CT scan-measured pulmonary artery to aorta ratio and echocardiography for detecting pulmonary hypertension in severe COPD

Prognostic value of pulmonary artery diameter/aorta diameter ratio in patients with acute pulmonary embolism

BACKGROUND

The ratio of pulmonary artery diameter (PAD) to ascending aortic diameter (AoD) has been reported to be a prognostic marker in several lung diseases; however, the usefulness of this tool in patients with acute pulmonary embolism (APE) is unknown. Here, we aimed to determine the long-term prognostic value of the PAD/AoD ratio in patients with APE.

METHODS

A total of 275 patients diagnosed with APE at our tertiary care center between November 2016 and February 2022 were included in the study. The patients were divided into two groups according to the presence of long-term mortality and their PAD/AoD ratios were compared.

RESULTS

Long-term mortality was observed in 48 patients during the median follow-up of 59 (39-73) months. The patients were divided into two groups for analysis: group 1, consisting of 227 patients without recorded mortality, and group 2, consisting of 48 patients with documented mortality. A multivariate Cox regression model indicated that the PAD/AoD ratio has the potential to predict long-term mortality (HR: 2.9116, 95% CI: 1.1544-7.3436, p = 0.023). Analysis of the receiver operating characteristic curve revealed that there was no discernible difference in discriminative ability between the simplified pulmonary embolism severity index (sPESI) and PAD/AoD ratio (area under the curve [AUC] = 0.679 vs. 0.684, respectively, p = 0.937). The long-term predictive ability of the PAD/AoD ratio was not inferior to the sPESI score.

CONCLUSIONS

The PAD/AoD ratio, which can be easily calculated from pulmonary computed tomography, may be a useful parameter for determining the prognosis of APE patients.

Prognostic implication of 1-year decline in diffusing capacity in newly diagnosed idiopathic pulmonary fibrosis

The progression of idiopathic pulmonary fibrosis (IPF) is assessed through serial monitoring of forced vital capacity (FVC). Currently, data regarding the clinical significance of longitudinal changes in diffusing capacity for carbon monoxide (DLCO) is lacking. We investigated the prognostic implications of a 1-year decline in DLCO in 319 patients newly diagnosed with IPF at a tertiary hospital between January 2010 and December 2020. Changes in FVC and DLCO over the first year after the initial diagnosis were reviewed; a decline in FVC ≥ 5% and DLCO ≥ 10% predicted were considered significant changes. During the first year after diagnosis, a significant decline in FVC and DLCO was observed in 101 (31.7%) and 64 (20.1%) patients, respectively. Multivariable analysis showed that a 1-year decline in FVC ≥ 5% predicted (aHR 2.74, 95% CI 1.88-4.00) and 1-year decline in DLCO ≥ 10% predicted (aHR 2.31, 95% CI 1.47-3.62) were independently associated with a higher risk of subsequent mortality. The prognostic impact of a decline in DLCO remained significant regardless of changes in FVC, presence of emphysema, or radiographic indications of pulmonary hypertension. Therefore, serial monitoring of DLCO should be recommended because it may offer additional prognostic information compared with monitoring of FVC alone.

Revisiting the Clinical Interpretation of CT-Measured Pulmonary Artery-to-Aorta Ratio-The Rotterdam Study

RATIONALE

The pulmonary artery (PA) diameter-to-aorta ratio (PA:A) ratio is a novel marker in cardiovascular imaging for detecting pulmonary hypertension. However, we question the effect of the varying aorta diameter on the ratio, which complicates the interpretation of the PA:A ratio.

OBJECTIVE

Investigate the variability of the PA:A ratio by examining the correlation between PA:A ratio and aorta diameter and by comparing the associations of the PA diameter, aorta diameters, and PA:A ratio.

METHODS

We included 2197 participants from the Rotterdam Study who underwent non-contrast multidetector computed tomography to measure the PA and aorta diameters. Pearson correlation coefficient was calculated between the PA:A ratio and aorta diameter. Multiple linear regression analyses were performed to compare the determinants of the individual diameters and PA:A ratio.

RESULTS

We found a statistically significant correlation between the PA:A ratio and aorta diameter (r = -0.38, p < 0.001). The PA diameter was statistically significantly associated with, height, weight, diastolic blood pressure, blood pressure medication, prevalence of atrial fibrillation, prevalence of heart failure, and prevalence of stroke (p < 0.05). Except for blood pressure medication, the PA:A ratio had similar determinants compared to the PA diameter but was also statistically significantly associated with sex, and systolic blood pressure (p < 0.05), which were statistically significantly associated with the aorta diameter (p < 0.05).

CONCLUSION

The PA:A ratio should not be interpreted without taking into account the variability of the individual components (PA and aorta diameter) according to the anthropomorphic and clinical characteristics.

COPD: pulmonary vascular volume associated with cardiac structure and function

BACKGROUND

Early recognition of cardiac dysfunction in patients with chronic obstructive pulmonary disease (COPD) may prevent future cardiac impairment and improve prognosis. Quantitative assessment of subsegmental and segmental vessel volume by Computed Tomographic (CT) imaging can provide a surrogate of pulmonary vascular remodeling. We aimed to examine the relationship between lung segmental- and subsegmental vessel volume, and echocardiographic measures of cardiac structure and function in patients with COPD.

METHODS

We studied 205 participants with COPD, included in a large cohort study of cardiovascular disease in COPD patients. Participants had an available CT scan and echocardiogram. Artificial intelligence (AI) algorithms calculated the subsegmental vessel fraction as the vascular volume in vessels below 10 mm2 in cross-sectional area, indexed to total intrapulmonary vessel volume. Linear regressions were conducted, and standardized ß-coefficients were calculated. Scatterplots were created to visualize the continuous correlations between the vessel fractions and echocardiographic parameters.

RESULTS

We found that lower subsegmental vessel fraction and higher segmental vessel volume were correlated with higher left ventricular (LV) mass, LV diastolic dysfunction, and inferior vena cava (IVC) dilatation. Subsegmental vessel fraction was correlated with right ventricular (RV) remodeling, while segmental vessel fraction was correlated with higher pulmonary pressure. Measures of LV mass and right atrial pressure displayed the strongest correlations with pulmonary vasculature measures.

CONCLUSION

Pulmonary vascular remodeling in patients with COPD, may negatively affect cardiac structure and function. AI-identified remodeling in pulmonary vasculature may provide a tool for early identification of COPD patients at higher risk for cardiac impairment.

Prevalence of pulmonary artery dilation in non-cystic fibrosis bronchiectasis: a computed tomography analysis from a cohort of the US Bronchiectasis and Nontuberculous Mycobacteria Research Registry

Although pulmonary artery (PA) dilation is independently associated with significant morbidity and mortality in patients with pulmonary diseases irrespective of diagnosed pulmonary hypertension, its relationship with nontuberculous mycobacteria (NTM) is unknown. The Bronchiectasis and NTM Research Registry is a multicenter registry created to foster research in non-cystic fibrosis (CF) bronchiectasis and NTM lung disease. The majority of patients with non-CF bronchiectasis at Oregon Health & Science University have NTM infections. To determine the prevalence of PA dilation in these patients and its association with supplemental oxygen use, severity of bronchiectasis, tobacco use, and NTM in the sputum culture, we evaluated the chest computed tomography (CT) scans from 321 patients in a cross-sectional analysis. We measured the severity of bronchiectasis by applying modified Reiff criteria and measured the diameters of the PA and aorta (Ao), with PA dilation defined as a PA:Ao ratio >0.9. In our cohort, the mean age was 67.3 years and 83.2% were female. The mean modified Reiff score was 7.1, indicating moderate disease severity. Forty-two patients (13.1%) were found to have PA dilation. PA dilation was positively associated with the use of supplemental oxygen (P<0.001), but there was no association between PA dilation and NTM infection.

Comparison of cardiovascular metrics on computed tomography pulmonary angiography of the updated and old diagnostic criteria for pulmonary hypertension in patients with chronic thromboembolic pulmonary hypertension

Background

In the 2022 European Society of Cardiology (ESC) and the European Respiratory Society (ERS) guidelines, the diagnostic criteria for pulmonary hypertension (PH) included a reduced mean pulmonary artery pressure (mPAP) of 20 mmHg (mPAP >20 mmHg). This study aimed to reassess cardiovascular metrics on computed tomography pulmonary angiography (CTPA) for chronic thromboembolic pulmonary hypertension (CTEPH) to optimize the timely diagnosis of patients with suspected PH.

Methods

Patients with suspected CTEPH who underwent CTPA and right heart catheterization (RHC) between January 2019 and December 2022 in China-Japan Friendship Hospital were retrospectively included. They were grouped into CTEPH and non-PH groups according to the new and old criteria (2022 and 2015 ESC/ERS guidelines) for the diagnosis of PH. Cardiovascular metrics including the main pulmonary artery diameter (MPAd), Cobb angle, and right ventricular free wall thickness (RVWT), among others, were measured. The correlation of these metrics with hemodynamic data was analyzed with Spearman rank correlation analysis, while the differences in cardiovascular metrics between the updated (mPAP >20 mmHg) and old PH criteria (mPAP ≥25 mmHg) were compared with independent samples t-test or the Mann-Whitney test. Receiver operator characteristic (ROC) curve analysis was performed for the prediction model.

Results

The study enrolled 180 patients (males n=86; age 55.5±12.0 years old). According to the old guidelines, 119 patients were placed into the PH group (mPAP ≥25 mmHg) , while according to the new guidelines, 130 patients were placed into the PH group (mPAP >20 mmHg). Cardiovascular metrics on CTPA between the updated and old guidelines were comparable (P>0.05). Compared to other metrics, an MPAd of 30.4 mm exhibited the highest area under the curve (AUC: 0.934±0.021), with a sensitivity of 0.88 and specificity of 0.90. MPAd [odds ratio (OR) =1.271], transverse diameter of the right ventricle (RVtd; OR =1.176), Cobb angle (OR =1.108), and RVWT (OR =3.655) were independent factors for diagnosing CTEPH (P<0.05). Cobb angle, right and left ventricular transverse diameter ratio, and right and left ventricular area ratio moderately correlated with mPAP (r=0.586, r=0.583, r=0.629) and pulmonary vascular resistance (PVR) (r=0.613, r=0.593, r=0.642).

Conclusions

Cardiovascular metrics on CTPA were comparable between the new and old guidelines for CTEPH diagnosis. Cardiovascular metrics on CTPA can noninvasively assess the hemodynamics of patients with CTEPH.

Quantitative CT measures of pulmonary vascular volume distribution in pulmonary hypertension associated with COPD: Association with clinical characteristics and outcomes

To determine whether quantitative computed tomography (qCT)-derived metrics of pulmonary vascular volume distribution could distinguish chronic obstructive pulmonary disease (COPD) subjects with associated pulmonary hypertension (PH) from those without and to characterize associations of these measurements with clinical and physiological characteristics and outcomes. We collected retrospective CT, pulmonary hemodynamic, clinical, and outcomes data from subjects with COPD and right-heart catheterization-confirmed PH (PH-COPD) and control subjects with COPD but without PH. We measured the volumes of pulmonary vessels < 5 and >10 mm2 in cross-sectional area as a percentage of total pulmonary vascular volume (qCT-derived volume of pulmonary vessels < 5 mm2 in cross-sectional area as a volume fraction of total pulmonary blood volume [BV5%] and qCT-derived volume of pulmonary vessels > 10 mm2 in cross-sectional area [BV10] as a volume fraction of total pulmonary blood volume [BV10%], respectively) using Functional Respiratory Imaging (FRI), an automated qCT platform, and compared them between PH and control arms and between subjects with mild-moderate PH and those with severe disease. Correlations of hemodynamics with pulmonary function and associations with survival were tested. Forty-five PH-COPD and 42 control subjects were studied. BV5% was lower in PH subjects (32.2% vs. 37.7%, p = 0.003), and BV10% was higher (50.2% vs. 43.5, p = 0.001). Subjects with severe PH did not differ from those with mild-moderate PH in qCT. Pulmonary vascular volumes were not associated with pulmonary function. BV10 was associated with mean pulmonary artery pressure (r = 0.3, p = 0.05). Associations with survival were observed for BV5% (hazard ratio 0.63, p = 0.02) and BV10% (hazard ratio 1.43, p = 0.03) in the PH-COPD arm, but not for controls. qCT-derived measures of pulmonary vascular volume may have diagnostic and prognostic significance in PH-COPD and should be investigated further as screening and risk stratification tools.

The association between pulmonary artery enlargement and mortality in an Emergency Department population undergoing computed tomography pulmonary angiography

Findings of an enlarged pulmonary artery diameter (PAd) and increased pulmonary artery to ascending aorta ratio (PA:AA) on contrast-enhanced computed tomography pulmonary angiography (CTPA) are associated with increased mortality in particular groups of patients with cardiopulmonary disease. However, the frequency and prognostic significance of these incidental findings has not been studied in unselected patients evaluated in the Emergency Department (ED). This study aims to determine the prevalence and associated prognosis of enlarged pulmonary artery measurements in an ED cohort. We measured PA and AA diameters on 990 CTPA studies performed in the ED. An enlarged PA diameter was defined as >27 mm in females and >29 mm in males, while an increased PA:AA was defined as >0.9. Poisson regression was performed to calculate prevalence ratios for relevant comorbidities, and multivariable Cox regression was performed to calculate hazard ratios (HR) for mortality of patients with enlarged pulmonary artery measurements. An enlarged PAd was observed in 27.9% of 990 patients and was more commonly observed in older patients and in patients with obesity or heart failure. Conversely, PA:AA was increased in 34.2% of subjects, and was more common in younger patients and those with peripheral vascular disease or obesity. After controlling for age, sex, and comorbidities, both enlarged PAd (HR 1.29, 95% CI 1.00-1.68, p = 0.05) and PA:AA (HR 1.70, 95% CI 1.31-2.22 p < 0.01) were independently associated with mortality. In sum, enlarged PAd and increased PA:AA are common in patients undergoing CTPAs in the ED setting and both are independently associated with mortality.

Prevalence of pulmonary artery dilation in non-cystic fibrosis bronchiectasis: A CT analysis from a cohort of the US Bronchiectasis and Nontuberculous Mycobacteria Research Registry

Although pulmonary artery (PA) dilation is independently associated with significant morbidity and mortality in patients with pulmonary diseases irrespective of diagnosed pulmonary hypertension, its relationship to nontuberculous mycobacteria (NTM) is unknown. To determine the prevalence of PA dilation in patients with NTM-predominant non-CF bronchiectasis, we evaluated the chest computed tomography (CT) scans from 321 patient in the United States based Bronchiectasis and NTM Research Registry. The majority of our cohort had NTM infection. We measured the severity of bronchiectasis using modified Reiff criteria and measured the diameters of the PA and aorta (Ao), with PA dilation defined as a PA:Ao ratio > 0.9. Forty-two patients (13%) were found to have PA dilation. PA dilation was positively associated with the use of supplemental oxygen (p < 0.001), but there was no association between PA dilation and NTM infection.

Preoperative Pulmonary Artery-to-Aorta Diameter Ratio as a Predictor of Postoperative Severe Right Ventricular Failure and 1-Year Mortality After Left Ventricular Assist Device Implantation

OBJECTIVES

To evaluate the association of pulmonary artery diameter and pulmonary artery- to-aorta diameter ratio (PA/Ao) with right ventricular failure and mortality within 1 year after left ventricular assist device implantation.

DESIGN

This was a retrospective observational study between March 2013 and July 2019.

SETTING

The study was conducted at a single, quaternary-care academic center.

PARTICIPANTS

Adults (≥18 years old) receiving a durable left ventricular assist device (LVAD). Inclusion if (1) a chest computed tomography scan was performed within 30 days before the LVAD and (2) a right and left heart catheterization was completed within 30 days before the LVAD.

INTERVENTIONS

A left ventricular assist device was used for intervention.

MEASUREMENTS AND MAIN RESULTS

A total of 176 patients were included in this study. Median PA diameter and PA/Ao ratio were significantly greater in the severe right ventricular failure (RVF) group (p = 0.001, p < 0.001, respectively). Receiver operating characteristic analysis revealed PA/Ao and RVF as predictors for mortality (area under the curve = 0.725 and 0.933, respectively). Logistic regression analysis-predicted probability gave a PA/Ao ratio cutoff point of 1.04 (p < 0.001). Survival probability was significantly worse in patients with a PA/Ao ratio ≥1.04 (p = 0.005).

CONCLUSIONS

The PA/Ao ratio is an easily measurable noninvasive indicator that can predict RVF and 1-year mortality after LVAD implantation.

Prevalence of reduced lung diffusing capacity and CT scan findings in smokers without airflow limitation: a population-based study

BACKGROUND

Population distribution of reduced diffusing capacity of the lungs for carbon monoxide (DLCO) in smokers and main consequences are not properly recognised. The objectives of this study were to describe the prevalence of reduced DLCO in a population-based sample of current and former smoker subjects without airflow limitation and to describe its morphological, functional and clinical implications.

METHODS

A sample of 405 subjects aged 40 years or older with postbronchodilator forced expiratory volume in 1 s/forced vital capacity (FVC) >0.70 was obtained from a random population-based sample of 9092 subjects evaluated in the EPISCAN II study. Baseline evaluation included clinical questionnaires, exhaled carbon monoxide (CO) measurement, spirometry, DLCO determination, 6 min walk test, routine blood analysis and low-dose CT scan with evaluation of lung density and airway wall thickness.

RESULTS

In never, former and current smokers, prevalence of reduced DLCO was 6.7%, 14.4% and 26.7%, respectively. Current and former smokers with reduced DLCO without airflow limitation were younger than the subjects with normal DLCO, and they had greater levels of dyspnoea and exhaled CO, greater pulmonary artery diameter and lower spirometric parameters, 6 min walk distance, daily physical activity and plasma albumin levels (all p<0.05), with no significant differences in other chronic respiratory symptoms or CT findings. FVC and exhaled CO were identified as independent risk factors for low DLCO.

CONCLUSION

Reduced DLCO is a frequent disorder among smokers without airflow limitation, associated with decreased exercise capacity and with CT findings suggesting that it may be a marker of smoking-induced early vascular damage.

TRIAL REGISTRATION NUMBER

NCT03028207.

Investigation of Pulmonary Artery and Ascending Aorta Morphology in the Coronavirus Disease 2019: A Radioanatomical Study

OBJECTIVE

This study aimed to determine the maximum diameters of the pulmonary artery and ascending aorta and their ratio to each other to enable early diagnosis and treatment of possible pulmonary hypertension and to prevent possible complications in patients infected with severe acute respiratory syndrome coronavirus 2.

MATERIAL AND METHODS

A total of 120 patients aged 40 years and older, 60 patients (30 females and 30 males) with severe acute respiratory syndrome coronavirus 2 infection and 60 individuals (30 females and 30 males), were included in this retrospective study. Maximum pulmonary artery and maximum ascending aorta diameters were measured at the level of bifurcatio trunci pulmonalis in the transverse axial plane by computed tomography, and their ratios to each other were determined.

RESULTS

Our study revealed a statistically significant increase in maximum pulmonary artery and maximum ascending aorta diameters in both genders in patients with coronavirus disease 2019 compared to the control group and a statistically significant increase was found in the maximum pulmonary artery-maximum ascending aorta ratio in women with coronavirus disease 2019 compared to the control group (P < .05).

CONCLUSIONS

Knowing the diameters of maximum pulmonary artery and maximum ascending aorta and the maximum pulmonary artery-maximum ascending aorta ratio in hospitalized severe acute respiratory syndrome coronavirus 2-infected patients is a valuable predictive marker of pulmonary hypertension and a guide in determining the appropriate treatment. These data, which are easy to calculate from thorax computed tomography, may be beneficial in the prognosis of the disease.

Automated 3D segmentation of the aorta and pulmonary artery for predicting outcomes after thoracoscopic lobectomy in lung cancer patients

Background

Preoperative two-dimensional manual measurement of pulmonary artery diameter in a single-cut axial view computed tomography (CT) image is a commonly used non-invasive prediction method for pulmonary hypertension. However, the accuracy may be unreliable. Thus, this study aimed to evaluate the correlation of short-term surgical outcomes and pulmonary artery/aorta (PA/Ao) diameter ratio measured by automated three-dimensional (3D) segmentation in lung cancer patients who underwent thoracoscopic lobectomy.

Materials and methods

We included 383 consecutive lung cancer patients with thin-slice CT images who underwent lobectomy at a single institute between January 1, 2011 and December 31, 2019. Automated 3D segmentation models were used for 3D vascular reconstruction and measurement of the average diameters of Ao and PA. Propensity-score matching incorporating age, Charlson comorbidity index, and lobectomy performed by uniportal VATS was used to compare clinical outcomes in patients with PA/Ao ratio ≥1 and those &lt;1.

Results

Our segmentation method measured 29 (7.57%) patients with a PA/Ao ratio ≥1. After propensity-score matching, a higher overall postoperative complication classified by the Clavien–Dindo classification (p = 0.016) were noted in patients with 3D PA/Ao diameter ratio ≥1 than those of &lt;1. By multivariate logistic regression, patients with a 3D PA/Ao ratio ≥ 1 (p = 0.013) and tumor diameter &gt; 3 cm (p = 0.002) both significantly predict the incidence of postoperative complications.

Conclusions

Pulmonary artery/aorta diameter ratio ≥ 1 measured by automated 3D segmentation may predict postoperative complications in lung cancer patients who underwent lobectomy.

Efficacy of computed tomography in diagnosing pulmonary hypertension: A systematic review and meta-analysis

Objective

This study seeks to evaluate the diagnostic value of computed tomography (CT) in pulmonary hypertension.

Method

PubMed, Embase, Scopus, and Web of Science databases were searched to obtain the relevant English literature, and the retrieval time until June 2022. The quality of the included studies is evaluated using the QUADAS-2 tool. The quality of the included studies was assessed, followed by a meta-analysis, analyze heterogeneity, summarize sensitivity and specificity, draw the comprehensive subject working characteristics (sROC) curve, calculate the area under the curve and conduct subgroup analysis and sensitivity analysis to find the source of the heterogeneity.

Results

A total of 12 articles were included, all with pulmonary artery diameter/liter aortic diameter >1 or 1 as the diagnostic criteria for pulmonary hypertension, and a total of 1,959 patients were included. Deek’s funnel plot analysis suggests that there is no significant publication bias (P = 0.102). The combined sensitivity was 0.652 (95% CI: 0.579, 0.719), combined specificity was 0.830 (95% CI: 0.796, 0.880), positive likelihood ratio was 3.837 (95% CI: 3.215, 4.579), negative likelihood ratio was 0.419 (95% CI: 0.346, 0.507), diagnostic odds ratio was 9.157 (95% CI: 6.748, 12.427) and area under the summary receiver operating characteristic (SROC) curve was 0.84 (95% CI: 0.81, 0.87).

Conclusion

The CT examination of pulmonary artery diameter/aortic artery hypertension is worthy of clinical application.

Prognostic utility of cardiovascular indices in COVID-19 infection: A single-center prospective study in India

Background

Cardiac signs can show illness progression and severity in a number of respiratory and cardiovascular disorders. The possible importance of CT findings in the prognosis and result of COVID-19 patients is related to the severity of lung disease and cardiac parameters. The CT-assessed cardiac indices are known for predicting the involvement of extent of diseases. Hence, the objective of this study was to correlate the extent of cardiovascular and respiratory involvement in predicting the severity of disease using CT-assessed cardiac indices in Indian population suffering from COVID-19.

Methodology

A total of 120 COVID-19 patients were included following the inclusion criteria for one year. The confounding factors were assessed and analyzed. The correlation between the cumulative hazard function of death and duration in hospital along with survival rate were done in terms of pulmonary artery-to-aorta ratio (PA/A), and cardiothoracic ratio (CTR).

Results

The analysis showed mean age of patients to be 49.5(±15.32) years in which mean females were 38(±31.7) and males were 82(±68.3). The interquartile range of CT severity was 8. The PA/A ratio in discharged patients was 0.85 when compared to deceased patients with 1.03 having statistically significant inference (P = 0.00). The CTR (P = 0.00), epicardial adipose thickness (P = 0.00), epicardial adipose density (P = 0.00), and D-dimer (P = 0.007) were showing statistically significant inference.

Conclusion

The predictive values of CT-assessed cardiac indices might be used for predicting the involvement of cardiovascular and respiratory involvement in COVID-19 patients. It could have an impact on improving the possibilities of survival of patients suffering from COVID-19 in India.

Evaluation of Pulmonary Hypertension in Dogs with Heartworm Disease Using the Computed Tomographic Pulmonary Trunk to Aorta Diameter Ratio

Dirofilaria immitis causes proliferative pulmonary endoarteritis that leads to the appearance of chronic precapillary pulmonary hypertension (PH) in dogs. Pulmonary trunk to aorta ratio (PT:Ao ratio) obtained by computed tomography (CT) was studied and the quantitative measure of the diameters of the pulmonary trunk (PT), the descending thoracic aorta (DAo) and ascending thoracic aorta (AAo) were evaluated for the determination of the presence of moderate to severe PH in 59 dogs. The diagnosis of PH was echocardiographically determined, based on the determination of the right pulmonary artery distensibility (RPAD) index (<29.5%), and compared with other parameters for estimating PH. The results showed a very high concordance: 0.976 (p-value 0.000) between the two CT methods (PT:DAo and PT:AAo) with an excellent intraclass correlation coefficient > 0.95. Moreover, cut-off values of ≥1.111 for PT:DAo, and ≥1.057 for PT:AAo were determined for dogs with an RPAD index < 29.5%, which suggests a cut-off value between healthy dogs and the presence of PH. As has been previously published, The PT:Ao ratios did not determine the presence of mild PH, so the measurements cannot be considered useful for the early diagnosis of PH in dogs with heartworm.

Emerging phenotypes of pulmonary hypertension associated with COPD: a field guide

PURPOSE OF REVIEW

Pulmonary hypertension (PH) is a common complication of chronic obstructive lung disease (COPD), but clinical presentation is variable and not always 'proportional' to the severity of the obstructive disease. This review aims to analyze heterogeneity in clinical features of PH-COPD, providing a guide for diagnosis and management according to phenotypes.

RECENT FINDINGS

Recent works have focused on severe PH in COPD, providing insights into the characteristics of patients with predominantly vascular disease. The recently recognized 'pulmonary vascular phenotype', characterized by severe PH and mild airflow obstruction with severe hypoxemia, has markedly worse prognosis and may be a candidate for large trials with pulmonary vasodilators. In severe PH, which might be best described by a pulmonary vascular resistance threshold, there may also be a need to distinguish patients with mild COPD (pulmonary vascular phenotype) from those with severe COPD ('Severe COPD-Severe PH' phenotype).

SUMMARY

Correct phenotyping is key to appropriate management of PH associated with COPD. The lack of evidence regarding the use of pulmonary vasodilators in PH-COPD may be due to the existence of previously unrecognized phenotypes with different responses to therapy. This review offers the clinician caring for patients with COPD and PH a phenotype-focused approach to diagnosis and management, aimed at personalized care.

Severe Pulmonary Hypertension in COPD: Impact on Survival and Diagnostic Approach

BACKGROUND

Severe pulmonary hypertension (PH) is prognostically highly relevant in patients with COPD. The criteria for severe PH have been defined based on hemodynamic thresholds in right heart catheterization.

RESEARCH QUESTION

Can noninvasive clinical tools predict severe PH in patients with COPD? How does the mortality risk change with increasing severity of airflow limitation and pulmonary vascular disease?

STUDY DESIGN AND METHODS

We retrospectively analyzed all consecutive patients with COPD with suspected PH undergoing in-depth clinical evaluation, including right heart catheterization, in our PH clinic between 2005 and 2018. Clinical variables potentially indicative of severe PH or death were analyzed using univariate and stepwise multivariate logistic regression and Cox regression analysis adjusted for age and sex.

RESULTS

We included 142 patients with median FEV1 of 55.0% predicted (interquartile range [IQR], 42.4%-69.4% predicted) and mean pulmonary arterial pressure of 35 mm Hg (IQR, 27-43 mm Hg). A multivariate model combining echocardiographic systolic pulmonary arterial pressure of ≥ 56 mm Hg, N-terminal pro-brain natriuretic peptide (NT-proBNP) plasma levels of ≥ 650 pg/mL, and pulmonary artery (PA) to ascending aorta (Ao) diameter ratio on chest CT scan of ≥ 0.93 predicted severe PH with high positive and negative predictive values (both 94%). After correction for age and sex, both airflow limitation (P = .002; Global Initiative for Chronic Obstructive Lung Disease [GOLD] stages 1-2 vs stage 3: hazard ratio [HR], 1.56 [95% CI, 0.90-2.71]; GOLD stages 1-2 vs stage 4: HR, 3.45 [95% CI, 1.75-6.79]) and PH severity (P = .012; HR, 1.85 [95% CI, 1.15-2.99]) remained associated independently with survival. The combination of GOLD stages 3 and 4 airflow limitation and severe PH showed the poorest survival (HR for death, 3.26 [95% CI, 1.62-6.57; P = .001] vs GOLD stages 1-2 combined with nonsevere PH).

INTERPRETATION

In patients with COPD, the combination of echocardiography, NT-proBNP level, and PA to Ao diameter ratio predicts severe PH with high sensitivity and specificity. The contribution of severe PH and severe airflow limitation to impaired survival is comparable.

Pulmonary Artery Diameter (PAD) and the Pulmonary Artery to Aorta Ratio (PAD/AAD) as Assessed by Non-contrast Cardiac CT: The Association with Left Ventricular (LV) Remodeling and the LV Function

Objective Dilatation of the pulmonary artery itself (PAD: pulmonary artery diameter) or in relation to the ascending aorta (PAD/AAD: pulmonary artery diameter to ascending aortic diameter ratio) has been reported to be associated with pulmonary hypertension and with a prognostic outcome of either heart failure or cardiovascular events. We herein aimed to assess the correlations between pulmonary hypertension-related parameters PAD (or PAD/AAD) and left ventricular (LV) remodeling and LV function. Methods This retrospective study included 193 patients (ages: 67±12 years) who underwent both coronary CT angiography (CCTA) and echocardiography. The PAD and the AAD were measured on a transaxial non-contrast CCTA image at the level of the pulmonary artery bifurcation. Left ventricular mass (LVM), relative wall thickness ratio (RWT), left ventricular ejection fraction (LVEF), left atrial volume (LAV), and early mitral inflow velocity to mitral annular early diastolic velocity ratio (E/e') were evaluated by echocardiography. The relationships between PAD (or PAD/AAD) and echocardiography parameters were assessed, and adjusted for the demographic data and cardiovascular disease (CVD) risk factors by a multivariable linear regression analysis. Results PAD (mean±SD: 2.6±0.4 cm) was positively correlated with LVM (r=0.34, p<0.001), LAV (r=0.41, p<0.001), and E/e' (r=0.29, p<0.001). PAD/AAD (mean±SD: 0.76±0.12 cm) was positively correlated with LVM (r=0.12, p=0.09), LAV (r=0.24, p<0.001), and E/e' (r=0.15, p=0.04). These correlations remained significant after adjusting for demographic data and CVD risk factors. PAD (or PAD/AAD) did not correlate with LVEF or RWT (p>0.05). Conclusion Greater PAD or PAD/AAD is significantly associated with LV remodeling and an impaired LV function.

Evaluating Signs of Pulmonary Hypertension on Computed Tomography and Correlating With Echocardiography: A Study at a Tertiary Care Hospital

Introduction: Pulmonary hypertension (PH) is a threatening condition, and it is far more common than previously assumed, especially after the COVID pandemic. Its outcome is not good; if detected late, and can lead to right ventricular failure, which can be fatal. Our goal was to evaluate CT signs of PH, correlate them with echocardiography, and identify the cut-off values of these signs in our population.

Method: In this study, 160 patients having both CT and echocardiography with a maximum gap of one month were assessed from June to November 2021. The association between CT signs and echocardiography to diagnose PH was investigated. The Pearson and Spearman correlation and area under receiver operating curve (AUROC) tests were performed in the analysis. Receiver operating characteristic curve analysis was also used to assess CT’s diagnostic capability and cut-off values.

Result: The correlation between main pulmonary artery (MPA) diameter and main pulmonary artery to aorta ratio (MPA/AO) with mean pulmonary artery pressure (mPAP) was weak but statistically significant (r = 0.316 and r = 0.321, p<0.001). However, there was a very weak correlation between the right and left pulmonary artery and mPAP with correlation coefficients (r) of 0.155 and 0.138, respectively. For the first time in our population, we measured the cut-off values of MPA and MPA/AO ratios for PH which were 26 and 0.88 mm, respectively.

Conclusions: The CT signs of PH correlate with echocardiography; however, should not be used solely; the cut-off values should be used according to race and population.

The Main Pulmonary Artery to the Ascending Aorta Diameter Ratio (PA/A) as a Predictor of Worse Outcomes in Hospitalized Patients with AECOPD

Purpose

The main pulmonary artery (PA) to ascending aorta diameter ratio (PA/A) greater than one is a promising indicator of pulmonary hypertension (PH) in acute exacerbation (AE) of chronic obstructive pulmonary disease (COPD) (AECOPD). This study aims to disclose the associations between the PA/A ratio and clinical outcomes in hospitalized patients with AECOPD.

Patients and Methods

Consecutive AECOPD patients admitted to the Department of Respiratory Medicine from September 2017 to July 2021 were reviewed. The treatment success of AECOPD patients was defined as improvement in the clinical condition when discharged from the hospital. Conversely, treatment failure was considered to be an event of in-hospital death or deterioration of the clinical condition prior to discharge.

Results

A total of 118 individuals were ultimately reviewed in this study: 74 individuals with a PA/A ratio <1 and 44 individuals with a PA/A ratio ≥1. The outcomes of 21 patients were treatment failure, and 97 patients were considered successes. Patients with a PA/A ratio ≥1 had significantly higher PaCO2, red cell distribution width, brain natriuretic peptide, PA diameters, RICU admission rates, and proportions of treatment failure than patients with PA/A ratios <1 (P < 0.05). The PA diameter and PA/A ratio were significantly increased in the treatment failure group compared with the success group (P < 0.05). A survival analysis indicated that patients with a PA/A ratio ≥1 had worse outcomes than patients with a PA/A ratio <1 during hospitalization (P < 0.05). A multivariate analysis showed that a PA/A ratio ≥1 was an independent risk factor for treatment failure in patients with AECOPD.

Conclusions

AECOPD patients with a PA/A ratio ≥1 may have worse outcomes during hospitalization. A PA/A ratio ≥1 may be a promising predictor of treatment failure in patients with AECOPD.

Utility of Noncancerous Chest CT Features for Predicting Overall Survival and Noncancer Death in Patients With Stage I Lung Cancer Treated With Stereotactic Body Radiotherapy

Background: Noncancerous imaging markers can be readily derived from pretreatment diagnostic and radiotherapy planning chest CT examinations. Objective: To explore the ability of noncancerous features on chest CT to predict overall survival (OS) and noncancer-related death in patients with stage I lung cancer treated with stereotactic body radiation therapy (SBRT). Methods: This retrospective study included 282 patients (168 female, 114 male; median age, 75 years) with stage I lung cancer treated with SBRT between January 2009 and June 2017. Pretreatment chest CT was used to quantify coronary artery calcium (CAC) score, pulmonary artery (PA)-to-aorta ratio, emphysema, and body composition in terms of the cross-sectional area and attenuation of skeletal muscle and subcutaneous adipose tissue at the T5, T8, and T10 vertebral levels. Associations of clinical and imaging features with OS were quantified using a multivariable Cox proportional hazards (PH) model. Penalized multivariable Cox PH models to predict OS were constructed using clinical features only and using both clinical and imaging features. Models' discriminatory ability was assessed by constructing time-varying ROC curves and computing AUC at prespecified times. Results: After a median OS of 60.8 months (95% CI 55.8-68.9), 148 (52.5%) patients died, including 83 (56.1%) with noncancer deaths. Higher CAC score (11-399: hazard ratio [HR] 1.83 [95% CI 1.15-2.91], P=.01; ≥400: HR 1.63 [95% CI 1.01-2.63], P=.04), higher PA-to-aorta ratio (HR 1.33 [95% CI 1.16-1.52], P<.001, per 0.1-unit increase), and lower thoracic skeletal muscle index (HR 0.88 [95% CI 0.79-0.98], P=.02, per 10 cm²/m² increase) were independently associated with shorter OS. Discriminatory ability for 5-year OS was greater for the model including clinical and imaging features than for the model including clinical features only (AUC, 0.75 [95% CI 0.68-0.83] versus 0.61 [95% CI 0.53-0.70], p < .01). The model's most important clinical or imaging feature based on mean standardized regression coefficients was the PA-to-aorta ratio. Conclusions: In patients undergoing SBRT for stage I lung cancer, higher CAC score, higher PA-to-aorta ratio, and lower thoracic skeletal muscle index independently predicted worse OS. Clinical Impact: Noncancerous imaging features on chest CT performed before SBRT improve survival prediction compared with clinical features alone.

Diagnostic value of computed tomography-based pulmonary artery to aorta ratio measurement in chronic obstructive pulmonary disease with pulmonary hypertension: A systematic review and meta-analysis

OBJECTIVE

We conducted a meta-analysis to systematic assess the diagnostic value of computed tomography (CT)-based pulmonary artery to aorta (PA:A) ratio measurement in COPD with pulmonary hypertension (COPD-PH).

METHODS

Published studies referring to diagnostic accuracy of PA:A ratio for COPD-PH were screened out from PubMed, Embase, Web of science, China National Knowledge databases (CNKI), Wan fang databases, and VIP databases. We used bivariate random-effects model to estimate pooled sensitivity (SEN), specificity (SPE), positive and negative likelihood ratios (PLR and NLR, respectively), and diagnostic odds ratios (DOR). Summary receiver operating characteristic (SROC) curves and area under the curve (AUC) were also calculated to summarize the aggregate diagnostic performance.

RESULTS

Nine eligible studies were included and the pooled SEN was 69% (95% CI: 59 ~ 78), SPE was 85% (95% CI: 77 ~ 90), PLR was 4.5 (95% CI: 2.8 ~ 7.5), and NLR was 0.36 (95% CI: 0.26 ~ 0.51), respectively. DOR reached 13.00 (95% CI: 6.00 ~ 28.00), and value of AUC was 0.84 (95% CI: 0.81 ~ 0.87). Subgroup analysis indicated that when the value of PA:A ratio was equal or greater than one (PA/A ≥ 1), the combined SEN, SPE, AUC, and DOR was 69%, 89%, 0.90, and 19.65, respectively.

CONCLUSIONS

PA:A ratio is helpful for appraisal of COPD-PH, and PA/A ≥ 1 possessed prominent diagnostic accuracy.

Lung volume determination by dual-source computed tomography in infants with pulmonary artery sling: a case-control study

BACKGROUND

Pulmonary artery sling (PAS) is associated with tracheal stenosis and left pulmonary artery (LPA) dysplasia in infants, both developmental abnormalities that may lead to pulmonary hypoplasia and lung volume changes. As such, we aimed to monitor the effects of tracheal stenosis and pulmonary vascular malformation on lung volumes in infants with PAS and their correlation with lung volumes in infants with PAS using dual-source computed tomography (DSCT).

METHODS

A case-control study was performed. From May 2009 to June 2017, we retrospectively enrolled patients with surgically confirmed PAS and compared them to matched normal controls (A healthy control group comprising age- and gender-matched patients with adequate imaging data was used for the comparisons.). All the patients underwent DSCT examinations. We measured and compared the diameters of the trachea, main bronchus, and main pulmonary artery (MPA) and its branches, and both lung volumes on the axial, and reconstructed CT images.

RESULTS

There were no statistical differences in the diameters of the MPA or right pulmonary artery (RPA) between patients (N=15) and controls (N=28). The diameter of the main bronchus, the bilateral trachea and the left pulmonary artery were all smaller in the PAS group than in the control group, and significant differences were evident in the left lung volume the right lung volume, and the right-to-left lung volume ratio between the 2 groups. Pearson's correlation and linear regression analyses between the diameters of the trachea and MPA, total lung volume, ipsilateral bronchial and pulmonary artery branches, and ipsilateral lung volume ranged from 0.71 to 0.87 and 0.57 to 0.77 for the control and PAS groups, respectively.

CONCLUSIONS

Tracheal stenosis and LPA dysplasia in infants with PAS cause alterations in lung tissue morphology and physiological development, resulting in reduced bilateral lung volumes.

Clinical Effect of Pulmonary Artery Diameter/Ascending Aorta Diameter Ratio on Left Ventricular Reverse Remodeling in Patients With Dilated Cardiomyopathy

BACKGROUND

Many patients with dilated cardiomyopathy (DCM) progress to heart failure (HF), although some demonstrate left ventricular (LV) reverse remodeling (LVRR), which is associated with better outcomes. The pulmonary artery diameter (PAD) to ascending aortic diameter (AoD) ratio has been used as a prognostic predictor in patients with HF, although this tool's usefulness in predicting LVRR remains unknown.Methods and Results:Data from a prospective observational study of 211 patients diagnosed in 2000-2020 with DCM were retrospectively analyzed. Sixty-nine patients with New York Heart Association class I or II HF were included. LVRR was observed in 23 patients (33.3%). The mean LV ejection fraction (29%) and LV end-diastolic dimension (64.5 mm) were similar in patients with and without LVRR. The PAD/AoD ratio was significantly lower in patients with LVRR than those without (81.4% vs. 92.4%, respectively; P=0.003). The optimal PAD/AoD cut-off value for detecting LVRR was 0.9 according to the receiver operating characteristic curve analysis. Multivariate analysis identified a PAD/AoD ratio ≥0.9 as an independent predictor of presence/absence of LVRR. Cardiac events were significantly more common in patients with a PAD/AoD ratio ≥0.9 than those with a ratio <0.9, after a median follow up of 2.5 years (log-rank, P=0.007).

CONCLUSIONS

The PAD/AoD ratio can predict LVRR in patients with DCM.

Role of cardiovascular computed tomography parameters and lungs findings in predicting severe COVID-19 patients: a single-centre retrospective study

Background

Results

Conclusions

Main pulmonary artery enlargement predicts 90-day readmissions in Chinese COPD patients

Background

Numerous studies have shown pulmonary artery enlargement when measured by chest computed tomography (CT) could predict a worse outcome in chronic obstructive pulmonary disease (COPD) patients. Herein, we studied the prognostic implication of main pulmonary artery diameter (MPAD) in Chinese COPD patients.

Methods

This is an observational case-control study. Patients with 90-day readmissions are case group and those without 90-day readmission are control group. The study comprised of 417 COPD patients who underwent chest CT in their initial admission due to acute exacerbation of COPD (AECOPD). We analyzed their clinical characteristics such as MPAD, arterial blood gas (ABG) results, other chest CT findings and comorbidities to identify the cause of readmission within 90 days.

Results

Median age of our study population is 75 years old, and 79.6% of them are male. The median MPAD is 2.8 cm and 80.6% were also diagnosed with community acquired pneumonia (CAP) in their first admission. The median MPAD in patients with 90-day readmission was 3.1 cm while patients without 90-day readmission had median MPAD of 2.8 cm. Through multivariate logistic regression analysis CAP (P=0.019, OR: 3.105, 95% CI: 1.203-8.019) and MPAD (P<0.001, OR: 2.898, 95% CI: 1.824-4.605) were statistically significant. In the second stage of analysis, subgroup of patients diagnosed with CAP and AECOPD (pAECOPD) were analyzed, MPAD remained statistically significant (P<0.001, OR: 3.490, 95% CI: 1.929-6.316) and receiver operative characteristic (ROC) curve for pAECOPD patients; area under the curve (AUC) was 0.704 (95% CI: 0.631-0.778) with a MPAD cut off value of 2.9 cm (sensitivity 72%, specificity 53%).

Conclusions

Enlarged MPAD and pAECOPD in initial admission are independent risk factors for 90-day readmission. In our pAECOPD patient population, MPAD >2.9 cm are at increased risk of 90-day readmission.

Utility of Computed Tomographic Angiography for Pulmonary Hypertension Assessment in a Cohort of West Highland White Terriers With or Without Canine Idiopathic Pulmonary Fibrosis

West Highland white terriers (WHWTs) affected with canine idiopathic pulmonary fibrosis (CIPF) are at risk of developing precapillary pulmonary hypertension (PH). In humans, thoracic computed tomography angiography (CTA) is commonly used to diagnose and monitor patients with lower airway diseases. In such patients, CTA helps to identify comorbidities, such as PH, that could negatively impact prognosis. Diameter of the pulmonary trunk (PT), pulmonary trunk-to-aorta ratio (PT/Ao), and right ventricle-to-left ventricle ratio (RV/LV) are CTA parameters commonly used to assess the presence of PH. Pulmonary vein-to-right pulmonary artery ratio (PV/PA) is a new echocardiographic parameter that can be used in dogs to diagnose PH. The primary aim of this study was to evaluate the use of various CTA parameters to diagnose PH. An additional aim was to evaluate the correlation of RV/LV measurements between different CTA planes. CTA and echocardiography were prospectively performed on a total of 47 WHWTs; 22 affected with CIPF and 25 presumed healthy control dogs. Dogs were considered to have PH if pulmonary vein-to-right pulmonary artery ratio (PV/PA) measured on 2D-mode echocardiography was less than to 0.7. WHWTs affected with CIPF had higher PT/Ao compared with control patients. In WHWTs affected with CIPF, PT size was larger in dogs with PH (15.4 mm) compared with dogs without PH (13 mm, p = 0.003). A cutoff value of 13.8 mm predicted PH in WHWTs affected with CIPF with a sensitivity of 90% and a specificity of 87% (AUC = 0.93). High correlations were observed between the different CTA planes of RV/LV. Results suggest that diameter of the PT measured by CTA can be used to diagnose PH in WHWTs with CIPF.

Prognostic utility of pulmonary artery and ascending aorta diameters derived from computed tomography in COVID-19 patients

Aim

Chest computed tomography (CT) imaging plays a diagnostic and prognostic role in Coronavirus disease 2019 (COVID‐19) patients. This study aimed to investigate and compare predictive capacity of main pulmonary artery diameter (MPA), ascending aorta diameter (AAo), and MPA‐to‐AAo ratio to determine in‐hospital mortality in COVID‐19 patients.

Materials and methods

This retrospective study included 255 hospitalized severe or critical COVID‐19 patients. MPA was measured at the level of pulmonary artery bifurcation perpendicular to the direction of the vessel through transverse axial images and AAo was measured by using the same CT slice at its maximal diameter. MPA‐to‐AAo ratio was calculated by division of MPA to AAo.

Results

Multivariate logistic regression model yielded MPA ≥29.15 mm (OR: 4.95, 95% CI: 2.01–12.2, p = 0.001), MPA (OR: 1.28, 95% CI: 1.13–1.46, p < 0.001), AAo (OR: .90, 95% CI: .81–.99, p = 0.040), and MPA‐to‐AAo ratio ≥.82 (OR: 4.67, 95% CI: 1.86–11.7, p = 0.001) as independent predictors of in‐hospital mortality. Time‐dependent multivariate Cox‐proportion regression model demonstrated MPA ≥29.15 mm (HR: 1.96, 95% CI: 1.03–3.90, p = 0.047) and MPA (HR: 1.08, 95% CI: 1.01–1.17, p = 0.048) as independent predictors of in‐hospital mortality, whereas AAo and MPA‐to‐AAo ratio did not reach statistical significance.

Conclusion

Pulmonary artery enlargement strongly predicts in‐hospital mortality in hospitalized COVID‐19 patients. MPA, which can be calculated easily from chest CT imaging, can be beneficial in the prognostication of these patients.

Secondary polycythemia in chronic obstructive pulmonary disease: prevalence and risk factors

BACKGROUND

Secondary polycythemia is associated with cigarette smoking and chronic obstructive pulmonary disease (COPD). However, the prevalence of polycythemia in COPD and the contributing risk factors for polycythemia in COPD have not been extensively studied.

METHODS

We analyzed the presence of secondary polycythemia in current and former smokers with moderate to very severe COPD at the five-year follow-up visit in the observational COPDGene study. We used logistic regression to evaluate the association of polycythemia with age, sex, race, altitude, current smoking status, spirometry, diffusing capacity for carbon monoxide (DLCO), quantitative chest CT measurements (including emphysema, airway wall thickness, and pulmonary artery to aorta diameter ratio), resting hypoxemia, exercise-induced hypoxemia, and long-term oxygen therapy.

RESULTS

In a total of 1928 COPDGene participants with moderate to very severe COPD, secondary polycythemia was found in 97 (9.2%) male and 31 (3.5%) female participants. In a multivariable logistic model, severe resting hypoxemia (OR 3.50, 95% CI 1.41-8.66), impaired DLCO (OR 1.28 for each 10-percent decrease in DLCO % predicted, CI 1.09-1.49), male sex (OR 3.60, CI 2.20-5.90), non-Hispanic white race (OR 3.33, CI 1.71-6.50), current smoking (OR 2.55, CI 1.49-4.38), and enrollment in the Denver clinical center (OR 4.42, CI 2.38-8.21) were associated with higher risk for polycythemia. In addition, continuous (OR 0.13, CI 0.05-0.35) and nocturnal (OR 0.46, CI 0.21-0.97) supplemental oxygen were associated with lower risk for polycythemia. Results were similar after excluding participants with anemia and participants enrolled at the Denver clinical center.

CONCLUSIONS

In a large cohort of individuals with moderate to very severe COPD, male sex, current smoking, enrollment at the Denver clinical center, impaired DLCO, and severe hypoxemia were associated with increased risk for secondary polycythemia. Continuous or nocturnal supplemental oxygen use were associated with decreased risk for polycythemia.

Machine Learning to Predict In-Hospital Mortality in COVID-19 Patients Using Computed Tomography-Derived Pulmonary and Vascular Features

Pulmonary parenchymal and vascular damage are frequently reported in COVID-19 patients and can be assessed with unenhanced chest computed tomography (CT), widely used as a triaging exam. Integrating clinical data, chest CT features, and CT-derived vascular metrics, we aimed to build a predictive model of in-hospital mortality using univariate analysis (Mann-Whitney U test) and machine learning models (support vectors machines (SVM) and multilayer perceptrons (MLP)). Patients with RT-PCR-confirmed SARS-CoV-2 infection and unenhanced chest CT performed on emergency department admission were included after retrieving their outcome (discharge or death), with an 85/15% training/test dataset split. Out of 897 patients, the 229 (26%) patients who died during hospitalization had higher median pulmonary artery diameter (29.0 mm) than patients who survived (27.0 mm, p < 0.001) and higher median ascending aortic diameter (36.6 mm versus 34.0 mm, p < 0.001). SVM and MLP best models considered the same ten input features, yielding a 0.747 (precision 0.522, recall 0.800) and 0.844 (precision 0.680, recall 0.567) area under the curve, respectively. In this model integrating clinical and radiological data, pulmonary artery diameter was the third most important predictor after age and parenchymal involvement extent, contributing to reliable in-hospital mortality prediction, highlighting the value of vascular metrics in improving patient stratification.

Structural and functional changes in COPD: What we have learned from imaging

Chronic obstructive pulmonary disease (COPD) is the third leading cause of mortality worldwide. It is a heterogeneous disease involving different components of the lung to varying extents. Developments in medical imaging and image analysis techniques provide new insights in the assessment of the structural and functional changes of the disease. This article reviews the leading imaging techniques: CT and MRI of the lung in research settings and clinical routine. Both visual and quantitative methods are reviewed, emphasizing their relevance to patient phenotyping and outcome prediction.

Our current understanding of and approach to the management of lung cancer with pulmonary hypertension

INTRODUCTION

Lung cancer is a frequent pathology for which the best curative treatment is pulmonary resection. Pulmonary arterial hypertension is a rare disease but pulmonary hypertension associated with parenchymal disease or left heart disease is frequently observed in these patients. The diagnosis of pulmonary hypertension before lung resection makes the perioperative management of these patients more difficult and sometimes leads to rejecting patients for surgery.

AREAS COVERED

We performed a review of literature on PubMed on Pulmonary hypertension associated lung resection, preoperative assessment of lung resection and perioperative management of PH patients, including guidelines and clinical trials.In this review, we summarize the current state of knowledge regarding the pre and perioperative management of patients with suspected or confirmed PH who can benefit from surgical treatment of lung cancer.

EXPERT OPINION

Management of PH patients before lung resection should include a very careful workup including at least right heart catheterization with evaluation of the targeted PH treatment in an expert center and evaluation of other comorbidities. Perioperative management must be carried out in a specialized center.

Association between ratio for diameters of pulmonary artery to ascending aorta bifurcation in chest CT scan and number of involved vessels in coronary angiography

Objective

Coronary artery disease (CAD) is an important cause of mortality and morbidity, therefore, recognizing its severity and related factors is important. This study was performed to evaluate the association between ratio for diameters of pulmonary artery to ascending aorta bifurcation in chest CT scan and number of involved vessels in coronary angiography. In this observational cross-sectional comparative study, 110 patients who were under coronary angiography in Firoozgar Hospital in 2017 were enrolled, and the association between ratio for diameters of pulmonary artery to ascending aorta bifurcation in their chest CT scan and number of involved vessels in angiography were assessed.

Results

In this study, number of involved vessels in angiography was related to PA/Ao ratio (P = 0.001) and further vessels were accompanied with higher ratio. It may be concluded that, a higher ratio for diameters of pulmonary artery to ascending aorta bifurcation in chest CT scan is related to higher number of involved vessels in coronary angiography, and it may have a predictive role.

Prognostic factors of pulmonary hypertension associated with connective tissue disease: pulmonary artery size measured by chest CT

OBJECTIVE

Pulmonary artery enlargement is a common manifestation of chest CT in patients with pulmonary arterial hypertension (PAH). The exact clinical significance of this phenomenon has not been clarified in connective tissue disease (CTD)-associated PAH (CTD-PAH). We aimed to explore the association between the dilatation of pulmonary artery and prognosis of CTD-PAH patients.

METHODS

We retrospectively investigated 140 CTD-PAH patients diagnosed by echocardiography from 2009 to 2018. A chest multi-slice CT was performed on all the patients. Main pulmonary artery (MPA), right pulmonary artery (RPA), left pulmonary artery (LPA), ascending aorta (AAo) and descending aorta (DAo) diameters were measured. The ratios MPA/AAo and MPA/DAo were also calculated. The primary end point was all-cause mortality.

RESULTS

During the observational period of 3.44 (0.23) years, 36 patients were followed to death. Cox univariate proportional hazard analysis showed that age, gender, MPA diameter, LPA diameter and RPA diameter were related to the risk of 5-year all-cause mortality in patients with CTD-PAH. In Cox multivariate proportional hazard analysis, MPA diameter and gender were predictors of all-cause mortality in CTD-PAH patients. An all-cause mortality risk prediction model revealed that baseline MPA diameter has the ability to predict 5-year all-cause mortality in CTD-PAH patients. Kaplan-Meier analysis showed that the 5-year survival rate was significantly lower in patients with MPA ≥37.70 mm (P ≤ 0.00012) compared with MPA ≤ 37.70 mm.

CONCLUSION

MPA diameter ≥37.70 mm measured by chest multi-slice CT was a potential independent risk factor of the poor long-term prognosis in Chinese CTD-PAH patients.

Imaging of pulmonary hypertension in adults: a position paper from the Fleischner Society

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure greater than 20 mmHg and classified into five different groups sharing similar pathophysiologic mechanisms, haemodynamic characteristics, and therapeutic management. Radiologists play a key role in the multidisciplinary assessment and management of PH. A working group was formed from within the Fleischner Society based on expertise in the imaging and/or management of patients with PH, as well as experience with methodologies of systematic reviews. The working group identified key questions focusing on the utility of CT, MRI, and nuclear medicine in the evaluation of PH: a) Is noninvasive imaging capable of identifying PH? b) What is the role of imaging in establishing the cause of PH? c) How does imaging determine the severity and complications of PH? d) How should imaging be used to assess chronic thromboembolic PH before treatment? e) Should imaging be performed after treatment of PH? This systematic review and position paper highlights the key role of imaging in the recognition, work-up, treatment planning, and follow-up of PH.

Imaging of Pulmonary Hypertension in Adults: A Position Paper from the Fleischner Society

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure greater than 20 mm Hg and classified into five different groups sharing similar pathophysiologic mechanisms, hemodynamic characteristics, and therapeutic management. Radiologists play a key role in the multidisciplinary assessment and management of PH. A working group was formed from within the Fleischner Society based on expertise in the imaging and/or management of patients with PH, as well as experience with methodologies of systematic reviews. The working group identified key questions focusing on the utility of CT, MRI, and nuclear medicine in the evaluation of PH: (a) Is noninvasive imaging capable of identifying PH? (b) What is the role of imaging in establishing the cause of PH? (c) How does imaging determine the severity and complications of PH? (d) How should imaging be used to assess chronic thromboembolic PH before treatment? (e) Should imaging be performed after treatment of PH? This systematic review and position paper highlights the key role of imaging in the recognition, work-up, treatment planning, and follow-up of PH. This article is a simultaneous joint publication in Radiology and European Respiratory Journal. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article. © 2021 RSNA and the European Respiratory Society. Online supplemental material is available for this article.

The Association of CT-measured Cardiac Indices with Lung Involvement and Clinical Outcome in Patients with COVID-19

RATIONALE AND OBJECTIVES

Cardiac indices can predict disease severity and survival in a multitude of respiratory and cardiovascular diseases. Herein, we hypothesized that CT-measured cardiac indices are correlated with severity of lung involvement and can predict survival in patients with COVID-19.

MATERIALS AND METHODS

Eighty-seven patients with confirmed COVID-19 who underwent chest CT were enrolled. Cardiac indices including pulmonary artery-to-aorta ratio (PA/A), cardiothoracic ratio (CTR), epicardial adipose tissue (EAT) thickness and EAT density, inferior vena cava diameter, and transverse-to-anteroposterior trachea ratio were measured by non-enhanced CT. Logistic regression and Cox-regression analyses evaluated the association of cardiac indices with patients' outcome (death vs discharge). Linear regression analysis was used to assess the relationship between the extent of lung involvement (based on CT score) and cardiac indices.

RESULTS

Mean (±SD) age of patients was 54.55 (±15.3) years old; 65.5% were male. Increased CTR (>0.49) was seen in 52.9% of patients and was significantly associated with increased odds and hazard of death (odds ratio [OR] = 12.5, p = 0.005; hazard ratio = 11.4, p = 0.006). PA/A >1 was present in 20.7% of patients and displayed a nonsignificant increase in odds of death (OR = 1.9, p = 0.36). Furthermore, extensive lung involvement was positively associated with elevated CTR and increased PA/A (p = 0.001).

CONCLUSION

CT-measured cardiac indices might have predictive value regarding survival and extent of lung involvement in hospitalized patients with COVID-19 and could possibly be used for the risk stratification of these patients and for guiding therapy decision-making. In particular, increased CTR is prevalent in patients with COVID-19 and is a powerful predictor of mortality.

Computed tomography appearances of the lung parenchyma in pulmonary hypertension

Computed tomography (CT) is a valuable tool in the workup of patients under investigation for pulmonary hypertension (PH) and may be the first test to suggest the diagnosis. CT parenchymal lung changes can help to differentiate the aetiology of PH. CT can demonstrate interstitial lung disease, emphysema associated with chronic obstructive pulmonary disease, features of left heart failure (including interstitial oedema), and changes secondary to miscellaneous conditions such as sarcoidosis. CT also demonstrates parenchymal changes secondary to chronic thromboembolic disease and venous diseases such as pulmonary venous occlusive disease (PVOD) and pulmonary capillary haemangiomatosis (PCH). It is important for the radiologist to be aware of the various manifestations of PH in the lung, to help facilitate an accurate and timely diagnosis. This pictorial review illustrates the parenchymal lung changes that can be seen in the various conditions causing PH.

Association of plain computed tomography-determined pulmonary artery-to-aorta ratio with clinical severity of coronavirus disease 2019

Coronavirus disease (COVID-19) is associated with pulmonary hypertension due to pulmonary embolism, which affects subsequent outcomes. However, definitive diagnosis of pulmonary hypertension is difficult because of the risk of spreading the infection. Here, we assess the utility of plane computed tomography in noninvasively predicting the clinical severity of COVID-19.

CT-Derived Pulmonary Artery Diameters to Preselect for Echocardiography in COPD Patients Eligible for Bronchoscopic Treatments

BACKGROUND

Currently, patients with COPD who are evaluated for bronchoscopic treatments are routinely screened for pulmonary hypertension (PH) and systolic left ventricle dysfunction by echocardiography.

OBJECTIVES

We evaluated the prevalence of PH and systolic left ventricle dysfunction in this patient group and investigated if the previously proposed CT-derived pulmonary artery to aorta (PA:A) ratio >1 and PA diameter measurements can be used as alternative screening tools for PH.

METHODS

Two hundred fifty-five patients were included in this retrospective analysis (FEV1 25%pred, RV 237%pred). All patients received transthoracic echocardiography and chest CT scans on which diameters of the aorta and pulmonary artery were measured at the bifurcation and proximal to the bifurcation.

RESULTS

Following echocardiography, 3 patients (1.2%) had PH and 1 (0.4%) had systolic left ventricle dysfunction. Using a PA:A ratio >1, only 10.3% of the patients with a right ventricular systolic pressure (RVSP) ≥35 mm Hg were detected and none of the patients with an RVSP >50 mm Hg were detected. Patients with an RVSP ≥35 mm Hg had significantly higher PA diameters (29.5 vs. 27.5 mm; p = 0.02) but no significantly different PA:A ratios. All patients with an RVSP >50 mm Hg had PA diameters >30 mm.

CONCLUSIONS

The prevalence of PH and systolic left ventricle dysfunction is low in this preselected cohort of patients with severe COPD. In this population, a PA:A ratio >1 is not a useful cardiac screening tool for PH. A PA diameter >30 mm could substitute for routinely performed echocardiography in the screening for PH in this patient group.

Relationship between Pulmonary Artery Diameter and Pulmonary to Aortic Artery Diameter Ratio in High Risk Individuals for Obstructive Sleep Apnea without Pulmonary Artery Hypertension Based on the Berlin Questionnaire

BACKGROUND

A significant association has been found between the pulmonary artery (PA) diameter and obstructive sleep apnea (OSA) in patients with pulmonary artery hypertension (PAH). We aimed to evaluate the relationship between the diameters of the PA trunk and aortic artery with their ratio as PAH markers in high risk cases for OSA based on the Berlin questionnaire without PAH.

MATERIALS AND METHODS

This case-control study included 161 non-PAH patients admitted to a multi-slice CT scan ward. Filling out the Berlin questionnaire, the patients were divided into high and low risk cases for OSA. The diameters of the PA trunk and aortic ascending aorta and their ratio were assessed using the multi-slice CT scan.

RESULTS

The PA to aortic ratios in the case and control groups were 0.89±0.17 and 0.88±0.17, respectively, which all were non-significant. With regard to gender, the PA diameter was significantly lower among males in the control group than in the case group (P=0.034). The mean PA to aortic ratio was slightly higher but statistically non-significant in the case group than in the control group. The aortic diameter showed a statistically significant increase by age in the case group (r=0.374, P=0.003) compared to the other group. However, the PA diameter increased significantly by age in both groups (r=0.184, P=0.020).

CONCLUSION

The PA diameter can be considered as a predicting factor for future cardiovascular diseases in high risk males for OSA based on the Berlin questionnaire without PAH. More studies are required to confirm these findings.

Advances in Chronic Obstructive Pulmonary Disease Imaging

Chest computed tomography (CT) imaging is a useful tool that provides in vivo information regarding lung structure. Imaging has contributed to a better understanding of COPD, allowing for the detection of early structural changes and the quantification of extra-pulmonary structures. Novel CT imaging techniques have provided insight into the progression of the main COPD subtypes, such as emphysema and small airway disease. This article serves as a review of new information relevant to COPD imaging. CT abnormalities, such as emphysema and loss of airways, are present even in smokers who do not meet the criteria for COPD and in those with mild-to-moderate disease. Subjects with mild-to-moderate COPD, with the highest loss of airways, also experience the highest decline in lung function. Extra-pulmonary manifestations of COPD, such as right ventricle enlargement and low muscle mass measured on CT, are associated with increased risk for all-cause mortality. CT longitudinal data has also given insight into the progression of COPD. Mechanically affected areas of lung parenchyma adjacent to emphysematous areas are associated with a greater decline in FEV₁. Subjects with the greatest percentage of small airway disease, as measured on matched inspiratory-expiratory CT scan, also present with the greatest decline in lung function.

The ratio of main pulmonary artery to ascending aorta diameter is associated with the right ventricular outflow tract ventriculararrhythmias

BACKGROUND

Although outflow tract (OT) ventricular arrhythmias (VAs) are generally regarded as benign, the relationship between circulation pressure and VAs has received considerable attention in recent years. Previous studies have shown that the ratio of main pulmonary artery (MPA) to ascending aorta (AA) diameter is associated with pulmonary pressure. Here, we investigated whether an elevated MPA/AA ratio is associated with right ventricular OT (RVOT) VAs.

METHODS

A total of 67 patients with OT VAs (47 patients with RVOT and 20 patients with LVOT) who underwent cardiac multidetector computed tomography and radiofrequency ablation were enrolled in this study. MPA and AA diameters were measured at the level of the bifurcation of the pulmonary artery. According to the MPA/AA ratio, patients were further divided into two groups: the MPA/AA ratio abnormal group (n = 19), which is defined as MPA/AA ratio ≥ 0.9, and the MPA/AA ratio normal group (n = 48) consisting of patients with an MPA/AA ratio < 0.9.

RESULTS

Patients with RVOT VAs exhibited an elevated MPA/AA ratio (0.84 ± 0.11 vs. 0.75 ± 0.11, p = 0.006). Furthermore, this MPA/AA ratio was shown to be an independent predictor for RVOT VAs (p = 0.013, 95% confidence interval: 1.016-1.145), with an abnormal MPA/AA ratio increasing the odds of RVOT VAs 5.1-fold in patients with OT VAs.

CONCLUSION

Patients with RVOT VAs exhibited significantly higher MPA/AA ratios compared with those LVOT VAs. The MPA/AA ratio was showed to be an independent predictor RVOT VAs.

Machine Learning and Prediction of All-Cause Mortality in COPD

BACKGROUND

COPD is a leading cause of mortality.

RESEARCH QUESTION

We hypothesized that applying machine learning to clinical and quantitative CT imaging features would improve mortality prediction in COPD.

STUDY DESIGN AND METHODS

We selected 30 clinical, spirometric, and imaging features as inputs for a random survival forest. We used top features in a Cox regression to create a machine learning mortality prediction (MLMP) in COPD model and also assessed the performance of other statistical and machine learning models. We trained the models in subjects with moderate to severe COPD from a subset of subjects in Genetic Epidemiology of COPD (COPDGene) and tested prediction performance in the remainder of individuals with moderate to severe COPD in COPDGene and Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE). We compared our model with the BMI, airflow obstruction, dyspnea, exercise capacity (BODE) index; BODE modifications; and the age, dyspnea, and airflow obstruction index.

RESULTS

We included 2,632 participants from COPDGene and 1,268 participants from ECLIPSE. The top predictors of mortality were 6-min walk distance, FEV1 % predicted, and age. The top imaging predictor was pulmonary artery-to-aorta ratio. The MLMP-COPD model resulted in a C index ≥ 0.7 in both COPDGene and ECLIPSE (6.4- and 7.2-year median follow-ups, respectively), significantly better than all tested mortality indexes (P < .05). The MLMP-COPD model had fewer predictors but similar performance to that of other models. The group with the highest BODE scores (7-10) had 64% mortality, whereas the highest mortality group defined by the MLMP-COPD model had 77% mortality (P = .012).

INTERPRETATION

An MLMP-COPD model outperformed four existing models for predicting all-cause mortality across two COPD cohorts. Performance of machine learning was similar to that of traditional statistical methods. The model is available online at: https://cdnm.shinyapps.io/cgmortalityapp/.