Performance of pulmonary artery dimensions measured on high-resolution computed tomography scan for identifying pulmonary hypertension

Imaging Approach to Pulmonary Hypertension

Pulmonary hypertension is a rare but important clinical problem that presents a sometimes challenging diagnostic dilemma. The diagnosis of pulmonary hypertension relies on a combination of clinical testing and radiologic imaging, with chest computed tomography (CT) often serving as the primary imaging modality for comprehensive evaluation of the chest. Chest CT can be used to evaluate for causes of pulmonary hypertension including chronic lung disease, pulmonary artery obstruction, and congenital heart disease. Recognizing common appearances of these conditions will enable expedient diagnosis.

Pulmonary hypertension associated with lung diseases

Pulmonary hypertension (PH) associated with chronic lung disease (CLD) is both common and underrecognised. The presence of PH in the setting of lung disease has been consistently shown to be associated with worse outcomes. Recent epidemiological studies have advanced understanding of the heterogeneity of this patient population and shown that defining both the specific type of CLD as well as the severity of PH (i.e. deeper phenotyping) is necessary to inform natural history and prognosis. A systematic diagnostic approach to screening and confirmation of suspected PH in CLD is recommended. Numerous uncontrolled studies and one phase 3 randomised, controlled trial have suggested a benefit in treating PH in some patients with CLD, specifically those with fibrotic interstitial lung disease (ILD). However, other studies in diseases such as COPD-PH showed adverse outcomes with some therapies. Given the expanding list of approved pharmacological treatments for pulmonary arterial hypertension, developing a treatment algorithm for specific phenotypes of CLD-PH is required. This article will summarise existing data in COPD, ILD and other chronic lung diseases, and provide recommendations for classification of CLD-PH and approach to the diagnosis and management of these challenging patients.

Noninvasive diagnostic modalities and prediction models for detecting pulmonary hypertension associated with interstitial lung disease: a narrative review

Pulmonary hypertension (PH) is highly prevalent in patients with interstitial lung disease (ILD) and is associated with increased morbidity and mortality. Widely available noninvasive screening tools are warranted to identify patients at risk for PH, especially severe PH, that could be managed at expert centres. This review summarises current evidence on noninvasive diagnostic modalities and prediction models for the timely detection of PH in patients with ILD. It critically evaluates these approaches and discusses future perspectives in the field. A comprehensive literature search was carried out in PubMed and Scopus, identifying 39 articles that fulfilled inclusion criteria. There is currently no single noninvasive test capable of accurately detecting and diagnosing PH in ILD patients. Estimated right ventricular pressure (RVSP) on Doppler echocardiography remains the single most predictive factor of PH, with other indirect echocardiographic markers increasing its diagnostic accuracy. However, RVSP can be difficult to estimate in patients due to suboptimal views from extensive lung disease. The majority of existing composite scores, including variables obtained from chest computed tomography, pulmonary function tests and cardiopulmonary exercise tests, were derived from retrospective studies, whilst lacking validation in external cohorts. Only two available scores, one based on a stepwise echocardiographic approach and the other on functional parameters, predicted the presence of PH with sufficient accuracy and used a validation cohort. Although several methodological limitations prohibit their generalisability, their use may help physicians to detect PH earlier. Further research on the potential of artificial intelligence may guide a more tailored approach, for timely PH diagnosis.

Pulmonary artery aneurysm: computed tomography (CT) imaging findings and diagnosis

Pulmonary artery aneurysm (PAA) is a rare pulmonary vascular disease with nonspecific symptoms and various etiologies. As the disease progresses, in addition to the dilation of the pulmonary arteries, it may be accompanied by remodeling of the cardiac structure and changes in the morphology of the aorta. Recognizing the cause of PAA is therefore a clinically challenging task. In this review article, we provide an overview of various causes of PAA with the support of corresponding imaging findings on computed tomography pulmonary angiography (CTPA) examination. Firstly, from the perspective of hemodynamics, a logical diagnosis is provided according to whether the main pulmonary artery (MPA) is dilated, and whether the PA is dilated locally or diffusely. Secondly, for the imaging examination of vascular wall lesions, due to the limitations of ultrasound examination and interventional procedures, the irreplaceability of dual-phase CTPA examination in disease assessment is especially emphasized. Finally, for highly suspected disorders, it is necessary to comprehensively check with the patient whether there is a family history or past medical history. For patients with PAA, especially those with Marfan syndrome (MFS) or arteritis, adequate preoperative imaging evaluation, regular postoperative radiographic follow-up, and concurrent treatment of the underlying disease (if necessary) are crucial, which are related to the prognosis and long-term quality of life of such patients. Despite the nonspecific features of PAA presentation, a thorough examination of the patient's clinical history and imaging characteristics will play an important role in diagnosing PAA and planning patient management strategies.

Chronic thromboembolic disease among patients undergoing surgical pulmonary embolectomy for acute pulmonary embolism

BACKGROUND

This study aimed to assess the prevalence of chronic thromboembolic lesions in the pulmonary arteries among patients undergoing pulmonary embolectomy for acute pulmonary embolism and their impact on treatment outcomes.

METHODS

We conducted a retrospective, single-center analysis of consecutive patients undergoing emergency pulmonary embolectomy for acute pulmonary embolism between 2013 and August 2021. According to European Society of Cardiology guidelines, the diagnosis was based on clinical presentation, imaging studies and laboratory tests. Surgery was selected as the optimal treatment modality within the Pulmonary Embolism Response Team. Based on the intraoperatively identified chronic lesions patients were divided into two groups: acute only and acute/chronic. The analysis comprised history, laboratory and imaging studies, early and long-term mortality, and postoperative complications. We determined predictive factors for chronic thromboembolic lesions and risk factors for death.

RESULTS

The analysis included 33 patients. Intraoperatively, 42% (14) of patients had chronic lesions. Predictive factors for these lesions are the duration of symptoms >1 week (OR=13.75), pulmonary artery dilatation >3.15 cm (OR=39.00) and right ventricle systolic pressure >52 mmHg (OR=29.33). No hospital deaths occurred in the acute only group and two in the acute/chronic group (0% vs. 14.3%; P=0.172). Risk factors for death are the duration of symptoms >3 weeks (HR=7.35) and postoperative use of extracorporeal membrane oxygenation (HR=7.04).

CONCLUSIONS

Acute thromboembolic disease overlapping chronic clots is relatively common among patients undergoing pulmonary artery embolectomy. A detailed evaluation of the patient's medical history and imaging studies can identify these patients, as they require special attention when making treatment decisions. Surgical treatment in a center of expertise in pulmonary endarterectomy seems reasonable.

Imaging of Pulmonary Sarcoidosis-A Review

Sarcoidosis is the classic multisystem granulomatous disease. First reported as a disorder of the skin, it is now clear that, in the overwhelming majority of patients with sarcoidosis, the lungs will bear the brunt of the disease. This review explores some of the key concepts in the imaging of pulmonary sarcoidosis: the wide array of typical (and some of the less common) findings on high-resolution computed tomography (HRCT) are reviewed and, with this, the concept of morphologic/HRCT phenotypes is discussed. The pathophysiologic insights provided by HRCT through studies where morphologic abnormalities and pulmonary function tests are compared are evaluated. Finally, this review outlines the important contribution of HRCT to disease monitoring and prognostication.

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.

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.

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.

Association between pulmonary artery to aorta diameter ratio with pulmonary hypertension and outcomes in diffuse cystic lung diseases

To investigate the importance of pulmonary vascular measurements on computed tomography (CT) in predicting pulmonary hypertension (PH) and worse outcomes in diffuse cystic lung diseases (DCLDs).We conducted a cross-sectional study of patients with DCLDs. Patients underwent pulmonary function tests, a six-minute walk test (6MWT), chest CT, transthoracic echocardiography, and right heart catheterization. Pulmonary artery (PA) diameter and PA-ascending aorta ratio (PA-Ao ratio) were obtained from CT. Mean pulmonary artery pressure (mPAP) from right heart catheterization was correlated with tomographic, functional, and echocardiographic variables. The association between the PA-Ao ratio with outcomes was determined by Kaplan-Meier curves.Thirty-four patients were included (18 with pulmonary Langerhans cell histiocytosis and 16 with lymphangioleiomyomatosis, mean age 46 ± 9 years). Forced expiratory volume in the first second and lung diffusing capacity for carbon monoxide were 47 ± 20% and 38 ± 21% predicted, respectively. PA diameter and PA-Ao ratio were 29 ± 6 mm and 0.95 ± 0.24, respectively. PA-Ao ratio > 1 occurred in 38.2% of patients. PA-Ao ratio was a good predictor of PH. mPAP correlated best with PA-Ao ratio, PA diameter, oxygen desaturation during six-minute walk test, and echocardiographic variables. Patients with PA-Ao ratio > 1 had greater mPAP, and a higher risk of death or lung transplantation (log-rank, P < .001) than those with PA-Ao ratio ≤ 1.The PA-Ao ratio measured on CT scan has a potential role as a non-invasive tool to predict the presence of PH and as a prognostic parameter in patients with DCLDs.

Risk factors for myocardial injury and death in patients with COVID-19: insights from a cohort study with chest computed tomography

AIMS

Whether pulmonary artery (PA) dimension and coronary artery calcium (CAC) score, as assessed by chest computed tomography (CT), are associated with myocardial injury in patients with coronavirus disease 2019 (COVID-19) is not known. The aim of this study was to explore the risk factors for myocardial injury and death and to investigate whether myocardial injury has an independent association with all-cause mortality in patients with COVID-19.

METHODS AND RESULTS

This is a single-centre cohort study including consecutive patients with laboratory-confirmed COVID-19 undergoing chest CT on admission. Myocardial injury was defined as high-sensitivity troponin I >20 ng/L on admission. A total of 332 patients with a median follow-up of 12 days were included. There were 68 (20.5%) deaths; 123 (37%) patients had myocardial injury. PA diameter was higher in patients with myocardial injury compared with patients without myocardial injury [29.0 (25th-75th percentile, 27-32) mm vs. 27.7 (25-30) mm, P < 0.001). PA diameter was independently associated with an increased risk of myocardial injury [adjusted odds ratio 1.10, 95% confidence interval (CI) 1.02-1.19, P = 0.01] and death [adjusted hazard ratio (HR) 1.09, 95% CI 1.02-1.17, P = 0.01]. Compared with patients without myocardial injury, patients with myocardial injury had a lower prevalence of a CAC score of zero (25% vs. 55%, P < 0.001); however, the CAC score did not emerge as a predictor of myocardial injury by multivariable logistic regression. Myocardial injury was independently associated with an increased risk of death by multivariable Cox regression (adjusted HR 2.25, 95% CI 1.27-3.96, P = 0.005). Older age, lower estimated glomerular filtration rate, and lower PaO2/FiO2 ratio on admission were other independent predictors for both myocardial injury and death.

CONCLUSIONS

An increased PA diameter, as assessed by chest CT, is an independent risk factor for myocardial injury and mortality in patients with COVID-19. Myocardial injury is independently associated with an approximately two-fold increased risk of death.