Computed tomography manifestation of acute exacerbation of chronic obstructive pulmonary disease: A pilot study

The effect of exacerbations on lung density in α1-antitrypsin deficiency

Background

Acute exacerbations of COPD (AECOPD) have unclear impacts on emphysema measurement using computed tomography (CT)-derived 15th percentile lung density (PD15). The aim of this study was to assess the influence of AECOPD on PD15 lung density in α₁-antitrypsin deficiency.

Methods

In a post hoc analysis of the RAPID (Randomised Trial of Augmentation Therapy in α₁-Proteinase Inhibitor Deficiency) trial, raw marginal residuals of PD15 (measured - predicted) were determined by fitting a regression line to individual patient CT data. These deviations from the expected slope were compared by age, sex, baseline forced expiratory volume in 1 s, diffusing capacity of the lungs for carbon monoxide % predicted and PD15, inhaled corticosteroid use and treatment group.

Results

Positive and negative residuals (reflecting higher or lower lung density than predicted from regression) were observed, which declined in magnitude over time following AECOPD events. Logistic regression confirmed a limited effect of patient characteristics on the absolute size of residuals, whereas AECOPD within 6 weeks of CT had a notable effect versus no AECOPD within 6 weeks (OR 5.707, 95% CI 3.375-9.652; p<0.0001).

Conclusion

AECOPD result in higher or lower CT lung density estimates; the effect is greatest in the 2 weeks immediately after an AECOPD and persists for <6 weeks. Patient characteristics were less relevant than AECOPD within 6 weeks, supporting the reliability of PD15 as a measure of lung density. An exacerbation-free period prior to CT scan is advisable to reduce signal-to-noise ratio in future clinical trials.

[Translated article] Prognostic Significance of Findings on CTPA Supporting an Alternative Diagnosis to PE Among Patients Hospitalized for an Exacerbation of COPD: Predefined Subanalysis of the SLICE Trial

BACKGROUND

Among patients hospitalized for an exacerbation of chronic obstructive pulmonary disease (COPD), the SLICE trial showed that the addition of an active diagnostic strategy for pulmonary embolism (PE) to usual care compared with usual care alone did not improve a composite set of health outcomes. The objective of this subanalysis was to determine the frequency and prognostic significance of findings on computed tomography pulmonary angiogram (CTPA) supporting an alternative diagnosis to PE.

METHODS

We analyzed all patients randomized to the intervention in the SLICE trial who received a CTPA that did not show PE. We used multivariable logistic regression to assess the independent association between findings supporting an alternative diagnosis to PE and a composite of readmission for COPD or death within 90 days after randomization.

RESULTS

Among the 746 patients who were randomized, this subanalysis included 175 patients in the intervention group who received a CTPA that did not show PE. Eighty-four (48.0%) patients had acute bronchial infection, 13 (7.4%) had lung cancer, 10 (5.7%) had congestive heart failure, 8 (4.6%), 18 (10.3%) had other diagnoses, and 42 (24.0%) had a normal CTPA. In multivariable analysis, findings supporting an alternative diagnosis to PE were not significantly associated with the primary outcome (odds ratio: 0.64; 95% confidence interval: 0.30-1.38; P=0.26).

CONCLUSIONS

Among patients hospitalized for an exacerbation of COPD, CTPA identified an alternative diagnosis in 76% of the patients. However, specific management of these patients was not associated with improved outcomes within 90 days after randomization.

Significado pronóstico de los diagnósticos alternativos a la TEP hallados en la tomografía computarizada de tórax de pacientes ingresados por agudización de EPOC: subanálisis predefinido del ensayo SLICE

BACKGROUND

Among patients hospitalized for an exacerbation of chronic obstructive pulmonary disease (COPD), the SLICE trial showed that the addition of an active diagnostic strategy for pulmonary embolism (PE) to usual care compared with usual care alone did not improve a composite set of health outcomes. The objective of this subanalysis was to determine the frequency and prognostic significance of findings on computed tomography pulmonary angiogram (CTPA) supporting an alternative diagnosis to PE.

METHODS

We analyzed all patients randomized to the intervention in the SLICE trial who received a CTPA that did not show PE. We used multivariable logistic regression to assess the independent association between findings supporting an alternative diagnosis to PE and a composite of readmission for COPD or death within 90 days after randomization.

RESULTS

Among the 746 patients who were randomized, this subanalysis included 175 patients in the intervention group who received a CTPA that did not show PE. Eighty-four (48.0%) patients had acute bronchial infection, 13 (7.4%) had lung cancer, 10 (5.7%) had congestive heart failure, 8 (4.6%), 18 (10.3%) had other diagnoses, and 42 (24.0%) had a normal CTPA. In multivariable analysis, findings supporting an alternative diagnosis to PE were not significantly associated with the primary outcome (odds ratio: 0.64; 95% confidence interval: 0.30-1.38; P=0.26).

CONCLUSIONS

Among patients hospitalized for an exacerbation of COPD, CTPA identified an alternative diagnosis in 76% of the patients. However, specific management of these patients was not associated with improved outcomes within 90 days after randomization.

Incidence and profile of severe exacerbations of chronic obstructive pulmonary disease due to biomass smoke or tobacco

INTRODUCTION AND OBJECTIVES:

Stable chronic obstructive pulmonary disease (COPD) caused by biomass smoke (B-COPD) has some differences from tobacco-induced-COPD (T-COPD), but acute exacerbations (AECOPD) have not been well characterized in B-COPD.

OBJECTIVE:

To compare the incidence, characteristics and outcomes of AECOPD in B-COPD with those of T-COPD.

METHODS:

A retrospective observational study that included consecutive patients seen at a specialized COPD clinic (2008–2021). The incidence of severe AECOPD that required hospital admission was studied. For the first AECOPD, the following variables were recorded: fever, coexistence of pneumonia, purulent sputum, eosinophil count, neutrophil to lymphocyte ratio, hypercapnia, and respiratory acidosis. Outcome variables were intensive care unit (ICU) admission, length of hospital stay, and mortality within 1 month of hospital admission.

RESULTS:

Of 1060 subjects, 195 (18.4%) belonged to the B-COPD group and 865 (81.6%) to the T-COPD group. During a follow-up of 67.9 (37.8–98.8) months, 75 (38.4%) patients in the B-COPD group and 319 (36.8%) in the T-COPD group suffered at least one severe AECOPD. The only difference between groups was in a higher risk of ICU admission for the T-COPD group. The incidence, characteristics, and the rest of the outcomes of AECOPD were similar for both groups.

CONCLUSION:

AECOPD are similar events for B-COPD and T-COPD and should be managed similarly.

2021 Guideline for the Management of COPD Exacerbations: Emergency Medicine Association of Turkey (EMAT) / Turkish Thoracic Society (TTS) Clinical Practice Guideline Task Force

Chronic obstructive pulmonary disease (COPD) is an important public health problem that manifests with exacerbations and causes serious mortality and morbidity in both developed and developing countries. COPD exacerbations usually present to emergency departments, where these patients are diagnosed and treated. Therefore, the Emergency Medicine Association of Turkey and the Turkish Thoracic Society jointly wanted to implement a guideline that evaluates the management of COPD exacerbations according to the current literature and provides evidence-based recommendations. In the management of COPD exacerbations, we aim to support the decision-making process of clinicians dealing with these patients in the emergency setting.

Thoracic Imaging at Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review

Exacerbations of chronic obstructive pulmonary disease (COPD) are currently diagnosed based on changes in respiratory symptoms. Characterizing the imaging manifestation of exacerbations could be useful for objective diagnosis of exacerbations in the clinic and clinical trials, as well as provide a mechanism for monitoring exacerbation treatment and recovery. In this systematic review, we employed a comprehensive search across three databases (Medline, EMBASE, Web of Science) to identify studies that performed imaging of the thorax at COPD exacerbation. We included 51 from a total of 5,047 articles which met all our inclusion criteria. We used an adapted version of the Modified Newcastle-Ottawa Quality Assessment Scale for cohort studies to assess the quality of the included studies. Conclusions were weighted towards higher-quality articles. We identified a total of 36 thoracic imaging features studied at exacerbation of COPD. Studies were generally heterogeneous in their measurements and focus. Nevertheless, considering studies which performed consecutive imaging at stable state and exacerbation, which scored highest for quality, we identified salient imaging biomarkers of exacerbations. An exacerbation is characterized by airway wall and airway calibre changes, hyperinflation, pulmonary vasoconstriction and imaging features suggestive of pulmonary arterial hypertension. Most information was gained from CT studies. We present the first ever composite imaging signature of COPD exacerbations. While imaging during an exacerbation is comparatively new and not comprehensively studied, it may uncover important insights into the acute pathophysiologic changes in the cardiorespiratory system during exacerbations of COPD, providing objective confirmation of events and a biomarker of recovery and treatment response.

Machine Learning Algorithms Utilizing Functional Respiratory Imaging May Predict COPD Exacerbations

RATIONALE AND OBJECTIVES

Acute chronic obstructive pulmonary disease exacerbations (AECOPD) have a significant negative impact on the quality of life and accelerate progression of the disease. Functional respiratory imaging (FRI) has the potential to better characterize this disease. The purpose of this study was to identify FRI parameters specific to AECOPD and assess their ability to predict future AECOPD, by use of machine learning algorithms, enabling a better understanding and quantification of disease manifestation and progression.

MATERIALS AND METHODS

A multicenter cohort of 62 patients with COPD was analyzed. FRI obtained from baseline high resolution CT data (unenhanced and volume gated), clinical, and pulmonary function test were analyzed and incorporated into machine learning algorithms.

RESULTS

A total of 11 baseline FRI parameters could significantly distinguish ( p < 0.05) the development of AECOPD from a stable period. In contrast, no baseline clinical or pulmonary function test parameters allowed significant classification. Furthermore, using Support Vector Machines, an accuracy of 80.65% and positive predictive value of 82.35% could be obtained by combining baseline FRI features such as total specific image-based airway volume and total specific image-based airway resistance, measured at functional residual capacity. Patients who developed an AECOPD, showed significantly smaller airway volumes and (hence) significantly higher airway resistances at baseline.

CONCLUSION

This study indicates that FRI is a sensitive tool (PPV 82.35%) for predicting future AECOPD on a patient specific level in contrast to classical clinical parameters.

Utility of Computed Tomography in a Differential Diagnosis for the Patients with an Initial Diagnosis of Chronic Obstructive Pulmonary Disease Exacerbation

Background

The utility of computed tomography (CT) in the differential diagnosis of patients with chronic obstructive pulmonary disease (COPD) exacerbation remains uncertain. However, due to the low cost associated with CT scan along with the impact of Koreas' health insurance system, there has been a rise in the number of CT scans in the patients with initial diagnosis of COPD exacerbations. Therefore, the utility of CT in the differential diagnosis was investigated to determine whether performing CT scans affect the clinical outcomes of the patients with an initial diagnosis of COPD exacerbation.

Methods

This study involved 202 COPD patients hospitalized with an initial diagnosis of COPD exacerbation. We evaluated the change in diagnosis or treatment after performing a CT scan, and compared the clinical outcomes of patient groups with vs. without performing CT (non-CT group vs. CT group).

Results

After performing CT, the diagnosis was changed for two (3.0%) while additional diagnoses were made for 27 of the 64 patients (42.1%). However, the treatment changed for only one (1.5%), and six patients (9.3%) received supplementary medication. There were no difference in the median length of hospital stay (8 [6–13] days vs. 8 [6–12] days, p=0.786) and intensive care unit care (14 [10.1%] vs. 11 [16.7%], p=0.236) between the CT and non-CT groups, respectively. These findings remained consistent even after the propensity score matching.

Conclusion

Utility of CT in patients with acute COPD exacerbation might not be helpful; therefore, we do not recommend chest CT scan as a routine initial diagnostic tool.

Comparison of procalcitonin, C-reactive protein, white blood cell count and clinical status in diagnosing pneumonia in patients hospitalized with acute exacerbations of COPD: A prospective observational study

Lower respiratory tract infection is the most common cause of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). The aim of the present study was to compare the accuracy of procalcitonin (PCT), C-reactive protein (CRP) and white blood cell count (WBC) as single diagnostic tests and in combination with clinical signs and symptoms to diagnose pneumonia in patients hospitalized with AECOPD. This was a prospective, single centre observational study. Patients with spirometry-confirmed COPD who were hospitalized due to AECOPD were consecutively recruited at the hospital's Emergency Unit. Pneumonia was defined as a new pulmonary infiltrate on chest X-ray. The values of PCT, CRP and WBC were determined at admission. Receiver operating characteristic (ROC) curve analysis was used to study the accuracy of various diagnostic tests. Of the 113 included patients, 35 (31%) had pneumonia at admission. Area under the ROC curve (AUC) for PCT, CRP and WBC as a single test to distinguish between patients with and without pneumonia was 0.67 (95% CI 0.55-0.79), 0.73 (95% CI 0.63-0.84) and 0.67 (95% CI 0.55-0.79), respectively ( p = 0.42 for the test of difference). The AUC for a model of clinical signs and symptoms was 0.84 (95% CI 0.76-0.92). When biomarkers were added to the clinical model, the AUCs of the combined models were not significantly different from that of the clinical model alone ( p = 0.54). PCT had about the same accuracy as CRP and WBC in predicting pneumonia in patients hospitalized with AECOPD both as a single test and in combination with clinical signs and symptoms.

Sagittal-lung CT measurements in the evaluation of asthma-COPD overlap syndrome: a distinctive phenotype from COPD alone

OBJECTIVES

This study aimed at investigating the capability of sagittal-lung computed tomography (CT) measurements in differentiating chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap syndrome (ACOS).

METHODS

Clinical and high-resolution CT of 229 patients including 123 pure COPD patients and 106 ACOS patients were included. Sagittal-lung CT measurements in terms of bilateral lung height (LH), anterior-posterior lung diameter (APLD), diaphragm height (DH), and anterior sterno-diaphragmatic angle (ASDA), as well as inter-pulmonary septum length (IPSL) on axial images were measured both before and after bronchodilator (BD) administration. Comparisons of clinical characteristics and CT measurements between patient groups were performed.

RESULTS

All pre-BD quantitative sagittal features measuring diaphragm flattening and hyperinflation were not significantly different between patients with COPD and patients with ACOS (P values all >0.05). Following BD administration, the ACOS patients exhibited lower left LH, bilateral APLD, and bilateral ASDA, but higher right DH, compared to pure COPD patients (P values all <0.05). Right LH, left DH and IPSL were not significantly different between patient groups. Besides, variations of all sagittal-lung CT measurements were significantly larger in patients with ACOS than in patients with pure COPD (P values all <0.001) and showed high performance in differentiating these two kinds of patient, with diagnostic sensitivities ranging from 76.4 to 97.2%, specificities ranging from 86.2 to 100.0%, and accuracies ranging from 80.9 to 90.7%.

CONCLUSIONS

Sagittal-lung CT measurements allow for differentiating patients with ACOS from those with pure COPD. The ACOS patients had larger post-BD variations of sagittal-lung CT measurements than patients with pure COPD.