Diagnosis of chronic thromboembolic pulmonary hypertension

COVID-19 imaging: Diagnostic approaches, challenges, and evolving advances

The role of radiology and the radiologist have evolved throughout the coronavirus disease-2019 (COVID-19) pandemic. Early on, chest computed tomography was used for screening and diagnosis of COVID-19; however, it is now indicated for high-risk patients, those with severe disease, or in areas where polymerase chain reaction testing is sparsely available. Chest radiography is now utilized mainly for monitoring disease progression in hospitalized patients showing signs of worsening clinical status. Additionally, many challenges at the operational level have been overcome within the field of radiology throughout the COVID-19 pandemic. The use of teleradiology and virtual care clinics greatly enhanced our ability to socially distance and both are likely to remain important mediums for diagnostic imaging delivery and patient care. Opportunities to better utilize of imaging for detection of extrapulmonary manifestations and complications of COVID-19 disease will continue to arise as a more detailed understanding of the pathophysiology of the virus continues to be uncovered and identification of predisposing risk factors for complication development continue to be better understood. Furthermore, unidentified advancements in areas such as standardized imaging reporting, point-of-care ultrasound, and artificial intelligence offer exciting discovery pathways that will inevitably lead to improved care for patients with COVID-19.

The United States Chronic Thromboembolic Pulmonary Hypertension Registry: Protocol for a Prospective, Longitudinal Study

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare sequela of acute pulmonary embolism that is treatable when recognized. Awareness of this disease has increased with recent advancements in therapeutic options, but delays in diagnosis remain common, and diagnostic and treatment guidelines are often not followed. Data gathered from international registries have improved our understanding of CTEPH, but these data may not be applicable to the US population owing to differences in demographics and medical practice patterns.

Objective

The US CTEPH Registry (US-CTEPH-R) was developed to provide essential information to better understand the demographics, risk factors, evaluation, and treatment of CTEPH in the United States, as well as the short- and long-term outcomes of surgical and nonsurgical therapies in the modern treatment era.

Methods

Thirty sites throughout the United States enrolled 750 subjects in this prospective, longitudinal, observational registry of patients newly diagnosed with CTEPH. Enrollment criteria included a mean pulmonary artery pressure ≥25 mmHg by right heart catheterization and radiologic confirmation of CTEPH by a multidisciplinary adjudication committee. Following enrollment, subjects were followed biannually until the conclusion of the study. Quality of life surveys were administered at enrollment and biannually, and all other testing was at the discretion of the treating clinician. Details regarding surgical therapy, balloon pulmonary angioplasty, and medical therapy were collected at enrollment and at follow-up, as well as information related to health care utilization and survival.

Results

Data from this registry will improve understanding of the demographics, risk factors, and treatment patterns of patients with CTEPH, and the longitudinal impact of therapies on quality of life, health care utilization, and survival.

Conclusions

This manuscript details the methodology and design of the first large, prospective, longitudinal registry of patients with CTEPH in the United States.

Trial Registration

ClinicalTrials.gov NCT02429284; https://www.clinicaltrials.gov/ct2/show/NCT02429284

International Registered Report Identifier (IRRID)

DERR1-10.2196/25397

Optimizing the diagnosis and assessment of chronic thromboembolic pulmonary hypertension with advancing imaging modalities

Imaging is key to nearly all aspects of chronic thromboembolic pulmonary hypertension including management for screening, assessing eligibility for pulmonary endarterectomy, and post-operative follow-up. While ventilation/perfusion scintigraphy, the gold standard technique for chronic thromboembolic pulmonary hypertension screening, can have excellent sensitivity, it can be confounded by other etiologies of pulmonary malperfusion, and does not provide structural information to guide operability assessment. Conventional computed tomography pulmonary angiography has high specificity, though findings of chronic thromboembolic pulmonary hypertension can be visually subtle and unrecognized. In addition, computed tomography pulmonary angiography can provide morphologic information to aid in pre-operative workup and assessment of other structural abnormalities. Advances in computed tomography imaging techniques, including dual-energy computed tomography and spectral-detector computed tomography, allow for improved sensitivity and specificity in detecting chronic thromboembolic pulmonary hypertension, comparable to that of ventilation/perfusion scans. Furthermore, these advanced computed tomography techniques, compared with conventional computed tomography, provide additional physiologic data from perfused blood volume maps and improved resolution to better visualize distal chronic thromboembolic pulmonary hypertension, an important consideration for balloon pulmonary angioplasty for inoperable patients. Electrocardiogram-synchronized techniques in electrocardiogram-gated computed tomography can also show further information regarding right ventricular function and structure. While the standard of care in the workup of chronic thromboembolic pulmonary hypertension includes a ventilation/perfusion scan, computed tomography pulmonary angiography, direct catheter angiography, echocardiogram, and coronary angiogram, in the future an electrocardiogram-gated dual-energy computed tomography angiography scan may enable a "one-stop" imaging study to guide diagnosis, operability assessment, and treatment decisions with less radiation exposure and cost than traditional chronic thromboembolic pulmonary hypertension imaging modalities.

Canadian Society of Thoracic Radiology/Canadian Association of Radiologists Best Practice Guidance for Investigation of Acute Pulmonary Embolism, Part 2: Technical Issues and Interpretation Pitfalls

The investigation of acute pulmonary embolism is a common task for radiologists in Canada. Technical image quality and reporting quality must be excellent; pulmonary embolism is a life-threatening disease that should not be missed but overdiagnosis and unnecessary treatment should be avoided. The most frequently performed imaging investigation, computed tomography pulmonary angiogram (CTPA), can be limited by poor pulmonary arterial opacification, technical artifacts and interpretative errors. Image quality can be affected by patient factors (such as body habitus, motion artifact and cardiac output), intravenous (IV) contrast protocols (including the timing, rate and volume of IV contrast administration) and common physics artifacts (including beam hardening). Mimics of acute pulmonary embolism can be seen in normal anatomic structures, disease in non-vascular structures and pulmonary artery filling defects not related to acute pulmonary emboli. Understanding these pitfalls can help mitigate error, improve diagnostic quality and optimize patient outcomes. Dual energy computed tomography holds promise to improve imaging diagnosis, particularly in clinical scenarios where routine CTPA may be problematic, including patients with impaired renal function and patients with altered cardiac anatomy.

Chronic thromboembolic pulmonary hypertension: evaluation of V/Q SPECT/CT and V/Q Quotient SPECT findings with postoperative results of pulmonary endarterectomy

OBJECTIVES

We aimed to perform a comparison between V/Q single-photon emission computed tomography/computed tomography (SPECT/CT) and V/Q Quotient single-photon emission computerized tomography (SPECT) in the detection of chronic thromboembolic pulmonary hypertension (CTEPH) and in depicting the extent of the disease on per-segment basis in patients with CTEPH.

METHODS

Between January 2015 and November 2019, a total of 412 patients with pulmonary hypertension secondary to CTEPH at the preoperative assessment underwent pulmonary endarterectomy (PEA), of whom 92 consecutive patients with their V/Q SPECT/CT scans have been performed in our institution prior to PEA were included in this study. Histopathological findings and post-PEA fully resected surgical specimens were used as the reference standard.

RESULTS

On a per-patient basis analysis, V/Q SPECT/CT and V/Q Quotient SPECT both revealed CTEPH in the same 85 of the 92 patients (κ = 1) with a detection rate of 92.4%. In six of these patients, chronic thromboembolic disease could not be reported on both of these two methods due to extensive 'matched' V/Q defects. On a per-segment basis analysis, V/Q SPECT/CT and V/Q Quotient SPECT showed a sensitivity of 75.8 and 73.1%, respectively. Correlation analysis results showed a significant correlation (κ = 0.933) between these two methods on a per-segment basis analysis.

CONCLUSION

In the light of histopathological findings and post-PEA surgical specimen examinations, the results of the present study indicated that both V/Q SPECT/CT and V/Q Quotient SPECT showed relatively high efficacy for the detection of CTEPH on per-patient and per-segment bases with an excellent agreement.

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.

COVID-19: looking beyond the peak. Challenges and tips for radiologists in follow-up of a novel patient cohort

As the coronavirus pandemic evolves, the focus of radiology departments has begun to change. The acute phase of imaging a new disease entity whilst rationalising radiology services in the face of lockdown has passed. Radiologists are now becoming familiar with the complications of COVID-19, particularly the lung parenchymal and pulmonary vascular sequelae and are considering the impact follow-up imaging may have on departments already struggling with a backlog of suspended imaging in the face of reduced capacity. This review from the British Society of Thoracic Imaging explores both the thoracic and extra-thoracic complications of COVID-19, recognising the importance of a holistic approach to patient follow-up. The British Thoracic Society guidelines for respiratory follow-up of COVID-19 will be discussed, together with newly developed reporting templates, which aim to provide consistency for clinicians as well as an opportunity for longer-term data collection.

Chronic Thromboembolic Pulmonary Hypertension: the Bedside

PURPOSE OF REVIEW

Chronic thromboembolic pulmonary hypertension (CTEPH), included in group 4 PH, is an uncommon complication of acute pulmonary embolism (PE), in which emboli in the pulmonary vasculature do not resolve but rather form into an organized scar-like obstruction which can result in right ventricular (RV) failure. Here we provide an overview of current diagnosis and management of CTEPH.

RECENT FINDINGS

CTEPH management is complex with treatments that range from surgery, percutaneous interventions, to medical therapies. Current CTEPH medical therapies have largely been repurposed from pulmonary arterial hypertension (PAH). The diagnosis of CTEPH can be challenging, requiring a multimodality approach to differentiate from disease mimics. While these treatments improve symptoms, they may not reverse the underlying pathology of CTEPH.

Possible immune regulation mechanisms for the progression of chronic thromboembolic pulmonary hypertension

PURPOSE

This study aimed to screen key genes significantly associated with chronic thromboembolic pulmonary hypertension (CTEPH) and predicted suitable drugs for the treatment of CTEPH from the perspective of immune cells.

METHODS

The dataset GSE130391 was used for this analysis. Differentially expressed genes (DEGs) between the CTEPH and control groups were screened. Abundance of infiltrating immune cells was analyzed and immune-related DEGs were identified. Next, the circular RNA (circRNA)-micro RNA (miRNA)-mRNA network was constructed, followed by functional enrichment analysis. Then, the protein-protein interaction (PPI) network was constructed and drug-gene interactions were predicted. Finally, miRNA and circRNA prediction results were verified by our previously published studies.

RESULTS

Five key immune cell-related DEGs [CD83 molecule (CD83), complement c5a receptor 1 (C5AR1), atypical chemokine receptor 1 (ACKR1), profilin 2 (PFN2), and solute carrier family 2 member 3 (SLC2A3)] were identified. Several circRNA-miRNA-mRNA interactions were obtained, including circ_0022342miR-503-5pSLC2A3 and circ_0002062miR-92b-3p/miR-92a-3pmannosidase alpha class 2A member 1 (MAN2A1). Immune cell for SLC2A3 was eosinophils and for MAN2A1 was regulatory T cells (Tregs). Additionally, Glufosfamide and Kifunensine might be suitable as candidate drugs for CTEPH treatment.

CONCLUSIONS

SLC2A3 and MAN2A1 may be important genes for the pathogenesis of CTEPH. Possible immune regulation mechanisms in CTEPH may be circ_0022342miR-503-5pSLC2A3 and circ_0002062miR-92b-3p/miR-92a-3pMAN2A1. These results may be helpful for the diagnosis and treatment of CTEPH from the perspective of immunology.

An Evaluation of the Learning Curve in Pulmonary Endarterectomy Using Propensity Score Matching

OBJECTIVE

Pulmonary endarterectomy (PEA) is the only causative, but demanding treatment of choice for chronic thromboembolic pulmonary hypertension (CTEPH). We analyzed our results with PEA to evaluate the learning curve.

METHODS

Consecutive 499 patients who underwent PEA between 1995 and 2014 were divided into two groups according to the temporal order: early cohort (n = 200, December 1995-March 2006), and late cohort (n = 299, March 2006-December 2014). We assessed perioperative outcomes after PEA as compared between the early and the late cohort also in propensity-score-matched cohorts.

RESULTS

Age at the surgery was older in the late cohort (p = 0.042). Preoperative mean pulmonary artery pressure (mPAP) was 46.8 ± 11.0 mm Hg in the early cohort and 43.5 ± 112.7 mm Hg in the late cohort (p = 0.0035). The in-hospital mortality in the early and late cohorts was 14.0% (28/200) and 4.7% (14/299), respectively (p = 0.00030). The duration of circulatory arrest (CA) became much shorter in the late cohort (42.0 ± 20.5 min in the early and 24.2 ± 11.6 min in the late cohort, respectively, p < .0001). In matched cohorts, the in-hospital mortality showed no significant difference (8.7% in the early cohort and 5.2% in the late cohort, < 0.0001). The CA duration, however, was still shorter in the late cohort (p <0.0001).

CONCLUSIONS

Over time, older patients have been accepted for surgery, more patients were operated for lesser severity of CTEPH. Duration of CA and mortality decreased even beyond the first 200 patients, indicating a long learning curve.

Diagnosis of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism

Chronic thromboembolic pulmonary hypertension (CTEPH) is the most severe long-term complication of acute pulmonary embolism (PE). Untreated CTEPH is fatal, but, if diagnosed in time, successful surgical (pulmonary endarterectomy), medical (pulmonary hypertension drugs) and/or interventional (balloon pulmonary angioplasty) therapies have been shown to improve clinical outcomes, especially in case of successful pulmonary endarterectomy. Early diagnosis has however been demonstrated to be challenging. Poor awareness of the disease by patients and physicians, high prevalence of the post-PE syndrome (i.e. persistent dyspnoea, functional limitations and/or decreased quality of life following an acute PE diagnosis), lack of clear guideline recommendations as well as inefficient application of diagnostic tests in clinical practice lead to a reported staggering diagnostic delay >1 year. Hence, there is a great need to improve current clinical practice and diagnose CTEPH earlier. In this review, we will focus on the clinical presentation of and risk factors for CTEPH, and provide best practices for PE follow-up programmes from expert centres, based on a clinical case.

Clinical Updates on the Diagnosis and Management of Chronic Thromboembolic Pulmonary Hypertension

Introduction: Chronic thromboembolic pulmonary hypertension (CTEPH) is a known sequela after acute pulmonary embolism (PE). It is a debilitating disease, and potentially fatal if left untreated. This review provides a clinically relevant overview of the disease and discusses the usefulness and limitations of the various investigational and treatment options. Methods: A PubMed search on articles relevant to pulmonary embolism, pulmonary hypertension, chronic thromboembolic pulmonary hypertension, pulmonary endarterectomy, and balloon pulmonary angioplasty were performed. A total of 68 articles were found to be relevant and were reviewed. Results: CTEPH occurs as a result of non-resolution of thrombotic material, with subsequent fibrosis and scarring of the pulmonary arteries. Risk factors have been identified, but the underlying mechanisms have yet to be fully elucidated. The cardinal symptom of CTEPH is dyspnoea on exertion, but the diagnosis is often challenging due to lack of awareness. The ventilation/perfusion scan is recommended for screening for CTEPH, with other modalities (eg. dual energy computed tomography pulmonary angiography) also being utilised in expert centres. Conventional pulmonary angiography with right heart catherisation is important in the final diagnosis of CTEPH. Conclusion: Operability assessment by a multidisciplinary team is crucial for the management of CTEPH, as pulmonary endarterectomy (PEA) remains the guideline recommended treatment and has the best chance of cure. For inoperable patients or those with residual disease post-PEA, medical therapy or balloon pulmonary angioplasty are potential treatment options. Keywords: Balloon pulmonary angioplasty, Chronic thromboembolic pulmonary hypertension, Pulmonary embolism, Pulmonary endarterectomy, Pulmonary hypertension

Chronic thromboembolic pulmonary hypertension in Saudi Arabia: preliminary results from the SAUDIPH registry

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare, progressive vascular disease with poor prognosis if left untreated. This study aims to assess the patient characteristics, treatment approach and clinical and survival outcomes for CTEPH patients enrolled in the Systematic Prospective Follow Up for Better Understanding of Clinical Characteristics of Patients with Pulmonary Hypertension Disease (SAUDIPH) registry.

Methods

This study presents a subanalysis of CTEPH patients enrolled in the SAUDIPH registry. This registry enrolled patients with pulmonary hypertension, established through right heart catheterisation, under clinical management at a specialised tertiary care centre. Patients received standard care during the period of the registry.

Results

At the time of this analysis, 64 CTEPH patients were enrolled in the registry. Mean age at diagnosis was 39.7 years and there was a female predominance (67.6%). At baseline, most patients were in World Health Organization functional classes III or IV (70.1%). At the last follow-up visit, most patients (63.2%) had undergone endarterectomy, showing significant improvement in disease severity from baseline. Patients who underwent endarterectomy showed numerically higher (p=0.126) probability of survival at 1 year (97.5%) versus those who did not undergo endarterectomy (94.4%).

Conclusion

Patients were diagnosed at relatively young age, but still showed high disease severity, suggesting delay in diagnosis. Patients who underwent surgical treatment showed substantial improvements in clinical and haemodynamic parameters, while the remaining patients tended to show disease progression. The 96.6% 1-year cumulative probability of survival was high compared to previous studies.

The SAUDIPH registry was designed to follow pulmonary hypertension patients in Saudi Arabia. This study assesses patient characteristics and treatment approaches of chronic thromboembolic pulmonary hypertension patients enrolled in the SAUDIPH registry.http://bit.ly/2uCWpBe

Assessment of ventilation-perfusion scans in patients with chronic thromboembolic pulmonary hypertension before and after surgery and correlation with clinical parameters

PURPOSE

We did a comparative analysis of matched and mismatched defects in pre- and post-operative V/Q scans in CTEPH patients. We correlated the number of these defects with pre-operative clinical and hemodynamic parameters.

METHODS

This was a retrospective study on 27 patients with CTEPH who underwent surgery. Pre- and post-operative V/Q scans were graded for each lung segment as normal, matched or mismatched defect. Additional pre- and post-operative clinical and hemodynamic parameters that were collected include New York Heart Association functional class, six-minute walk distance in feet, N-terminal pro b-type natriuretic peptide, forced expiratory volume in one second/forced vital capacity, diffusing capacity of the lung for carbon monoxide, pulmonary arterial pressure (systolic, diastolic and mean), right atrial pressure, cardiac output and cardiac index. Pulmonary vascular resistance was then calculated.

RESULTS

On a segmental basis, 176 mismatched defects were noted in 27 patients, of which 111 improved post-surgery (63%). 22 of the 34 matched defects improved following surgery (64%). 31 new mismatched defects were observed. The number of pre-operative matched defects per patient ranged from 0 to 6. No statistically significant associations were observed between the number of pre-operative matched defects and pre-operative clinical parameters. No statistically significant associations were observed between the number of improved matched defects and the change in clinical parameters (pre- to post-surgery).

CONCLUSION

Both matched and mismatched defects on preoperative V/Q scans can show normalization post-surgery. The extent of matched defects on a preoperative V/Q scan does not correlate significantly with other clinical and hemodynamic parameters.

Pulmonary chronic thromboembolic disease

Persistent thrombotic lesions are common in patients with pulmonary embolism. These lesions occur on a clinical spectrum, ranging from an asymptomatic course with complete functional recovery to chronic thromboembolic pulmonary hypertension. The concept of chronic thromboembolic disease has emerged in recent years to describe a subgroup of patients with persistent thrombotic lesions who have symptoms on exertion and pulmonary vascular dysfunction, but no pulmonary hypertension at rest. The prevalence of this entity is unknown and the criteria for diagnosing it are not defined. The aim of this article is to analyze post-pulmonary embolism sequelae and review existing evidence on chronic thromboembolic disease, with special emphasis on its diagnosis and therapeutic approach.

Pulmonary Embolectomy for Acute Pulmonary Embolism: A Word of Caution

Pulmonary embolectomy is an effective treatment of acute pulmonary embolism (APE) but not for chronic pulmonary thromboembolism. We described surgical experience of two patients with APE in preexistent unidentified chronic pulmonary thromboembolism. One patient who presented with severe hypoxia but stable hemodynamics underwent successful pulmonary endarterectomy for proximal organized thrombus instead of pulmonary embolectomy. The other patient who required extracorporeal membrane oxygenation for severe hypoxia developed right heart failure because of residual distal organized thrombus after pulmonary embolectomy. Clinical and radiographical presentation of APE in chronic pulmonary thromboembolism mimics APE, and thus, candidates of pulmonary embolectomy should be carefully selected.

Imaging of Chronic Thromboembolic Disease

Acute pulmonary embolism (PE) is a leading cause of cardiovascular morbidity. The most common long-term complication of acute PE is chronic thromboembolic disease, a heterogenous entity which ranges from asymptomatic imaging sequelae to persistent symptoms. Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease that can develop in this population and represents the only treatable type of pulmonary hypertension. Recognition of the characteristic findings of chronic pulmonary embolism and CTEPH provides not only diagnostic information, but is also crucial for guiding therapy. The present state-of-the-art review focuses on the multimodality imaging features of chronic pulmonary embolism. Detailed description and illustrations of relevant imaging findings will be demonstrated for ventilation/perfusion (V/Q) scan, CT scan and Dual-Energy CT and MRI and features that distinguish chronic PE from common imaging mimics.

Surgical and Percutaneous Interventions for Chronic Thromboembolic Pulmonary Hypertension

The treatment of chronic thromboembolic pulmonary hypertension has expanded considerably. The ability to endarterectomize chronic thromboembolic material, the availability of pulmonary hypertension medical therapy to treat inoperable chronic thromboembolic pulmonary hypertension and/or residual pulmonary hypertension, and the rebirth of pulmonary balloon angioplasty have changed the management landscape. Patient selection requires a multidisciplinary evaluation at an experienced center. What is inoperable chronic thromboembolic pulmonary hypertension to one group may be operable chronic thromboembolic pulmonary hypertension to another. The ultimate challenge then becomes which intervention provides the optimal long-term outcome for any individual patient.

Mimickers of chronic thromboembolic pulmonary hypertension on imaging tests: a review

Chronic thromboembolic pulmonary hypertension (CTEPH) is caused by mechanical obstruction of large pulmonary arteries secondary to one or more episodes of pulmonary embolism. Ventilation perfusion scan is the recommended initial screening test for this condition and typically shows multiple large mismatched perfusion defects. However, not all patients with an abnormal ventilation perfusion scan have CTEPH since there are other conditions that be associated with a positive ventilation perfusion scan. These conditions include in situ thrombosis, pulmonary artery sarcoma, fibrosing mediastinitis, pulmonary vasculitis and sarcoidosis, among others. Although these conditions cannot be distinguished from CTEPH using a ventilation perfusion scan, they have certain characteristic radiological features that can be demonstrated on other imaging techniques such as computed tomography scan and can help in differentiation of these conditions. In this review, we have summarized some key clinical and radiological features that can help differentiate CTEPH from the CTEPH mimics.

Evaluation of the CT imaging findings in the diagnosis of pulmonary hypertension due to chronic thromboembolism

PURPOSE

Chronic thromboembolic pulmonary hypertension (CTEPH) is the only pulmonary hypertension that can be treated surgically. Multidedector computerized tomography angiography (MDCTA) is considered as an important tool. In this study, the important CT findings of CTEPH and the vascular MDCTA findings of CTEPH were classified as central, peripheral, central and peripheral. The aim of this study was to investigate the relationship between these groups with parenchymal and hemodynamic findings.

MATERIALS AND METHODS

MDCTA examinations of 26 patients who had been diagnosed with CTEPH were retrospectively reviewed. Vascular, cardiac and parenchymal findings were examined in MDCTA. Patients were divided into three groups as peripheral, central and peripheral and central chronic thromboembolism. The relationship between these groups with demographic, vascular, parenchymal and hemodynamic findings was investigated.

RESULTS

The most common vascular finding was the wall filling defects attached to the lobar and/or segmental arterial walls, while the parenchymal finding was the fibrotic shrinkage. There were no statistically significant differences between the three groups compared to parenchymal findings which are mosaic pattern, brochiectasis, fibrotic changes and atelectasis, pulmonary artery diameter, right atrial diameter and RV/LV ratio. Age and sex were not different in patients between the three groups.

CONCLUSION

The results of the this study confirm the important role of MDCTA in the evaluation of vascular, cardiac and parenchymal findings in the patients with CTEPH and identifying patients that would most benefit from surgical treatment by visualization of the segmental and subsegmental branches of the pulmonary arteries.

EANM guideline for ventilation/perfusion single-photon emission computed tomography (SPECT) for diagnosis of pulmonary embolism and beyond

These guidelines update the previous EANM 2009 guidelines on the diagnosis of pulmonary embolism (PE). Relevant new aspects are related to (a) quantification of PE and other ventilation/perfusion defects; (b) follow-up of patients with PE; (c) chronic PE; and (d) description of additional pulmonary physiological changes leading to diagnoses of left ventricular heart failure (HF), chronic obstructive pulmonary disease (COPD) and pneumonia. The diagnosis of PE should be reported when a mismatch of one segment or two subsegments is found. For ventilation, Technegas or krypton gas is preferred over diethylene triamine pentaacetic acid (DTPA) in patients with COPD. Tomographic imaging with V/PSPECT has higher sensitivity and specificity for PE compared with planar imaging. Absence of contraindications makes V/PSPECT an essential method for the diagnosis of PE. When V/PSPECT is combined with a low-dose CT, the specificity of the test can be further improved, especially in patients with other lung diseases. Pitfalls in V/PSPECT interpretation are discussed. In conclusion, V/PSPECT is strongly recommended as it accurately establishes the diagnosis of PE even in the presence of diseases like COPD, HF and pneumonia and has no contraindications.

CTPA, DECT, MRI, V/Q Scan, and SPECT/CT V/Q for the noninvasive diagnosis of chronic thromboembolic pulmonary hypertension: A protocol for systemic review and network meta-analysis of diagnostic test accuracy

BACKGROUND

To determine the diagnostic accuracy of techniques with chronic thromboembolic pulmonary hypertension (CTEPH) patients via a protocol for systemic review and network meta-analysis.

METHODS

We will search PubMed, EMBASE, Web of Science, and Google Scholar from inception to October 1, 2018. The reference lists of the retrieved articles are also consulted. Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) will be used to assess the risk of bias in each study. The direct meta-analyses, network meta-analyses, and ranking of competing diagnostic tests will be used by STATA 12.0 and WINBUGS 1.4. Heterogeneity and inconsistency are assessed.

RESULTS

This study is ongoing, will be submitted to a peer-reviewed journal publication once completed.

CONCLUSION

This study will provide a comprehensive evidence summary of diagnostic test accuracy in detecting the CTEPH, and can help patients and clinicians to select appropriate or best diagnostic test.

ETHICS AND COMMUNICATION

No ethical approval and patient consent are required, because it is based on published researches.

PROSPERO REGISTRATION NUMBER

CRD42019121279.

ICAM-1 promotes the abnormal endothelial cell phenotype in chronic thromboembolic pulmonary hypertension

BACKGROUND

Pulmonary endothelial cells play a key role in the pathogenesis of Chronic Thromboembolic Pulmonary Hypertension (CTEPH). Increased synthesis and/or the release of intercellular adhesion molecule-1 (ICAM-1) by pulmonary endothelial cells of patients with CTEPH has been recently reported, suggesting a potential role for ICAM-1 in CTEPH.

METHODS

We studied pulmonary endarterectomy specimens from 172 patients with CTEPH and pulmonary artery specimens from 97 controls undergoing lobectomy for low-stage cancer without metastasis.

RESULTS

ICAM-1 was overexpressed in vitro in isolated and cultured endothelial cells from endarterectomy specimens. Endothelial cell growth and apoptosis resistance were significantly higher in CTEPH specimens than in the controls (p < 0.001). Both abnormalities were abolished by pharmacological inhibition of ICAM-1 synthesis or activity. The overexpression of ICAM-1 contributed to the acquisition and maintenance of abnormal EC growth and apoptosis resistance via the phosphorylation of SRC, p38 and ERK1/2 and the overproduction of survivin. Regarding the ICAM-1 E469K polymorphism, the KE heterozygote genotype was significantly more frequent in CTEPH than in the controls, but it was not associated with disease severity among patients with CTEPH.

CONCLUSIONS

ICAM-1 contributes to maintaining the abnormal endothelial cell phenotype in CTEPH.

Pulmonary embolism: update on diagnosis and management

Pulmonary embolism (PE) is a potentially life-threatening condition, mandating urgent diagnosis and treatment. The symptoms of PE may be non-specific; diagnosis therefore relies on a clinical assessment and objective diagnostic testing. A clinical decision rule can determine the pre-test probability of PE. If PE is "unlikely", refer for a D-dimer test. If the D-dimer result is normal, PE can be excluded. If D-dimer levels are increased, refer for chest imaging. If PE is "likely", refer for chest imaging. Imaging with computed tomography pulmonary angiogram is accurate and preferred for diagnosing PE, but may detect asymptomatic PE of uncertain clinical significance. Imaging with ventilation-perfusion (VQ) scan is associated with lower radiation exposure than computed tomography pulmonary angiogram, and may be preferred in younger patients and pregnancy. A low probability or high probability VQ scan is helpful for ruling out or confirming PE, respectively; however, an intermediate probability VQ scan requires further investigation. The direct oral anticoagulants have expanded the anticoagulation options for PE. These are the preferred anticoagulant for most patients with PE because they are associated with a lower risk of bleeding, and have the practical advantages of fixed dosage, no need for routine monitoring, and fewer drug interactions compared with vitamin K antagonists. Initial parenteral treatment is required before dabigatran and edoxaban.

2018 TSOC guideline focused update on diagnosis and treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized as a progressive and sustained increase in pulmonary vascular resistance, which may induce right ventricular failure. In 2014, the Working Group on Pulmonary Hypertension of the Taiwan Society of Cardiology (TSOC) conducted a review of data and developed a guideline for the management of PAH.⁴ In recent years, several advancements in diagnosis and treatment of PAH has occurred. Therefore, the Working Group on Pulmonary Hypertension of TSOC decided to come up with a focused update that addresses clinically important advances in PAH diagnosis and treatment. This 2018 focused update deals with: (1) the role of echocardiography in PAH; (2) new diagnostic algorithm for the evaluation of PAH; (3) comprehensive prognostic evaluation and risk assessment; (4) treatment goals and follow-up strategy; (5) updated PAH targeted therapy; (6) combination therapy and goal-orientated therapy; (7) updated treatment for PAH associated with congenital heart disease; (8) updated treatment for PAH associated with connective tissue disease; and (9) updated treatment for chronic thromboembolic pulmonary hypertension.

Overcoming challenges of venous thromboembolism in sickle cell disease treatment

INTRODUCTION

Venous thromboembolism (VTE) is a common comorbid condition found in sickle cell disease (SCD) and is associated with increased mortality for adults with SCD. The pathophysiology that leads to the thrombophilic state in SCD has been previously reviewed; however, evidence-based guidelines to aid in diagnosis, prevention, and management of VTE are lacking. Areas covered: This review article will cover the pathophysiology underlying the hypercoagulable state, the epidemiology of VTE, and management strategies of VTE in SCD. Expert opinion: Providers should have a high suspicion for diagnosing VTE to help reduce morbidity and mortality in the SCD population. Unlike other thrombophilias, the risk of life-threatening anemia while being treated with anticoagulation is compounded with the potential complications surrounding red blood cell transfusions in this population (i.e. alloimmunization, hyperhemolysis) and this provides another complexity to managing VTE in this population. Clinical trials evaluating the risk and benefit of treatment and treatment duration are needed.

Critical Care of Patients After Pulmonary Thromboendarterectomy

Pulmonary thromboendarterectomy (PTE) remains the only curative surgery for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Postoperative intensive care unit care challenges providers with unique disease physiology, operative sequelae, and the potential for detrimental complications. Central concerns in patients with CTEPH immediately after PTE relate to neurologic, pulmonary, hemodynamic, and hematologic aspects. Institutional experience in critical care for the CTEPH population, a multidisciplinary team approach, patient risk assessment, and integration of current concepts in critical care determine outcomes after PTE surgery. In this review, the authors will focus on specific aspects unique to this population, with integration of current available evidence and future directions. The goal of this review is to provide the cardiac anesthesiologist and intensivist with a comprehensive understanding of postoperative physiology, potential complications, and contemporary intensive care unit management immediately after pulmonary endarterectomy.

Deep learning cardiac motion analysis for human survival prediction

Motion analysis is used in computer vision to understand the behaviour of moving objects in sequences of images. Optimising the interpretation of dynamic biological systems requires accurate and precise motion tracking as well as efficient representations of high-dimensional motion trajectories so that these can be used for prediction tasks. Here we use image sequences of the heart, acquired using cardiac magnetic resonance imaging, to create time-resolved three-dimensional segmentations using a fully convolutional network trained on anatomical shape priors. This dense motion model formed the input to a supervised denoising autoencoder (4Dsurvival), which is a hybrid network consisting of an autoencoder that learns a task-specific latent code representation trained on observed outcome data, yielding a latent representation optimised for survival prediction. To handle right-censored survival outcomes, our network used a Cox partial likelihood loss function. In a study of 302 patients the predictive accuracy (quantified by Harrell's C-index) was significantly higher (p = .0012) for our model C=0.75 (95% CI: 0.70 - 0.79) than the human benchmark of C=0.59 (95% CI: 0.53 - 0.65). This work demonstrates how a complex computer vision task using high-dimensional medical image data can efficiently predict human survival.

Validation of a claims-based algorithm to identify patients with chronic thromboembolic pulmonary hypertension using electronic health record data

This study aimed to validate an algorithm developed to identify chronic thromboembolic pulmonary hypertension (CTEPH) among patients with a history of pulmonary embolism. Validation was halted because too few patients had gold-standard evidence of CTEPH in the administrative claims/electronic health records database, suggesting that CTEPH is underdiagnosed.

Chronic Thromboembolic Pulmonary Hypertension: Epidemiology, Diagnosis, and Management

Chronic thromboembolic pulmonary hypertension (CTEPH), classified as World Health Organization (WHO) group 4 pulmonary hypertension (PH), is an interesting and rare pulmonary vascular disorder secondary to mechanical obstruction of the pulmonary vasculature from thromboembolism resulting in PH. The pathophysiology is complex, beginning with mechanical obstruction of the pulmonary arteries, which eventually leads to arteriopathic changes and vascular remodeling in the nonoccluded arteries and in the distal segments of the occluded arteries mediated by thrombus nonresolution, abnormal angiogenesis, endothelial dysfunction, and various local growth factors. Based on available data, CTEPH is a rare disease entity occurring in a small proportion (0.5-3%) of patients after acute pulmonary embolism with an annual incidence ranging anywhere between 1 and 7 cases per million population. It is often underdiagnosed or misdiagnosed as idiopathic pulmonary arterial hypertension due to a lack of clinical suspicion or the under-utilization of radionuclide ventilation/perfusion scan. Although the current standard remains planar ventilation/perfusion scintigraphy as the initial imaging study to screen for CTEPH, and invasive pulmonary angiography with right heart catheterization as confirmatory modalities, they are likely to be replaced by modalities that can provide both anatomic and functional data while minimizing radiation exposure. Surgery is the gold standard treatment and offers better improvements in clinical and hemodynamic parameters compared with medical therapy. The management of CTEPH requires a multidisciplinary team, operability assessment, experienced surgical center, and the consideration of medical PH-directed therapies in patients who have inoperable disease, in addition to supportive therapies. Although, balloon pulmonary angioplasty is gaining interest to improve pulmonary hemodynamics and symptoms in CTEPH patients not amenable to surgery, further investigative randomized studies are needed to validate its use. It is very important for the present-day physician to be familiar with the disease entity and its appropriate evaluation to facilitate early diagnosis and appropriate management.

Incidence of chronic thromboembolic pulmonary hypertension in Thammasat University Hospital

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is usually underrecognized due to nonspecific presentations. Undiagnosed CTEPH leads to unnecessary investigations for other diseases, and more importantly, increased morbidities and mortality.

OBJECTIVES

The aim of this study was to define overall CTEPH incidence and the rate of CTEPH after acute pulmonary embolism (APE) in a tertiary care university hospital and to record risk factors, clinical and imaging characteristics, diagnosis assessment, and management methods.

MATERIALS AND METHODS

The retrospective 5-year data, between 2012 and 2016, was extracted. Out of 1751 patients, we screened, 286 had, at least, evidence of pulmonary embolism. CTEPH was diagnosed in 20 patients, and 12 in this group had characteristics of combined APE or history of APE.

RESULTS

The overall incidence of CTEPH was 37.8 cases per million patients, and the incidence of CTEPH after APE was 5.1%. The most common presentation was progressive exertional dyspnea (50%). All patients were diagnosed by computed tomography pulmonary angiography combined with echocardiogram. Surprisingly, only two patients had investigations with ventilation/perfusion lung scan. None underwent the preferred curative surgical treatment of pulmonary endarterectomy and two had balloon pulmonary angioplasty. All patients received anticoagulants, while only 5 patients were treated with pulmonary arterial hypertension-specific drugs.

CONCLUSION

CTEPH was uncommon in our institute, with an underuse of the standard test. Suboptimal diagnosis assessment and management remain critical problems. Developing a properly trained CTEPH care team would improve patient outcomes, but cost/resources may be prohibitive for such a relatively rare disease.

TRIAL REGISTRATION

TCTR20180220008 registered February 19, 2018.

CT derived left atrial size identifies left heart disease in suspected pulmonary hypertension: Derivation and validation of predictive thresholds

Background

Patients with pulmonary hypertension due to left heart disease (PH-LHD) have overlapping clinical features with pulmonary arterial hypertension making diagnosis reliant on right heart catheterization (RHC). This study aimed to investigate computed tomography pulmonary angiography (CTPA) derived cardiopulmonary structural metrics, in comparison to magnetic resonance imaging (MRI) for the diagnosis of left heart disease in patients with suspected pulmonary hypertension.

Methods

Patients with suspected pulmonary hypertension who underwent CTPA, MRI and RHC were identified. Measurements of the cardiac chambers and vessels were recorded from CTPA and MRI. The diagnostic thresholds of individual measurements to detect elevated pulmonary arterial wedge pressure (PAWP) were identified in a derivation cohort (n = 235). Individual CT and MRI derived metrics were tested in validation cohort (n = 211).

Results

446 patients, of which 88 had left heart disease. Left atrial area was a strong predictor of elevated PAWP>15 mm Hg and PAWP>18 mm Hg, area under curve (AUC) 0.854, and AUC 0.873 respectively. Similar accuracy was also identified for MRI derived LA volume, AUC 0.852 and AUC 0.878 for PAWP > 15 and 18 mm Hg, respectively. Left atrial area of 26.8 cm² and 30.0 cm² were optimal specific thresholds for identification of PAWP > 15 and 18 mm Hg, had sensitivity of 60%/53% and specificity 89%/94%, respectively in a validation cohort.

Conclusions

CTPA and MRI derived left atrial size identifies left heart disease in suspected pulmonary hypertension with high specificity. The proposed diagnostic thresholds for elevated left atrial area on routine CTPA may be a useful to indicate the diagnosis of left heart disease in suspected pulmonary hypertension.

•

Routine CTPA can diagnose left heart disease in suspected pulmonary hypertension.

•

Complex multiparameter models do not improve LHD diagnosis.

•

Highly specific thresholds have been derived and validated.

The changing landscape of chronic thromboembolic pulmonary hypertension management

For patients with chronic thromboembolic pulmonary hypertension (CTEPH), the current standard of care involves surgical removal of fibro-thrombotic obstructions by pulmonary endarterectomy. While this approach has excellent outcomes, significant proportions of patients are not eligible for surgery or suffer from persistent/recurrent pulmonary hypertension after the procedure. The availability of balloon pulmonary angioplasty and the approval of the first medical therapy for use in CTEPH have significantly improved the outlook for patients ineligible for pulmonary endarterectomy. In this comprehensive review, we discuss the latest developments in the rapidly evolving field of CTEPH. These include improvements in imaging modalities and advances in surgical and interventional techniques, which have broadened the range of patients who may benefit from such procedures. The efficacy and safety of targeted medical therapies in CTEPH patients are also discussed, particularly the encouraging data from the recent MERIT-1 trial, which demonstrated the beneficial impact of using macitentan to treat patients with inoperable CTEPH, including those on background therapy. As the treatment options for CTEPH improve, hybrid management involving more than one intervention in the same patient may become a viable option in the near future.

Management of CTEPH is evolving rapidly, leading to improved patient outcomeshttp://ow.ly/rHrt30gUQWX

An epidemiological analysis of the burden of chronic thromboembolic pulmonary hypertension in the USA, Europe and Japan

Epidemiological data for chronic thromboembolic pulmonary hypertension (CTEPH) are limited and there are conflicting reports regarding its pathogenesis.

A literature review was conducted to identify CTEPH epidemiological data up to June 2014. Data were analysed to provide estimates of the incidence of CTEPH in the USA, Europe and Japan. An epidemiological projection model derived country-specific estimates of future incidence and diagnosis rates of CTEPH.

Overall, 25 publications and 14 databases provided quantitative epidemiological data. In the USA and Europe, the crude annual incidence of diagnosed pulmonary embolism and crude annual full (i.e. diagnosed and undiagnosed) incidence of CTEPH were 66–104 and 3–5 cases per 100 000 population, respectively, while in Japan these rates were lower at 6.7 and 1.9 per 100 000 population, respectively. In 2013, 7–29% of CTEPH cases in Europe and the USA were diagnosed, and the majority of patients were in New York Heart Association functional class III/IV at diagnosis. The projection model indicated that incidence of CTEPH will continue to increase over the next decade.

These data suggest that CTEPH is underdiagnosed and undertreated, and there is an urgent need to increase awareness of CTEPH. High-quality epidemiological studies are required to increase understanding of CTEPH.

Epidemiological data suggest that CTEPH is underdiagnosed and there is an urgent need to improve disease awarenesshttp://ow.ly/J0KC3095U2W

Medical management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) results from incomplete resolution of acute pulmonary emboli, organised into fibrotic material that obstructs large pulmonary arteries, and distal small-vessel arteriopathy. Pulmonary endarterectomy (PEA) is the treatment of choice for eligible patients with CTEPH; in expert centres, PEA has low in-hospital mortality rates and excellent long-term survival. Supportive medical therapy consists of lifelong anticoagulation plus diuretics and oxygen, as needed.

An important recent advance in medical therapy for CTEPH is the arrival of medical therapies for patients with inoperable disease or persistent/recurrent pulmonary hypertension after PEA. The soluble guanylate cyclase stimulator riociguat is licensed for the treatment of CTEPH in patients with inoperable disease or with recurrent/persistent pulmonary hypertension after PEA. Clinical trials of this agent have shown improvements in patients' haemodynamics and exercise capacity. Phosphodiesterase-5 inhibitors, endothelin receptor antagonists and prostanoids have been used in the treatment of CTEPH, but evidence of benefit is limited. Challenges in the future development of medical therapy for CTEPH include better understanding of the underlying pathology, end-points to monitor the condition's progress, and the optimisation of pulmonary arterial hypertension therapies in relation to diverse patient characteristics and emerging options such as balloon pulmonary angioplasty.