaled corticosteroid (ICS) use and serum CRP levels. Methods: Cross sectional analyses comparing cohorts of 88 patients with COPD, 33 smokers (S), and 38 non-smoker (NS) controls were performed. Clinical assessments included a complete medical history, pulmonary function, 6 minute walk test (6MWT), cardiopulmonary exercise test, and high sensitivity serum CRP measurements. Results: Serum CRP levels were significantly higher in patients with COPD (5.03 (1.51) mg/l) than in controls (adjusted odds ratio 9.51; 95% confidence interval 2.97 to 30.45) but were similar in the two control groups (S: 2.02 (1.04) mg/l; NS: 2.24 (1.04) mg/l). There was no clinical or exercise evidence of unstable IHD in any of the subjects. CRP levels were lower in COPD patients treated with ICS than in those not treated (3.7 (3.0) mg/l v 6.3 (3.6) mg/l); this association was confirmed in an adjusted regression model (p<0.05). Conclusion: CRP levels are raised in COPD patients without clinically relevant IHD and independent of cigarette smoking, and reduced in patients with COPD using ICS. CRP may be a systemic marker of the inflammatory process that occurs in patients with COPD.

Profiling serum biomarkers in patients with COPD: associations with clinical parameters

Background: Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease associated with significant systemic consequences. Recognition of the systemic manifestations has stimulated interest in identifying circulating biomarkers in these patients. A systematic analysis was undertaken of multiple protein analytes in the serum of well characterised patients with COPD and matched controls using novel protein microarray platform (PMP) technology. Methods: Forty-eight patients (65% men) with COPD (forced expiratory volume in 1 s <55%) and 48 matched controls were studied. Anthropometric parameters, pulmonary function tests, 6-minute walk distance, the BODE index and the number of exacerbations were measured and the association of these outcomes with the baseline levels of 143 serum biomarkers measured by PMP was explored. Results: Thirty biomarker clusters were identified and ranked by computing the predictive value of each cluster for COPD (partial least squares discriminant analysis). From the 19 best predictive clusters, 2–3 biomarkers were selected based on their pathophysiological profile (chemoattractants, inflammation, tissue destruction and repair) and the statistical significance of their relationship with clinically important end points was tested. The selected panel of 24 biomarkers correlated (p<0.01) with forced expiratory volume in 1 s, carbon monoxide transfer factor, 6-minute walk distance, BODE index and exacerbation frequency. Conclusion: PMP technology can be useful in identifying potential biomarkers in patients with COPD. Panels of selected serum markers are associated with important clinical predictors of outcome in these patients.

Determinants of Depression in the ECLIPSE Chronic Obstructive Pulmonary Disease Cohort

RATIONALE Depression is prevalent in patients with chronic obstructive pulmonary disease (COPD); however, its etiology and relationship to the clinical features of COPD are not well understood. OBJECTIVES Using data from a large cohort, we explored prevalence and determinants of depression in subjects with COPD. METHODS The Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints study is an observational 3-year multicenter study that enrolled smokers with and without COPD and nonsmoker controls. At baseline, several patient-reported outcomes were measured including the Center for Epidemiologic Studies of Depression Scale. For the purposes of this analysis, depression was defined as a score of 16 and higher on this scale, which reflects a high load of depressive symptoms and has a good correspondence with a clinical diagnosis of major depression. MEASUREMENTS AND MAIN RESULTS The study cohort consisted of 2,118 subjects with COPD; 335 smokers without COPD (smokers); and 243 nonsmokers without COPD (nonsmokers). A total of 26%, 12%, and 7% of COPD, smokers, and nonsmokers, respectively, suffered from depression. In subjects with COPD, higher depression prevalence was seen in females, current smokers, and those with severe disease (Global Initiative for Obstructive Lung Disease [GOLD]-defined). Multivariate modeling of depression determinants in subjects with COPD revealed that increased fatigue, higher St. Georges Respiratory Questionnaire for COPD patients score, younger age, female sex, history of cardiovascular disease, and current smoking status were all significantly associated with depression; physiologic and biologic measures were weak or nonsignificant descriptors. CONCLUSIONS Depression is more prevalent in subjects with COPD compared with smokers and nonsmokers without COPD. Clinical and biologic measures were less important determinants of depression in COPD than disease symptoms and quality-of-life. Clinical trial registered with www.clinicaltrials.gov (NCT 00292552).

Characteristics, stability and outcomes of the 2011 GOLD COPD groups in the ECLIPSE cohort

The 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) classifies patients with chronic obstructive pulmonary disease (COPD) into four groups (A to D). We explored the characteristics, stability and relationship to outcomes of these groups within the ECLIPSE study (Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points) (n = 2101). Main results showed that: 1) these groups differed in several clinical, functional, imaging and biological characteristics in addition to those used for their own definition; 2) A and D groups were relatively stable over time, whereas groups B and C showed more temporal variability; 3) the risk of exacerbation over 3 years increased progressively from A to D, whereas that of hospitalisation and mortality were lowest in A, highest in D and intermediate and similar in B and C, despite the former having milder airflow limitation. The prevalence of comorbidities and persistent systemic inflammation were highest in group B. The different longitudinal behaviour of group A versus B and C versus D (each pair with similar forced expiratory volume in1 s (FEV1) values supports the 2011 GOLD proposal of assessing COPD patients by more than FEV1 only. However the assumption that symptoms do not equate to risk appears to be naïve, as groups B and C carry equally poor clinical outcomes, though for different reasons. Exploring distribution, characteristics, temporal stability and relationship with 2011 GOLD group outcomes in ECLIPSE http://ow.ly/mjJ8p

Cardiovascular Comorbidity in COPD: Systematic Literature Review

BACKGROUND Cardiovascular disease (CVD) is common among patients with COPD. However, it is not clear whether this is due to shared risk factors or if COPD increases the risk for CVD independently. This study aimed to provide a systematic review of studies that investigated the association between COPD and CVD outcomes, assessing any effect of confounding by common risk factors. METHODS A search was conducted in MEDLINE (via PubMed) for observational studies published between January 1990 and March 2012 reporting cardiovascular comorbidity in patients with COPD (or vice versa). RESULTS Of the 7,322 citations identified, 25 studies were relevant for this systematic review. Twenty-two studies provided an estimate for CVD risk in COPD, whereas four studies provided estimates of COPD risk in CVD. The crude prevalence for the aggregate CVD category ranged from 28% to 70%, likely due to differences in populations studied and CVD definitions; unadjusted rate ratio (RR) estimates of unspecified CVD among patients with COPD compared with patients without COPD ranged from 2.1 to 5.0. The association between COPD and CVD persisted after adjustment for shared risk factors in the majority of the studies. Two studies found a relationship between the severity of airflow limitation and CVD risk. Increased RRs were observed for individual CVD types, but their estimates varied considerably for congestive heart failure, coronary heart disease, arrhythmias, stroke, arterial hypertension, and peripheral arterial disease. CONCLUSIONS Available observational data support the hypothesis that COPD is associated with an increased risk of CVD.

The natural history of community-acquired pneumonia in COPD patients: a population database analysis.

BACKGROUND Patients with Chronic Obstructive Pulmonary Disease (COPD) are at higher risk of developing Community-Acquired Pneumonia (CAP) than patients in the general population. However, no studies have been performed in general practice assessing longitudinal incidence rates for CAP in COPD patients or risk factors for pneumonia onset. METHODS A cohort of COPD patients aged ≥ 45 years, was identified in the General Research Practice Database (GPRD) between 1996 and 2005, and annual and 10-year incidence rates of CAP evaluated. A nested case-control analysis was performed, comparing descriptors in COPD patients with and without CAP using conditional logistic regression generating odds ratios (OR) and 95% confidence intervals (CI). RESULTS The COPD cohort consisted of 40,414 adults. During the observation period, 3149 patients (8%) experienced CAP, producing an incidence rate of 22.4 (95% CI 21.7-23.2) per 1000 person years. 92% of patients with pneumonia diagnosis had suffered only one episode. Multivariate modelling of pneumonia descriptors in COPD indicate that age over 65 years was significantly associated with increased risk of CAP. Other independent risk factors associated with CAP were co-morbidities including congestive heart failure (OR 1.4, 95% CI 1.2-1.6), and dementia (OR 2.6, 95%CI 1.9-3.). Prior severe COPD exacerbations requiring hospitalization (OR 2.7, 95% CI 2.3-3.2) and severe COPD requiring home oxygen or nebulised therapy (OR 1.4, 95% CI 1.1-1.6) were also significantly associated with risk of CAP. CONCLUSION COPD patients presenting in general practice with specific co-morbidities, severe COPD, and age >65 years are at increased risk of CAP.

Hospitalized exacerbations of COPD: risk factors and outcomes in the ECLIPSE cohort.

OBJECTIVE Exacerbations of COPD requiring hospital admission have important clinical and societal implications. We sought to investigate the incidence, recurrence, risk factors, and mortality of patients with COPD exacerbations requiring hospital admission compared with those without hospital admission during 3-year follow-up. Patients with COPD (N = 2,138) were identified from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) observational cohort. METHODS An analysis of time to first event of hospital admission was performed using Kaplan-Meier curves and Cox proportional hazard regression adjusting for possible confounders. RESULTS Of the 2,138 patients, 670 (31%) reported a total of 1,452 COPD exacerbations requiring hospital admission during the study period; 313 patients (15%) reported multiple events. A prior history of exacerbation of COPD requiring hospital admission was the factor associated with the highest risk of a new hospitalization for exacerbation (hazard ratio, 2.71; 95% CI, 2.24-3.29; P < .001). Other risk factors included more severe airflow limitation, poorer health status, older age, radiologic evidence of emphysema, and higher WBC count. Having been hospitalized for exacerbation significantly increased the risk of mortality (P < .001). CONCLUSIONS Exacerbations of COPD requiring hospital admission occur across all stages of airflow limitation and are a significant prognostic factor of reduced survival across all COPD stages. Patients with COPD at a high risk for hospitalization can be identified by their past history for similar events, and other factors, including the severity of airflow limitation, poor health status, age, presence of emphysema, and leukocytosis. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT00292552; URL: www.clinicaltrials.gov.

Validation of chronic obstructive pulmonary disease recording in the Clinical Practice Research Datalink (CPRD-GOLD)

Objectives The optimal method of identifying people with chronic obstructive pulmonary disease (COPD) from electronic primary care records is not known. We assessed the accuracy of different approaches using the Clinical Practice Research Datalink, a UK electronic health record database. Setting 951 participants registered with a CPRD practice in the UK between 1 January 2004 and 31 December 2012. Individuals were selected for ≥1 of 8 algorithms to identify people with COPD. General practitioners were sent a brief questionnaire and additional evidence to support a COPD diagnosis was requested. All information received was reviewed independently by two respiratory physicians whose opinion was taken as the gold standard. Primary outcome measure The primary measure of accuracy was the positive predictive value (PPV), the proportion of people identified by each algorithm for whom COPD was confirmed. Results 951 questionnaires were sent and 738 (78%) returned. After quality control, 696 (73.2%) patients were included in the final analysis. All four algorithms including a specific COPD diagnostic code performed well. Using a diagnostic code alone, the PPV was 86.5% (77.5–92.3%) while requiring a diagnosis plus spirometry plus specific medication; the PPV was slightly higher at 89.4% (80.7–94.5%) but reduced case numbers by 10%. Algorithms without specific diagnostic codes had low PPVs (range 12.2–44.4%). Conclusions Patients with COPD can be accurately identified from UK primary care records using specific diagnostic codes. Requiring spirometry or COPD medications only marginally improved accuracy. The high accuracy applies since the introduction of an incentivised disease register for COPD as part of Quality and Outcomes Framework in 2004.

Inflammatory and Repair Serum Biomarker Pattern. Association to Clinical Outcomes in COPD

BackgroundThe relationship between serum biomarkers and clinical expressions of COPD is limited. We planned to further describe this association using markers of inflammation and injury and repair.MethodsWe studied lung function, comorbidities, exercise tolerance, BODE index, and quality of life in 253 COPD patients and recorded mortality over three years. Serum levels of Interleukins 6,8 and16, tumor necrosis factor alpha (TNF α) [inflammatory panel], vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9) [injury and repair panel] and pulmonary and activation-regulated chemokine (PARC/CCL-18) and monocyte chemotactic protein 1 (MCP-1/CCL2) [chemoattractant panel] were measured. We related the pattern of the biomarker levels to minimal clinically important differences (MCID) using a novel visualization method [ObServed Clinical Association Results (OSCAR) plot].ResultsLevels of the inflammatory markers IL-6, TNF α were higher and those of injury and repair lower (p < 0.01) with more advanced disease (GOLD 1 vs. 4). Using the OSCAR plot, we found that patients in the highest quartile of inflammatory and lowest quartile of injury and repair biomarkers level were more clinically compromised and had higher mortality (p < 0.05).ConclusionsIn COPD, serum biomarkers of inflammation and repair are distinctly associated with important clinical parameters and survival.