Determinants of diagnostic delay in chronic thromboembolic pulmonary hypertension: results from the European CTEPH Registry

Chronic Thromboembolic Pulmonary Hypertension: Clinical and Imaging Evaluation

Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of pulmonary embolism and is an important cause of pulmonary hypertension. As a clinical entity, it is frequently underdiagnosed with prolonged diagnostic delays. This study reviews the clinical and radiographic findings associated with CTEPH to improve awareness and recognition. Strengths and limitations of multiple imaging modalities are reviewed. Accompanying images are provided to supplement the text and provide examples of important findings for the reader.

Preexisting Chronic Thromboembolic Pulmonary Hypertension in Acute Pulmonary Embolism? A Case Report and Discussion

A 61-year-old male presented with New York Heart Association class II breathlessness. Three years earlier, he had presented with a swollen leg, had received a diagnosis of deep vein thrombosis on ultrasound and of low-risk acute pulmonary embolism, and had been discharged on a direct oral anticoagulant after 8 hours. The patient also had a history of thyroidectomy and was on levothyroxine substitution. The case illustrates a patient with acute pulmonary embolism who developed chronic thrombotic pulmonary vascular lesions within 3 years after acute pulmonary embolism in the presence of typical risk factors.

Comorbidities, Treatment and Survival Rates of Chronic Thromboembolic Pulmonary Hypertension in a Regional Centre

Background/Objectives: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by a multitude of underlying causes, treatment modalities and prognostic outcomes. Our aim was to evaluate the underlying causes, comorbidities and survival rates of CTEPH patients. Methods: A retrospective analysis was conducted regarding the evolution of CTEPH patients confirmed by right heart catheterization under treatment with specific vasodilator medication in our centre between 2008 and 2023. Results: We treated 14 CTEPH patients, 78.57% female, 52.79 ± 13.64 years at inclusion, representing 11.29% of our pulmonary arterial hypertension registry. Initially, the distribution of patients' NYHA class was II-14.28%, III-71.42% and IV-14.28%. In total, 71.42% of these patients were technically operable due to the central location of the thrombus, but 42.85% presented severe comorbidities and 28.57% refused the surgery or it was financially inaccessible. Only four patients were operated on by pulmonary endarterectomy (PEA). Unfortunately, all the post-PEA patients had persistent pulmonary hypertension and had to continue vasodilator treatment. Overall, 64.28% of patients had monotherapy, 21.42% double therapy and 14.28% triple therapy. Regarding underlying causes and comorbidities, we found the following incidences: 78.57% chronic venous insufficiency, 42.85% obesity, 35.71% thyroid disease, hypertension and hyperuricemia, 21.42% thrombophilia and ischemic heart disease, 14.28% atrial fibrillation, vasculitis and lung disease, and 14.28% neoplastic history and diabetes. Seven patients died (50%), six of whom were unoperated and one of whom was lost (abandoned the program). The survival rates at 1, 3, 5 and 7 years for unoperated patients were 100%, 58.3%, 29.2% and 29.2% versus 100%, 75%, 75% and 75% in post-PEA patients. Conclusions: CTEPH, marked by delayed diagnosis, multiple comorbidities and limited intervention options, requires proactive screening and comprehensive multimodal therapies, including PEA, to improve survival rates.

Performance-based outcome measures for assessing physical capacity in patients with pulmonary embolism: A scoping review

INTRODUCTION

Up to 50 % of patients surviving a pulmonary embolism (PE) report persisting shortness of breath, reduced physical capacity and psychological distress. As the PE population is heterogeneous compared to other cardiovascular patient groups, outcome measures for assessing physical capacity traditionally used in cardiac populations may not be reliable for the PE population as a whole. This scoping review aims to 1) map performance-based outcome measures (PBOMs) used for assessing physical capacity in PE research, and 2) to report the psychometric properties of the identified PBOMs in a PE population.

METHODS

The review was conducted according to the Joanna Briggs Institute framework for scoping reviews and reported according to the PRISMA-Extension for Scoping Reviews guideline.

RESULTS

The systematic search of five databases identified 4585 studies, of which 243 studies met the inclusion criteria. Of these, 185 studies focused on a subgroup of patients with chronic thromboembolic pulmonary hypertension. Ten different PBOMs were identified in the included studies. The 6-minute walk test (6MWT) and cardiopulmonary exercise test (CPET) were the most commonly used, followed by the (Modified) Bruce protocol and Incremental Shuttle Walk test. No studies reported psychometric properties of any of the identified PBOMs in a PE population.

CONCLUSIONS

Publication of studies measuring physical capacity within PE populations has increased significantly over the past 5-10 years. Still, not one study was identified, reporting the validity, reliability, or responsiveness for any of the identified PBOMs in a PE population. This should be a priority for future research in the field.

Diagnosis and Treatment Patterns of Chronic Thromboembolic Pulmonary Hypertension in Russia, Kazakhstan, Turkey, Lebanon, and Saudi Arabia: A Registry Study

BACKGROUND

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) in countries with limited resources have, to date, been poorly represented in registries.

OBJECTIVE

This work assesses the epidemiology, diagnosis, hemodynamic and functional parameters, and treatment of CTEPH in Russia, Kazakhstan, Turkey, Lebanon, and Saudi Arabia.

METHODS

A prospective, cohort, phase IV, observational registry with 3-year follow-up (n = 212) in patients aged ≥ 18 years diagnosed with CTEPH was created. Clinical, hemodynamic, and functional parameters were obtained at an initial visit, follow-up visits, and a final visit at the end of 3 years' observation or end of follow-up. Data were recorded on electronic case report forms. Parameters evaluated included 6-minute walking distance (6MWD), use of pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA), pulmonary hypertension (PH)-targeted therapy, and survival. All statistical analyses were exploratory and descriptive, and were performed in the overall population.

RESULTS

The most common symptoms were typical of those expected for CTEPH. Almost 90% of patients underwent right heart catheterization at diagnosis or initial study visit. In total, 66 patients (31%) underwent PEA before the initial visit; 95 patients (45%) were considered operable, 115 (54%) were inoperable, and two (1%) had no operability data. Only 26 patients (12%) had been assessed for BPA at their initial visit. PH-targeted therapy was documented at diagnosis for 77 patients (36%), most commonly a phosphodiesterase type 5 inhibitor (23%). Use of PH-targeted therapy increased to 142 patients (67%) at the initial visit, remaining similar after 3 years. Use of riociguat increased from 6% of patients at diagnosis to 38% at 3 years. Between baseline and end of observation, results for patients with paired data showed an increase in 6MWD. Survival at the end of observation was 88%.

CONCLUSIONS

These data highlight the current diagnosis and management of CTEPH in the participating countries. They show that early CTEPH diagnosis remains challenging, and use of off-label PH-targeted therapy is common.

CLINICALTRIALS

gov: NCT02637050; registered December 2015.

[Update in the management of chronic thrombo-embolic pulmonary hypertension]

Chronic thrombo-embolic pulmonary hypertension (CTEPH) is a potentially curable form of pulmonary hypertension (PH) that develops in up to 3% of patients after pulmonary embolism (PE). In these patients, PE does not resolve, leading to organized fibrotic clots, with the development of precapillary PH as a result of the proximal obstruction of the pulmonary arteries. In addition, a distal microvasculopathy may also develop, contributing to the increase of pulmonary vascular resistance. Transthoracic echocardiography is the diagnostic tool that allows to establish the suspicion of PH. Ventilation-perfusion lung scintigraphy is the fundamental tool in the study of patients with suspected CTEPH; if it is normal, virtually rules out the diagnosis. Right heart catheterization is mandatory for the diagnosis of these patients. CTEPH is defined as the existence of symptoms, residual perfusion defects and precapillary PH after a minimum period of three months of anticoagulation. Pulmonary angiography helps determine the extent and surgical accessibility of thromboembolic lesions. CTEPH patients are candidates for long-term anticoagulation. Pulmonary endarterectomy is the treatment of choice, resulting in significant clinical and hemodynamic improvement. About 25% of patients have residual PH post-endarterectomy. Balloon pulmonary angioplasty is an endovascular technique that targets more distal lesions, being potentially useful for patients with inoperable CTEPH or persistent/recurrent PH post-endarterectomy. Both types of patients may also benefit from pharmacological treatment for PH. These three therapies are the cornerstone of CTEPH treatment, which has evolved towards a multimodal approach.

Chronic Thromboembolic Pulmonary Hypertension after Pulmonary Embolism in SARS-CoV-2

INTRODUCTION

Chronic thromboembolic pulmonary disease (CTEPD) consists of persistent pulmonary vascular obstruction on imaging and involves long-term functional limitations, with or without chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this study was to evaluate the incidence and risk factors of both persistent pulmonary vascular defects and CTEPH after hospitalization in patients with COVID-19 and PE during a 2-year follow-up.

METHODS

A prospective observational study was carried out in a tertiary hospital center. Patients were hospitalized between March 2020 and December 2021 with a diagnosis of PE during SARS-CoV-2 infection. Patients received anticoagulant treatment for at least 3 months and were followed up for 2 years. Between the third and fourth months after discharge, all patients were evaluated for the presence of residual thrombotic defects by CTPA and/or perfusion pulmonary scintigraphy. Clinical findings, lung function tests with DLCO, exercise capacity, and echocardiograms were also assessed.

RESULTS

Of the 133 patients included, 18% had persistent thrombotic defects on lung imaging at follow-up. The incidence of CTEPD was 0.75% at 2 years of follow-up. Patients with persistent defects were significantly older, had a higher prevalence of systemic arterial hypertension, higher D-dimer and NT-proBNP levels, and more severe PE at diagnosis. Furthermore, there was a higher prevalence of right ventricular dysfunction on echocardiogram at diagnosis of PE (25.0% vs. 2.7%, p = 0.006). This was the only variable independently related to persistent defects in multivariate analyses (OR: 8.13 [95% CI: 1.82-36.32], p = 0.006).

CONCLUSION

The persistence of thrombotic defects after PE is a common finding after SARS-CoV-2 infection, affecting 18% of the population. However, the incidence of CTEPH appears to be lower (0.75%) in COVID-19-related PE compared to that previously observed in PE unrelated to COVID-19.

Dynamic chest radiography for pulmonary vascular diseases: clinical applications and correlation with other imaging modalities

Dynamic chest radiography (DCR) is a novel functional radiographic imaging technique that can be used to visualize pulmonary perfusion without using contrast media. Although it has many advantages and clinical utility, most radiologists are unfamiliar with this technique because of its novelty. This review aims to (1) explain the basic principles of lung perfusion assessment using DCR, (2) discuss the advantages of DCR over other imaging modalities, and (3) review multiple specific clinical applications of DCR for pulmonary vascular diseases and compare them with other imaging modalities.

Symptom-related screening programme for early detection of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism: the SYSPPE study

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is the most severe long-term complication of acute pulmonary embolism (PE). We aimed to evaluate the impact of a symptom screening programme to detect CTEPH in PE survivors.

METHODS

This was a multicentre cohort study of patients diagnosed with acute symptomatic PE between January 2017 and December 2018 in 16 centres in Spain. Patients were contacted by phone 2 years after the index PE diagnosis. Those with dyspnoea corresponding to a New York Heart Association (NYHA)/WHO scale≥II, visited the outpatient clinic for echocardiography and further diagnostic tests including right heart catheterisation (RHC). The primary outcome was the new diagnosis of CTEPH confirmed by RHC.

RESULTS

Out of 1077 patients with acute PE, 646 were included in the symptom screening. At 2 years, 21.8% (n=141) reported dyspnoea NYHA/WHO scale≥II. Before symptom screening protocol, five patients were diagnosed with CTEPH following routine care. In patients with NYHA/WHO scale≥II, after symptom screening protocol, the echocardiographic probability of pulmonary hypertension (PH) was low, intermediate and high in 76.6% (n=95), 21.8% (n=27) and 1.6% (n=2), respectively. After performing additional diagnostic test in the latter 2 groups, 12 additional CTEPH cases were confirmed.

CONCLUSIONS

The implementation of this simple strategy based on symptom evaluation by phone diagnosed more than doubled the number of CTEPH cases. Dedicated follow-up algorithms for PE survivors help diagnosing CTEPH earlier.

TRIAL REGISTRATION NUMBER

NCT03953560.

Pulmonary Embolism (PE) to Chronic Thromboembolic Pulmonary Disease (CTEPD): Findings from a Survey of UK Physicians

Chronic thromboembolic pulmonary disease (CTEPD) is a complication of pulmonary embolism (PE). We conducted an online survey of UK PE-treating physicians to understand practices in the follow-up of PE and awareness of CTEPD. The physicians surveyed (N = 175) included 50 each from cardiology, respiratory and internal medicine, plus 25 haematologists. Most (89%) participants had local guidelines for PE management, and 65% reported a PE follow-up clinic, of which 69% were joint clinics. Almost half (47%) had a protocol for the investigation of CTEPD. According to participants, 129 (74%) routinely consider a diagnosis of CTEPD and 97 (55%) routinely investigate for CTEPD, with 76% of those 97 participants investigating in patients who are symptomatic at 3 months and 22% investigating in all patients. This survey demonstrated variability in the follow-up of PE and the awareness of CTEPD and its investigation. The findings support the conduct of a national audit to understand the barriers to the timely detection of CTEPD.

Recognition, diagnosis, and operability assessment of chronic thromboembolic pulmonary hypertension (CTEPH): A global cross-sectional scientific survey (CLARITY)

Early recognition and diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) is crucial for improving prognosis and reducing the disease burden. Established clinical practice guidelines describe interventions for the diagnosis and evaluation of CTEPH, yet limited insight remains into clinical practice variation and barriers to care. The CTEPH global cross-sectional scientific survey (CLARITY) was developed to gather insights into the current diagnosis, treatment, and management of CTEPH and to identify unmet medical needs. This paper focuses on the recognition and diagnosis of CTEPH and the referral and evaluation of these patients. The survey was offered to hospital-based medical specialists through Scientific Societies and other medical organizations, from September 2021 to May 2022. Response data from 353 physicians showed that self-reported awareness of CTEPH increased over the past 10 years among 96% of respondents. Clinical practices in acute pulmonary embolism (PE) follow-up and CTEPH diagnosis differed among respondents. While 50% of respondents working in a nonexpert center reported to refer patients to an expert pulmonary hypertension/CTEPH center when CTEPH is suspected, 51% of these physicians did not report referral of patients with a confirmed diagnosis for further evaluation. Up to 50% of respondents involved in the evaluation of referred patients have concluded a different operability status than that indicated by the referring center. This study indicates that early diagnosis and timely treatment of CTEPH is challenged by suboptimal acute PE follow-up and patient referral practices. Nonadherence to guideline recommendations may be impacted by various barriers to care, which were shown to vary by geographical region.

Clinical-radiological-pathological correlation in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare and potentially life-threatening complication of acute pulmonary embolism. It is characterised by persistent fibro-thrombotic pulmonary vascular obstructions and elevated pulmonary artery pressure leading to right heart failure. The diagnosis is based on two steps, as follows: 1) suspicion based on symptoms, echocardiography and ventilation/perfusion scan and 2) confirmation with right heart catheterisation, computed tomography pulmonary angiography and, in most cases, digital subtraction angiography. The management of CTEPH requires a multimodal approach, involving medical therapy, interventional procedures and surgical intervention. This clinical-radiological-pathological correlation paper illustrates the diagnostic and therapeutic management of two patients. The first had chronic thromboembolic pulmonary disease without pulmonary hypertension at rest but with significant physical limitation and was successfully treated with pulmonary endarterectomy. The second patient had CTEPH associated with splenectomy and was considered unsuitable for surgery because of exclusive subsegmental lesions combined with severe pulmonary hypertension. The patient benefited from multimodal treatment involving medical therapy followed by multiple sessions of balloon pulmonary angioplasty. Both patients had normalised functional capacity and pulmonary haemodynamics 3-6 months after the interventional treatment. These two examples show that chronic thromboembolic pulmonary diseases are curable if diagnosed promptly and referred to CTEPH centres for specialist treatment.

The Early Detection of Pulmonary Hypertension

BACKGROUND

Up to 1% of the world population and 10% of all persons over age 65 suffer from pulmonary hypertension (PH). The latency from the first symptom to the diagnosis is more than one year on average, and more than three years in 20% of patients. 40% seek help from more than four different physicians until their condition is finally diagnosed.

METHODS

This review is based on publications retrieved by a selective literature search on pulmonary hypertension.

RESULTS

The most common causes of pulmonary hypertension are left heart diseases and lung diseases. Its cardinal symptom is exertional dyspnea that worsens as the disease progresses. Additional symptoms of right heart failure are seen in advanced stages. Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are rare, difficult to diagnose, and of particular clinical relevance because specific treatments are available. For this reason, strategies for the early detection of PAH and CTEPH have been developed. The clinical suspicion of PH arises in a patient who has nonspecific symptoms, electrocardiographic changes, and an abnormal (NT-pro-)BNP concentration. Once the suspicion of PH has been confirmed by echocardiography and, if necessary, differential-diagnostic evaluation with a cardiopulmonary stress test, and after the exclusion of a primary left heart disease or lung disease, the patient should be referred to a PH center for further diagnostic assessment, classification, and treatment.

CONCLUSION

If both the (NT-pro-)BNP and the ECG are normal, PH is unlikely. Knowledge of the characteristic clinical manifestations and test results of PH is needed so that patients can be properly selected for referral to specialists and experts in PH.

Two pregnancies in a patient following pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

Pregnancies complicated by pulmonary hypertension are associated with a high rate of maternal morbidity and mortality. Pulmonary endarterectomy is a curative treatment for pulmonary hypertension in select patients with chronic thromboembolic pulmonary hypertension. Limited data exist regarding the maternal and perinatal outcomes following pulmonary endarterectomy.We present the case of a patient in her 20s with antiphospholipid antibody syndrome and chronic thromboembolic pulmonary hypertension who underwent pulmonary endarterectomy and subsequently carried two pregnancies. Her cardiopulmonary status remained stable throughout both pregnancies. Her first pregnancy was complicated by HELLP syndrome requiring induction of labour at 30 weeks, and her second child was born at term. In summary, this patient's course provides cautious optimism that a curative pulmonary endarterectomy may allow a patient to avoid complications of pulmonary hypertension during pregnancy.

Post-Pulmonary Embolism Syndrome and Functional Outcomes after Acute Pulmonary Embolism

Survivors of acute pulmonary embolism (PE) are at risk of developing persistent, sometimes disabling symptoms of dyspnea and/or functional limitations despite adequate anticoagulant treatment, fulfilling the criteria of the post-PE syndrome (PPES). PPES includes chronic thromboembolic pulmonary hypertension (CTEPH), chronic thromboembolic pulmonary disease, post-PE cardiac impairment (characterized as persistent right ventricle impairment after PE), and post-PE functional impairment. To improve the overall health outcomes of patients with acute PE, adequate measures to diagnose PPES and strategies to prevent and treat PPES are essential. Patient-reported outcome measures are very helpful to identify patients with persistent symptoms and functional impairment. The primary concern is to identify and adequately treat patients with CTEPH as early as possible. After CTEPH is ruled out, additional diagnostic tests including cardiopulmonary exercise tests, echocardiography, and imaging of the pulmonary vasculature may be helpful to rule out non-PE-related comorbidities and confirm the ultimate diagnosis. Most PPES patients will show signs of physical deconditioning as main explanation for their clinical presentation. Therefore, cardiopulmonary rehabilitation provides a good potential treatment option for this patient category, which warrants testing in adequately designed and executed randomized trials. In this review, we describe the definition and characteristics of PPES and its diagnosis and management.

Evaluation and Management of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a treatable form of pulmonary hypertension and right heart failure. CTEPH (group 4 pulmonary hypertension) is caused by persistent organized thromboembolic obstruction of the pulmonary arteries from incompletely resolved acute pulmonary embolism. CTEPH also may present without prior VTE history, which can contribute to its underrecognition. The true incidence of CTEPH is unclear, but is estimated to be approximately 3% after acute pulmonary embolism. V˙/Q˙ scintigraphy is the best screening test for CTEPH, with CT scan imaging and other advanced imaging methods now playing a larger role in disease detection and confirmation. Perfusion defects on V˙/Q˙ scintigraphy in the setting of pulmonary hypertension are suggestive of CTEPH, but pulmonary angiography and right heart catheterization are required for confirmation and treatment planning. CTEPH potentially is curative with pulmonary thromboendarterectomy surgery, with mortality rates of approximately 2% at expert centers. Advances in operative techniques are allowing more distal endarterectomies to be performed successfully with favorable outcomes. However, more than one-third of patients may be considered inoperable. Although these patients previously had minimal therapeutic options, effective treatments now are available with pharmacotherapy and balloon pulmonary angioplasty. Diagnosis of CTEPH should be considered in all patients with suspicion of pulmonary hypertension. Treatments for CTEPH have advanced with improvements in outcomes for both operable and inoperable patients. Therapy should be tailored based on multidisciplinary team evaluation to ensure optimal treatment response.

Leveraging open dataset and transfer learning for accurate recognition of chronic pulmonary embolism from CT angiogram maximum intensity projection images

BACKGROUND

Early diagnosis of the potentially fatal but curable chronic pulmonary embolism (CPE) is challenging. We have developed and investigated a novel convolutional neural network (CNN) model to recognise CPE from CT pulmonary angiograms (CTPA) based on the general vascular morphology in two-dimensional (2D) maximum intensity projection images.

METHODS

A CNN model was trained on a curated subset of a public pulmonary embolism CT dataset (RSPECT) with 755 CTPA studies, including patient-level labels of CPE, acute pulmonary embolism (APE), or no pulmonary embolism. CPE patients with right-to-left-ventricular ratio (RV/LV) < 1 and APE patients with RV/LV ≥ 1 were excluded from the training. Additional CNN model selection and testing were done on local data with 78 patients without the RV/LV-based exclusion. We calculated area under the receiver operating characteristic curves (AUC) and balanced accuracies to evaluate the CNN performance.

RESULTS

We achieved a very high CPE versus no-CPE classification AUC 0.94 and balanced accuracy 0.89 on the local dataset using an ensemble model and considering CPE to be present in either one or both lungs.

CONCLUSIONS

We propose a novel CNN model with excellent predictive accuracy to differentiate chronic pulmonary embolism with RV/LV ≥ 1 from acute pulmonary embolism and non-embolic cases from 2D maximum intensity projection reconstructions of CTPA.

RELEVANCE STATEMENT

A DL CNN model identifies chronic pulmonary embolism from CTA with an excellent predictive accuracy.

KEY POINTS

• Automatic recognition of CPE from computed tomography pulmonary angiography was developed. • Deep learning was applied on two-dimensional maximum intensity projection images. • A large public dataset was used for training the deep learning model. • The proposed model showed an excellent predictive accuracy.

Automated quantification of the pulmonary vasculature in pulmonary embolism and chronic thromboembolic pulmonary hypertension

The shape and distribution of vascular lesions in pulmonary embolism (PE) and chronic thromboembolic pulmonary hypertension (CTEPH) are different. We investigated whether automated quantification of pulmonary vascular morphology and densitometry in arteries and veins imaged by computed tomographic pulmonary angiography (CTPA) could distinguish PE from CTEPH. We analyzed CTPA images from a cohort of 16 PE patients, 6 CTEPH patients, and 15 controls. Pulmonary vessels were extracted with a graph-cut method, and separated into arteries and veins using deep-learning classification. Vascular morphology was quantified by the slope (α) and intercept (β) of the vessel radii distribution. To quantify lung perfusion defects, the median pulmonary vascular density was calculated. By combining these measurements with densities measured in parenchymal areas, pulmonary trunk, and descending aorta, a static perfusion curve was constructed. All separate quantifications were compared between the three groups. No vascular morphology differences were detected in contrast to vascular density values. The median vascular density (interquartile range) was -567 (113), -452 (95), and -470 (323) HU, for the control, PE, and CTEPH group. The static perfusion curves showed different patterns between groups, with a statistically significant difference in aorta-pulmonary trunk gradient between the PE and CTEPH groups (p = 0.008). In this proof of concept study, not vasculature morphology but densities differentiated between patients of three groups. Further technical improvements are needed to allow for accurate differentiation between PE and CTEPH, which in this study was only possible statistically by measuring the density gradient between aorta and pulmonary trunk.

Societal costs associated to chronic thromboembolic pulmonary hypertension: A study utilizing linked national registries

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but serious complication after a pulmonary embolism. Healthcare resource utilization (HCRU; hospitalization, outpatient visits, and drug utilization) as well as productivity loss (sick leave and disability pension) before and after the CTEPH diagnosis is sparsely studied. By linking several Swedish national databases, this study estimated the societal costs in a national CTEPH cohort (n = 369, diagnosed with CTEPH in 2008-2019) 5 years before and 5 years after diagnosis (index date) and compared to an age, sex, and geographically matched control group (n = 1845, 1:5 match). HCRU and productivity loss were estimated per patient per year. Patients were stratified as operated with pulmonary endarterectomy (PEA group) or not operated (non-PEA group). Direct and indirect societal costs were 2.1 times higher before, and 8.1 times higher after the index date for patients with CTEPH compared to the matched control groups. The higher costs were evident already several years preceding the index date. The main cost driver before the index date in both the PEA and the non-PEA groups was productivity loss. The productivity loss remained high for both groups in the 5-year period following the index date, but the main cost drivers were prescribed drugs and hospitalizations for patients that underwent PEA and prescribed drugs in the non-PEA group. In conclusion, CTEPH was associated with large societal costs related to healthcare consumption and productivity loss, both before and after diagnosis.

Clinical controversies in the management of acute pulmonary embolism: evaluation of four important but controversial aspects of acute pulmonary embolism management that are still subject of debate and research

INTRODUCTION

Acute pulmonary embolism (PE) is a disease with a broad spectrum of clinical presentations. While some patients can be treated at home or may even be left untreated, other patients require an aggressive approach with reperfusion treatment.

AREAS COVERED

(1) Advanced reperfusion treatment in hemodynamically stable acute PE patients considered to be at high risk of decompensation and death, (2) the treatment of subsegmental pulmonary embolism, (3) outpatient treatment for hemodynamically stable PE patients with signs of right ventricle (RV) dysfunction, and (4) the optimal approach to identify and treatpost-PE syndrome.

EXPERT OPINION

Outside clinical trials, hemodynamically stable acute PE patients should not be treated with primary reperfusion therapy. Thrombolysis and/or catheter-directed therapy are only to be considered as rescue treatment. Subsegmental PE can be left untreated in selected low-risk patients, after proximal deep vein thrombosis has been ruled out. Patients with an sPESI or Hestia score of 0 criteria can be treated at home, independent of the presence of RV overload. Finally, health-care providers should be aware of post-PE syndrome and diagnose chronic thromboembolic pulmonary disease (CTEPD) as early as possible. Persistently symptomatic patients without CTEPD benefit from exercise training and cardiopulmonary rehabilitation.

Efficacy of Dynamic Chest Radiography for Chronic Thromboembolic Pulmonary Hypertension

Background While current guidelines require lung ventilation-perfusion (V/Q) scanning as the first step to diagnose chronic pulmonary embolism in pulmonary hypertension (PH), its use may be limited by low availability and/or exposure to ionizing radiation. Purpose To compare the performance of dynamic chest radiography (DCR) and lung V/Q scanning for detection of chronic thromboembolic PH (CTEPH). Materials and Methods Patients with PH who underwent DCR and V/Q scanning in the supine position from December 2019 to July 2021 were retrospectively screened. The diagnosis of CTEPH was confirmed with right heart catheterization and invasive pulmonary angiography. Observer tests were conducted to evaluate the diagnostic accuracy of DCR and V/Q scanning. The lungs were divided into six areas (upper, middle, and lower for both) in the anteroposterior image, and the number of lung areas with thromboembolic perfusion defects was scored. Diagnostic performance was compared between DCR and V/Q scanning using the area under the receiver operating characteristic curve. Agreement between the interpretation of DCR and that of V/Q scanning was assessed using the Cohen kappa coefficient and percent agreement. Results A total of 50 patients with PH were analyzed: 29 with CTEPH (mean age, 64 years ± 15 [SD]; 19 women) and 21 without CTEPH (mean age, 61 years ± 22; 14 women). The sensitivity, specificity, and accuracy of DCR were 97%, 86%, and 92%, respectively, and those of V/Q scanning were 100%, 86%, and 94%, respectively. Areas under the receiver operating characteristic curve for DCR and V/Q scanning were 0.92 (95% CI: 0.79, 0.97) and 0.93 (95% CI: 0.78, 0.98). Agreement between the consensus interpretation of DCR and that of V/Q scanning was substantial (κ = 0.79 [95% CI: 0.61, 0.96], percent agreement = 0.9 [95% CI: 0.79, 0.95]). Conclusion Dynamic chest radiography had similar efficacy to ventilation-perfusion scanning in the detection of chronic thromboembolic pulmonary hypertension. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Wandtke and Koproth-Joslin in this issue.

Highlights from the International Chronic Thromboembolic Pulmonary Hypertension Congress 2021

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. It is caused by persistent obstruction of pulmonary arteries by chronic organised fibrotic clots, despite adequate anticoagulation. The pulmonary hypertension is also caused by concomitant microvasculopathy which may progress without timely treatment. Timely and accurate diagnosis requires the combination of imaging and haemodynamic assessment. Optimal therapy should be individualised to each case and determined by an experienced multidisciplinary CTEPH team with the ability to offer all current treatment modalities. This report summarises current knowledge and presents key messages from the International CTEPH Conference, Bad Nauheim, Germany, 2021. Sessions were dedicated to 1) disease definition; 2) pathophysiology, including the impact of the hypertrophied bronchial circulation, right ventricle (dys)function, genetics and inflammation; 3) diagnosis, early after acute pulmonary embolism, using computed tomography and perfusion techniques, and supporting the selection of appropriate therapies; 4) surgical treatment, pulmonary endarterectomy for proximal and distal disease, and peri-operative management; 5) percutaneous approach or balloon pulmonary angioplasty, techniques and complications; and 6) medical treatment, including anticoagulation and pulmonary hypertension drugs, and in combination with interventional treatments. Chronic thromboembolic pulmonary disease without pulmonary hypertension is also discussed in terms of its diagnostic and therapeutic aspects.

Time to diagnosis of pulmonary hypertension and diagnostic burden: A retrospective analysis of nationwide US healthcare data

The main aim of this analysis was to investigate time from symptom onset (chronic unexplained dyspnoea [CUD]) to diagnosis of Group 1 pulmonary hypertension (PH)-pulmonary arterial hypertension (PAH)-and to characterize healthcare resource utilization leading up to diagnosis using a nationwide US claims and an electronic health record (EHR) database from Optum^©. Eligible patients were ≥18 years old at first CUD diagnosis (index event) and had a PAH diagnosis on or after index date. Based on administrative codes, PAH was defined as right heart catheterization (RHC), ≥ 2 PAH diagnoses (1 within a year of RHC), and ≥1 post-RHC prescription for PAH treatment. All values are median (1st quartile-3rd quartile) unless otherwise stated. Of 854,722 patients with CUD in the claims database, 582 (0.1%) had PAH. Time from CUD to PAH diagnosis was 2.26 (0.73-4.22) years. PAH patients experienced 3 (2-4) transthoracic echocardiograms (TTEs), 6 (3-12) specialist visits, and 2 (1-4) hospitalizations during the diagnostic interval. Almost one-third of patients (29%) waited 10 months or more to have a TTE. Findings from the EHR database were broadly similar. Resource utilization during the diagnostic interval was also analyzed in an overall PH cohort: findings were generally similar to the PAH cohort (2 [1-3] TTEs, 4 [2-9] specialist visits and 2 [1-4] hospitalizations). These data indicate a delay in the diagnostic pathway for PAH, and illustrate the burden associated with PAH diagnosis.

Preexisting Chronic Thromboembolic Pulmonary Hypertension in Acute Pulmonary Embolism

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is considered a complication of pulmonary embolism (PE). However, signs of CTEPH may exist in patients with a first symptomatic PE.

RESEARCH QUESTION

Which radiologic findings on CT pulmonary angiography (CTPA) at the time of acute PE could indicate the presence of preexisting CTEPH?

STUDY DESIGN AND METHODS

This study included unselected patients with acute PE who were prospectively followed up for 2 years with a structured visit schedule. Two expert radiologists independently assessed patients' baseline CTPAs for preexisting CTEPH; in case of disagreement, a decision was reached by a 2:1 majority with a third expert radiologist. In addition, the radiologists checked for predefined individual parameters suggesting chronic PE and pulmonary hypertension.

RESULTS

Signs of chronic PE or CTEPH at baseline were identified in 46 of 303 included patients (15%). Intravascular webs, arterial narrowing or retraction, dilated bronchial arteries, and right ventricular hypertrophy were the main drivers of the assessment. Five (1.7%) patients were diagnosed with CTEPH during follow-up. All four patients diagnosed with CTEPH early (83-108 days following acute PE) were found in enriched subgroups based on the experts' overall assessment or fulfilling a minimum number of the predefined radiologic criteria at baseline. The specificity of preexisting CTEPH diagnosis and the level of radiologists' agreement improved as the number of required criteria increased.

INTERPRETATION

Searching for predefined radiologic parameters suggesting preexisting CTEPH at the time of acute PE diagnosis may allow for targeted follow-up strategies and risk-adapted CTEPH screening, thus facilitating earlier CTEPH diagnosis.

Electrocardiogram, Echocardiogram and NT-proBNP in Screening for Thromboembolism Pulmonary Hypertension in Patients after Pulmonary Embolism

Background: The annual mortality of patients with untreated chronic thromboembolism pulmonary hypertension (CTEPH) is approximately 50% unless a timely diagnosis is followed by adequate treatment. In pulmonary embolism (PE) survivors with functional limitation, the diagnostic work-up starts with echocardiography. It is followed by lung scintigraphy and right heart catheterization. However, noninvasive tests providing diagnostic clues to CTEPH, or ascertaining this diagnosis as very unlikely, would be extremely useful since the majority of post PE functional limitations are caused by deconditioning. Methods: Patients after acute PE underwent a structured clinical evaluation with electrocardiogram, routine laboratory tests including NT-proBNP and echocardiography. The aim of this study was to verify whether the parameters from echocardiographic or perhaps electrocardiographic examination and NT-proBNP concentration best determine the risk of CTEPH. Results: Out of the total number of patients (n = 261, male n = 123) after PE who were included in the study, in the group of 155 patients (59.4%) with reported functional impairment, 13 patients (8.4%) had CTEPH and 7 PE survivors had chronic thromboembolic pulmonary disease (CTEPD) (4.5%). Echo parameters differed significantly between CTEPH/CTEPD cases and other symptomatic PE survivors. Patients with CTEPH/CTEPD also had higher levels of NT-proBNP (p = 0.022) but concentration of NT-proBNP above 125 pg/mL did not differentiate patients with CTEPH/CTEPD (p > 0.05). Additionally, the proportion of patients with right bundle brunch block registered in ECG was higher in the CTEPH/CTED group (23.5% vs. 5.8%, p = 0.034) but there were no differences between the other ECG characteristics of right ventricle overload. Conclusions: Screening for CTEPH/CTEPD should be performed in patients with reduced exercise tolerance compared to the pre PE period. It is not effective in asymptomatic PE survivors. Patients with CTEPH/CTED predominantly had abnormalities indicating chronic thromboembolism in the echocardiographic assessment. NT-proBNP and electrocardiographic characteristics of right ventricle overload proved to be insufficient in predicting CTEPH/CTEPD development.

["Guiding lights" for the diagnosis of chronic thromboembolic pulmonary hypertension in the flow of patients with pulmonary embolism]

On December 13, 2021, an expert council was held to determine the position of experts of different specialties regarding the reasons for the low level of diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) in real clinical practice in a pandemic of a new coronavirus infection and possible ways to improve detection in patients with pulmonary embolism (PE) ) in history. The reasons for the low level of diagnosis of CTEPH are the insufficient level of knowledge of specialists, especially primary care physicians; lack of clear regulatory documents and expert centers for the management of this category of patients. Primary diagnosis of CTEPH in a pandemic can be strengthened through the widespread use of telemedicine for consultations of primary care physicians with specialists from expert centers; to maximize the role of echocardiography and computed tomography (CT) as differential diagnostic tools for dyspnea, in particular in patients with COVID-19. To increase the detection rate of CTEPH, diagnostic vigilance is required in patients with risk factors and episodes of venous thromboembolism. To improve the screening of CTEPH, it is necessary to create an algorithm for monitoring patients who have had PE; provide educational activities, including through the media; create materials for patients with accessible information. The regulatory documents should designate the circle of responsible specialists who will be engaged in long-term monitoring of patients with PE. Educational programs are needed for primary care physicians, cardiologists, and other physicians who come into the field of view of patients with CTEPH; introduction of a program to create expert centers for monitoring and managing patients with the possibility of performing ventilation-perfusion lung scintigraphy, cardiopulmonary stress test, CT, right heart catheterization. It seems important to build cooperation with the Ministry of Health of Russia in order to create special protocols, procedures for managing patients with PE and CTEPH.

Diagnostic efficacy of ECG-derived ventricular gradient for the detection of chronic thromboembolic pulmonary hypertension in patients with acute pulmonary embolism

INTRODUCTION

Application of the chronic thromboembolic pulmonary hypertension (CTEPH) rule out criteria (manual electrocardiogram [ECG] reading and N-terminal pro-brain natriuretic peptide [NTproBNP] test) can rule out CTEPH in pulmonary embolism (PE) patients with persistent dyspnea (InShape II algorithm). Increased pulmonary pressure may also be identified using automated ECG-derived ventricular gradient optimized for right ventricular pressure overload (VG-RVPO).

METHOD

A predefined analysis of the InShape II study was performed. The diagnostic performance of the VG-RVPO for the detection of CTEPH and the incremental diagnostic value of the VG-RVPO as new rule-out criteria in the InShape II algorithm were evaluated.

RESULTS

60 patients were included; 5 (8.3%) were ultimately diagnosed with CTEPH. The mean baseline VG-RVPO (at time of PE diagnosis) was -18.12 mV·ms for CTEPH patients and - 21.57 mV·ms for non-CTEPH patients (mean difference 3.46 mV·ms [95%CI -29.03 to 35.94]). The VG-RVPO (after 3-6 months follow-up) normalized in patients with and without CTEPH, without a clear between-group difference (mean Δ VG-RVPO of -8.68 and - 8.42 mV·ms respectively; mean difference of -0.25 mV·ms, [95%CI -12.94 to 12.44]). The overall predictive accuracy of baseline VG-RVPO, follow-up RVPO and Δ VG-RVPO for CTEPH was moderate to poor (ROC AUC 0.611, 0.514 and 0.539, respectively). Up to 76% of the required echocardiograms could have been avoided with VG-RVPO criteria replacing the InShape II rule-out criteria, however at cost of missing up to 80% of the CTEPH diagnoses.

CONCLUSION

We could not demonstrate (additional) diagnostic value of VG-RVPO as standalone test or as on top of the InShape II algorithm.

Chronic thromboembolic pulmonary hypertension: diagnosis, operability assessment and patient selection for pulmonary endarterectomy

Healthcare providers outside pulmonary hypertension (PH) centers having misinformation or insufficient education, and a general lack of treatment awareness contribute to a massive underdiagnosis of chronic thromboembolic pulmonary hypertension (CTEPH), diagnostic delay and refusal of surgery by patients. Together with the subjective operability assessment, this leads to too few patients undergoing pulmonary endarterectomy (PEA); even though this surgery results in improved survival and exercise capacity. Acute pulmonary embolism (PE) survivors should undergo a CTEPH screening strategy. Patients screened positive and those with CTEPH symptoms (with or without history of PE), should undergo transthoracic echocardiography (TTE) to determine the probability of PH. High PH probability patients should undergo a ventilation/perfusion (V/Q) scan. A negative scan rules out CTEPH. Patients with a positive V/Q scan, but also patients with findings suggestive for CTEPH on computed tomography pulmonary angiography (CTPA) to diagnose acute PE, should be referred to a CTEPH center. Further diagnostic work-up currently consists of catheter based pulmonary angiography, CTPA and right heart catheterization. However, new imaging technologies might replace them in the near future, with one single imaging tool to screen, diagnose and assess operability as the ultimate goal. Operability assessment should be performed by a multidisciplinary CTEPH team. PEA surgery should be organized in a single center per country or for each forty to fifty million inhabitants in order to offer the highest level of expertise. Informing patients about PEA should preferably be done by the treating surgeon. Based on the estimated incidence of CTEPH and with a better education of patients and healthcare providers, despite the advent of new interventional and medical therapies for CTEPH, the number of PEA surgeries performed should still have the potential to grow significantly.

A Novel Doppler TRPG/AcT Index Improves Echocardiographic Diagnosis of Pulmonary Hypertension after Pulmonary Embolism

BACKGROUND

We hypothesized that a Doppler index, the ratio of tricuspid regurgitation peak gradient (TRPG) to pulmonary ejection acceleration time (AcT), improves the assessment of the echocardiographic probability of pulmonary hypertension in the identification of CTEPH and chronic thromboembolic pulmonary disease (CTED) in symptomatic patients after PE. Doppler echocardiography is recommended as the initial imaging tool for the diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) after acute pulmonary embolism (PE).

METHODS

We analyzed the data from 845 consecutive PE (468 women; 61 ± 18 years) survivors who completed at least 6 months of anticoagulation therapy. Here, 555 patients (325 women; 66 ± 16 years) reporting functional impairment (FI) underwent transthoracic echocardiography. We included 506 patients (297 women; age 63.4 ± 16.6 years) in whom both AcT and TRPG were available into the current study. The presence of a minimum of intermediate echocardiographic probability of PH necessitated the diagnosis of CTEPH.

RESULTS

Echocardiography revealed a high echocardiographic probability of PH in 69 (13.6%) and intermediate echocardiographic probability in 109 (21.5%) patients. CTEPH was diagnosed in 35 (6.9%) patients and CTED in 22 (4.3%) patients. TRPG/AcT was significantly higher in the combined CTEPH + CTED group than in those with other causes of FI (0.412 (0.100-2.197) vs. 0.208 (0.026-0.115), p < 0.001), and the area under the receiver operating characteristic curve of the TRPG/AcT for CTEPH + CTED was 0.804 (95% confidence interval (CI): 0.731-0.876). Importantly, multiple logistic regression showed that TRPG/AcT is a significant predictor of CTEPH + CTED after considering echocardiographic probability (odds ratio = 1.51, 95% CI: 1.25-1.91, p < 0.001). Conditional inference trees analysis revealed that TRPG/AcT > 0.595 identified patients with CTEPH or CTED with a positive predictive value of 78.6% and negative predictive value of 92.7%.

CONCLUSIONS

A Doppler index TRPG/AcT improves the assessment of symptomatic PE survivors. TRPG/AcT > 0.6 indicates a high probability of CTEPH or CTED, whereas TRPG/AcT < 0.6 allows for the safe exclusion of CTEPH + CTED in patients with a low echocardiographic probability of PH.

Association of Electrocardiographic Signs of Right Ventricular Hypertrophy and Clot Localization in Chronic Thromboembolic Pulmonary Hypertension

The role of electrocardiography (ECG) in chronic thromboembolic pulmonary hypertension (CTEPH) diagnosis and prognosticating has not been yet established. We aimed to assess the relationships of the recommended ECG criteria of right ventricular hypertrophy (RVH) with clot localization in CTEPH patients. ECG patterns of RVH according to the American College of Cardiology Foundation were assessed in patients with newly diagnosed CTEPH. We enrolled 58 (45.3%) patients with proximal and 70 (54.7%) with distal CTEPH. Receiver-operating characteristics curves analysis indicated that the following ECG abnormalities predicted proximal CTEPH localization: R_V1 > 6 mm—AUC 0.75 (CI: 0.66–0.84, p < 0.00001); S_V6 > 3 mm—AUC 0.70 (CI: 0.60–0.79, p < 0.00001); S_I > R_I wave—AUC 0.67 (CI: 0.58–0.77, p = 0.0004); R_V1:S_V1 > 1.0—AUC 0.66 (CI: 0.56–0.76, p = 0.0009); R_V1 peak > 0.035 s (QRS < 120 ms)—AUC 0.66 (CI: 0.56–0.75, p = 0.0016); R_V1:S_V1 > R_V3(V4):S_V3(V4)—AUC-0.65 (CI: 0.54–0.75, p = 0.0081); R_aVR > 4 mm—AUC 0.62 (CI: 0.52–0.71, p = 0.002) and P_II > 2.5 mm—AUC 0.62 (CI: 0.52–0.72, p = 0.00162). Pulmonary vascular resistance significantly correlated with amplitudes of R_V1 (r = 0.34, p = 0.008), S_V6 (r = 0.53, p = 0.000027) and P_II (r = 0.44, p = 0.00007). In patients with CTEPH, only 8 out of 23 ECG RVH criteria were useful for differentiating between proximal and distal CTEPH localization and we found that R_V1 and S_V6 may contribute as potential discriminators.

A model for estimating the health economic impact of earlier diagnosis of chronic thromboembolic pulmonary hypertension

Background

Diagnostic delay of chronic thromboembolic pulmonary hypertension (CTEPH) exceeds 1 year, contributing to higher mortality. Health economic consequences of late CTEPH diagnosis are unknown. We aimed to develop a model for quantifying the impact of diagnosing CTEPH earlier on survival, quality-adjusted life-years (QALYs) and healthcare costs.

Material and methods

A Markov model was developed to estimate lifelong outcomes, depending on the degree of delay. Data on survival and quality of life were obtained from published literature. Hospital costs were assessed from patient records (n=498) at the Amsterdam UMC – VUmc, which is a Dutch CTEPH referral center. Medication costs were based on a mix of standard medication regimens.

Results

For 63-year-old CTEPH patients with a 14-month diagnostic delay of CTEPH (median age and delay of patients in the European CTEPH Registry), lifelong healthcare costs were estimated at EUR 117 100 for a mix of treatment options. In a hypothetical scenario of maximal reduction of current delay, improved survival was estimated at a gain of 3.01 life-years and 2.04 QALYs. The associated cost increase was EUR 44 654, of which 87% was due to prolonged medication use. This accounts for an incremental cost–utility ratio of EUR 21 900/QALY.

Conclusion

Our constructed model based on the Dutch healthcare setting demonstrates a substantial health gain when CTEPH is diagnosed earlier. According to Dutch health economic standards, additional costs remain below the deemed acceptable limit of EUR 50 000/QALY for the particular disease burden. This model can be used for evaluating cost-effectiveness of diagnostic strategies aimed at reducing the diagnostic delay.

This constructed model based on the Dutch healthcare setting can be used for evaluating cost-effectiveness of diagnostic strategies aimed at reducing the diagnostic delay of chronic thromboembolic pulmonary hypertensionhttps://bit.ly/35yXPM3

Prediction of chronic thromboembolic pulmonary hypertension with standardised evaluation of initial computed tomography pulmonary angiography performed for suspected acute pulmonary embolism

Objectives

Closer reading of computed tomography pulmonary angiography (CTPA) scans of patients presenting with acute pulmonary embolism (PE) may identify those at high risk of developing chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to validate the predictive value of six radiological predictors that were previously proposed.

Methods

Three hundred forty-one patients with acute PE were prospectively followed for development of CTEPH in six European hospitals. Index CTPAs were analysed post hoc by expert chest radiologists blinded to the final diagnosis. The accuracy of the predictors using a predefined threshold for ‘high risk’ (≥ 3 predictors) and the expert overall judgment on the presence of CTEPH were assessed.

Results

CTEPH was confirmed in nine patients (2.6%) during 2-year follow-up. Any sign of chronic thrombi was already present in 74/341 patients (22%) on the index CTPA, which was associated with CTEPH (OR 7.8, 95%CI 1.9–32); 37 patients (11%) had ≥ 3 of 6 radiological predictors, of whom 4 (11%) were diagnosed with CTEPH (sensitivity 44%, 95%CI 14–79; specificity 90%, 95%CI 86–93). Expert judgment raised suspicion of CTEPH in 27 patients, which was confirmed in 8 (30%; sensitivity 89%, 95%CI 52–100; specificity 94%, 95%CI 91–97).

Conclusions

The presence of ≥ 3 of 6 predefined radiological predictors was highly specific for a future CTEPH diagnosis, comparable to overall expert judgment, while the latter was associated with higher sensitivity. Dedicated CTPA reading for signs of CTEPH may therefore help in early detection of CTEPH after PE, although in our cohort this strategy would not have detected all cases.

Key Points

• Three expert chest radiologists re-assessed CTPA scans performed at the moment of acute pulmonary embolism diagnosis and observed a high prevalence of chronic thrombi and signs of pulmonary hypertension.

• On these index scans, the presence of ≥ 3 of 6 predefined radiological predictors was highly specific for a future diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH), comparable to overall expert judgment.

• Dedicated CTPA reading for signs of CTEPH may help in early detection of CTEPH after acute pulmonary embolism.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08364-0.

Clinical and physiological characteristics of, medically treated, chronic thromboembolic pulmonary hypertension patients in Saudi Arabia: A single center experience

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is uncommon but well-known sequel of venous thromboembolism (VTE). At present, it is the only potential curable subtype of pulmonary hypertension. The aim of this study is to describe the medically treated-CTEPH patients' characteristics in a single specialized PH center in Saudi Arabia.

METHODS

This study presents demographic, clinical, physiological, and hemodynamic characteristics of medically treated-CTEPH patients in a single PH center, namely Prince Sultan Military Medical City, Riyadh, Saudi Arabia. Both incident and prevalent cases are included.

RESULTS

A total of 20 patients with a confirmed diagnosis of CTEPH were included. Mean age at diagnosis was 43 years with a female preponderance of 75%. Most common presenting symptom was dyspnea (100%) followed by syncope (58%). At diagnosis, a mean of 15 ± 10 months had passed since symptoms onset. About 45% of patients were in WHO functional class IV. At baseline, mean 6-min walk distance was 354.3 meters. Overall, VTE was the most frequent risk factor identified (65% of all patients). Nearly 30% of patients had sickle cell disease. 13 out of 20 patients had radiographic (i.e., computed tomography [CT] pulmonary angiogram) features of chronic thromboembolism. About 75% of patients were found to have distal disease on radiographic imaging. At the time of diagnosis, 7 out of 20 (35%) patients demonstrated right ventricular failure on echocardiography. Mean tricuspid annular plane systolic excursion was 17.7 ± 1.20. Median NT-proBNP levels were found to be 688 pg/ml. Mean diffusing capacity for carbon monoxide was 74.8%.

CONCLUSIONS

Diagnosis of CTEPH was established at a relatively younger age. Majority of patients had advanced but distal disease on radiographic imaging, not amenable to surgery.

Identification of chronic thromboembolic pulmonary hypertension on CTPAs performed for diagnosing acute pulmonary embolism depending on level of expertise

BACKGROUND

Expert reading often reveals radiological signs of chronic thromboembolic pulmonary hypertension (CTEPH) or chronic PE on computed tomography pulmonary angiography (CTPA) performed at the time of acute pulmonary embolism (PE) presentation preceding CTEPH. Little is known about the accuracy and reproducibility of CTPA reading by radiologists in training in this setting.

OBJECTIVES

To evaluate 1) whether signs of CTEPH or chronic PE are routinely reported on CTPA for suspected PE; and 2) whether CTEPH-non-expert readers achieve comparable predictive accuracy to CTEPH-expert radiologists after dedicated instruction.

METHODS

Original reports of CTPAs demonstrating acute PE in 50 patients whom ultimately developed CTEPH, and those of 50 PE who did not, were screened for documented signs of CTEPH. All scans were re-assessed by three CTEPH-expert readers and two CTEPH-non-expert readers (blinded and independently) for predefined signs and overall presence of CTEPH.

RESULTS

Signs of chronic PE were mentioned in the original reports of 14/50 cases (28%), while CTEPH-expert radiologists had recognized 44/50 (88%). Using a standardized definition (≥3 predefined radiological signs), moderate-to-good agreement was reached between CTEPH-non-expert readers and the experts' consensus (k-statistics 0.46; 0.61) at slightly lower sensitivities. The CTEPH-non-expert readers had moderate agreement on the presence of CTEPH (κ-statistic 0.38), but both correctly identified most cases (80% and 88%, respectively).

CONCLUSIONS

Concomitant signs of CTEPH were poorly documented in daily practice, while most CTEPH patients were identified by CTEPH-non-expert readers after dedicated instruction. These findings underline the feasibility of achieving earlier CTEPH diagnosis by assessing CTPAs more attentively.

Chronic thromboembolic pulmonary hypertension anno 2021

PURPOSE OF REVIEW

In the past decades, the diagnostic and therapeutic management of chronic thromboembolic pulmonary hypertension (CTEPH) has been revolutionized.

RECENT FINDINGS

Advances in epidemiological knowledge and follow-up studies of pulmonary embolism patients have provided more insight in the incidence and prevalence. Improved diagnostic imaging techniques allow accurate assessment of the location and extend of the thromboembolic burden in the pulmonary artery tree, which is important for the determination of the optimal treatment strategy. Next to the pulmonary endarterectomy, the newly introduced technique percutaneous pulmonary balloon angioplasty and/or P(A)H-targeted medical therapy has been shown to be beneficial in selected patients with CTEPH and might also be of importance in patients with chronic thromboembolic pulmonary vascular disease.

SUMMARY

In this era of a comprehensive approach to CTEPH with different treatment modalities, a multidisciplinary approach guides management decisions leading to optimal treatment and follow-up of patients with CTEPH.

Characteristics of chronic thromboembolic pulmonary hypertension in Ireland

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare and under-recognised complication of acute pulmonary embolism. Information regarding the characteristics of CTEPH in Ireland is limited, and the aim of this retrospective cohort study was to address this knowledge gap. Seventy-two cases of CTEPH were diagnosed in the National Pulmonary Hypertension Unit (NPHU) in Ireland between 2010 and 2020. This accounted for 6% of all referrals to the unit and translates to an estimated annual incidence of 1.39 per million population (95% confidence interval, 0.33-2.46). The prevalence of diagnosed CTEPH in Ireland in 2020 was estimated at 12.05 per million population (95% CI 9.00-15.10). The average duration of symptoms prior to CTEPH diagnosis was 23 (±22) months. Patients with CTEPH were more likely to be male (n = 40, 56%), older (60 ± 17 years) and have identifiable risk factors for CTEPH (n = 61, 85%) at diagnosis. Regarding treatment, pulmonary hypertension (PH) vasodilator therapy was prescribed in 75% (n = 54) within 12 months of diagnosis, inferior vena cava filters were placed in 24% (n = 17) and 97% (n = 70) of cases were anticoagulated. Pulmonary endarterectomy was performed in 35% (n = 25), balloon pulmonary angioplasty in 6% (n = 4). One-, three- and five-year survival was 93%, 80% and 65% from the time of diagnosis, and this was significantly better in patients who underwent pulmonary endarterectomy (p = 0.01). This is the first study describing the characteristics of CTEPH in Ireland and highlights suboptimal disease recognition and referral for the assessment for pulmonary endarterectomy.

Development and validation of a claims-based model to identify patients at risk of chronic thromboembolic pulmonary hypertension following acute pulmonary embolism

OBJECTIVE

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease that often follows pulmonary embolism (PE). Screening for CTEPH is challenging, often delaying diagnosis and worsening prognosis. Predictive risk models for CTEPH could help identify at-risk patients, but existing models require multiple clinical inputs. We developed and validated a predictive risk model for CTEPH using health insurance claims that can be used by payers/quality-of-care organizations to screen patients post-PE.

METHODS

Adult patients newly diagnosed with acute PE (index date) were identified from the Optum De-identified Clinformatics Extended DataMart (January 2007-March 2018; development set) and IBM MarketScan (January 2008-June 2019; validation set) databases. Predictors were identified 12 months before or on the index PE. Risk of "likely CTEPH" was assessed post-PE based on CTEPH-related diagnoses and procedures since the CTEPH diagnosis code (ICD-10-CM: I27.24) was not available until 1 October 2017. Stepwise variable selection was used to build the model using the development set; model validation was subsequently conducted using the validation set.

RESULTS

The development set included 93,428 patients, of whom 11,878 (12.7%) developed likely CTEPH. Older age (odds ratios [OR] = 1.16-1.49), female (OR = 1.09), unprovoked PE (i.e. without thrombotic factors; OR = 1.14), hypertension (OR = 1.07), osteoarthritis (OR = 1.08), diabetes (OR = 1.07), chronic obstructive pulmonary disease (OR = 1.11), obesity (OR = 1.21) were associated with higher odds of likely CTEPH, and oral anticoagulants with lower odds (OR= 0.50, all p < .01). C-statistic was 0.77 in the development and validation sets.

CONCLUSION

A claims-based risk model reliably predicted the risk of CTEPH post-PE and could be used to identify high-risk patients who may benefit from focused monitoring.

Evaluation and management of patients with chronic thromboembolic pulmonary hypertension - consensus statement from the ISHLT

ISHLT members have recognized the importance of a consensus statement on the evaluation and management of patients with chronic thromboembolic pulmonary hypertension. The creation of this document required multiple steps, including the engagement of the ISHLT councils, approval by the Standards and Guidelines Committee, identification and selection of experts in the field, and the development of 6 working groups. Each working group provided a separate section based on an extensive literature search. These sections were then coalesced into a single document that was circulated to all members of the working groups. Key points were summarized at the end of each section. Due to the limited number of comparative trials in this field, the document was written as a literature review with expert opinion rather than based on level of evidence.

Prophylaxis and treatment of COVID-19 related venous thromboembolism

COVID-19 pneumonia has been associated with high rates of thrombo-embolic complications, mostly venous thromboembolism (VTE), which is thought to be a combination of conventional VTE and in situ immunothrombosis in the pulmonary vascular tree. The incidence of thrombotic complications is dependent on setting (intensive care unit (ICU) versus general ward) and the threshold for performing diagnostic tests (screening versus diagnostic algorithms triggered by symptoms). Since these thrombotic complications are associated with in-hospital mortality, all current guidelines and consensus papers propose pharmacological thromboprophylaxis in all hospitalized patients with COVID-19. Several trials are ongoing to study the optimal intensity of anticoagulation for this purpose. As for the management of thrombotic complications, treatment regimens from non-COVID-19 guidelines can be adapted, with choice of anticoagulant drug class dependent on the situation. Parenteral anticoagulation is preferred for patients on ICUs or with impending clinical deterioration, while oral treatment can be started in stable patients. This review describes current knowledge on incidence and pathophysiology of COVID-19 associated VTE and provides an overview of guideline recommendations on thromboprophylaxis and treatment of established VTE in COVID-19 patients.

Raising the bar to ultradisciplinary collaborations in management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension is an underdiagnosed and potentially fatal subgroup of pulmonary hypertension, if left untreated. Clinical signs include exertional dyspnea and non-specific symptoms. Diagnosis requires multimodality imaging and heart catheterization. Pulmonary endarterectomy, an open heart surgery, is the gold standard treatment of choice in selected patients in specialized centers. Targeted medical therapy and balloon pulmonary angioplasty can be effective in high-risk patients with significant comorbidities, distal pulmonary vascular obstructions, or recurrent/persistent pulmonary hypertension after pulmonary endarterectomy. Currently, there is a limited number of data regarding novel coronavirus-2019 infection in patients with chronic thromboembolic pulmonary hypertension and the changing spectrum of the disease during the pandemic. Challenging times during this outbreak due to healthcare crisis and relatively higher case-fatality rates require convergence; that is an ultradisciplinary collaboration, which crosses disciplinary and sectorial boundaries to develop integrated knowledge and new paradigms. Management strategies for the "new normal" such as virtual care, preparedness for further threats, redesigned standards and working conditions, reevaluation of specific recommendations, and online collaborations for optimal decisions for chronic thromboembolic pulmonary hypertension patients may change the poor outcomes.

Comparison of dual-energy computer tomography and dynamic contrast-enhanced MRI for evaluating lung perfusion defects in chronic thromboembolic pulmonary hypertension

OBJECTIVES

To evaluate the agreement in detecting pulmonary perfusion defects in patients with chronic thromboembolic pulmonary hypertension using dual-energy CT and dynamic contrast-enhanced MRI. Second, to compare both imaging modalities in monitoring lung perfusion changes in these patients after undergoing pulmonary endarterectomy.

METHODS

20 patients were examined with CT and MRI before and/or after pulmonary endarterectomy. Estimated perfusion defect percentage from both modalities was compared in a lobe-based analysis. Spatial agreement of perfusion defect maps was also assessed.

RESULTS

A significant correlation between CT and MRI based perfusion defect percentage was calculated in all lung lobes (r > 0.78; p < 0.001). In addition, a good spatial agreement between perfusion defect maps was found (mean spatial overlap for the whole lung was 68.2%; SD = 6.9). Both CT and MRI detected improvements in pulmonary perfusion after pulmonary endarterectomy: 8% and 7% decrease in whole lung perfusion defect percentage (p = 0.007 and 0.004), respectively. In a lobe-wise analysis, improvements were statistically significant only in lower lobes using both modalities (reduction in defect percentage ranged from 16-29%; p < 0.02).

CONCLUSIONS

Dual-energy CT is an alternative to MRI in monitoring chronic thromboembolic pulmonary hypertension. Both imaging modalities provided comparable estimations of perfusion defects and could detect similar improvement in lung perfusion after pulmonary endarterectomy.