Pulmonary arterial enlargement and acute exacerbations of COPD

Clinical impact of episodic nocturnal hypercapnia and its treatment with noninvasive positive pressure ventilation in patients with stable advanced COPD

Purpose

Episodic nocturnal hypercapnia (eNH) caused by rapid eye movement (REM) sleep-related hypoventilation is often noted in patients with advanced COPD. The purpose of this study was to clarify the clinical significance of eNH and the effectiveness of eNH-targeted noninvasive positive pressure ventilation (NPPV).

Patients and methods

We enrolled patients with stable, severe, or very severe COPD with daytime arterial partial oxygen pressure PaO₂ ≥55 mmHg and daytime arterial partial carbon dioxide pressure PaCO₂ <55 mmHg, who underwent overnight transcutaneous carbon dioxide pressure (PtcCO₂) monitoring from April 2013 to April 2016. We retrospectively compared clinical characteristics, daytime blood gas analysis, frequency of exacerbation, serum albumin levels, and ratio of pulmonary artery to aorta diameter (PA:A ratio), between patients with COPD with and without eNH. For those with eNH, we applied NPPV and compared these clinical characteristics before and after NPPV.

Results

Twenty-one patients were finally included in this study. Ten patients (47.6%) were evaluated to have eNH. These patients had lower albumin levels (p=0.027), larger PA:A ratio (p=0.019), and higher frequency of exacerbations during the last year (p=0.036). NPPV for the patients with eNH improved daytime PaCO₂ compared with that 12 months after NPPV (p=0.011). The frequency of exacerbations 1 year before NPPV decreased 1 year after NPPV (p=0.030). Serum albumin levels improved 1 year after NPPV (p=0.001).

Conclusion

In patients with stable severe or very severe COPD, eNH may be a risk factor of exacerbations, hypoalbuminemia, and pulmonary hypertension. NPPV may be effective against hypoalbuminemia and acute exacerbations. However, further study is necessary to validate these findings.

Multiorgan structures detection using deep convolutional neural networks

Many automatic image analysis algorithms in medical imaging require a good initialization to work properly. A similar problem occurs in many imaging-based clinical workflows, which depend on anatomical landmarks. The localization of anatomic structures based on a defined context provides with a solution to that problem, which turns out to be more challenging in medical imaging where labeled images are difficult to obtain. We propose a two-stage process to detect and regress 2D bounding boxes of predefined anatomical structures based on a 2D surrounding context. First, we use a deep convolutional neural network (DCNN) architecture to detect the optimal slice where an anatomical structure is present, based on relevant landmark features. After this detection, we employ a similar architecture to perform a 2D regression with the aim of proposing a bounding box where the structure is encompassed. We trained and tested our system for 57 anatomical structures defined in axial, sagittal and coronal planes with a dataset of 504 labeled Computed Tomography (CT) scans. We compared our method with a well-known object detection algorithm (Viola Jones) and with the inter-rater error for two human experts. Despite the relatively small number of scans and the exhaustive number of structures analyzed, our method obtained promising and consistent results, which proves our architecture very generalizable to other anatomical structures.

Co-existence of COPD and bronchiectasis: a risk factor for a high ratio of main pulmonary artery to aorta diameter (PA:A) from computed tomography in COPD patients

Background

Pulmonary vascular disease, especially pulmonary hypertension, is an important complication of COPD. Bronchiectasis is considered not only a comorbidity of COPD, but also a risk factor for vascular diseases. The main pulmonary artery to aorta diameter ratio (PA:A ratio) has been found to be a reliable indicator of pulmonary vascular disease. It is hypothesized that the co-existence of COPD and bronchiectasis may be associated with relative pulmonary artery enlargement (PA:A ratio >1).

Methods

This retrospective study enrolled COPD patients from 2012 through 2016. Demographic and clinical data were collected. Bhalla score was used to determine the severity of bronchiectasis. Patient characteristics were analyzed in two ways: the high (PA:A >1) and low (PA:A ≤1) ratio groups; and COPD with and without bronchiectasis groups. Logistic regression analysis was used to assess risk factors for high PA:A ratios.

Results

In this study, 480 COPD patients were included, of whom 168 had radiographic bronchiectasis. Patients with pulmonary artery enlargement presented with poorer nutrition (albumin, 35.6±5.1 vs 38.3±4.9, P<0.001), lower oxygen partial pressure (74.4±34.5 vs 81.3±25.4, P<0.001), more severe airflow obstruction (FEV1.0, 0.9±0.5 vs 1.1±0.6, P=0.004), and a higher frequency of bronchiectasis (60% vs 28.8%, P<0.001) than patients in the low ratio group. Patients with both COPD and bronchiectasis had higher levels of systemic inflammation (erythrocyte sedimentation rate, P<0.001 and fibrinogen, P=0.006) and PA:A ratios (P<0.001). A higher PA:A ratio was significantly closely correlated with a higher Bhalla score (r=0.412, P<0.001). Patients with both COPD and bronchiectasis with high ratios presented higher levels of NT-proBNP (P<0.001) and systolic pulmonary artery pressure (P<0.001). Multiple logistic analyses have indicated that bronchiectasis is an independent risk factor for high PA:A ratios in COPD patients (OR =3.707; 95% CI =1.888-7.278; P<0.001).

Conclusion

Bronchiectasis in COPD has been demonstrated to be independently associated with relative pulmonary artery enlargement.

AT-RVD1 repairs mouse lung after cigarette smoke-induced emphysema via downregulation of oxidative stress by NRF2/KEAP1 pathway

Long-term exposure to cigarette smoke (CS) results in alveolar parenchyma destruction due to chronic inflammatory response and the imbalance between oxidants and antioxidants, and proteases and antiproteases. Emphysema is the main symptom of chronic obstructive pulmonary disease. Current treatment focuses on relieving respiratory symptoms, and inflammation resolution failure is an important pathophysiological element of the disease. Specialized pro-resolving mediators (SPMs) synthesized endogenously during resolution processes demonstrated beneficial effects in murine models of airway inflammation. Here, we aimed to test the SPM AT-RvD1 in a murine model of CS-induced emphysema. AT-RvD1 restored elastic fibers and lung morphology, with reduction in MMP-3, neutrophils, and myeloperoxidase activity and increases in macrophages and IL-10 levels. AT-RvD1 also decreased levels of oxidative stress markers and ROS via upregulation of the Nrf2/Keap1 pathway. Therefore, we suggest that AT-RvD1 causes pro-resolutive action in our murine model of CS-induced emphysema by upregulation of the Nrf2/Keap1 pathway.

Leveraging the coronary calcium scan beyond the coronary calcium score

Non-contrast cardiac computed tomography in order to obtain the coronary artery calcium score has become an established diagnostic procedure in the clinical setting, and is commonly employed in clinical and population-based research. This state-of-the-art review paper highlights the potential gain in information that can be obtained from the non-contrast coronary calcium scans without any necessary modifications to the scan protocol. This includes markers of cardio-metabolic health, such as the amount of epicardial fat and liver fat, but also markers of general health including bone density and lung density. Finally, this paper addresses the importance of incidental findings and of radiation exposure accompanying imaging with non-contrast cardiac computed tomography. Despite the fact that coronary calcium scan protocols have been optimized for the visualization of coronary calcification in terms image quality and radiation exposure, it is important for radiologists, cardiologists and medical specialists in the field of preventive medicine to acknowledge that numerous additional markers of cardio-metabolic health and general health can be readily identified on a coronary calcium scan.

KEY POINTS

• The coronary artery calcium score substantially increased the use of cardiac CT. • Cardio-metabolic and general health markers may be derived without changes to the scan protocol. • Those include epicardial fat, aortic valve calcifications, liver fat, bone density, and lung density. • Clinicians must be aware of this potential additional yield from non-contrast cardiac CT.

Clinical and prognostic relationships of pulmonary artery to aorta diameter ratio in patients with heart failure: a cardiac magnetic resonance imaging study

BACKGROUND

The pulmonary artery (PA) distends as pressure increases.

HYPOTHESIS

The ratio of PA to aortic (Ao) diameter may be an indicator of pulmonary hypertension and consequently carry prognostic information in patients with chronic heart failure (HF).

METHODS

Patients with chronic HF and control subjects undergoing cardiac magnetic resonance imaging were evaluated. The main PA diameter and the transverse axial Ao diameter at the level of bifurcation of the main PA were measured. The maximum diameter of both vessels was measured throughout the cardiac cycle and the PA/Ao ratio was calculated.

RESULTS

A total of 384 patients (mean age, 69 years; mean left ventricular ejection fraction, 40%; median NT-proBNP, 1010 ng/L [interquartile range, 448-2262 ng/L]) and 38 controls were included. Controls and patients with chronic HF had similar maximum Ao and PA diameters and PA/Ao ratio. During a median follow-up of 1759 days (interquartile range, 998-2269 days), 181 patients with HF were hospitalized for HF or died. Neither PA diameter nor PA/Ao ratio predicted outcome in univariable analysis. In a multivariable model, only age and NT-proBNP were independent predictors of adverse events.

CONCLUSIONS

The PA/Ao ratio is not a useful method to stratify prognosis in patients with HF.

Disease Staging and Prognosis in Smokers Using Deep Learning in Chest Computed Tomography

RATIONALE

Deep learning is a powerful tool that may allow for improved outcome prediction.

OBJECTIVES

To determine if deep learning, specifically convolutional neural network (CNN) analysis, could detect and stage chronic obstructive pulmonary disease (COPD) and predict acute respiratory disease (ARD) events and mortality in smokers.

METHODS

A CNN was trained using computed tomography scans from 7,983 COPDGene participants and evaluated using 1,000 nonoverlapping COPDGene participants and 1,672 ECLIPSE participants. Logistic regression (C statistic and the Hosmer-Lemeshow test) was used to assess COPD diagnosis and ARD prediction. Cox regression (C index and the Greenwood-Nam-D'Agnostino test) was used to assess mortality.

MEASUREMENTS AND MAIN RESULTS

In COPDGene, the C statistic for the detection of COPD was 0.856. A total of 51.1% of participants in COPDGene were accurately staged and 74.95% were within one stage. In ECLIPSE, 29.4% were accurately staged and 74.6% were within one stage. In COPDGene and ECLIPSE, the C statistics for ARD events were 0.64 and 0.55, respectively, and the Hosmer-Lemeshow P values were 0.502 and 0.380, respectively, suggesting no evidence of poor calibration. In COPDGene and ECLIPSE, CNN predicted mortality with fair discrimination (C indices, 0.72 and 0.60, respectively), and without evidence of poor calibration (Greenwood-Nam-D'Agnostino P values, 0.307 and 0.331, respectively).

CONCLUSIONS

A deep-learning approach that uses only computed tomography imaging data can identify those smokers who have COPD and predict who are most likely to have ARD events and those with the highest mortality. At a population level CNN analysis may be a powerful tool for risk assessment.

CT measurements of central pulmonary vasculature as predictors of severe exacerbation in COPD

To identify a predictive value for the exacerbation status of chronic obstructive pulmonary disease (COPD) subjects, we evaluated the relationship between pulmonary vascular measurements on chest CT and severe COPD exacerbation.Six hundred three subjects enrolled in the COPDGene population were included and divided into nonexacerbator (n = 313) and severe exacerbator (n = 290) groups, based on whether they had an emergency room visit and/or hospitalization for COPD exacerbation. We measured the diameter of the main pulmonary artery (MPA) and ascending aorta (AA) at 2 different sites of the MPA (the tubular midportion and bifurcation) on both axial images and multiplanar reconstructions. Using multiple logistic regression analyses, we evaluated the relationship between each CT-measured pulmonary vasculature and exacerbation status.Axial and multiplanar MPA to AA diameter ratios (PA:AA ratios) at the tubular midportion and the axial PA:AA ratios at the bifurcation indicated significant association with severe exacerbation. The strongest association was found with the axial PA:mean AA ratio at the bifurcation (adjusted odds ratio [OR] = 12.53, 95% confidence interval [CI] = 2.35-66.74, P = .003) and the axial PA:major AA ratio at the tubular midportion (adjusted OR = 10.72, 95% CI = 1.99-57.86, P = .006). No differences were observed in the MPA diameter. Receiver operating characteristic analysis of these variables indicates that they may serve as a good predictive value for severe exacerbation (area under the curve, 0.77-0.78). The range of cut-off value for PA:AA ratio was 0.8 to 0.87.CT-measured PA:AA ratios at either the bifurcation or the tubular site, measured either on axial or multiplanar images, are useful for identification of the risk of severe exacerbation, and consequently can be helpful in guiding the management of COPD. Although CT measurement was used at the level of pulmonary bifurcation in previous studies, we suggest that future studies should monitor the tubular site of the MPA for maximum diagnostic value of CT in pulmonary hypertension or severe COPD exacerbation, as the tubular site of the MPA remains relatively constant on CT images.

Extracorporeal carbon dioxide removal in acute exacerbations of chronic obstructive pulmonary disease

Extracorporeal carbon dioxide removal (ECCO2R) has been proposed as an adjunctive intervention to avoid worsening respiratory acidosis, thereby preventing or shortening the duration of invasive mechanical ventilation (IMV) in patients with exacerbation of chronic obstructive pulmonary disease (COPD). This review will present a comprehensive summary of the pathophysiological rationale and clinical evidence of ECCO2R in patients suffering from severe COPD exacerbations.

What do polymorphisms tell us about the mechanisms of COPD?

COPD (chronic obstructive pulmonary disease) is characterized by irreversible lung airflow obstruction. Cigarette smoke is the major risk factor for COPD development. However, only a minority number of smokers develop COPD, and there are substantial variations in lung function among smokers, suggesting that genetic determinants in COPD susceptibility. During the past decade, genome-wide association studies and exome sequencing have been instrumental to identify the genetic determinants of complex traits, including COPD. Focused studies have revealed mechanisms by which genetic variants contribute to COPD and have led to novel insights in COPD pathogenesis. Through functional investigations of causal variants in COPD, from the proteinase-antiproteinase theory to emerging roles of developmental pathways (such as Hedgehog and Wnt pathways) in COPD, we have greatly expanded our understanding on this complex pulmonary disease. In this review, we critically review functional investigations on roles of genetic polymorphisms in COPD, and discuss future challenges and opportunities in discovering novel mechanisms of functional variants.

The Role of Computed Tomography for the Evaluation of Lung Disease in Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency (AATD) is characterized by low serum levels of or dysfunctional alpha-1 proteinase inhibitor. In the lung parenchyma, this results in a loss of protection against the activity of serine proteases, particularly neutrophil elastase. The resultant imbalance in protease and antiprotease activity leads to an increased risk for the development of early-onset emphysema and COPD. As in traditional smoke-related COPD, the assessment of the severity and disease progression of lung disease in AATD is conventionally based on lung function; however, pulmonary function tests are unable to discriminate between emphysema and airways disease, the two hallmark pathologic features of COPD. CT imaging has been used as a tool to further characterize lung structure and evaluate therapeutic interventions in AATD-related COPD. Moreover, recent advances in quantitative CT have significantly improved our assessment of the lung architecture, which has provided investigators and clinicians with a more detailed evaluation of the extent and severity of emphysema and airways disease in AATD. In addition, serial CT imaging measures are becoming increasingly important, as they provide a tool to monitor emphysema progression. This review describes the principles of CT technology and the role of CT imaging in assessing pulmonary disease progression in AATD, including the effect of therapeutic interventions.

Correlates and assessment of excess cardiovascular risk in bronchiectasis

Patients with bronchiectasis are at increased risk of cardiovascular disease. We aimed to identify factors associated with elevated cardiovascular risk in bronchiectasis, measured using aortic stiffness and cardiac biomarkers. In addition, we sought to compare these direct measures against calculated QRISK2 scores.Aortic stiffness, cardiac biomarkers and systemic inflammation were measured in 101 adults with stable bronchiectasis. In addition, clinical and demographic data were collected to allow calculation of QRISK2 score and the bronchiectasis severity index (BSI) for each patient.The BSI score correlated with measured cardiovascular risk assessments, partly due to greater exacerbation frequency and lower forced expiratory volume in 1 s. Pulse-wave velocity was significantly higher in frequent exacerbators (≥3 events·year^-1) than infrequent exacerbators (<3 events·year^-1; 10.5 versus 9.2 m·s^-1, p=0.01). In addition, frequent exacerbators had elevated serum C-reactive protein concentration, suggesting increased systemic inflammation (4.8 versus 2.2 mg·L^-1, p=0.005). QRISK2 systematically underestimated cardiovascular risk in this population (median change in relative risk 1.29). Underestimation was associated with frequent exacerbations and male sex.Patients with bronchiectasis have greater cardiovascular risk than published reference populations. Excess cardiovascular risk is associated with exacerbation frequency and impaired lung function. Cardiovascular risk assessment in bronchiectasis should be individualised, as calculation tools are likely to underestimate the risk in this population.

Lung cancer–associated pulmonary hypertension: Role of microenvironmental inflammation based on tumor cell–immune cell cross-talk

Lung cancer–associated pulmonary hypertension is associated with microenvironmental inflammation caused by tumor cell–immune cell cross-talk.

Higher BMI is associated with higher expiratory airflow normalised for lung volume (FEF25-75/FVC) in COPD

INTRODUCTION

The obesity paradox in chronic obstructive pulmonary disease (COPD), whereby patients with higher body mass index (BMI) fare better, is poorly understood. Higher BMIs are associated with lower lung volumes and greater lung elastic recoil, a key determinant of expiratory airflow. The forced expiratory flow (25-75) (FEF25-75)/forced vital capacity (FVC) ratio reflects effort-independent expiratory airflow in the context of lung volume and could be modulated by BMI.

METHODS

We analysed data from the COPDGene study, an observational study of 10 192 subjects, with at least a 10 pack-year smoking history. Data were limited to subjects with BMI 20-40 kg/m2 (n=9222). Subjects were stratified according to forced expiratory volume in 1 s (FEV1) (%predicted)-quintiles. In regression analyses and Cox proportional hazard models, we analysed the association between BMI, the FEF25-75/FVC ratio, the imaging phenotype, COPD exacerbations, hospitalisations and death.

RESULTS

There was no correlation between BMI and FEV1(%predicted). However, a higher BMI is correlated with a higher FEF25-75/FVC ratio. In CT scans, a higher BMI was associated with less emphysema and less air trapping. In risk-adjusted models, the quintile with the highest FEF25-75/FVC ratio was associated with a 46% lower risk of COPD exacerbations (OR 0.54, p<0.001) and a 40% lower risk of death (HR 0.60, p=0.02), compared with the lowest quintile. BMI was not independently associated with these outcomes.

CONCLUSIONS

A higher BMI is associated with lower lung volumes and higher expiratory airflows when normalised for lung volume, as quantified by the FEF25-75/FVC ratio. A higher FEF25-75/FVC ratio is associated with a lower risk of COPD exacerbations and death and might quantify functional aspects of the paradoxical effect of higher BMIs on COPD.

High rate of isolated right ventricular dysfunction in patients with non-significant CT pulmonary angiography

BACKGROUND

Right ventricular (RV) dysfunction and pulmonary hypertension (PH) are commonly unrecognized in the emergency department (ED), but are associated with poor outcomes. Prior research has found a 30% prevalence of isolated RV dysfunction in ED patients after non-significant computed tomographic pulmonary angiography (CTPA). We aimed to prospectively define the prevalence of RV dysfunction and/or PH in short of breath ED patients, and assess outcomes.

METHODS

Prospective observational study of patients with a non-significant CTPA. Isolated RV dysfunction and/or PH was defined as normal left ventricular function plus RV dilation, moderate to severe tricuspid regurgitation or RV systolic pressure>40mmHg on comprehensive echocardiography.

RESULTS

Of 83 patients, 20 (24%, 95% [confidence interval] CI: 16-34%) had isolated RV dysfunction and/or PH. These patients had 40% ED recidivism and 30% hospital readmission at 30-days. When compared to patients with normal echocardiographic function, they had significantly longer intensive care unit and hospital length of stays.

CONCLUSIONS

In a prospective cohort of ED patients, we found a high prevalence of isolated RV dysfunction and/or PH after a non-significant CTPA. These patients had high rates of recidivism and hospital readmission. This data supports a continued need for ED based screening and specialty referral.

Left Atrium Maximal Axial Cross-Sectional Area is a Specific Computed Tomographic Imaging Biomarker of World Health Organization Group 2 Pulmonary Hypertension

PURPOSE

Left heart disease is associated with left atrial enlargement and is a common cause of pulmonary hypertension (PH). We investigated the relationship between left atrium maximal axial cross-sectional area (LA-MACSA), as measured on chest computed tomography (CT), and PH due to left heart disease (World Health Organization group 2) in patients with right heart catheterization-proven PH.

MATERIALS AND METHODS

A total of 165 patients with PH who had undergone right heart catheterization with pulmonary artery pressure and pulmonary capillary wedge pressure (PCWP) measurements and nongated chest CTs were included. LA-MACSA, LA anterior-posterior, and LA transverse measurements were independently obtained using the hand-drawn region-of-interest and distance measurement tools on standard PACS by 2 blinded cardiothoracic radiologists. Nonparametric statistical analyses and receiver operating characteristic curve were performed.

RESULTS

Forty-three patients had group 2 PH (PCWP>15 mm Hg), and 122 had nongroup 2 PH (PCWP≤15 mm Hg). Median LA-MACSA was significantly different between the group 2 PH and nongroup 2 PH patients (2312 vs. 1762 mm, P<0.001). Interobserver concordance correlation for LA-MACSA was high at 0.91 (P<0.001). At a threshold of 2400 mm, LA-MACSA demonstrated 93% specificity for classifying group 2 PH (area under the curve, 0.73; P<0.001).

CONCLUSIONS

LA-MACSA is a readily obtainable and reproducible measurement of left atrial enlargement on CT and can distinguish between group 2 and nongroup 2 PH with high specificity.

CT imaging of chronic obstructive pulmonary disease: insights, disappointments, and promise

CT imaging is a readily quantifiable tool that can provide in-vivo assessments of lung structure in conditions such as chronic obstructive pulmonary disease (COPD). The information extracted from these data has been used in many clinical, epidemiological, and genetic investigations for patient stratification and prognostication, and to determine intermediate endpoints for clinical trials. Although these efforts have informed our understanding of the heterogeneity of pulmonary disease in smokers, they have not yet translated into new treatments for COPD or the personalisation of patient care. There are a multitude of potential reasons for this, including the lack of insight that static imaging provides for lung function and dysfunction, the limited resolution of clinical CT scanning for microscopic changes to the lung architecture, and the challenges that the biomedical community faces when trying to translate discovery to therapy. Such limitations might be addressed through novel image analysis techniques, up-and-coming CT-based and MRI-based technologies, closer ties between academia and industry, and an expanded endeavour to share data across the biomedical community.

Usefulness of the desaturation-distance ratio from the six-minute walk test for patients with COPD

Purpose

A straightforward, noninvasive method is needed to assess emphysema and pulmonary hypertension (PH) in COPD patients. The desaturation–distance ratio (DDR) is an index derived from the distance traveled and level of desaturation during a six-minute walk test (6MWT); it has previously been shown to be associated with percentage of forced expiratory volume in the first second of expiration (%FEV_1.0) and percentage of diffusion capacity of the lung for carbon monoxide (%DLCO). The aim of this study was to examine the associations between DDR and emphysema and PH.

Patients and methods

We collected the following data for 74 stable COPD outpatients: lung function tests (%FEV_1.0 and %DLCO), 6MWT distance and desaturation, and area of emphysema on computed tomography (percentage of low attenuation area). Enlargement of the pulmonary artery (PA) was assessed by the ratio of the diameter of the PA to that of the aorta (PA:A ratio) as an index of PH. DDR was calculated by the distance traveled and the degree of desaturation reached during a 6MWT. The relationships between study outcomes were assessed with Spearman’s rank-correlation analysis. Receiver operating characteristic (ROC) curves were used to determine the threshold values with the optimum cutoff points for predicting severe or very severe airway obstruction, pulmonary diffusing capacity disorder, moderate or severe emphysema, and enlargement of the PA.

Results

DDR correlated significantly with %FEV_1.0, %DLCO, %LAA, and PA:A ratio. DDR showed high accuracy (area under the ROC curve >0.7) for predicting severe or very severe airway obstruction, pulmonary diffusing capacity disorder, moderate or severe emphysema, and enlargement of the PA.

Conclusion

The results suggest that DDR is a good index of emphysema and PH in COPD patients. The 6MWT is widely used to assess COPD, and DDR could help with the early diagnosis of COPD.

Chronic Obstructive Pulmonary Disease in Elderly Patients

Chronic obstructive pulmonary disease (COPD) is prevalent in the elderly population, with high impact on quality of life, morbidity, and mortality. The diagnosis is usually made based on symptoms and spirometry values that support the presence of airflow obstruction. However, the condition is frequently underdiagnosed. COPD is associated with premature aging and several other medical conditions that can partially explain its underdiagnosis and management. There are several pharmacologic and nonpharmacologic interventions proven to be effective in ameliorating the symptoms of COPD. Appropriate drug delivery and reduction of side effects is also pivotal in the management of patients with COPD.

Imaging approaches to understand disease complexity: chronic obstructive pulmonary disease as a clinical model

The clinical manifestations of chronic obstructive pulmonary disease (COPD) reflect an aggregate of multiple pulmonary and extrapulmonary processes. It is increasingly clear that full assessment of these processes is essential to characterize disease burden and to tailor therapy. Medical imaging has advanced such that it is now possible to obtain in vivo insight in the presence and severity of lung disease-associated features. In this review, we have assembled data from multiple disciplines of medical imaging research to review the role of imaging in characterization of COPD. Topics include imaging of the lungs, body composition, and extrapulmonary tissue metabolism. The primary focus is on imaging modalities that are widely available in clinical care settings and that potentially contribute to describing COPD heterogeneity and enhance our insight in underlying pathophysiological processes and their structural and functional effects.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report. GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 report focuses primarily on the revised and novel parts of the document. The most significant changes include: (1) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; (2) for each of the groups A to D, escalation strategies for pharmacologic treatments are proposed; (3) the concept of deescalation of therapy is introduced in the treatment assessment scheme; (4) nonpharmacologic therapies are comprehensively presented; and (5) the importance of comorbid conditions in managing chronic obstructive pulmonary disease is reviewed.

Emergency Physicians Are Able to Detect Right Ventricular Dilation With Good Agreement Compared to Cardiology

OBJECTIVE

Focused cardiac ultrasound (FOCUS) is a useful tool in evaluating patients presenting to the emergency department (ED) with acute dyspnea. Prior work has shown that right ventricular (RV) dilation is associated with repeat hospitalizations and shorter life expectancy. Traditionally, RV assessment has been evaluated by cardiologist-interpreted comprehensive echocardiography. The primary goal of this study was to determine the inter-rater reliability between emergency physicians (EPs) and a cardiologist for determining RV dilation on FOCUS performed on ED patients with acute dyspnea.

METHODS

This was a prospective, observational study at two urban academic EDs; patients were enrolled if they had acute dyspnea and a computed tomographic pulmonary angiogram without acute disease. All patients had an EP-performed FOCUS to assess for RV dilation. RV dilation was defined as an RV to left ventricular ratio greater than 1. FOCUS interpretations were compared to a blinded cardiologist FOCUS interpretation using agreement and kappa statistics.

RESULTS

Of 84 FOCUS examinations performed on 83 patients, 17% had RV dilation. Agreement and kappa, for EP-performed FOCUS for RV dilation were 89% (95% confidence interval [CI] 80-95%) and 0.68 (95% CI 0.48-0.88), respectively.

CONCLUSIONS

Emergency physician sonographers are able to detect RV dilation with good agreement when compared to cardiology. These results support the wider use of EP-performed FOCUS to evaluate for RV dilation in ED patients with dyspnea.

Pulmonary artery to aorta ratio and risk of all-cause mortality in the general population: the Rotterdam Study

A pulmonary artery to aorta ratio (PA:A) >1 is a proxy of pulmonary hypertension. It is not known whether this measure carries prognostic information in the general population and in individuals with chronic obstructive pulmonary disease (COPD).

Between 2003 and 2006, 2197 participants from the population-based Rotterdam Study (mean±sd age 69.7±6.7 years; 51.3% female), underwent cardiac computed tomography (CT) scanning with PA:A quantification, defined as the ratio between the diameters of the pulmonary artery and the aorta. COPD was diagnosed based on spirometry or clinical presentation and obstructive lung function measured by a treating physician. Cox regression was used to investigate the risk of mortality.

We observed no association between 1-sd increase of PA:A and mortality in the general population. Larger PA:A was associated with an increased risk of mortality in individuals with COPD, particularly in moderate-to-severe COPD (hazard ratio 1.36, 95% CI 1.03–1.79). We demonstrated that the risk of mortality in COPD was driven by severe COPD, and that this risk increased with decreasing diffusing capacity.

Larger PA:A is not associated with mortality in an older general population, but is an independent determinant of mortality in moderate-to-severe COPD. Measuring PA:A in CT scans obtained for other indications may yield important prognostic information in individuals with COPD.

Diameter of the Pulmonary Artery in Relation to the Ascending Aorta: Association with Cardiovascular Outcome

Purpose To investigate whether the pulmonary artery (PA)-to-ascending aorta (Ao) ratio is associated with outcome in unselected patients referred for cardiac magnetic resonance (MR) imaging. Materials and Methods This study prospectively enrolled 650 consecutive patients (47.2% women; mean age, 56.1 years ± 17.7 [standard deviation]). Diameters of PA and Ao were measured in axial black blood images. On the basis of previous results, a PA-to-Ao ratio of 1.0 or greater was chosen as the cutoff for further analysis. Univariable and multivariable Cox regression models were used to investigate the primary end point, which was defined as a composite of cardiovascular hospitalization and death. Results A PA-to-Ao ratio of 1.0 or greater was present in 131 (20.2%) patients. Patients with a PA-to-Ao ratio of 1.0 or greater were predominantly women (P = .010); more frequently presented with atrial fibrillation (P < .001), diabetes (P < .001), and impaired renal function (P < .001); and had higher N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels (P < .001), larger left (P = .023) and right ventricles (RV; P = .002), and worse RV function (P < .001). Patients were followed for 17.8 months ± 12.9, during which 110 patients (16.9%) reached the primary end point. By Kaplan-Meier analysis, event-free survival was significantly worse in patients with a PA-to-Ao ratio of 1.0 or greater (log-rank test, P < .001). A PA-to-Ao ratio of 1.0 or greater was independently associated with outcome by multivariable Cox regression analysis, in addition to age, NT-proBNP serum levels, and RV size. Conclusion A PA-to-Ao ratio of 1.0 or greater identified patients at risk, most likely because of elevated PA pressures. On the basis of these results, the PA-to-Ao ratio should routinely be reported at cardiac MR imaging. ^© RSNA, 2017 Online supplemental material is available for this article.

Pulmonary artery to aorta ratio is associated with cardiac structure and functional changes in mild-to-moderate COPD

Background

The ratio of the diameter of the pulmonary artery (PA) to the diameter of the aorta (PA:A) on computed tomography (CT) imaging is associated with both COPD exacerbation and pulmonary hypertension. The mechanisms of PA enlargement in COPD are poorly understood.

Methods

In this retrospective, single center study we evaluated pulmonary function, CT scans, right heart catheterizations, and echocardiography in 88 subjects with mild-to-moderately severe COPD. A sensitivity analysis was performed in 43 subjects in whom CT scan and echocardiogram were performed within 50 days of each other. To evaluate the association between PA:A ratio and echocardiographic parameters and hemodynamics, we performed simple correlations and multivariable linear regression analysis adjusting for lung function, age, sex, race, and diastolic function.

Results

All subjects had preserved left ventricular (LV) systolic function (LV ejection fraction 62.7%±5.5%). Among them, 56.8% had evidence of diastolic dysfunction. There was no association between PA:A ratio and the presence of diastolic dysfunction. In a multivariable model, PA:A ratio was associated with right ventricular (RV) chamber size (β=0.015; P<0.003), RV wall thickness (β=0.56; P<0.002), and RV function (−0.49; P=0.05). In the subgroup of subjects with testing within 50 days, the association with RV chamber size persisted (β=0.017; P=0.04), as did the lack of association with diastolic function. PA:A ratio was also associated with elevated PA systolic pressures (r=0.62; P=0.006) and pulmonary vascular resistance (r=0.46; P=0.05), but not pulmonary arterial wedge pressure (r=0.17; P=0.5) in a subset of patients undergoing right heart catheterization.

Conclusion

In patients with mild-to-moderately severe COPD and preserved LV function, increased PA:A ratio occurs independent of LV diastolic dysfunction. Furthermore, the PA:A ratio is associated with right heart structure and function changes, as well as pulmonary hemodynamics. These findings indicate that PA:A ratio is a marker of intrinsic pulmonary vascular changes rather than impaired LV filling.

Pulmonary hyperinflation due to gas trapping and pulmonary artery size: The MESA COPD Study

BACKGROUND

Pulmonary hypertension is associated with increased morbidity and mortality in chronic obstructive pulmonary disease (COPD). Since pulmonary artery (PA) size increases in pulmonary hypertension, we measured PA cross-sectional area using magnetic resonance imaging (MRI) to test the hypothesis that pulmonary hyperinflation due to gas trapping is associated with PA cross-sectional area in COPD.

METHODS

The MESA COPD Study recruited participants with COPD and controls from two population-based cohort studies ages 50-79 years with 10 or more pack-years and free of clinical cardiovascular disease. Body plethysmography was performed according to standard criteria. Cardiac MRI was performed at functional residual capacity to measure the cross-sectional area of the main PA. Percent emphysema was defined as the percentage of lung voxels less than -950 Hounsfield units as assessed via x-ray computed tomography. Analyses were adjusted for age, gender, height, weight, race-ethnicity, the forced expiratory volume in one second, smoking status, pack-years, lung function, oxygen saturation, blood pressure, left ventricular ejection fraction and percent emphysema.

RESULTS

Among 106 participants, mean residual volume was 1.98±0.71 L and the mean PA cross-sectional area was 7.23±1.72 cm2. A one standard deviation increase in residual volume was independently associated with an increase in main PA cross-sectional area of 0.55 cm2 (95% CI 0.18 to 0.92; p = 0.003). In contrast, there was no evidence for an association with percent emphysema or total lung capacity.

CONCLUSION

Increased residual volume was associated with a larger PA in COPD, suggesting that gas trapping may contribute to pulmonary hypertension in COPD.

Ventricular Geometry From Non-contrast Non-ECG-gated CT Scans: An Imaging Marker of Cardiopulmonary Disease in Smokers

RATIONALE AND OBJECTIVES

Imaging-based assessment of cardiovascular structure and function provides clinically relevant information in smokers. Non-cardiac-gated thoracic computed tomographic (CT) scanning is increasingly leveraged for clinical care and lung cancer screening. We sought to determine if more comprehensive measures of ventricular geometry could be obtained from CT using an atlas-based surface model of the heart.

MATERIALS AND METHODS

Subcohorts of 24 subjects with cardiac magnetic resonance imaging (MRI) and 262 subjects with echocardiography were identified from COPDGene, a longitudinal observational study of smokers. A surface model of the heart was manually initialized, and then automatically optimized to fit the epicardium for each CT. Estimates of right and left ventricular (RV and LV) volume and free-wall curvature were then calculated and compared to structural and functional metrics obtained from MRI and echocardiograms.

RESULTS

CT measures of RV dimension and curvature correlated with similar measures obtained using MRI. RV and LV volume obtained from CT inversely correlated with echocardiogram-based estimates of RV systolic pressure using tricuspid regurgitation jet velocity and LV ejection fraction respectively. Patients with evidence of RV or LV dysfunction on echocardiogram had larger RV and LV dimensions on CT. Logistic regression models based on demographics and ventricular measures from CT had an area under the curve of >0.7 for the prediction of elevated right ventricular systolic pressure and ventricular failure.

CONCLUSIONS

These data suggest that non-cardiac-gated, non-contrast-enhanced thoracic CT scanning may provide insight into cardiac structure and function in smokers.

Pulmonary Artery Dimensions as a Prognosticator of Transplant-Free Survival in Scleroderma Interstitial Lung Disease

BACKGROUND

Systemic sclerosis is a chronic debilitating autoimmune disease characterized by endothelial dysfunction and multi-organ fibrosis. Interstitial lung disease, a common manifestation of SSc, is termed scleroderma-related interstitial lung disease (SSc-ILD) and along with pulmonary hypertension contributes to a majority of deaths in SSc. SSc-ILD patients frequently develop pulmonary hypertension, which prognosticates a poorer outcome. We investigated pulmonary artery dimensions as an outcome predictor in patients with SSc-ILD.

METHODS

A retrospective chart review abstracting data from SSc-ILD patients evaluated at a large tertiary care center was performed. HRCT imaging was reviewed and pulmonary artery (PA) and ascending aorta (Ao) diameters were measured for calculation of the PA:Ao ratio. Additionally, demographics, vital signs, spirometric parameters, comorbidities, and mean pulmonary artery pressures were collected when available. Outcome analysis with lung transplant or death events within 4 years based on pulmonary artery size as well as PA:Ao ratio was performed.

RESULTS

70 SSc-ILD patients were identified. Mean pulmonary artery diameter and PA:Ao ratio was 31.17 and 1.07 mm, respectively. Patients with a pulmonary artery diameter ≥32 mm had higher risk of lung transplantation or death (p < 0.001) within 4 years. Patients with a PA:Ao ratio ≥1.1 also had higher risk of lung transplantation or death (p < 0.001) within 4 years. Unadjusted outcomes analyses also identified PA:Ao ratio ≥1.1 as an independent outcome predictor (hazard ratio 3.30, p < 0.001).

CONCLUSIONS/CLINICAL IMPLICATIONS

In SSc-ILD patients, a PA:Ao ratio ≥1.1 is associated with higher risk of lung transplant or death. These data suggest that PA:Ao dimension may be used for prognostication in SSc-ILD.

CT Findings, Radiologic-Pathologic Correlation, and Imaging Predictors of Survival for Patients With Interstitial Pneumonia With Autoimmune Features

OBJECTIVE

The objective of this study is to determine the CT findings and patterns of interstitial pneumonia with autoimmune features (IPAF) and to assess whether imaging can predict survival for patients with IPAF.

MATERIALS AND METHODS

The study included 136 subjects who met the criteria for IPAF and had diagnostic-quality chest CT scans obtained from 2006 to 2015; a total of 74 of these subjects had pathologic samples available for review within 1 year of chest CT examination. CT findings and the presence of an usual interstitial pneumonitis (UIP) pattern of disease were assessed, as was the UIP pattern noted on pathologic analysis. Analysis of chest CT findings associated with survival was performed using standard univariate and multivariate Cox proportional hazards methods as well as the unadjusted log-rank test. Survival data were visually presented using the Kaplan-Meier survival curve estimator.

RESULTS

Most subjects with IPAF (57.4%; 78/136) had a high-confidence diagnosis of a UIP pattern on CT. Substantially fewer subjects (28.7%; 39/136) had a pattern that was inconsistent with UIP noted on CT. The presence of a UIP pattern on CT was associated with smoking (p < 0.01), male sex (p < 0.01), and older age (p < 0.001). Approximately one-fourth of the subjects had a nonspecific interstitial pneumonitis pattern on CT. Of interest, nearly one-tenth of the subjects had a CT pattern that was most consistent with hypersensitivity pneumonitis rather than the customary CT patterns ascribed to lung disease resulting from connective tissue disease. Most subjects with a possible UIP pattern on CT (83.3%) had UIP diagnosed on the basis of pathologic findings. Focused multivariate analysis showed that honeycombing on CT (hazard ratio, 2.17; 95% CI, 1.05-4.47) and pulmonary artery enlargement on CT (hazard ratio, 2.08; 95% CI, 1.02-4.20) were independent predictors of survival.

CONCLUSION

IPAF most often presents with a UIP pattern on CT and is associated with worse survival when concomitant honeycombing or pulmonary artery enlargement is present.

The recent advances of phenotypes in acute exacerbations of COPD

Exacerbations of COPD are clinically relevant events with therapeutic and prognostic implications. Yet, significant heterogeneity of clinical presentation and disease progression exists within acute exacerbations of COPD (AECOPD). Currently, different phenotypes have been widely used to describe the characteristics among patients with AECOPD. This has proved to be significant in the treatment and prediction of the outcomes of the disease. In this review of published literature, the phenotypes of AECOPD were classified according to etiology, inflammatory biomarkers, clinical manifestation, comorbidity, the frequency of exacerbations, and so on. This review concentrates on advancements in the use of phenotypes of AECOPD.

Growth differentiation factor-15 is a predictor of important disease outcomes in patients with COPD

Increased levels of growth differentiation factor-15 (GDF15) are associated with cachexia, cardiovascular disease and all-cause mortality. The role of GDF15 in chronic obstructive pulmonary disease (COPD) is unknown.

The study included 413 patients with COPD from the Bergen COPD Cohort Study. All patients had a forced expiratory volume in 1 s (FEV1) <80% predicted, a FEV1 to forced vital capacity (FVC) ratio <0.7 and a history of smoking. Spirometry, fat free mass index, blood gases and plasma GDF15 were measured at baseline. Patients were followed for 3 years regarding exacerbations and changes in lung function, and 9 years for mortality. Yearly exacerbation rate, survival and yearly change in FEV1/FVC were evaluated with regression models.

Median plasma GDF15 was 0.86 ng·mL−1 (interquartile range 0.64–1.12 ng·mL−1). The distribution was not normal and GDF15 was analysed as a categorical variable. High levels of GDF15 were associated with a higher exacerbation rate (incidence rate ratio 1.39, 95% CI 1.1–1.74, p=0.006, adjusted values). Furthermore, high levels of GDF15 were associated with higher mortality (hazard ratio 2.07, 95% CI 1.4–3.1, p<0.001) and an increased decline in both FEV1 (4.29% versus 3.25%) and FVC (2.63% versus 1.44%) in comparison to low levels (p<0.01 for both).

In patients with COPD, high levels of GDF15 were independently associated with a higher yearly rate of exacerbations, higher mortality and increased decline in both FEV1 and FVC.

Global Strategy for the Diagnosis, Management and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: (i) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; (ii) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; (iii) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; (iv)non-pharmacological therapies are comprehensively presented and (v) the importance of co-morbid conditions in managing COPD is reviewed.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: 1) the assessment of COPD has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; 2) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; 3) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; 4) nonpharmacologic therapies are comprehensively presented and; 5) the importance of comorbid conditions in managing COPD is reviewed.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: 1) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; 2) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; 3) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; 4) nonpharmacologic therapies are comprehensively presented and; 5) the importance of comorbid conditions in managing COPD is reviewed.

GDF-15 plasma levels in chronic obstructive pulmonary disease are associated with subclinical coronary artery disease

BACKGROUND

Growth differentiation factor-15 (GDF-15), a cytokine associated with cardiovascular mortality, increases during chronic obstructive pulmonary disease (COPD) exacerbations, but any role in stable COPD is unknown. We tested associations between GDF-15 and subclinical coronary atherosclerosis, assessed by coronary artery calcium (CAC) score, in COPD subjects free of clinical cardiovascular disease (CVD).

METHODS

Cross-sectional analysis of COPD participants (GOLD stages 2-4) in the COPDGene cohort without CVD at enrollment, using baseline CAC (from non-EKG-gated chest computed tomography) and plasma GDF-15 (by custom ELISA). We used multinomial logistic modeling of GDF-15 associations with CAC, adjusting for demographics, baseline risk (calculated using the HEART: Personal Heart Early Assessment Risk Tool (Budoff et al. 114:1761-1791, 2006) score), smoking history, measures of airflow obstruction, emphysema and airway disease severity.

RESULTS

Among 694 participants with COPD (47% women, mean age 63.6 years) mean GDF-15 was 1,304 pg/mL, and mean CAC score was 198. Relative to the lower GDF-15 tertile, higher tertiles showed bivariate association with increasing CAC score (mid tertile odds ratio [OR] 1.80, 95% confidence interval [CI] 1.29, 2.51; higher tertile OR 2.86, CI 2.04, 4.02). This association was maintained after additionally adjusting for baseline CVD risk, for co-morbidities and descriptors of COPD severity and impact, markers of cardiac stress (N-terminal pro-B-type natriuretic peptide, troponin T) and of inflammation (Interleukin-6), and in subgroup analysis excluding men, diabetics, current smokers or those with limited ambulation.

CONCLUSIONS

In ever-smokers with COPD free of clinical CVD, GDF-15 contributes independently to subclinical coronary atherosclerosis.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00608764 . Registered 28 January 2008.

Importance of pulmonary artery to ascending aorta ratio in chronic obstructive pulmonary disease

INTRODUCTION

Recent articles revealed that an increased main pulmonary artery to ascending aorta ratio (PA/A) in thorax computed tomography (CT) correlated with pulmonary hypertension, and might be linked to a high probability of chronic obstructive pulmonary disease (COPD) exacerbations.

OBJECTIVES

In this study, our aim was to evaluate the clinical importance of PA/A in patients with exacerbations of COPD and investigate its relationship with the number of exacerbations in 1 year or short/long-term mortality after hospital discharge.

METHODS

One hundred fifty-six patients hospitalized for COPD exacerbations who fulfilled our inclusion criteria were enrolled in the study. We recorded the number of exacerbations in 1 year from hospital records, checked mortality status, and calculated the PA/A ratio from thorax CT images.

RESULTS

PA/A ratio positively correlated with the number of hospitalizations for COPD exacerbations and the total number of exacerbations (hospitalized or not) in 1 year, and baseline PaCO₂ level during hospitalization (r = 0.376, P < 0.001, r = 0.230, P = 0.004, and r = 0.328, P < 0.001, respectively). There was no relationship between mortality and PA/A.

CONCLUSION

Our study showed that PA/A was related with the number of hospitalizations and the total number of exacerbations due to COPD in 1 year. However, there was no relationship between PA/A and mortality.

Arterial and Venous Pulmonary Vascular Morphology and Their Relationship to Findings in Cardiac Magnetic Resonance Imaging in Smokers

OBJECTIVE

Prior work has described the relationship between pulmonary vascular pruning on computed tomography (CT) scans and metrics of right-sided heart dysfunction in smokers. In this analysis, we sought to look at pruning on a lobar level, as well as examine the effect of the arterial and venous circulation on this association.

METHODS

Automated vessel segmentation applied to noncontrast CT scans from the COPDGene Study in 24 subjects with cardiac magnetic resonance imaging scans was used to create a blood volume distribution profile. These vessels were then manually tracked to their origin and characterized as artery or vein.

RESULTS

Assessment of pruning on a lobar level revealed associations between pruning and right ventricular function previously not observed on a global level. The right ventricular mass index, the right ventricular end-systolic volume index, and pulmonary arterial-to-aorta ratio were associated with both arterial and venous pruning, whereas right ventricular ejection fraction was associated with only arterial pruning.

CONCLUSIONS

Lobar assessment and segmentation of the parenchymal vasculature into arterial and venous components provide additional information about the relationship between loss of vasculature on CT scans and right ventricular dysfunction.

Comprehensive Diagnostic Assessment of Health Status of Patients with Asthma or COPD: A Delphi Panel Study among Dutch Experts

A comprehensive diagnostic assessment is needed to improve understanding of the health status of patients with chronic obstructive pulmonary disease (COPD) or asthma. Therefore, this study investigated which components and subsequent instruments should be part of a holistic assessment in secondary care. We also explored which data need to be exchanged for an adequate transfer of patients between primary and secondary care, and vice versa. A cross-sectional Web-based survey was conducted among Dutch healthcare professionals using a Delphi-like procedure; these included professionals working in primary or secondary care, medical advisors of health insurance companies and patients' representatives. The national guidelines were used as a starting point, resulting in a questionnaire addressing 55 components related to a comprehensive diagnostic assessment, covering the domains physiological impairments, symptoms, functional limitations and quality of life. Of the 151 experts and stakeholders invited, 92 (60.9%) completed the first round and 79 (52.3%) the second round; most respondents were pulmonologists. There was a high level of agreement between respondents from primary versus secondary care regarding which components should be measured during a comprehensive assessment of patients with asthma or COPD in secondary care and the instruments to measure these components. Regarding the exchange of information, upon referral, pulmonologists required little information from the general practitioners, whereas general practitioners required more extensive information after referral. An overview is provided of what should be part of a holistic assessment of health status in asthma and COPD. This information can be used as input for integrated care pathways.

Clinical, physiologic, and radiographic factors contributing to development of hypoxemia in moderate to severe COPD: a cohort study

Background

Hypoxemia is a major complication of COPD and is a strong predictor of mortality. We previously identified independent risk factors for the presence of resting hypoxemia in the COPDGene cohort. However, little is known about characteristics that predict onset of resting hypoxemia in patients who are normoxic at baseline. We hypothesized that a combination of clinical, physiologic, and radiographic characteristics would predict development of resting hypoxemia after 5-years of follow-up in participants with moderate to severe COPD

Methods

We analyzed 678 participants with moderate-to-severe COPD recruited into the COPDGene cohort who completed baseline and 5-year follow-up visits and who were normoxic by pulse oximetry at baseline. Development of resting hypoxemia was defined as an oxygen saturation ≤88% on ambient air at rest during follow-up. Demographic and clinical characteristics, lung function, and radiographic indices were analyzed with logistic regression models to identify predictors of the development of hypoxemia.

Results

Forty-six participants (7%) developed resting hypoxemia at follow-up. Enrollment at Denver (OR 8.30, 95%CI 3.05–22.6), lower baseline oxygen saturation (OR 0.70, 95%CI 0.58–0.85), self-reported heart failure (OR 6.92, 95%CI 1.56–30.6), pulmonary artery (PA) enlargement on computed tomography (OR 2.81, 95%CI 1.17–6.74), and prior severe COPD exacerbation (OR 3.31, 95%CI 1.38–7.90) were independently associated with development of resting hypoxemia. Participants who developed hypoxemia had greater decline in 6-min walk distance and greater 5-year decline in quality of life compared to those who remained normoxic at follow-up.

Conclusions

Development of clinically significant hypoxemia over a 5-year span is associated with comorbid heart failure, PA enlargement and severe COPD exacerbation. Further studies are needed to determine if treatments targeting these factors can prevent new onset hypoxemia.

Trial registration

COPDGene is registered at ClinicalTrials.gov: NCT00608764 (Registration Date: January 28, 2008)

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0331-0) contains supplementary material, which is available to authorized users.

Pulmonary vascular and ventricular dysfunction in the susceptible patient (2015 Grover Conference series)

Pulmonary blood vessel structure and tone are maintained by a complex interplay between endogenous vasoactive factors and oxygen-sensing intermediaries. Under physiological conditions, these signaling networks function as an adaptive interface between the pulmonary circulation and environmental or acquired perturbations to preserve oxygenation and maintain systemic delivery of oxygen-rich hemoglobin. Chronic exposure to hypoxia, however, triggers a range of pathogenetic mechanisms that include hypoxia-inducible factor 1α (HIF-1α)-dependent upregulation of the vasoconstrictor peptide endothelin 1 in pulmonary endothelial cells. In pulmonary arterial smooth muscle cells, chronic hypoxia induces HIF-1α-mediated upregulation of canonical transient receptor potential proteins, as well as increased Rho kinase-Ca2+ signaling and pulmonary arteriole synthesis of the profibrotic hormone aldosterone. Collectively, these mechanisms contribute to a contractile or hypertrophic pulmonary vascular phenotype. Genetically inherited disorders in hemoglobin structure are also an important etiology of abnormal pulmonary vasoreactivity. In sickle cell anemia, for example, consumption of the vasodilator and antimitogenic molecule nitric oxide by cell-free hemoglobin is an important mechanism underpinning pulmonary hypertension. Contemporary genomic and transcriptomic analytic methods have also allowed for the discovery of novel risk factors relevant to sickle cell disease, including GALNT13 gene variants. In this report, we review cutting-edge observations characterizing these and other pathobiological mechanisms that contribute to pulmonary vascular and right ventricular vulnerability.