Redefining Cut-Points for High Symptom Burden of the Global Initiative for Chronic Obstructive Lung Disease Classification in 18,577 Patients With Chronic Obstructive Pulmonary Disease

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) can be classified into groups A/C or B/D based on symptom intensity. Different threshold values for symptom questionnaires can result in misclassification and, in turn, different treatment recommendations. The primary aim was to find the best fitting cut-points for Global initiative for chronic Obstructive Lung Disease (GOLD) symptom measures, with an modified Medical Research Council dyspnea grade of 2 or higher as point of reference.

METHODS

After a computerized search, data from 41 cohorts and whose authors agreed to provide data were pooled. COPD studies were eligible for analyses if they included, at least age, sex, postbronchodilator spirometry, modified Medical Research Council, and COPD Assessment Test (CAT) total scores.

MAIN OUTCOMES

Receiver operating characteristic curves and the Youden index were used to determine the best calibration threshold for CAT, COPD Clinical Questionnaire, and St. Georges Respiratory Questionnaire total scores. Following, GOLD A/B/C/D frequencies were calculated based on current cut-points and the newly derived cut-points.

FINDINGS

A total of 18,577 patients with COPD [72.0% male; mean age: 66.3 years (standard deviation 9.6)] were analyzed. Most patients had a moderate or severe degree of airflow limitation (GOLD spirometric grade 1, 10.9%; grade 2, 46.6%; grade 3, 32.4%; and grade 4, 10.3%). The best calibration threshold for CAT total score was 18 points, for COPD Clinical Questionnaire total score 1.9 points, and for St. Georges Respiratory Questionnaire total score 46.0 points.

CONCLUSIONS

The application of these new cut-points would reclassify about one-third of the patients with COPD and, thus, would impact on individual disease management. Further validation in prospective studies of these new values are needed.

Prevalence of persistent blood eosinophilia: relation to outcomes in patients with COPD

The impact of blood eosinophilia in chronic obstructive pulmonary disease (COPD) remains controversial.

To evaluate the prevalence and stability of a high level of blood eosinophils (≥300 cells·μL–1) and its relationship to outcomes, we determined blood eosinophils at baseline and over 2 years in 424 COPD patients (forced expiratory volume in 1 s (FEV1) 60% predicted) and 67 smokers without COPD from the CHAIN cohort, and in 308 COPD patients (FEV1 60% predicted) in the BODE cohort. We related eosinophil levels to exacerbations and survival using Cox hazard analysis.

In COPD patients, 15.8% in the CHAIN cohort and 12.3% in the BODE cohort had persistently elevated blood eosinophils at all three visits. A significant proportion (43.8%) of patients had counts that oscillated above and below the cut-off points, while the rest had persistent eosinophil levels <300 cells·μL–1. A similar eosinophil blood pattern was observed in controls. Exacerbation rates did not differ in patients with and without eosinophilia. All-cause mortality was lower in patients with high eosinophils compared with those with values <300 cells·μL–1 (15.8% versus 33.7%; p=0.026).

In patients with COPD, blood eosinophils ≥300 cells·μL–1 persisting over 2 years was not a risk factor for COPD exacerbations. High eosinophil count was associated with better survival.

Differential Effect of Modified Medical Research Council Dyspnea, COPD Assessment Test, and Clinical COPD Questionnaire for Symptoms Evaluation Within the New GOLD Staging and Mortality in COPD

OBJECTIVE

The modified Medical Research Council (mMRC) dyspnea, the COPD Assessment Test (CAT), and the Clinical COPD Questionnaire (CCQ) have been interchangeably proposed by GOLD (Global Initiative for Chronic Obstructive Lung Disease) for assessing symptoms in patients with COPD. However, there are no data on the prognostic value of these tools in terms of mortality. We endeavored to evaluate the prognostic value of the CAT and CCQ scores and compare them with mMRC dyspnea.

METHODS

We analyzed the ability of these tests to predict mortality in an observational cohort of 768 patients with COPD (82% men; FEV1, 60%) from the COPD History Assessment in Spain (CHAIN) study, a multicenter observational Spanish cohort, who were monitored annually for a mean follow-up time of 38 months.

RESULTS

Subjects who died (n = 73; 9.5%) had higher CAT (14 vs 11, P = .022), CCQ (1.6 vs 1.3, P = .033), and mMRC dyspnea scores (2 vs 1, P < .001) than survivors. Receiver operating characteristic analysis showed that higher CAT, CCQ, and mMRC dyspnea scores were associated with higher mortality (area under the curve: 0.589, 0.588, and 0.649, respectively). CAT scores ≥ 17 and CCQ scores > 2.5 provided a similar sensitivity than mMRC dyspnea scores ≥ 2 to predict all-cause mortality.

CONCLUSIONS

The CAT and the CCQ have similar ability for predicting all-cause mortality in patients with COPD, but were inferior to mMRC dyspnea scores. We suggest new thresholds for CAT and CCQ scores based on mortality risk that could be useful for the new GOLD grading classification.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01122758; URL: www.clinicaltrials.gov.

New GOLD classification: longitudinal data on group assignment

Rationale

Little is known about the longitudinal changes associated with using the 2013 update of the multidimensional GOLD strategy for chronic obstructive pulmonary disease (COPD).

Objective

To determine the COPD patient distribution of the new GOLD proposal and evaluate how this classification changes over one year compared with the previous GOLD staging based on spirometry only.

Methods

We analyzed data from the CHAIN study, a multicenter observational Spanish cohort of COPD patients who are monitored annually. Categories were defined according to the proposed GOLD: FEV₁%, mMRC dyspnea, COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ), and exacerbations-hospitalizations. One-year follow-up information was available for all variables except CCQ data.

Results

At baseline, 828 stable COPD patients were evaluated. On the basis of mMRC dyspnea versus CAT, the patients were distributed as follows: 38.2% vs. 27.2% in group A, 17.6% vs. 28.3% in group B, 15.8% vs. 12.9% in group C, and 28.4% vs. 31.6% in group D. Information was available for 526 patients at one year: 64.2% of patients remained in the same group but groups C and D show different degrees of variability. The annual progression by group was mainly associated with one-year changes in CAT scores (RR, 1.138; 95%CI: 1.074-1.206) and BODE index values (RR, 2.012; 95%CI: 1.487-2.722).

Conclusions

In the new GOLD grading classification, the type of tool used to determine the level of symptoms can substantially alter the group assignment. A change in category after one year was associated with longitudinal changes in the CAT and BODE index.

Chronic obstructive pulmonary disease as a cardiovascular risk factor. Results of a case-control study (CONSISTE study)

Introduction

Chronic obstructive pulmonary disease (COPD) patients present a high prevalence of cardiovascular disease. This excess of comorbidity could be related to a common pathogenic mechanism, but it could also be explained by the existence of common risk factors. The objective of this study was to determine whether COPD patients present greater cardiovascular comorbidity than control subjects and whether COPD can be considered a risk factor per se.

Methods

1200 COPD patients and 300 control subjects were recruited for this multicenter, cross-sectional, case–control study.

Results

Compared with the control group, the COPD group showed a significantly higher prevalence of ischemic heart disease (12.5% versus 4.7%; P < 0.0001), cerebrovascular disease (10% versus 2%; P < 0.0001), and peripheral vascular disease (16.4% versus 4.1%; P < 0.001). In the univariate risk analysis, COPD, hypertension, diabetes, obesity, and dyslipidemia were risk factors for ischemic heart disease. In the multivariate analysis adjusted for the remaining factors, COPD was still an independent risk factor (odds ratio: 2.23; 95% confidence interval: 1.18–4.24; P = 0.014).

Conclusion

COPD patients show a high prevalence of cardiovascular disease, higher than expected given their age and the coexistence of classic cardiovascular risk factors.

[Cardiovascular risk factors in chronic obstructive pulmonary disease: results of the ARCE study]

OBJECTIVE

Cardiovascular disease is a common cause of death in patients with chronic obstructive pulmonary disease (COPD). It is not clear whether the high cardiovascular comorbidity is due to an increase in traditional risk factors or whether, in contrast, COPD can be considered an independent risk factor. The aim of this study was to analyze the prevalence of risk factors and cardiovascular comorbidity in a community-based population treated for COPD.

PATIENTS AND METHODS

This was a concurrent multicenter, cross-sectional study that included 572 patients with confirmed diagnosis of COPD. Information on cardiovascular risk factors and comorbidity was collected by extracting data from the medical records of the participating center.

RESULTS

The mean (SD) forced expiratory volume in 1 second (FEV1) was 53.7% (16.85%) of predicted and the ratio of FEV1 to forced vital capacity was 57.9% (10.9%). Hypertension was reported in 53%, obesity in 27%, dyslipidemia in 26%, and diabetes in 23% of the patients. The prevalence of risk factors was not related to disease severity, but there was a trend towards an association with age. In the study group, 16.4% had ischemic heart disease, 7% cerebrovascular disease, and 17% peripheral vascular disease. Cardiovascular disease was not associated with COPD severity, but such an association was reported for age and traditional risk factors.

CONCLUSIONS

Cardiovascular risk factors are highly prevalent in patients with COPD. The prevalence of cardiovascular and cerebrovascular disease exceeds that reported in the general population. No relationship was found between the severity of airflow obstruction and the presence of cardiovascular comorbidity.