Using Post-bronchodilator FEV1 is Better Than Pre-bronchodilator FEV1 in Evaluation of COPD Severity

Development and validation of a prediction index for recent mortality in advanced COPD patients

The primary barrier to initiating palliative care for advanced COPD patients is the unpredictable course of the disease. We enroll 752 COPD patients into the study and validate the prediction tools for 1-year mortality using the current guidelines for palliative care. We also develop a composite prediction index for 1-year mortality and validate it in another cohort of 342 patients. Using the current prognostic models for recent mortality in palliative care, the best area under the curve (AUC) for predicting mortality is 0.68. Using the Modified Medical Research Council dyspnea score and oxygen saturation to define the combined dyspnea and oxygenation (DO) index, we find that the AUC of the DO index is 0.84 for predicting mortality in the validated cohort. Predictions of 1-year mortality based on the current palliative care guideline for COPD patients are poor. The DO index exhibits better predictive ability than other models in the study.

Life expectancy (LE) and loss-of-LE for patients with chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVES

Prognosis of COPD is usually expressed as a 3-year survival rate, which might not be easily understood by lay people. This study estimates the life expectancy (LE) and loss-of-LE for COPD patients with different GOLD stages and patients with a history of acute exacerbation (AE) requiring hospitalization (severe AE) in the preceding year.

METHODS

532 patients who were diagnosed with COPD according to the GOLD criteria at NCKU hospital between 2006 and 2016 were recruited. Survival was estimated by Kaplan-Meier method, and extrapolated to lifetime to obtain the LE. The loss-of-LE was quantified by subtracting the LE of the COPD cohort from national life tables. The survival of patients with severe AE history was validated by a nation-wide cohort from the National Health Insurance dataset.

RESULTS

The survival of patients with severe stage COPD (GOLD grades 3 and 4) was almost the same as those patients with a history of severe AE and the loss-of-LE for the former and the latter were 9.3 (1.1) and 9.4 (1.3) years, respectively. The nation-wide cohort with severe AE history (n = 44,764) showed a loss-of-LE of 8.3 (0.1) years. The loss-of-LE of patients with moderate stage COPD (GOLD grade 2) was 6.2 years, but no reduction in LE was noted for mild stage COPD (GOLD grade 1).

CONCLUSIONS

We successfully estimated LE and loss of LE in COPD patients under the GOLD criteria. The survival of severe stage COPD patients is almost the same as those with severe AE history, or about 8-9 years of life lost.

Comparison of pre- and post-bronchodilator lung function as predictors of mortality: The HUNT Study

BACKGROUND AND OBJECTIVE

Post-bronchodilator (BD) lung function is recommended for the diagnosis of chronic obstructive pulmonary disease (COPD). However, often only pre-BD lung function is used in clinical practice or epidemiological studies. We aimed to compare the discrimination ability of pre-BD and post-BD lung function to predict all-cause mortality.

METHODS

Participants aged ≥40 years with airflow limitation (n = 2538) and COPD (n = 1262) in the second survey of the Nord-Trøndelag Health Study (HUNT2, 1995-1997) were followed up until 31 December 2015. Survival analysis and time-dependent area under the receiver operating characteristic curves (AUC) were used to compare the discrimination ability of pre-BD and post-BD lung function (percent-predicted forced expiratory volume in the first second (FEV1 ) (ppFEV1 ), FEV1 z-score, FEV1 quotient (FEV1 Q), modified Global Initiative for Chronic Obstructive Lung Disease (GOLD) categories or GOLD grades).

RESULTS

Among 2538 participants, 1387 died. The AUC for pre-BD and post-BD ppFEV1 to predict mortality were 60.8 and 61.8 (P = 0.005), respectively, at 20 years' follow-up. The corresponding AUC for FEV1 z-score were 58.5 and 60.4 (P < 0.001), for FEV1 Q were 68.7 and 70.1 (P = 0.002) and for modified GOLD categories were 62.3 and 64.5 (P < 0.001). Among participants with COPD, the AUC for pre-BD and post-BD ppFEV1 were 57.0 and 58.8 (P < 0.001), respectively. The corresponding AUC for FEV1 z-score were 53.1 and 55.8 (P < 0.001), for FEV1 Q were 63.6 and 65.1 (P = 0.037) and for GOLD grades were 56.0 and 57.0 (P = 0.268).

CONCLUSION

Mortality was better predicted by post-BD than by pre-BD lung function; however, they differed only by a small margin. The discrimination ability using GOLD grades among COPD participants was similar.

Spirometric indices of early airflow impairment in individuals at risk of developing COPD: Spirometry beyond FEV1/FVC

Spirometry is the current gold standard for diagnosing and monitoring the progression of Chronic Obstructive Pulmonary Disease (COPD). However, many current and former smokers who do not meet established spirometric criteria for the diagnosis of this disease have symptoms and clinical courses similar to those with diagnosed COPD. Large longitudinal observational studies following individuals at risk of developing COPD offer us additional insight into spirometric patterns of disease development and progression. Analysis of forced expiratory maneuver changes over time may allow us to better understand early changes predictive of progressive disease. This review discusses the theoretical ability of spirometry to capture fine pathophysiologic changes in early airway disease, highlights the shortcomings of current diagnostic criteria, and reviews existing evidence for spirometric measures which may be used to better detect early airflow impairment.

Associations between statins and coronary artery disease and stroke risks in patients with asthma-chronic obstructive pulmonary disease overlap syndrome: A time-dependent regression study

BACKGOUND AND AIMS

We aimed at determining the effects of statin use on coronary artery disease (CAD) and stroke risks in patients with asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS).

METHODS

We retrospectively enrolled patients with ACOS treated with (N = 916) and without (N = 6338) statins. The cumulative incidence of CAD and stroke (ischemic and hemorrhagic) was analyzed through time-dependent Cox proportional regression. After adjustment for sex, age, comorbidities, inhaled corticosteroid steroid (ICS) use, and oral steroid (OS) use, we calculated the adjusted hazard ratios (aHRs) and their 95% confidence intervals (CIs) for CAD or stroke in the statin users (long-term [>600 days] and short-term [≤600 days]) compared with the non-users.

RESULTS

Among the statin users, aHRs (95% CIs) for CAD and stroke were 0.50 (0.41-0.62) and 0.83 (0.63-1.09), respectively; moreover, aHRs were 0.30 (0.09-0.99) and 0.90 (0.68-1.20) for ischemic and hemorrhagic stroke, respectively. aHRs (95% CIs) for CAD and stroke were 0.58 (0.47-0.71) and 0.93 (0.70-1.23), respectively, in the short-term users and 0.23 (0.13-0.41) and 0.42 (0.19-0.89), respectively, in the long-term users.

CONCLUSIONS

CAD risk was lower in all statin users, regardless of the duration of use, whereas ischemic stroke risk was lower only in the long-term statin users. No association was observed between hemorrhagic stroke risk and statin use.

Validation of the GOLD 2017 and new 16 subgroups (1A-4D) classifications in predicting exacerbation and mortality in COPD patients

BACKGROUND AND OBJECTIVE

A multidimensional assessment of COPD was recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) in 2013 and revised in 2017. We examined the ability of the GOLD 2017 and the new 16 subgroup (1A-4D) classifications to predict clinical outcomes, including exacerbation and mortality, and compared them with the GOLD 2013 classifications.

METHODS

Patients with COPD were recruited from January 2006 to December 2017. The predictive abilities of grades 1-4 and groups A-D were examined through a logistic regression analysis with receiver operating curve estimations and area under the curve (AUC).

RESULTS

A total of 553 subjects with COPD were analyzed. The mortality rate was 48.6% during a median follow-up period of 5.2 years. Both the GOLD 2017 and the 2013 group A-D classifications had good predictive ability for total and severe exacerbations, for which the AUCs were 0.79 vs 0.77 and 0.79 vs 0.78, respectively. The AUCs for the GOLD 2017 groups A-D, grades 1-4, and the GOLD 2013 group A-D classifications were 0.70, 0.66, and 0.70 for all-cause mortality and 0.73, 0.71, and 0.74 for respiratory cause mortality, respectively. Combining the spirometric staging with the grouping for the GOLD 2017 subgroups (1A-4D), the all-cause mortality rate for group B and D patients was significantly increased from subgroups 1B-4B (27.7%, 50.6%, 53.3%, and 69.2%, respectively) and groups 1D-4D (55.0%, 68.8%, 82.1%, and 90.5%, respectively). The AUCs of subgroups (1A-4D) were 0.73 and 0.77 for all-cause and respiratory mortality, respectively; the new classification was determined more accurate than the GOLD 2017 for predicting mortality (P<0.0001).

CONCLUSION

The GOLD 2017 classification performed well by identifying individuals at risk of exacerbation, but its predictive ability for mortality was poor among COPD patients. Combining the spirometric staging with the grouping increased the predictive ability for all-cause and respiratory mortality.

SUMMARY AT A GLANCE

We validate the ability of the GOLD 2017 and 16 subgroup (1A-4D) classifications to predict clinical outcome for COPD patients. The GOLD 2017 classification performed well by identifying individuals at risk of exacerbation, but its predictive ability for mortality was poor. The new 16 subgroup (1A-4D) classification combining the spirometric 1-4 staging and the A-D grouping increased the predictive ability for mortality and was better than the GOLD 2017 for predicting all-cause and respiratory mortality among COPD patients.

Comparison of different staging methods for COPD in predicting outcomes

Chronic obstructive pulmonary disease (COPD) is commonly staged according to the percentage of predicted forced expiratory volume in 1 s (FEV₁ % pred), but other methods have been proposed. In this study we compared the performance of seven staging methods in predicting outcomes.We retrospectively studied 296 COPD outpatients. For each patient the disease severity was staged by separately applying the following methods: the criteria proposed by the Global Initiative for Chronic Obstructive Lung Disease (GOLD), quartiles of FEV₁ % pred and z-score of FEV₁, quartiles and specified cut-off points of the ratio of FEV₁ over height squared ((FEV₁·Ht^-2)_A and (FEV₁·Ht^-2)_B, respectively), and quartiles of the ratio of FEV₁ over height cubed (FEV₁·Ht^-3) and of FEV₁ quotient (FEV₁Q). We evaluated the performance of these methods in predicting the risks of severe acute exacerbation and all-cause mortality.Overall, staging based on the reference-independent FEV₁Q performed best in predicting the risks of severe acute exacerbation (including frequent exacerbation) and mortality, followed by (FEV₁·Ht^-2)_B The performance of staging methods could also be influenced by the choice of cut-off values. Future work using large and ethnically diverse populations to refine and validate the cut-off values would enhance the prediction of outcomes.

Predictive value of prebronchodilator and postbronchodilator spirometry for COPD features and outcomes

Introduction

We compared the predictive value of prebronchodilator and postbronchodilator spirometry for chronic obstructive pulmonary disease (COPD) features and outcomes.

Methods

We analysed COPDGene data of 10 192 subjects with smoking history. We created regressions models with the following dependent variables: clinical, functional and radiographic features, and the following independent variables: prebronchodilator airflow obstruction (PREO) and postbronchodilator airflow obstruction (POSTO), prebronchodilator and postbronchodilator FEV₁% predicted. We compared the model performance using the Akaike information criterion (AIC).

Results

The COPD prevalence was higher using PREO. About 8.5% had PREO but no airflow obstruction in postbronchodilator spirometry (POSTN) (PREO-POSTN) and 3% of all subjects had no aiflow obstruction in prebronchodilator spirometry (PREN) but POSTO (PREN-POSTO). We found no difference in COPD features and outcomes between PREO-POSTN and PREN-POSTO subjects. Although, both prebronchodilator and postbronchodilator spirometries are both associated with chronic bronchitis, dyspnoea, exercise capacity and COPD radiographic findings, models that included postbronchodilator spirometric measures performed better than models with prebronchodilator measures to predict these COPD features. The predictive value of prebronchodilator and postbronchodilator spirometries for respiratory exacerbations, change in forced expiratory volume in 1 s, dyspnoea and exercise capacity during a 5-year period is relatively similar, but postbronchodilator spirometric measures are better predictors of mortality based on AIC.

Conclusions

Postbronchodilator spirometry may be a more accurate predictor of COPD features and outcomes.

Obvious emphysema on computed tomography during an acute exacerbation of chronic obstructive pulmonary disease predicts a poor prognosis

BACKGROUND

Emphysematous change on computed tomography (CT) during the stable phase of chronic obstructive pulmonary disease (COPD) is reported to correlate with COPD prognosis. Acute exacerbation of COPD (AECOPD) is associated with a high risk of mortality and a poor prognosis.

AIMS

This study aims to study the relationship between prognosis and emphysematous changes on CT during an AECOPD.

METHODS

Histories were recorded, and CT acquired for 106 patients who visited the emergency department for an AECOPD. Emphysematous change was quantified by measuring the percentage of low-attenuation areas (LAA%) in the entire lung on CT images with a threshold of -950 Hounsfield units. Other factors that could influence AECOPD prognosis were also recorded on admission and analysed. At follow ups conducted in 1 year, patient survival, the modified Medical Research Council (mMRC) Dyspnoea Scale, and performance status (PS) were evaluated, and a COPD Assessment Test (CAT) was completed.

RESULTS

The 1-year follow up was completed by 103 of 106 patients. The median LAA% was significantly higher in non-survivors (11%, n = 16) than in survivors (5.69%, n = 87) (P = 0.006) at the 1-year follow up. LAA% was significantly correlated with mMRC grade (r = 0.285, P = 0.008), PS (r = 0.397, P < 0.001) and CAT score (r = 0.27, P = 0.017) at the 3-month follow up, and with mMRC grade (r = 0.405, P < 0.001) and PS (r = 0.377, P < 0.001) at the 1-year follow up. LAA% > 7.5% was a significant predictor of 1-year mortality, higher mMRC and PS at the 3-month and 1-year follow ups, after adjustment for other prognostic predictors.

CONCLUSION

Obvious emphysematous changes on CT (LAA% > 7.5%) during an AECOPD predicts a poor prognosis independent of other known indicators.

Association of incidental emphysema with annual lung function decline and future development of airflow limitation

Objectives

Emphysema is one of the prognostic factors for rapid lung function decline in patients with COPD, but the impact of incidentally detected emphysema on population without spirometric abnormalities has not been evaluated. This study aimed to determine whether emphysema detected upon computed tomography (CT) screening would accelerate the rate of lung function decline and influence the possibility of future development of airflow limitation in a population without spirometric abnormalities.

Materials and methods

Subjects who participated in a routine screening for health checkup and follow-up pulmonary function tests for at least 3 years between 2004 and 2010 were retrospectively enrolled. The percentage of low-attenuation area below −950 Hounsfield units (%LAA₋₉₅₀) was calculated automatically. A calculated value of %LAA₋₉₅₀ that exceeded 10% was defined as emphysema. Adjusted annual lung function decline was analyzed using random-slope, random-intercept mixed linear regression models.

Results

A total of 628 healthy subjects within the normal range of spriometric values were included. Multivariable analysis showed that the emphysema group exhibited a faster decline in forced vital capacity (−33.9 versus −18.8 mL/year; P=0.02). Emphysema was not associated with the development of airflow limitation during follow-up.

Conclusion

Incidental emphysema quantified using CT scan was significantly associated with a more rapid decline in forced vital capacity in the population with normative spirometric values. However, an association between emphysema and future development of airflow limitation was not observed.

Paranasal sinus opacification at MRI in lower airway disease (the HUNT study-MRI)

The study builds on the concept of united airways, which describes the link between the upper and lower airways. Explorations of this concept have mainly related to asthma and less to chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate paranasal sinus opacification at magnetic resonance imaging (MRI) in COPD, self-reported asthma and respiratory symptoms. In this cross-sectional study, 880 randomly selected participants in the Nord-Trøndelag health survey (HUNT) (mean age 57.7 years, range 50-66 years, 463 women) were investigated using MRI of the paranasal sinuses. Participants were allocated to four mutually exclusive groups: (1) COPD (n = 20), (2) asthma (n = 89), (3) respiratory symptoms (n = 199), and (4) reference group (n = 572). Paranasal sinus opacifications were categorised as mucosal thickening, polyps and retention cysts, and fluid. In each participant, measurements ≥1 mm from all sinuses were summed to give a total for each category of opacities. The sums for these three categories were further added together, and referred to as the total sum. Using the 75th percentile cut-off values, the likelihood of having paranasal sinus opacifications was more than six times higher in participants with COPD and twice as high in participants with asthma than among the reference group. Respiratory symptoms were only associated with mucosal thickening. The present study shows that paranasal sinus opacification is associated not only with asthma, but also with COPD and respiratory symptoms. This is in accordance with the united airways hypothesis, and should be kept in mind when handling patients with these conditions.

Comparison of global initiative for chronic obstructive pulmonary disease 2013 classification and body mass index, airflow obstruction, dyspnea, and exacerbations index in predicting mortality and exacerbations in elderly adults with chronic obstructive pulmonary disease

OBJECTIVES

To examine whether the Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) 2013 revision offers greater predictive ability than the body mass index, airflow obstruction, dyspnea, and exacerbations (BODEx) index in elderly adults with chronic obstructive pulmonary disease (COPD).

DESIGN

Prospective cohort study.

SETTING

University-affiliated medical center.

PARTICIPANTS

Taiwanese outpatients with COPD (N = 354).

MEASUREMENTS

Participants were classified as Group A (low risk with mild dyspnea), Group B (low risk with more-severe dyspnea), Group C (high risk with mild dyspnea), and Group D (high risk with more-severe dyspnea) for GOLD 2013 and from Quartile 1 (0-2 points) to 4 (7-9 points) for BODEx score. Ability to predict exacerbations and mortality was compared using logistic regression analysis with receiver operating characteristic (ROC) curve estimations and area under the ROC curve (AUC).

RESULTS

Mortality was 14.1% for GOLD Group A, 14.5% for Group B, 6.5% for Group C, and 35.8% for Group D and 15.2% for BODEx Quartile 1, 22.5% for Quartile 2, 28.1% for Quartile 3, and 79.2% for Quartile 4. Risk of exacerbation relative to Group A was 1.7 (95% confidence interval (CI) = 0.6-4.3) for Group B, 14.1 (95% CI = 4.6-43.2) for Group C, and 17.9 (95% CI = 7.6-42.0) for Group D. The AUC for the GOLD classification and BODEx index were 0.65 and 0.67 for mortality (P = .60) and 0.79 and 0.73 for exacerbation (P = .03).

CONCLUSION

The GOLD 2013 classification performed well in identifying individuals at risk of exacerbations, and its predictive ability for exacerbations was better than that of the BODEx index, although the predictive ability for mortality in elderly adults with COPD was poor for both indices.

Conflicting role of sarcopenia and obesity in male patients with chronic obstructive pulmonary disease: Korean National Health and Nutrition Examination Survey

OBJECTIVE

To determine the impact of sarcopenia and obesity on pulmonary function and quality of life (QOL) in chronic obstructive pulmonary disease (COPD) patients.

RESEARCH DESIGN AND METHODS

Data were obtained from the Korea National Health and Nutrition Examination Survey, including data from health interviews, health examinations, nutritional questionnaires, and laboratory findings. Laboratory data included pulmonary function assessment and dual energy X-ray absorptiometry results. Sarcopenia was measured by dual energy X-ray absorptiometry, and obesity was defined by body mass index. Male COPD patients were then classified into 4 groups according to the presence of sarcopenia and obesity.

RESULTS

In male patients with COPD, the prevalence of sarcopenia was found to be 29.3%, and that of sarcopenic obesity was 14.2%. Furthermore, 22.5% of the patients observed in this study had impaired QOL. Following multivariable statistical analysis, both sarcopenia and obesity were independent risk factors for worsening lung function. Adjusted values of forced vital capacity and forced expiratory volume in 1 second were the lowest in the sarcopenic obesity group. Sarcopenia was also associated with more subjective activity limitation and poorer QOL; however obesity was related to less subjective limitation and better QOL after multivariable analysis. Adjusted value of QOL was the lowest in sarcopenic subjects without obesity, and the highest in obese subject without sarcopenia.

CONCLUSIONS

Both sarcopenia and obesity were found to be associated with worsening lung function in male COPD patients. However, obesity was positively correlated with improved QOL while sarcopenia was negatively correlated with QQL.

Admixture mapping identifies a quantitative trait locus associated with FEV1/FVC in the COPDGene Study

African Americans are admixed with genetic contributions from European and African ancestral populations. Admixture mapping leverages this information to map genes influencing differential disease risk across populations. We performed admixture and association mapping in 3,300 African American current or former smokers from the COPDGene Study. We analyzed estimated local ancestry and SNP genotype information to identify regions associated with FEV1 /FVC, the ratio of forced expiratory volume in one second to forced vital capacity, measured by spirometry performed after bronchodilator administration. Global African ancestry inversely associated with FEV1 /FVC (P = 0.035). Genome-wide admixture analysis, controlling for age, gender, body mass index, current smoking status, pack-years smoked, and four principal components summarizing the genetic background of African Americans in the COPDGene Study, identified a region on chromosome 12q14.1 associated with FEV1 /FVC (P = 2.1 × 10(-6) ) when regressed on local ancestry. Allelic association in this region of chromosome 12 identified an intronic variant in FAM19A2 (rs348644) as associated with FEV1 /FVC (P = 1.76 × 10(-6) ). By combining admixture and association mapping, a marker on chromosome 12q14.1 was identified as being associated with reduced FEV1 /FVC ratio among African Americans in the COPDGene Study.