Application of Global Lung Function Initiative Global Spirometry Reference Equations across a Large, Multicenter Pulmonary Function Lab Population

Rationale: Global Lung Function Initiative (GLI) Global spirometry reference equations were recently derived to offer a "race-neutral" interpretation option. The impact of transitioning from the race-specific GLI-2012 to the GLI Global reference equations is unknown. Objectives: Describe the direction and magnitude of changes in predicted lung function measurements in a population of diverse race and ethnicity using GLI Global in place of GLI-2012 reference equations. Methods: In this multicenter cross-sectional study using a large pulmonary function laboratory database, 109,447 spirometry tests were reanalyzed using GLI Global reference equations and compared with the existing GLI-2012 standard, stratified by self-reported race and ethnicity. Measurements and Main Results: Mean FEV1 and FVC percent predicted increased in the White and Northeast Asian groups and decreased in the Black, Southeast Asian, and mixed/other race groups. The prevalence of obstruction increased by 9.7% in the White group, and prevalences of possible restriction increased by 51.1% and 37.1% in the Black and Southeast Asian groups, respectively. Using GLI Global in a population with equal representation of all five race and ethnicity groups altered the interpretation category for 10.2% of spirometry tests. Subjects who self-identified as Black were the only group with a relative increase in the frequency of abnormal spirometry test results (32.9%). Conclusions: The use of GLI Global reference equations will significantly impact spirometry interpretation. Although GLI Global offers an innovative approach to transition from race-specific reference equations, it is important to recognize the continued need to place these data within an appropriate clinical context.

Adjusting diffusing capacity for anemia in patients undergoing allogeneic HCT: a comparison of two methodologies

BACKGROUND

Diffusing capacity (DLCO) measurements are affected by hemoglobin. Two adjustment equations are used: Cotes (recommended by ATS/ERS) and Dinakara (used in the hematopoietic stem cell transplantation comorbidity index [HCT-CI]). It is unknown how these methods compare, and which is better from a prognostication standpoint.

STUDY DESIGN

This is a retrospective cohort of 1273 adult patients who underwent allogeneic HCT, completed a pre-transplant DLCO and had a concurrent hemoglobin measurement. Non-relapse mortality was measured using competing risk analysis.

RESULTS

Patients had normal spirometry (FEV1 99.7% [IQR: 89.4-109.8%; FVC 100.1% [IQR: 91.0-109.6%] predicted), left ventricular ejection fraction (57.2[6.7]%) and right ventricular systolic pressure (30.1[7.0] mmHg). Cotes-DLCO was 85.6% (IQR: 76.5-95.7%) and Dinakara-DLCO was 103.6% (IQR: 90.7-117.2%) predicted. For anemic patients (Hb<10g/dL), Cotes-DLCO was 84.2% (IQR: 73.9-94.1%) while Dinakara-DLCO 111.0% (97.3-124.7%) predicted. Cotes-DLCO increased HCT-CI score for 323 (25.4%) and decreased for 4 (0.3%) patients. Cotes-DLCO was superior for predicting non-relapse mortality: for both mild (66-80% predicted, HR 1.55 [95%CI: 1.26-1.92, p < 0.001]) and moderate (<65% predicted, HR 2.11 [95%CI: 1.55-2.87, p<0.001]) impairment. In contrast, for Dinakara-DLCO, only mild impairment (HR 1.69 [95%CI 1.26-2.27, p < 0.001]) was associated with lower survival while moderate impairment was not (HR 1.44 [95%CI: 0.64-3.21, p = 0.4]). In multivariable analyses, after adjusting for demographics, hematologic variables, cardiac function and FEV1, Cotes-DLCO was predictive of overall survival at 1-year (OR 0.98 [95%CI: 0.97-1.00], p = 0.01), but Dinakara-DLCO was not (OR 1.00 [95%CI: 0.98-1.00], p = 0.20).

CONCLUSION

The ERS/ATS recommended Cotes method likely underestimates DLCO in patients with anemia, whereas the Dinakara (used in the HCT-CI score) overestimates DLCO. The Cotes method is superior to the Dinakara method score in predicting overall survival and relapse-free survival in patients undergoing allogeneic HCT.

Combined Pulmonary Fibrosis and Emphysema: A Narrative Review

Combined pulmonary fibrosis and emphysema (CPFE) syndrome refers to co-occurrence of two disease processes in the lung that can be difficult to diagnose but is associated with high morbidity and mortality burden. Diagnosis of CPFE is challenging because the two diseases can counterbalance respective impairments resulting in deceivingly normal-appearing chest radiography and spirometry in a dyspneic patient. Although an international committee published the terminology and definitions of CPFE in 2022, consensus on exact diagnostic criteria and optimal management strategy is yet to be determined. Herein, we provide a narrative review summarizing the literature on CPFE from 1990 to 2022, including historical background, epidemiology, pathogenesis, clinical features, imaging and pulmonary function findings, diagnosis, prognosis, complications, and treatment. Although CPFE was initially conceived as a variant presentation of idiopathic pulmonary fibrosis, it has been recognized to occur in patients with a wide variety of interstitial lung diseases, including connective tissue disease-associated interstitial lung diseases, and hypersensitivity pneumonitis. The affected patients have a heightened risk for pulmonary hypertension and lung cancer. Clinicians need to recognize the characteristic presenting features of CPFE along with prognostic implications of this entity.

Use of a Viral Filter to Reduce Exposure to Exhaled Aerosol Does Not Affect Methacholine Dose Delivery During Bronchoprovocation Testing

BACKGROUND

Methacholine challenge testing (MCT) is a common bronchoprovocation technique used to assess airway hyper-responsiveness. We previously demonstrated that the addition of a viral filter to the nebulizer exhalation limb substantially reduced expelled particles during MCT. Our aim was to evaluate whether this modification affects the delivered dose of methacholine.

METHODS

A mechanical ventilator was connected to a lung simulator with breathing frequency 15 breaths/min, tidal volume 500 mL, inspiratory-expiratory ratio 1:1, with a sinusoidal waveform. We compared methacholine dose delivery using the Hudson Micro Mist or AeroEclipse II BAN nebulizers powered by either a dry gas source or a compressor system. A filter placed in line between the nebulizer and test lung was weighed before and after 1 min of nebulized methacholine delivery. Mean inhaled mass was measured with and without a viral filter on the exhalation limb. Dose delivery was calculated by multiplying the mean inhaled mass by the respirable fraction (particles < 5 μm) and inhalation time. Unpaired t test was used to compare methacholine dose delivery with and without viral filter placement.

RESULTS

The addition of a viral filter did not significantly affect methacholine dose delivery across all devices tested. Using a 50-psi dry gas source, dose delivered with or without a viral filter did not differ with the Hudson (422.3 μg vs 282.0 μg, P = .11) or the AeroEclipse nebulizer (563.0 μg vs 657.6 μg, P = .59). Using the compressor, dose delivered with and without a viral filter did not differ with the Hudson (974.0 μg vs 868.0 μg, P = .03) or the AeroEclipse nebulizer (818.0 μg vs 628.5 μg, P = .42).

CONCLUSIONS

The addition of a viral filter to the nebulizer exhalation limb did not affect methacholine dose during bronchoprovocation testing. Routine use of a viral filter should be considered to improve pulmonary function technician safety and infection control measures during the ongoing COVID-19 pandemic.

Impact of hepatopulmonary syndrome in liver transplantation candidates and the role of angiogenesis

BACKGROUND

Hepatopulmonary syndrome affects 10-30% of patients with cirrhosis and portal hypertension. We evaluated the serum angiogenic profile of hepatopulmonary syndrome and assessed the clinical impact of hepatopulmonary syndrome in patients evaluated for liver transplantation.

METHODS

The Pulmonary Vascular Complications of Liver Disease 2 study was a multicentre, prospective cohort study of adults undergoing their first liver transplantation evaluation. Hepatopulmonary syndrome was defined as an alveolar-arterial oxygen gradient ≥15 mmHg (≥20 mmHg if age >64 years), positive contrast-enhanced transthoracic echocardiography and absence of lung disease.

RESULTS

We included 85 patients with hepatopulmonary syndrome and 146 patients without hepatopulmonary syndrome. Patients with hepatopulmonary syndrome had more complications of portal hypertension and slightly higher Model for End-Stage Liver Disease-Na score compared to those without hepatopulmonary syndrome (median (interquartile range) 15 (12-19) versus 14 (10-17), p=0.006). Hepatopulmonary syndrome patients had significantly lower 6-min walk distance and worse functional class. Hepatopulmonary syndrome patients had higher circulating angiopoietin 2, Tie2, tenascin C, tyrosine protein kinase Kit (c-Kit), vascular cell adhesion molecule 1 and von Willebrand factor levels, and lower E-selectin levels. Patients with hepatopulmonary syndrome had an increased risk of death (hazard ratio 1.80, 95% CI 1.03-3.16, p=0.04), which persisted despite adjustment for covariates (hazard ratio 1.79, 95% CI 1.02-3.15, p=0.04). This association did not vary based on levels of oxygenation, reflecting the severity of hepatopulmonary syndrome.

CONCLUSION

Hepatopulmonary syndrome was associated with a profile of abnormal systemic angiogenesis, worse exercise and functional capacity, and an overall increased risk of death.

Aerosol Generation and Mitigation During Methacholine Bronchoprovocation Testing: Infection Control Implications in the Era of COVID-19

BACKGROUND

Methacholine bronchoprovocation or challenge testing (MCT) is commonly performed to assess airway hyper-responsiveness in the setting of suspected asthma. Nebulization is an aerosol-generating procedure, but little is known about the risks of MCT in the context of the ongoing coronavirus disease 2019 (COVID-19) pandemic. We aimed to quantify and characterize aerosol generation during MCT by using different delivery methods and to assess the impact of adding a viral filter.

METHODS

Seven healthy subjects performed simulated MCT in a near particle-free laboratory space with 4 different nebulizers and with a dosimeter. Two devices continuously sampled the ambient air during the procedure, which detected ultrafine particles, from 0.02-1 μm, and particles of sizes 0.3, 0.5, 1.0, 2.0, 5.0, and 10 µm, respectively. Particle generation was compared among all the devices, with and without viral filter placement.

RESULTS

Ultrafine-particle generation during simulated MCT was significant across all the devices. Ultrafine-particle (0.02-1 μm) concentrations decreased 77%-91% with the addition of a viral filter and varied significantly between unfiltered (P < .001) and filtered devices (P < .001). Ultrafine-particle generation was lowest when using the dosimeter with filtered Hudson nebulizer (1,258 ± 1,644 particle/mL). Ultrafine-particle concentrations with the filtered nebulizer devices using a compressor were higher than particle concentrations detected when using the dosimeter: Monaghan (3,472 ± 1,794 particles/mL), PARI (4,403 ± 2,948), Hudson (6,320 ± 1,787) and AirLife (9,523 ± 5,098).

CONCLUSIONS

The high particle concentrations generated during MCT pose significant infection control concerns during the COVID-19 pandemic. Particle generation during MCT was significantly reduced by using breath-actuated delivery and a viral filter, which offers an effective mitigation strategy.

Metoprolol for the Prevention of Acute Exacerbations of COPD

BACKGROUND

Observational studies suggest that beta-blockers may reduce the risk of exacerbations and death in patients with moderate or severe chronic obstructive pulmonary disease (COPD), but these findings have not been confirmed in randomized trials.

METHODS

In this prospective, randomized trial, we assigned patients between the ages of 40 and 85 years who had COPD to receive either a beta-blocker (extended-release metoprolol) or placebo. All the patients had a clinical history of COPD, along with moderate airflow limitation and an increased risk of exacerbations, as evidenced by a history of exacerbations during the previous year or the prescribed use of supplemental oxygen. We excluded patients who were already taking a beta-blocker or who had an established indication for the use of such drugs. The primary end point was the time until the first exacerbation of COPD during the treatment period, which ranged from 336 to 350 days, depending on the adjusted dose of metoprolol.

RESULTS

A total of 532 patients underwent randomization. The mean (±SD) age of the patients was 65.0±7.8 years; the mean forced expiratory volume in 1 second (FEV1) was 41.1±16.3% of the predicted value. The trial was stopped early because of futility with respect to the primary end point and safety concerns. There was no significant between-group difference in the median time until the first exacerbation, which was 202 days in the metoprolol group and 222 days in the placebo group (hazard ratio for metoprolol vs. placebo, 1.05; 95% confidence interval [CI], 0.84 to 1.32; P = 0.66). Metoprolol was associated with a higher risk of exacerbation leading to hospitalization (hazard ratio, 1.91; 95% CI, 1.29 to 2.83). The frequency of side effects that were possibly related to metoprolol was similar in the two groups, as was the overall rate of nonrespiratory serious adverse events. During the treatment period, there were 11 deaths in the metoprolol group and 5 in the placebo group.

CONCLUSIONS

Among patients with moderate or severe COPD who did not have an established indication for beta-blocker use, the time until the first COPD exacerbation was similar in the metoprolol group and the placebo group. Hospitalization for exacerbation was more common among the patients treated with metoprolol. (Funded by the Department of Defense; BLOCK COPD ClinicalTrials.gov number, NCT02587351.).

Pulse Oximetry Is Insensitive for Detection of Hepatopulmonary Syndrome in Patients Evaluated for Liver Transplantation

Screening for hepatopulmonary syndrome (HPS) using pulse oximetry is recommended in liver transplant (LT) candidates because mortality is increased, independently of the severity of the oxygenation defect. LT exception points may be afforded to those with HPS and severe hypoxemia. We assessed the screening characteristics of pulse oximetry for HPS. The Pulmonary Vascular Complications of Liver Disease 2 study is a multicenter, prospective cohort study of adults undergoing their first LT evaluation. Patients underwent protocolized assessment of oxygen saturation by pulse oximetry (SpO₂ ), arterial blood gas, spirometry, and contrast-enhanced echocardiography (CE). HPS was defined as an alveolar-arterial gradient ≥15 mm Hg (≥20 mm Hg if age >64 years), intrapulmonary vascular dilatation on CE, and absence of lung disease. The study sample included 363 patients. Of these, 75 (20.7%; 95% confidence interval [CI], 16.6%-25.2%) met the criteria for HPS. The area under the receiver operating characteristic curve (or c-statistic) for SpO₂ in discriminating HPS was 0.59 (95% CI, 0.51-0.66). An SpO₂ <96%, recommended by practice guidelines as a threshold to require further testing, had low sensitivity (28%; 95% CI, 18%-28%). The c-statistic of SpO₂ in discriminating HPS with a partial pressure of oxygen (PaO₂ ) <60 mm Hg (eligible for LT exception points) was 0.76 (95% CI, 0.46-1.00). An SpO₂ cutoff of <96% had higher sensitivity for detecting HPS with PaO₂ <60 mm Hg (71%; 95% CI, 38%-100%) but was still inadequate. Conclusion: Pulse oximetry is not sufficiently sensitive to screen for HPS in LT candidates. Arterial blood gas and CE are required in LT candidates for diagnosis of HPS.

COPD Guidelines: A Review of the 2018 GOLD Report

Global Strategy for the Diagnosis, Management, and Prevention of COPD 2018 is a consensus report published periodically since 2001 by an international panel of health professionals from respiratory medicine, socioeconomics, public health, and education comprising the Global Initiative for Chronic Obstructive Lung Disease (GOLD). The GOLD documents endeavor to incorporate latest evidence and expert consensus and are intended for use as "strategy documents" for implementation of effective care for chronic obstructive lung disease (COPD) on a global level. The GOLD 2018 report defines COPD as a "common, preventable and treatable disease that is characterized by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities, usually caused by significant exposure to noxious particles or gases," with the criteria of "persistent respiratory symptoms" being a new and controversial inclusion since 2017. With the availability of newer pharmacotherapy options, treatment recommendations are made on the basis of a review of the latest literature and directed by symptom burden and health care utilization. Apart from the change in definition, a major shift in the recommendations is the exclusion of severity of airflow limitation as one of the major factors in guiding therapy. We review the salient features of the GOLD 2018 document and provide commentary on features that merit further discussion based on our clinical experience and practice as well as literature review current as of February 2018.

Pulmonary Function Tests for the Generalist: A Brief Review

One of the frequent reasons patients see their primary care physicians is for the symptom of dyspnea. Among the objective tests to quantify this symptom is the pulmonary function test, which includes several different studies: spirometry with flow-volume loop, lung volumes, and diffusing capacity of lung for carbon monoxide. The results may indicate both respiratory and nonrespiratory disorders, including helping in the diagnosis of cardiac or neuromuscular diseases. This review, intended for the generalist, describes common findings of pulmonary function tests and provides a road map for interpretation.

A brief bedside visual art intervention decreases anxiety and improves pain and mood in patients with haematologic malignancies

Treatment of cancer-related symptoms represents a major challenge for physicians. The purpose of this pilot study was to determine whether a brief bedside visual art intervention (BVAI) facilitated by art educators improves mood, reduces pain and anxiety in patients with haematological malignancies. Thirty-one patients (21 women and 10 men) were invited to participate in a BVAI where the goal of the session was to teach art technique for ~30 min. Primary outcome measures included the change in visual analog scale, the State-Trait Anxiety Inventory and the Positive and Negative Affect Schedule scale, from baseline prior to and immediately post-BVAI. Total of 21 patients (19 women and two men) participated. A significant improvement in positive mood and pain scores (p = .003 and p = .017 respectively) as well as a decrease in negative mood and anxiety (p = .016 and p = .001 respectively) was observed. Patients perceived BVAI as overall positive (95%) and wished to participate in future art-based interventions (85%). This accessible experience, provided by artists within the community, may be considered as an adjunct to conventional treatments in patients with cancer-related mood symptoms and pain, and future studies with balanced gender participation may support the generalisability of these findings.

Clinical Impact of Intrapulmonary Vascular Dilatation in Candidates for Liver Transplant

BACKGROUND

Intrapulmonary vascular dilatations (IPVD) frequently are detected in patients with liver disease by the delayed appearance of microbubbles at contrast-enhanced echocardiography. IPVD with an elevated alveolar-arterial (A-a) gradient define hepatopulmonary syndrome (HPS); however, the importance of IPVD in the absence of abnormal gas exchange is unknown. We aimed to determine the clinical impact of IPVD in patients with liver disease.

METHODS

We performed a cross-sectional study within the Pulmonary Vascular Complications of Liver Disease 2 Study, a multicenter, prospective cohort study of patients being evaluated for liver transplant. We excluded patients with obstructive or restrictive lung disease, HPS, or intracardiac shunting. We compared patients with and those without IPVD.

RESULTS

Forty-six patients with IPVD and 81 patients without IPVD were included. Patients with IPVD were more likely to have autoimmune hepatitis and less likely to have cryptogenic cirrhosis and hepatocellular carcinoma. Patients with IPVD had higher Child-Pugh scores (6 [interquartile range (IQR), 5-7] vs 5 [IQR, 4-7]; P = .04), possibly higher Model for End-Stage Liver Disease scores (14.5 [IQR, 11.6-15.8] vs 12.2 [IQR, 9.4-15.5]; P = .06), higher PaO₂ levels (97.9 [IQR, 92.0-103.0] vs 89.0 [IQR, 82.0-96.9] mm Hg; P < .001), and lower A-a gradients (9.9 [IQR, 6.2-13.5] vs 14.9 [IQR, 9.0-21.8] mm Hg; P < .001). Symptoms and quality of life were similar between the groups.

CONCLUSIONS

Autoimmune hepatitis and increased liver disease severity were associated with the presence of IPVD, which was characterized by higher PaO₂ levels. Future studies to better characterize IPVD pathogenesis and the relationship of IPVD to HPS are warranted.

Chronic obstructive pulmonary disease as a risk factor for ventricular arrhythmias independent of left ventricular function

BACKGROUND

The association between chronic obstructive pulmonary disease (COPD) and sudden cardiac death has not been fully elucidated.

OBJECTIVE

The purpose of this study was to investigate whether decreased left ventricular ejection fraction (LVEF) can explain the increased rate of ventricular tachycardia (VT) in COPD.

METHODS

This retrospective study included consecutive adult patients who underwent pulmonary function testing (PFT), Holter monitoring, and transthoracic echocardiography. COPD was correlated with the frequency of VT in a multivariate analysis that adjusted for known confounders including LVEF. Long-term all-cause mortality of patients with COPD and VT was examined.

RESULTS

Of the 6351 patients included in this study (age 66 ± 15 years; 48% woman; 92% Caucasian, LVEF 59% ± 12%), 2800 (44%) had PFT indicative of COPD. VT was nearly twice as likely to occur during Holter monitoring in COPD patients (13% vs 23%; P <.001), and the severity of COPD correlated with the risk of VT (21% vs 28% vs 37% for mild-moderate, severe, and very severe COPD; P <.001). COPD and VT remained independently associated (P <.001) even after adjusting for LVEF, demographics, and comorbidities (age, sex, body mass index, hypertension, chronic kidney disease, coronary artery disease, cancer history, diabetes mellitus). COPD was associated with all-cause mortality independently of LVEF (P <.001).

CONCLUSION

COPD patients are at higher risk for VT and mortality. This may not be fully attributed to the confounding effect of systolic heart failure measured by LVEF. Further studies are needed to explore the mechanistic interactions between VT and COPD in order to determine whether antiarrhythmic strategies would apply especially to patients with severe COPD.

Effect of beta-blockers on exacerbation rate and lung function in chronic obstructive pulmonary disease (COPD)

BACKGROUND

Beta-blockers are commonly prescribed for patients with cardiovascular disease. Providers have been wary of treating chronic obstructive pulmonary disease (COPD) patients with beta-blockers due to concern for bronchospasm, but retrospective studies have shown that cardio-selective beta-blockers are safe in COPD and possibly beneficial. However, these benefits may reflect symptom improvements due to the cardiac effects of the medication. The purpose of this study is to evaluate associations between beta-blocker use and both exacerbation rates and longitudinal measures of lung function in two well-characterized COPD cohorts.

METHODS

We retrospectively analyzed 1219 participants with over 180 days of follow up from the STATCOPE trial, which excluded most cardiac comorbidities, and from the placebo arm of the MACRO trial. Primary endpoints were exacerbation rates per person-year and change in spirometry over time in association with beta blocker use.

RESULTS

Overall 13.9% (170/1219) of participants reported taking beta-blockers at enrollment. We found no statistically significant differences in exacerbation rates with respect to beta-blocker use regardless of the prevalence of cardiac comorbidities. In the MACRO cohort, patients taking beta-blockers had an exacerbation rate of 1.72/person-year versus a rate of 1.71/person-year in patients not taking beta-blockers. In the STATCOPE cohort, patients taking beta-blockers had an exacerbation rate of 1.14/person-year. Patients without beta-blockers had an exacerbation rate of 1.34/person-year. We found no detrimental effect of beta blockers with respect to change in lung function over time.

CONCLUSION

We found no evidence that beta-blocker use was unsafe or associated with worse pulmonary outcomes in study participants with moderate to severe COPD.

The sawtooth sign is predictive of obstructive sleep apnea

BACKGROUND

The sawtooth sign in spirometry is associated with redundant upper airway tissue and snoring, but its predictive value for identifying obstructive sleep apnea (OSA) is disputed. We retrospectively assessed the predictive value of the spirometric sawtooth sign in terms of the odds ratio (OR) of association with a diagnosis of OSA compared to those without the sign.

METHODS

Consecutive spirometry reports showing a sawtooth sign were identified from our laboratory. We identified 50 subjects with sawtooth sign and 100 control subjects without sawtooth sign, matched for age, BMI, and gender. The electronic medical record of each patient was queried for a diagnosis of OSA based on physician-reported diagnoses.

RESULTS

Of the 50 subjects with sawtooth sign, 22 were found to have a current diagnosis of OSA (44%). Twenty-seven of the 100 controls (27%) also had OSA. From logistic regression analysis, sawtooth sign was associated with an increased likelihood of OSA (OR = 2.12, 95% C.I. 1.04 to 4.35). Similar results were obtained after adjustment for age, gender, pack years, and BMI (OR = 2.61, 95% C.I. 1.13 to 6.21).

CONCLUSIONS

Patients with the sawtooth sign have greater odds of having a diagnosis of OSA compared with those without the sign. If prospectively evaluated, as a result of improved identification, we hypothesize that the sawtooth sign may show an even stronger association with OSA. This relatively common finding, which adds no cost to routine spirometry, may serve as an indicator for OSA workup for some individuals not already identified as having OSA.

Association of Inhaled Corticosteroids with Incident Pneumonia and Mortality in COPD Patients; Systematic Review and Meta-Analysis

BACKGROUND

Inhaled corticosteroids are commonly prescribed for patients with severe COPD. They have been associated with increased risk of pneumonia but not with increased pneumonia-associated or overall mortality.

METHODS

To further examine the effects of inhaled corticosteroids on pneumonia incidence, and mortality in COPD patients, we searched for potentially relevant articles in PubMed, Medline, CENTRAL, EMBASE, Scopus, Web of Science and manufacturers' web clinical trial registries from 1994 to February 4, 2014. Additionally, we checked the included and excluded studies' bibliographies. We subsequently performed systematic review and meta-analysis of included randomized controlled trials and observational studies on the topic.

RESULTS

We identified 38 studies: 29 randomized controlled trials and nine observational studies. The estimated unadjusted risk of pneumonia was increased in randomized trials: RR 1.61; 95% CI 1.35-1.93, p < 0.001; as well as in observational studies: OR 1.89; 95% CI 1.39-2.58, p < 0·001. Six randomized trials and seven observational studies were useful in estimating unadjusted risk of pneumonia -case-fatality: RR 0.91; 95% CI 0.52-1.59, p = 0.74; and OR 0.72; 95% CI 0.59-0.88, p = 0.001, respectively. Twenty-nine randomized trials and six observational studies allowed estimation of unadjusted risk of overall mortality: RR 0.95; 95% CI 0.85-1.05, p = 0.31; and OR 0.79; 95% CI 0.65-0.97, p = 0.02, respectively.

CONCLUSIONS

Despite a substantial and significant increase in unadjusted risk of pneumonia associated with inhaled corticosteroid use, pneumonia fatality and overall mortality were found not to be increased in randomized controlled trials and were decreased in observational studies.

Incident pneumonia and mortality in patients with chronic obstructive pulmonary disease. A double effect of inhaled corticosteroids?

Inhaled corticosteroids are commonly prescribed for patients with severe chronic obstructive pulmonary disease. Although their use improves quality of life and reduces exacerbations, it is associated with increased risk of pneumonia. Curiously, their use has not been associated with increased risk of pneumonia-related or overall mortality. We review pertinent literature to further explore the effects of inhaled corticosteroids on incident pneumonia and mortality in patients with chronic obstructive pulmonary disease. The association of use of inhaled corticosteroids and incident pneumonia is substantial and has been present in the majority of the studies on the topic. This includes both randomized controlled trials and observational studies. However, all of the studies have substantial risk of bias. Most randomized trials are limited by lack of systematic ascertainment of pneumonia; they depended on adverse event reporting. Many observational studies included proper radiographic assessment of pneumonia, but they are limited by their retrospective, observational design. The unadjusted higher risk of pneumonia is associated with longer duration of use, more potent ICS compounds, and higher doses. That implies a dose-effect relationship. Unlike pneumonia, mortality is a precise outcome. Despite the robust association of inhaled corticosteroid use with increased risk of pneumonia, all studies find either no difference or a reduction in pulmonary-related and overall mortality associated with the use of inhaled corticosteroids. These observations suggest a double effect of inhaled corticosteroids (i.e., an adverse effect plus an unexplained mitigating effect).

Predictors of chronic obstructive pulmonary disease exacerbation reduction in response to daily azithromycin therapy

RATIONALE

Daily azithromycin decreases acute exacerbations of chronic obstructive pulmonary disease (AECOPD), but long-term side effects are unknown.

OBJECTIVES

To identify the types of exacerbations most likely to be reduced and clinical subgroups most likely to benefit from azithromycin, 250 mg daily, added to usual care.

METHODS

Enrollment criteria included irreversible airflow limitation and AECOPD requiring corticosteroids, emergency department visit, or hospitalization in the prior year or use of supplemental oxygen. Recurrent events and cumulative incidence analyses compared treatment received for AECOPD by randomization group, stratified by subgroups of interest. Cox proportional hazards models estimated treatment effects in subgroups adjusted for age, sex, smoking status, FEV1% predicted, concomitant COPD medications, and oxygen use.

MEASUREMENTS AND MAIN RESULTS

Azithromycin was most effective in reducing AECOPD requiring both antibiotic and steroid treatment (n = 1,113; cumulative incidence analysis, P = 0.0002; recurrent events analysis, P = 0.002). No difference in treatment response by sex (P = 0.75), presence of chronic bronchitis (P = 0.19), concomitant inhaled therapy (P = 0.29), or supplemental oxygen use (P = 0.23) was observed. Older age and milder Global Initiative for Chronic Obstructive Lung Disease stage were associated with better treatment response (P = 0.02 and 0.04, respectively). A significant interaction between treatment and current smoking was seen (P = 0.03) and azithromycin did not reduce exacerbations in current smokers (hazard ratio, 0.99; 95% confidence interval, 0.71-1.38; P = 0.95).

CONCLUSIONS

Azithromycin is most effective in preventing AECOPD requiring both antibiotic and steroid treatment. Adjusting for confounders, we saw no difference in efficacy by sex, history of chronic bronchitis, oxygen use, or concomitant COPD therapy. Greater efficacy was seen in older patients and milder Global Initiative for Chronic Obstructive Lung Disease stages. We found little evidence of treatment effect among current smokers. Clinical trial registered with www.clinicaltrials.gov (NCT0011986 and NCT00325897).

Relation of chronic obstructive pulmonary disease to atrial and ventricular arrhythmias

Chronic obstructive pulmonary disease (COPD) is associated with increased cardiovascular morbidity and mortality, yet the exact pathophysiological links remain unclear. Whether the presence and severity of COPD are associated with atrial or ventricular arrhythmias recorded on continuous electrocardiographic monitoring is unknown. We identified consecutive adult patients who underwent clinically indicated pulmonary function testing as well as 24-hour Holter monitoring at the Mayo Clinic, Rochester, from 2000 to 2009. Demographic data and relevant co-morbidities were gathered from the electronic medical record; severity of COPD was classified according to the GOLD classification, and arrhythmias were classified in concordance with the current clinical guidelines. From 7,441 patients who were included (age 64±16 years, 49% woman, 92% Caucasian), COPD was diagnosed in 3,121 (41.9%). Compared with those without COPD, the presence and severity of COPD were associated with increased likelihood of atrial fibrillation/atrial flutter (AF/AFL; 23.3% vs 11.0%, respectively, p<0.0001), nonsustained ventricular tachycardia (NSVT; 13.0% vs 5.9%, respectively, p<0.0001), and sustained ventricular tachycardia (0.9% vs 1.6%, respectively, p<0.0001). COPD remained a significant predictor of AF/AFL and NSVT (p<0.0001 and p<0.0001, respectively) after adjusting for age, gender, tobacco use, obesity, hypertension, coronary artery disease, heart failure, diabetes, anemia, cancer, chronic kidney disease, and rate/rhythm control medications. In conclusion, the independent association between the presence and severity of COPD and arrhythmias (AF/AFL and NSVT) provides further insight into the markedly increased cardiovascular mortality of patients with COPD. Further studies should explore which anti-arrhythmic strategies would best apply to the patients with COPD.

A prospective study of chronic obstructive pulmonary disease and the risk for mild cognitive impairment

IMPORTANCE

Previous studies suggest cross-sectional associations between a diagnosis of chronic obstructive pulmonary disease (COPD) and mild cognitive impairment (MCI). However, few studies have assessed whether COPD, a potentially modifiable factor, is associated with an increased risk for MCI and whether the relation is specific to the type of MCI.

OBJECTIVE

To investigate whether a diagnosis of COPD and duration of COPD are associated with an increased risk for incident MCI and MCI subtypes (amnestic MCI [A-MCI] and nonamnestic MCI [NA-MCI]).

DESIGN, SETTING, AND PARTICIPANTS

A prospective population-based cohort from the Mayo Clinic Study on Aging. We included 1425 cognitively normal individuals aged 70 to 89 years who were randomly selected from Olmsted County, Minnesota, on October 1, 2004, using the medical records linkage system. At baseline and every 15 months thereafter, participants underwent assessment with a nurse interview, neurologic examination, and neuropsychological testing. A diagnosis of COPD was confirmed via medical record review. A baseline diagnosis of COPD and duration of COPD were examined as risk factors for MCI and MCI subtypes using Cox proportional hazards models and adjusting for demographic variables and medical comorbidities, with age as the time scale.

EXPOSURE

A baseline diagnosis of COPD and duration of COPD.

MAIN OUTCOMES AND MEASURES

Incident MCI, A-MCI, and NA-MCI.

RESULTS

Of the 1425 participants with normal cognition at baseline, 370 developed incident MCI. The median duration of follow-up was 5.1 years (interquartile range, 3.8-5.4 years). A diagnosis of COPD significantly increased the risk for NA-MCI by 83% (hazard ratio, 1.83 [95% CI, 1.04-3.23]), but not of any MCI or A-MCI in multivariate analyses. We found a dose-response relationship such that individuals with COPD duration of longer than 5 years at baseline had the greatest risk for any MCI (hazard ratio, 1.58 [95% CI, 1.04-2.40]) and NA-MCI (2.58 [1.32-5.06]).

CONCLUSIONS AND RELEVANCE

A diagnosis of COPD is associated with an increased risk for MCI, particularly NA-MCI. We have found a dose-response relationship between COPD duration and risk for MCI. These findings highlight the importance of COPD as a risk factor for MCI and may provide a substrate for early intervention to prevent or delay the onset and progression of MCI, particularly NA-MCI.

Simvastatin for the prevention of exacerbations in moderate-to-severe COPD

BACKGROUND

Retrospective studies have shown that statins decrease the rate and severity of exacerbations, the rate of hospitalization, and mortality in chronic obstructive pulmonary disease (COPD). We prospectively studied the efficacy of simvastatin in preventing exacerbations in a large, multicenter, randomized trial.

METHODS

We designed the Prospective Randomized Placebo-Controlled Trial of Simvastatin in the Prevention of COPD Exacerbations (STATCOPE) as a randomized, controlled trial of simvastatin (at a daily dose of 40 mg) versus placebo, with annual exacerbation rates as the primary outcome. Patients were eligible if they were 40 to 80 years of age, had COPD (defined by a forced expiratory volume in 1 second [FEV1] of less than 80% and a ratio of FEV1 to forced vital capacity of less than 70%), and had a smoking history of 10 or more pack-years, were receiving supplemental oxygen or treatment with glucocorticoids or antibiotic agents, or had had an emergency department visit or hospitalization for COPD within the past year. Patients with diabetes or cardiovascular disease and those who were taking statins or who required statins on the basis of Adult Treatment Panel III criteria were excluded. Participants were treated from 12 to 36 months at 45 centers.

RESULTS

A total of 885 participants with COPD were enrolled for approximately 641 days; 44% of the patients were women. The patients had a mean (±SD) age of 62.2±8.4 years, an FEV1 that was 41.6±17.7% of the predicted value, and a smoking history of 50.6±27.4 pack-years. At the time of study closeout, the low-density lipoprotein cholesterol levels were lower in the simvastatin-treated patients than in those who received placebo. The mean number of exacerbations per person-year was similar in the simvastatin and placebo groups: 1.36±1.61 exacerbations and 1.39±1.73 exacerbations, respectively (P=0.54). The median number of days to the first exacerbation was also similar: 223 days (95% confidence interval [CI], 195 to 275) and 231 days (95% CI, 193 to 303), respectively (P=0.34). The number of nonfatal serious adverse events per person-year was similar, as well: 0.63 events with simvastatin and 0.62 events with placebo. There were 30 deaths in the placebo group and 28 in the simvastatin group (P=0.89).

CONCLUSIONS

Simvastatin at a daily dose of 40 mg did not affect exacerbation rates or the time to a first exacerbation in patients with COPD who were at high risk for exacerbations. (Funded by the National Heart, Lung, and Blood Institute and the Canadian Institutes of Health Research; STATCOPE ClinicalTrials.gov number, NCT01061671.).

Sputum PGP is reduced by azithromycin treatment in patients with COPD and correlates with exacerbations

RATIONALE

Proline-glycine-proline (PGP), a neutrophil chemoattractant derived from the enzymatic breakdown of collagen, is elevated in sputum of patients with chronic obstructive pulmonary disease (COPD) and may contribute to disease progression. Whether sputum levels of PGP respond to therapy for COPD or predict outcomes is unknown.

OBJECTIVES

We conducted a study ancillary to a multicenter trial of the efficacy of azithromycin treatment for 1 year in preventing COPD exacerbations to test whether sputum levels of PGP were altered by treatment or associated with exacerbation frequency.

METHODS

We collected remnant sputa from trial participants and assayed them in a blinded fashion for PGP, myeloperoxidase and matrix metalloproteinase (MMP)-9 and for the ability to generate PGP from collagen ex vivo. Once the parent trial was unblinded, the results were correlated with use of azithromycin or placebo and exacerbations in participants.

RESULTS

Azithromycin treatment significantly reduced sputum levels of PGP and myeloperoxidase in patients with COPD, particularly with increased duration of therapy. We found no difference in sputum MMP-9 or PGP generation between participants taking azithromycin or placebo. Sputum PGP levels were highest around the time of an exacerbation and declined with successful treatment.

CONCLUSIONS

These data support a role for PGP in the airway and parenchymal neutrophilic inflammation that drives COPD progression and exacerbations, and provide new information on the anti-inflammatory properties of macrolides. PGP may have potential as a target for novel anti-inflammatory therapies in COPD and as a biomarker for clinical trials.

Chronic obstructive pulmonary disease and association with mild cognitive impairment: the Mayo Clinic Study of Aging

OBJECTIVE

To investigate the association of chronic obstructive pulmonary disease (COPD) with mild cognitive impairment (MCI) and MCI subtype: amnestic MCI and nonamnestic MCI, in a population-based study of elderly patients.

PATIENTS AND METHODS

Participants included 1927 individuals aged 70 to 89 years enrolled in the population-based Mayo Clinic Study of Aging. Participants were evaluated by using a nurse assessment, neurological evaluation, and neuropsychological testing, and the diagnosis of MCI was made by a consensus panel according to the standardized criteria. Chronic obstructive pulmonary disease was identified by the review of medical records. The study was conducted from October 1, 2004, through July 31, 2007. The associations of COPD and disease duration with MCI and its subtypes were evaluated by using logistic regression models adjusted for potential covariates.

RESULTS

Of 1927 participants, 288 had COPD (men vs women: 18% vs 12%; P<.001). As compared with patients without COPD, patients with COPD had a higher prevalence of MCI (27% vs 15%; P<.001). The odds ratio (OR) for MCI was almost 2 times higher in patients with COPD than in those without (OR, 1.87; 95% CI, 1.34-2.61), with a similar effect in men and women. The OR for MCI increased from 1.60 (95% CI, 0.97-2.57) in patients with a COPD duration of 5 years or less to 2.10 (95% CI, 1.38-3.14) in patients with a COPD duration of more than 5 years.

CONCLUSION

This population-based study suggests that COPD is associated with increased odds of having MCI and its subtypes. There was a dose-response relationship with the duration of COPD after controlling for the potential covariates.

Chronic productive cough is associated with death in smokers with early COPD

Cough and phlegm are common in COPD. Previous studies have shown conflicting evidence regarding their association with mortality and lung function. We sought to better understand how cough and phlegm impact mortality and lung function in COPD. We analyzed data from the Lung Health Study, consisting of 5,887 smokers with mild to moderate airflow obstruction followed longitudinally. We assessed the association between baseline symptoms of cough alone, phlegm alone, and cough and phlegm with 12.5-year mortality and annual lung function decline. Average age at entry was 48.5 years (± 6.8) with 63% males and 4% African Americans. Cough alone was present in 17%, phlegm alone in 12%, while 31% had both. Neither symptom alone was associated with death, but the combination was associated with increased risk of death after adjustment for age, gender, race, smoking status at year 5, pack-years smoked, randomization group, baseline FEV1 percent predicted (HR 1.27, 95% CI 1.02-1.59). Individuals with cough and phlegm together more commonly died of respiratory causes than those without. Cough with phlegm was associated with 48 mL lower baseline FEV1 (95% CI -90, -6), while neither symptom alone was associated with baseline FEV1. No symptom was associated with FEV1 longitudinally. Cough and phlegm together are associated with mortality and lung function decrement in mild-to-moderate COPD, independent of lung function and smoking status. Respiratory causes of death are common among those with cough and phlegm. Such information can help to identify subsets of individuals with COPD having higher risk for adverse outcomes.

Estimates of restrictive ventilatory defect in the mining industry. Considerations for epidemiological investigations: a cross-sectional study

OBJECTIVES

(1) To assess the impact of American Thoracic Society and European Respiratory Society (ATS/ERS) 'acceptability' and 'usability' criteria for spirometry on the estimates of restrictive ventilatory defect in a population of taconite miners. (2) To compare estimates of restrictive ventilatory defect with three different pulmonary function tests (spirometry, alveolar volume (VA) and diffusing capacity (DL,CO)). (3) To assess the role of population characteristics on these estimates.

DESIGN

Cross-sectional study.

SETTING

Current and former workers in six current taconite mining operations of northeastern Minnesota were surveyed.

PARTICIPANTS

We attempted to enrol 3313 participants. Of these, 1353 responded while 1188 current and former workers fully participated in the survey and 1084 performed complete pulmonary function testing and were assessed.

PRIMARY AND SECONDARY OUTCOME MEASURES

We applied ATS/ERS acceptability criteria for all tests and categorised participants into groups according to whether they fully met, partially met or did not meet acceptability criteria for spirometry. Obstruction and restriction were defined utilising the lower limit of normal for all tests. When using VA, restriction was identified after excluding obstruction.

RESULTS

Only 519 (47.9%) tests fully met ATS/ERS spirometry acceptability criteria. Within this group, 5% had obstruction and 6%, restriction on spirometry. In contrast, among all participants (N=1084), 16.8% had obstruction, while 4.5% had restriction. VA showed similar results in all groups after obstruction was excluded. Impaired gas transfer (reduced DL,CO) was identified in less than 50% of restriction identified by either spirometry or VA. Body mass index (BMI) was significantly related to spirometric restriction in all groups.

CONCLUSIONS

Population estimates of restriction using spirometry or VA varied by spirometric acceptability criteria. Other factors identified as important considerations in the estimation of restrictive ventilatory defect included increased BMI and gas transfer impairment in a relatively smaller proportion of those with spirometric restriction. These insights are important when interpreting population-based physiological data in occupational settings.

Long-term comparative immunogenicity of protein conjugate and free polysaccharide pneumococcal vaccines in chronic obstructive pulmonary disease

BACKGROUND

Although the 23-valent pneumococcal polysaccharide vaccine (PPSV23) protects against invasive disease in young healthy persons, randomized controlled trials in chronic obstructive pulmonary disease (COPD) have demonstrated no benefit in the intention-to-treat population. We previously reported that the 7-valent diphtheria-conjugated pneumococcal polysaccharide vaccine (PCV7) is safe and induced greater serotype-specific immunoglobulin G (IgG) and functional antibody than did PPSV23 1 month after vaccination. We hypothesized that these advantages would persist at 1 and 2 years.

METHODS

One hundred eighty-one patients with moderate to severe COPD were randomized to receive PPSV23 (n = 90) or PCV7 (1.0 mL; n = 91). We measured IgG by enzyme-linked immunosorbent assay and assessed functional antibody activity by a standardized opsonophagocytosis assay, reported as a killing index (OPK). We determined differences in IgG and OPK between vaccine groups at 1 and 2 years.

RESULTS

Relative to PPSV23, PCV7 induced greater OPK at both 1 and 2 years for 6 of 7 serotypes (not 19F). This response was statistically greater for 5 of 7 serotypes at 1 year and 4 of 7 at 2 years. Comparable differences in IgG were observed but were less often statistically significant. Despite meeting Centers for Disease Control and Prevention criteria for PPSV23 administration, almost 50% of individuals had never been vaccinated. No differences in the frequency of acute exacerbations, pneumonia, or hospitalization were observed.

CONCLUSIONS

PCV7 induces a greater functional antibody response than PPSV23 in patients with COPD that persists for 2 years after vaccination. This superior functional response supports testing of conjugate vaccination in studies examining clinical end points.

CLINICAL TRIALS REGISTRATION

NCT00457977.

Spirometric predictors of lung function decline and mortality in early chronic obstructive pulmonary disease

RATIONALE

The course of lung function decline for smokers with early airflow obstruction remains undefined. It is also unclear which early spirometric characteristics identify individuals at risk for rapid decline and increased mortality.

OBJECTIVES

To determine the association between spirometric measures and 5-year decline in FEV(1) and 12-year mortality.

METHODS

We analyzed longitudinal data from the Lung Health Study, a clinical trial of intensive smoking cessation intervention with or without bronchodilator therapy in 5,887 smokers with mild to moderate airflow obstruction. Participants were stratified into bins of baseline FEV(1) to FVC ratio, using bins of 5%, and separately into bins of Z-score (difference between actual and predicted FEV(1)/FVC, normalized to SD of predicted FEV(1)/FVC). Associations between spirometric measures and FEV(1) decline and mortality were determined after adjusting for baseline characteristics and time-varying smoking status.

MEASUREMENTS AND MAIN RESULTS

The cohort was approximately two-thirds male, predominantly of white race (96%), and with mean age of 49 ± 7 years. In general, individuals with lower lung function by any metric had more rapid adjusted FEV(1) decline. A threshold for differential decline was present at FEV(1)/FVC less than 0.65 (P < 0.001) and Z-score less than -2 (2.3 percentile) (P < 0.001). At year 12, 575 (7.2%) of the cohort had died. Lower thresholds of each spirometric metric were associated with increasing adjusted hazard of death.

CONCLUSIONS

Smokers at risk or with mild to moderate chronic obstructive pulmonary disease have accelerated lung function decline. Individuals with lower baseline FEV(1)/FVC have more rapid decline and worse mortality.

Genetic variants associated with the risk of chronic obstructive pulmonary disease with and without lung cancer

Chronic obstructive pulmonary disease (COPD) is a strong risk factor for lung cancer. Published studies about variations of genes encoding glutathione metabolism, DNA repair, and inflammatory response pathways in susceptibility to COPD were inconclusive. We evaluated 470 single-nucleotide polymorphisms (SNP) from 56 genes of these three pathways in 620 cases and 893 controls to identify susceptibility markers for COPD risk, using existing resources. We assessed SNP- and gene-level effects adjusting for sex, age, and smoking status. Differential genetic effects on disease risk with and without lung cancer were also assessed; cumulative risk models were established. Twenty-one SNPs were found to be significantly associated with risk of COPD (P < 0.01); gene-based analyses confirmed two genes (GCLC and GSS) and identified three additional genes (GSTO2, ERCC1, and RRM1). Carrying 12 high-risk alleles may increase risk by 2.7-fold; eight SNPs altered COPD risk without lung cancer by 3.1-fold and 4 SNPs altered the risk with lung cancer by 2.3-fold. Our findings indicate that multiple genetic variations in the three selected pathways contribute to COPD risk through GCLC, GSS, GSTO2, ERCC1, and RRM1 genes. Functional studies are needed to elucidate the mechanisms of these genes in the development of COPD, lung cancer, or both.

Changes in forced expiratory volume in 1 second over time in COPD

BACKGROUND

A key feature of chronic obstructive pulmonary disease (COPD) is an accelerated rate of decline in forced expiratory volume in 1 second (FEV(1)), but data on the variability and determinants of this change in patients who have established disease are scarce.

METHODS

We analyzed the changes in FEV(1) after administration of a bronchodilator over a 3-year period in 2163 patients. A random-coefficient model was used to evaluate possible predictors of both FEV(1) levels and their changes over time.

RESULTS

The mean (±SE) rate of change in FEV(1) was a decline of 33±2 ml per year, with significant variation among the patients studied. The between-patient standard deviation for the rate of decline was 59 ml per year. Over the 3-year study period, 38% of patients had an estimated decline in FEV(1) of more than 40 ml per year, 31% had a decline of 21 to 40 ml per year, 23% had a change in FEV(1) that ranged from a decrease of 20 ml per year to an increase of 20 ml per year, and 8% had an increase of more than 20 ml per year. The mean rate of decline in FEV(1) was 21±4 ml per year greater in current smokers than in current nonsmokers, 13±4 ml per year greater in patients with emphysema than in those without emphysema, and 17±4 ml per year greater in patients with bronchodilator reversibility than in those without reversibility.

CONCLUSIONS

The rate of change in FEV(1) among patients with COPD is highly variable, with increased rates of decline among current smokers, patients with bronchodilator reversibility, and patients with emphysema.

Azithromycin for prevention of exacerbations of COPD

BACKGROUND

Acute exacerbations adversely affect patients with chronic obstructive pulmonary disease (COPD). Macrolide antibiotics benefit patients with a variety of inflammatory airway diseases.

METHODS

We performed a randomized trial to determine whether azithromycin decreased the frequency of exacerbations in participants with COPD who had an increased risk of exacerbations but no hearing impairment, resting tachycardia, or apparent risk of prolongation of the corrected QT interval.

RESULTS

A total of 1577 subjects were screened; 1142 (72%) were randomly assigned to receive azithromycin, at a dose of 250 mg daily (570 participants), or placebo (572 participants) for 1 year in addition to their usual care. The rate of 1-year follow-up was 89% in the azithromycin group and 90% in the placebo group. The median time to the first exacerbation was 266 days (95% confidence interval [CI], 227 to 313) among participants receiving azithromycin, as compared with 174 days (95% CI, 143 to 215) among participants receiving placebo (P<0.001). The frequency of exacerbations was 1.48 exacerbations per patient-year in the azithromycin group, as compared with 1.83 per patient-year in the placebo group (P=0.01), and the hazard ratio for having an acute exacerbation of COPD per patient-year in the azithromycin group was 0.73 (95% CI, 0.63 to 0.84; P<0.001). The scores on the St. George's Respiratory Questionnaire (on a scale of 0 to 100, with lower scores indicating better functioning) improved more in the azithromycin group than in the placebo group (a mean [±SD] decrease of 2.8±12.8 vs. 0.6±11.4, P=0.004); the percentage of participants with more than the minimal clinically important difference of -4 units was 43% in the azithromycin group, as compared with 36% in the placebo group (P=0.03). Hearing decrements were more common in the azithromycin group than in the placebo group (25% vs. 20%, P=0.04).

CONCLUSIONS

Among selected subjects with COPD, azithromycin taken daily for 1 year, when added to usual treatment, decreased the frequency of exacerbations and improved quality of life but caused hearing decrements in a small percentage of subjects. Although this intervention could change microbial resistance patterns, the effect of this change is not known. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00325897.).

Telling the patient's story: using theatre training to improve case presentation skills

A medical student's ability to present a case history is a critical skill that is difficult to teach. Case histories presented without theatrical engagement may fail to catch the attention of their intended recipients. More engaging presentations incorporate 'stage presence', eye contact, vocal inflection, interesting detail and succinct, well organised performances. They convey stories effectively without wasting time. To address the didactic challenge for instructing future doctors in how to 'act', the Mayo Medical School and The Mayo Clinic Center for Humanities in Medicine partnered with the Guthrie Theater to pilot the programme 'Telling the Patient's Story'. Guthrie teaching artists taught storytelling skills to medical students through improvisation, writing, movement and acting exercises. Mayo Clinic doctors participated and provided students with feedback on presentations and stories from their own experiences in patient care. The course's primary objective was to build students' confidence and expertise in storytelling. These skills were then applied to presenting cases and communicating with patients in a fresher, more engaging way. This paper outlines the instructional activities as aligned with course objectives. Progress was tracked by comparing pre-course and post-course surveys from the seven participating students. All agreed that the theatrical techniques were effective teaching methods. Moreover, this project can serve as an innovative model for how arts and humanities professionals can be incorporated for teaching and professional development initiatives at all levels of medical education.

Randomized trial of zileuton for treatment of COPD exacerbations requiring hospitalization

RATIONALE

Leukotrienes have been implicated in the pathogenesis of acute exacerbations of COPD, but leukotriene modifiers have not been studied as a possible therapy for exacerbations.

OBJECTIVE

We sought to test the safety and efficacy of adding oral zileuton (a 5-lipoxygenase inhibitor) to usual treatment for acute exacerbations of COPD requiring hospitalization.

METHODS

Randomized double-blind, placebo-controlled, parallel group study of zileuton 600 mg orally, 4 times daily versus placebo for 14 days starting within 12 hours of hospital admission for COPD exacerbation. Primary outcome measure was hospital length of stay; secondary outcomes included treatment failure and biomarkers of leukotriene production.

MAIN FINDINGS

Sixty subjects were randomized to zileuton and 59 to placebo (the study was stopped short of enrollment goals because of slow recruitment). There was no difference in hospital length of stay (3.75 +/- 2.19 vs. 3.86 +/- 3.06 days for zileuton vs. placebo, p = 0.39) or treatment failure (23% vs. 27% for zileuton vs. placebo, p = 0.63) despite a decline in urinary LTE(4) levels in the zileuton-treated group as compared to placebo at 24 hours (change in natural log-transformed ng/mg creatinine -1.38 +/- 1.19 vs. 0.14 +/- 1.51, p < 0.0001) and 72 hours (-1.32 +/- 2.08 vs. 0.26 +/- 1.93, p<0.006). Adverse events were similar in both groups.

PRINCIPAL CONCLUSIONS

While oral zileuton during COPD exacerbations that require hospital admission is safe and reduces urinary LTE(4) levels, we found no evidence suggesting that this intervention shortened hospital stay, with the limitation that our sample size may have been insufficient to detect a modest but potentially meaningful clinical improvement.

The nonspecific pulmonary function test: longitudinal follow-up and outcomes

BACKGROUND

The nonspecific (NS) pulmonary function (PF) pattern refers to a PF test with a normal total lung capacity (TLC), normal FEV₁/FVC ratio, and a low FEV₁, a low FVC, or both. Currently, no information is available regarding the long-term stability of the NS pattern or variables that predict changes in subjects with an initial NS PF pattern.

METHODS

From 1990 to 2005 we identified 1,284 subjects with an NS pattern on initial PF testing with one or more follow-up PF tests 6 months or more after the initial NS test result. Lung volumes, diffusing capacity, and spirometry data were analyzed. A multivariate, multinomial logistic regression model was used to study the association between different variables and the final PF pattern.

RESULTS

Overall, 3,674 PF tests were performed in 1,284 subjects over a median follow-up period of 3 years. At last follow-up, 818/1,284 (64%) subjects continued to show the NS pattern, whereas 208/1,284 (16%) showed a restrictive pattern, 191/1,284 (15%) an obstructive pattern, 42/1,284 (3%) a normal pattern, and 25/1,284 (2%) a mixed pattern. The multinomial logistic regression analysis showed that increasing values for specific airway resistance and the difference between TLC and alveolar volume were predictors of a change to an obstructive pattern on follow-up.

CONCLUSIONS

The NS pattern is a distinct and stable PF test pattern with roughly two-thirds of patients continuing to show this pattern on follow-up testing. Current interpretation guidelines erroneously label the NS pattern as representing obstruction and need to be changed to reflect these data.

Superior immune response to protein-conjugate versus free pneumococcal polysaccharide vaccine in chronic obstructive pulmonary disease

RATIONALE

Debate exists about the immunogenicity and protective efficacy of antibodies produced by the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in chronic obstructive pulmonary disease (COPD). The 7-valent diphtheria-conjugated pneumococcal polysaccharide vaccine (PCV7) induces a more robust immune response than PPSV23 in healthy elderly adults.

OBJECTIVES

We hypothesized that serotype-specific IgG antibody concentration and functional antibody activity would be superior after PCV7 vaccination compared with PPSV23 in moderate to severe COPD. We also posited that older age and prior PPSV23 vaccination would be associated with reduced vaccine responsiveness.

METHODS

One hundred twenty patients with COPD were randomized to PPSV23 (63 subjects) or PCV7 (57 subjects). IgG concentrations were determined by ELISA; functional antibody activity was assayed with a standardized opsonophagocytosis assay and reported as an opsonization killing index (OPK). Increases in serotype-specific IgG and OPK at 1 month post vaccination were compared within and between vaccine groups.

MEASUREMENTS AND MAIN RESULTS

Both vaccines were well tolerated. Within each study group, postvaccination IgG and OPK were higher than baseline (P < 0.01) for all serotypes. Adjusted for baseline levels, postvaccination IgG was higher in the PCV7 group than the PPSV23 group for all seven serotypes, reaching statistical significance for five (P < 0.05). PCV7 resulted in a higher OPK for six of seven serotypes (statistically greater for four) compared with PPSV23. In multivariate analyses, younger age, vaccine naivety, and receipt of PCV7 were associated with increased OPK responses.

CONCLUSIONS

PCV7 induces a superior immune response at 1 month post vaccination compared with PPSV23 in COPD. Older age and prior PPSV23 reduce vaccine responsiveness. Clinical trial registered with www.clinicaltrials.gov (NCT00457977).

Genetic determinants of emphysema distribution in the national emphysema treatment trial

RATIONALE

Computed tomography (CT) scanning of the lung may reduce phenotypic heterogeneity in defining subjects with chronic obstructive pulmonary disease (COPD), and allow identification of genetic determinants of emphysema severity and distribution.

OBJECTIVES

We sought to identify genes associated with CT scan distribution of emphysema in individuals without alpha1-antitrypsin deficiency but with severe COPD.

METHODS

We evaluated baseline CT densitometry phenotypes in 282 individuals with emphysema enrolled in the Genetics Ancillary Study of the National Emphysema Treatment Trial, and used regression models to identify genetic variants associated with emphysema distribution.

MEASUREMENTS AND MAIN RESULTS

Emphysema distribution was assessed by two methods--assessment by radiologists and by computerized density mask quantitation, using a threshold of -950 Hounsfield units. A total of 77 polymorphisms in 20 candidate genes were analyzed for association with distribution of emphysema. GSTP1, EPHX1, and MMP1 polymorphisms were associated with the densitometric, apical-predominant distribution of emphysema (p value range = 0.001-0.050). When an apical-predominant phenotype was defined by the radiologist scoring method, GSTP1 and EPHX1 single-nucleotide polymorphisms were found to be significantly associated. In a case-control analysis of COPD susceptibility limited to cases with densitometric upper-lobe-predominant cases, the EPHX1 His139Arg single-nucleotide polymorphism was associated with COPD (p = 0.005).

CONCLUSIONS

Apical and basal emphysematous destruction appears to be influenced by different genes. Polymorphisms in the xenobiotic enzymes, GSTP1 and EPHX1, are associated with apical-predominant emphysema. Altered detoxification of cigarette smoke metabolites may contribute to emphysema distribution, and these findings may lead to further insight into genetic determinants of emphysema.

Genetic association analysis of functional impairment in chronic obstructive pulmonary disease

RATIONALE

Patients with severe chronic obstructive pulmonary disease (COPD) may have varying levels of disability despite similar levels of lung function. This variation may reflect different COPD subtypes, which may have different genetic predispositions.

OBJECTIVES

To identify genetic associations for COPD-related phenotypes, including measures of exercise capacity, pulmonary function, and respiratory symptoms.

METHODS

In 304 subjects from the National Emphysema Treatment Trial, we genotyped 80 markers in 22 positional and/or biologically plausible candidate genes. Regression models were used to test for association, using a test-replication approach to guard against false-positive results. For significant associations, effect estimates were recalculated using the entire cohort. Positive associations with dyspnea were confirmed in families from the Boston Early-Onset COPD Study.

RESULTS

The test-replication approach identified four genes-microsomal epoxide hydrolase (EPHX1), latent transforming growth factor-beta binding protein-4 (LTBP4), surfactant protein B (SFTPB), and transforming growth factor-beta1 (TGFB1)-that were associated with COPD-related phenotypes. In all subjects, single-nucleotide polymorphisms (SNPs) in EPHX1 (p < or = 0.03) and in LTBP4 (p < or = 0.03) were associated with maximal output on cardiopulmonary exercise testing. Markers in LTBP4 (p < or = 0.05) and SFTPB (p = 0.005) were associated with 6-min walk test distance. SNPs in EPHX1 were associated with carbon monoxide diffusing capacity (p < or = 0.04). Three SNPs in TGFB1 were associated with dyspnea (p < or = 0.002), one of which replicated in the family study (p = 0.02).

CONCLUSIONS

Polymorphisms in several genes seem to be associated with COPD-related traits other than FEV(1). These associations may identify genes in pathways important for COPD pathogenesis.

Neurohumoral activation as a link to systemic manifestations of chronic lung disease

COPD is a major cause of death and disability worldwide. Treatment of COPD improves lung function but is unlikely to slow the steady downhill course of the disease or reduce mortality. In COPD, numerous abnormalities can be found outside the lung. These include systemic inflammation, cachexia, and skeletal muscle dysfunction. Thus, COPD has been called a systemic disease. Convincing data demonstrate that COPD causes neurohumoral activation. By precedents derived from chronic heart failure and other diseases characterized by neurohumoral activation, we propose that the negative consequences of neurohumoral activation, namely inflammation, cachexia, effects on ventilation, and skeletal muscle dysfunction, give rise to a self-perpetuating cycle that contributes to the pathogenesis of COPD, and which may involve respiratory muscle dysfunction as well as systemic inflammation. This concept may further help explain the increased cardiovascular morbidity and mortality in COPD patients. Currently, little is known about the effect of treatments directed at neurohumoral activation and COPD. As this aspect of COPD becomes better understood, new insights may direct novel therapeutic approaches.