Diagnosis of chronic thromboembolic pulmonary hypertension

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.

Dual-layer dual-energy CT-derived pulmonary perfusion for the differentiation of acute pulmonary embolism and chronic thromboembolic pulmonary hypertension

OBJECTIVES

To evaluate dual-layer dual-energy computed tomography (dlDECT)-derived pulmonary perfusion maps for differentiation between acute pulmonary embolism (PE) and chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS

This retrospective study included 131 patients (57 patients with acute PE, 52 CTEPH, 22 controls), who underwent CT pulmonary angiography on a dlDECT. Normal and malperfused areas of lung parenchyma were semiautomatically contoured using iodine density overlay (IDO) maps. First-order histogram features of normal and malperfused lung tissue were extracted. Iodine density (ID) was normalized to the mean pulmonary artery (MPA) and the left atrium (LA). Furthermore, morphological imaging features for both acute and chronic PE, as well as the combination of histogram and morphological imaging features, were evaluated.

RESULTS

In acute PE, normal perfused lung areas showed a higher mean and peak iodine uptake normalized to the MPA than in CTEPH (both p < 0.001). After normalizing mean ID in perfusion defects to the LA, patients with acute PE had a reduced average perfusion (IDmean,LA) compared to both CTEPH patients and controls (p < 0.001 for both). IDmean,LA allowed for a differentiation between acute PE and CTEPH with moderate accuracy (AUC: 0.72, sensitivity 74%, specificity 64%), resulting in a PPV and NPV for CTEPH of 64% and 70%. Combining IDmean,LA in the malperfused areas with the diameter of the MPA (MPAdia) significantly increased its ability to differentiate between acute PE and CTEPH (sole MPAdia: AUC: 0.76, 95%-CI: 0.68-0.85 vs. MPAdia + 256.3 * IDmean,LA - 40.0: AUC: 0.82, 95%-CI: 0.74-0.90, p = 0.04).

CONCLUSION

dlDECT enables quantification and characterization of pulmonary perfusion patterns in acute PE and CTEPH. Although these lack precision when used as a standalone criterion, when combined with morphological CT parameters, they hold potential to enhance differentiation between the two diseases.

CLINICAL RELEVANCE STATEMENT

Differentiating between acute PE and CTEPH based on morphological CT parameters is challenging, often leading to a delay in CTEPH diagnosis. By revealing distinct pulmonary perfusion patterns in both entities, dlDECT may facilitate timely diagnosis of CTEPH, ultimately improving clinical management.

KEY POINTS

• Morphological imaging parameters derived from CT pulmonary angiography to distinguish between acute pulmonary embolism and chronic thromboembolic pulmonary hypertension lack diagnostic accuracy. • Dual-layer dual-energy CT reveals different pulmonary perfusion patterns between acute pulmonary embolism and chronic thromboembolic pulmonary hypertension. • The identified parameters yield potential to enable more timely identification of patients with chronic thromboembolic pulmonary hypertension.

Diagnostic Performance of Perfusion-Only SPECT/CT for Chronic Thromboembolic Pulmonary Hypertension in Comparison With Ventilation-Perfusion Planar, SPECT, and SPECT/CT Imaging

PURPOSE

The aim of this study was to assess the diagnostic performance of perfusion-only SPECT/CT (Q SPECT/CT) in comparison with that of ventilation/perfusion planar scintigraphy (V/Q planar), perfusion SPECT with ventilation scan (V/Q SPECT), and perfusion SPECT/CT with ventilation scan (V/Q SPECT/CT) in chronic thromboembolic pulmonary hypertension (CTEPH).

PATIENTS AND METHODS

Patients with pulmonary hypertension who underwent ventilation-perfusion planar and SPECT/CT were retrospectively recruited. Two nuclear medicine physicians interpreted V/Q planar, V/Q SPECT, V/Q SPECT/CT, and Q SPECT/CT according to the European Association of Nuclear Medicine criteria. The diagnostic accuracy of these modalities for CTEPH was compared using a composite reference standard of pulmonary angiography, imaging test, cardiorespiratory assessment, and follow-up.

RESULTS

A total of 192 patients were enrolled, including 85 with CTEPH. The sensitivity of Q SPECT/CT was 98.8%, which similar to that of V/Q planar (97.6%), V/Q SPECT (96.5%), or V/Q SPECT/CT (100.0%). In contrast, Q SPECT/CT exhibited significantly lower specificity (73.8%) compared with V/Q planar (86.9%, P = 0.001), V/Q SPECT (87.9%, P < 0.001), and V/Q SPECT/CT (88.8%, P < 0.001). The significantly lower specificity of Q SPECT/CT, compared with the 3 others, was observed in the subgroup aged ≥50 years ( P < 0.001 for all), but not in those <50 years.

CONCLUSIONS

Q SPECT/CT exhibited lower specificity compared with V/Q planar, V/Q SPECT, and V/Q SPECT/CT in diagnosing CTEPH. It might underscore the essential role of a ventilation scan in patients with PH, even with the introduction of SPECT/CT.

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.

10-year success story in CTEPH treatment: breaking the myth of rareness

Unlike acute pulmonary embolism (PE), the resolution of thrombi is ineffective in chronic thromboembolic pulmonary hypertension (CTEPH), leading to reorganisation and fibrotic changes within the pulmonary arteries. The authors report the case of a man in his 60s with polycythemia vera, under warfarin, following an acute PE. He was admitted a year later with right heart failure and haemodynamic instability. Acute over chronic PE caused this severe presentation, confirmed by right heart catheterisation and pulmonary scintigraphy. The challenging diagnosis and management involved transfer to a centre specialised in pulmonary vascular disease. Normalisation of functional and haemodynamic parameters, sustained in 10-year follow-up, was achieved with anticoagulation and triple therapy with prostanoids as a bridge to pulmonary thromboendarterectomy. Targeted medical therapy, not standard at that time, was crucial to recovering conditions for transfer. An individualised approach, integrating multidisciplinary pulmonary hypertension expertise, provides the basis for the best care for CTEPH.

Clinical-radiological-pathological correlation in pulmonary arterial hypertension

Pulmonary hypertension (PH) is defined by the presence of a mean pulmonary arterial pressure >20 mmHg. Current guidelines describe five groups of PH with shared pathophysiological and clinical features. In this paper, the first of a series covering all five PH classification groups, the clinical, radiological and pathological features of pulmonary arterial hypertension (PAH) will be reviewed. PAH may develop in the presence of associated medical conditions or a family history, following exposure to certain medications or drugs, or may be idiopathic in nature. Although all forms of PAH share common histopathological features, the presence of certain pulmonary arterial abnormalities, such as plexiform lesions, and extent of co-existing pulmonary venous involvement differs between the different subgroups. Radiological investigations are key to diagnosing the correct form of PH and a systematic approach to interpretation, especially of computed tomography, is essential.

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.

Speckle tracking tissue motion mitral annulus displacement to assess early changes in the left ventricle and its association with lung function in patients with chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the early changes in left ventricular (LV) in patients with chronic obstructive pulmonary disease (COPD) by measuring tissue motion mitral annulus displacement (TMAD) and three-dimensional (3D) parameters using speckle tracking imaging (STI), and to explore its correlation with lung function.

METHODS

Forty two COPD patients (GOLD I, GOLD II, GOLD III) and 30 healthy individuals (control group) were included. STI was used to assess the changes in LV structure and systolic function. Receiver operating characteristic (ROC) curves were drawn, and correlations among TMAD parameters, LV systolic function, structural, pulmonary artery systolic pressure (PASP), and lung function were analyzed.

RESULTS

Compared to the control group, COPD patients were able to undergo LV remodeling, with a decrease in the absolute value of global longitudinal strain (GLS) and TMAD, but no significant modification of LVEF. Correlation analysis showed that TMAD was positively related to the absolute value of GLS (r > 0.51, P < 0.01) and predicted forced expiratory volume in the first second (FEV1%) (r > 0.56, P < 0.01), and negatively to PASP (r < -0.52, P < 0.01). The LV posterior wall thickness (LVPWd), relative wall thickness (RWT), end-diastolic volume (LVEDV) and PASP negatively correlated with FEV1%.

CONCLUSION

The LV geometric changes and systolic function impairment in COPD patients were found to correlate with airflow restriction (FEV1%). TMAD aided in detection of early changes in LV systolic function in COPD patients. It negatively correlated with PASP and positively with FEV1%. Moreover, it was more convenient than GLS.

Role of pulmonary perfusion magnetic resonance imaging for the diagnosis of pulmonary hypertension: A review

Among five types of pulmonary hypertension, chronic thromboembolic pulmonary hypertension (CTEPH) is the only curable form, but prompt and accurate diagnosis can be challenging. Computed tomography and nuclear medicine-based techniques are standard imaging modalities to non-invasively diagnose CTEPH, however these are limited by radiation exposure, subjective qualitative bias, and lack of cardiac functional assessment. This review aims to assess the methodology, diagnostic accuracy of pulmonary perfusion imaging in the current literature and discuss its advantages, limitations and future research scope.

Single-Center Experience of Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension: The Results from the Tabriz University Medical Sciences (TUMS) CTEPH Program

INTRODUCTION

Pulmonary endarterectomy (PEA) remains the preferred and potentially curative option for patients with chronic thromboembolic pulmonary hypertension (CTEPH). This study aimed to report the results of PEA for CTEPH in a tertiary center in Tabriz, Iran.

METHODS

We analyzed the results of 42 CTEPH patients undergoing PEA, who were enrolled in the Tabriz University of Medical Sciences (TUMS-CTEPH) from January 2016 to October 2020. The main outcome measures included the New York Heart Association (NYHA) functional classification, the 6-Minute Walk Distance, hemodynamic measures in right heart catheterization, morbidity, and mortality.

RESULTS

There was a significant improvement in the NYHA function class (2.6 ± 0.5 vs 1.1 ± 0.34), mean pulmonary arterial pressure (47.1 ± 13 vs 27.9 ± 8 mm Hg), cardiac output (4.3 ± 1.06 vs 5.9 ± 1.2 L/min), and pulmonary vascular resistance (709.4 ± 297.5 vs 214 ± 77 dyn s/cm5). Fifteen patients (35%) developed complications. The most common complication (10 [23%]) was reperfusion injury. Also, postsurgical mortality was 4% during hospital admission and 1-year follow-up.

CONCLUSION

This is the first single-center report of PEA from Iran. Post-PEA and 1-year survival were acceptable as a referral center. PEA can be performed safe with low mortality. Greater awareness of PEA and patients' access to experienced CTEPH centers are important issues.

Chronic thromboembolic pulmonary hypertension and the post-pulmonary embolism (PE) syndrome

Over a third of patients surviving acute pulmonary embolism (PE) will experience long-term cardiopulmonary limitations. Persistent thrombi, impaired gas exchange, and altered hemodynamics account for aspects of the postpulmonary embolism syndrome that spans mild functional limitations to debilitating chronic thromboembolic pulmonary hypertension (CTEPH), the most worrisome long-term consequence. Though pulmonary endarterectomy is potentially curative for the latter, less is understood surrounding chronic thromboembolic disease (CTED) and post-PE dyspnea. Advances in pulmonary vasodilator therapies and growing expertise in balloon pulmonary angioplasty provide options for a large group of patients ineligible for surgery, or those with persistent postoperative pulmonary hypertension. In this clinical review, we discuss epidemiology and pathophysiology as well as advances in diagnostics and therapeutics surrounding the spectrum of disease that may follow months after acute PE.

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.

Diagnostic importance of lung perfusion/ventilation scans in the evaluation of pulmonary embolism in COVID-19 patients: systematic review of the literature

OBJECTIVE

To investigate the outcomes of ventilation/perfusion scintigraphy on the diagnosis of pulmonary embolism in coronavirus disease 2019 (COVID-19) patients, we performed a systematic review of the available literature.

MATERIALS AND METHODS

PubMed and Scopus were systematically searched up to 4 June 2022, for relevant studies. We included studies on patients with COVID-19 who have performed ventilation/perfusion scintigraphy for diagnosis of pulmonary embolism to describe any diagnosis outcome. Irrelevant and non-English articles were excluded.

RESULTS

Overall, 27 articles were included in our review. The database search yielded studies from PubMed, Scopus, and studies identified through reviewing the reference list of included studies. Extracted information from the included studies could be categorized into several aspects: Diagnosis of pulmonary embolism with Q single-photon emission computed tomography (SPECT) CT, Tracheobronchial uptake, Diagnostic value of V/Q rather than Q at diagnosis pulmonary embolism, Different characteristics (morphological alterations) of COVID-19 in ventilation orperfusion scan, the prevalence of pulmonary embolism with Q or V/Q criteria, and Design of radiotherapy planning in lung cancer patients with COVID-19.

CONCLUSION

Different perfusion patterns in COVID-19 are challenging but can be alleviated by adding SPECT/computed tomography (CT) to lung perfusion scans. Although perfusion only SPECT/CT can rule out or rule in others in considerable number of patients, ventilation scan is still needed in certain patients.

Update on the roles of imaging in the management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH), classified as group 4 pulmonary hypertension (PH), is caused by stenosis and obstruction of the pulmonary arteries by organized thrombi that are incompletely resolved after acute pulmonary embolism. The prognosis of patients with CTEPH is poor if untreated; however, in expert centers with multidisciplinary teams, a treatment strategy for CTEPH has been established, dramatically improving its prognosis. CTEPH is currently not a fatal disease and is the only curable form of PH. Despite these advances and the establishment of treatment approaches, early diagnosis is still challenging, especially for non-experts, for several reasons. One of the reasons for this is insufficient knowledge of the various diagnostic imaging modalities, which are essential in the clinical practice of CTEPH. Imaging modalities should detect the following pathological findings: lung perfusion defects, thromboembolic lesions in pulmonary arteries, and right ventricular remodeling and dysfunction. Perfusion lung scintigraphy and catheter angiography have long been considered gold standards for the detection of perfusion defects and assessment of vascular lesions, respectively. However, advances in imaging technology of computed tomography and magnetic resonance imaging have enabled the non-invasive detection of these abnormal findings in a single examination. Cardiac magnetic resonance (CMR) is the gold standard for evaluating the morphology and function of the right heart; however, state-of-the-art techniques in CMR allow the assessment of cardiac tissue characterization and hemodynamics in the pulmonary arteries. Comprehensive knowledge of the role of imaging in CTEPH enables appropriate use of imaging modalities and accurate image interpretation, resulting in early diagnosis, determination of treatment strategies, and appropriate evaluation of treatment efficacy. This review summarizes the current roles of imaging in the clinical practice for CTEPH, demonstrating the characteristic findings observed in each modality.

Pathophysiology and Treatment of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a condition in which an organic thrombus remains in the pulmonary artery (PA) even after receiving anticoagulation therapy for more than 3 months and is complicated by pulmonary hypertension (PH), leading to right-sided heart failure and death. CTEPH is a progressive pulmonary vascular disease with a poor prognosis if left untreated. The standard treatment for CTEPH is pulmonary endarterectomy (PEA), which is usually performed only in specialized centers. In recent years, balloon pulmonary angioplasty (BPA) and drug therapy for CTEPH have also shown good results. This review discusses the complex pathogenesis of CTEPH and presents the standard of care, PEA, as well as a new device called BPA, which is showing remarkable progress in efficacy and safety. Additionally, several drugs are now demonstrating established evidence of efficacy in treating CTEPH.

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.

[Pulmonary Endarterectomy and Treatment for Chronic Thromboembolic Pulmonary Hypertension]

Pulmonary Endarterectomy and Treatment for Chronic Thromboembolic Pulmonary Hypertension Abstract. Chronic thromboembolic pulmonary hypertension is a relatively rare disease which mostly evolves as a complication of acute pulmonary embolism resulting from the fibrotic organization of residual thrombotic material despite adequate anticoagulation leading to precapillary pulmonary hypertension and persistence of its symptoms. The elevated pulmonary vascular resistance leads to right ventricular heart failure, its symptoms and reduced prognosis. The therapy of choice is the pulmonary endarterectomy, which leads to a reduction of symptoms, optimization of the hemodynamics and improved prognosis. Misdiagnosis and delayed referral often lead to disease progression along with poor surgical outcome. In case of more distal, surgically non-accessible disease, treatment consists of balloon pulmonary angioplasty and pulmonary vasodilator drugs.

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.

Clinical Presentations and Multimodal Imaging Diagnosis in Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but life-threatening pulmonary vascular disease caused by the presence of a prolonged thrombus in the pulmonary artery. CTEPH is a distinct disease entity classified as group 4 pulmonary hypertension according to the World Symposium on Pulmonary Hypertension. It is the only potentially curable cause of pulmonary hypertension. However, timely diagnosis and treatment are often hampered by nonspecific symptoms and signs and a lack of physician awareness regarding the condition. Thus, it is important to be familiar with the clinical features of CTEPH and the associated diagnostic processes. Herein, we cover the diagnostic approach for CTEPH using multimodal imaging tools in a clinical setting.

The diagnostic performance of CT pulmonary angiography in the detection of chronic thromboembolic pulmonary hypertension-systematic review and meta-analysis

OBJECTIVES

To examine the diagnostic performance of CT of the pulmonary artery (CTPA) as a potential first-choice imaging modality in patients with pulmonary arterial hypertension and suspected chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS

A systematic review and meta-analysis were conducted in accordance with the PRISMA reporting checklist. Six scientific databases and registers (PubMed, EMBASE, Scopus, Web of Science, Cochrane, ClinicalTrials.gov ) were searched for studies evaluating the diagnostic performance of CTPA in suspected CTEPH in adult patients. Results were pooled separately for studies based on the evaluation of the pulmonary artery and those that relied solely on changes in parenchymal perfusion.

RESULTS

Ten single-center studies with 734 patients were eligible for pooling of the diagnostic performance of CTPA by evaluation of the pulmonary artery. The pooled sensitivity, specificity, PPV, NPV, accuracy, and diagnostic odds ratio (DOR) estimates for CTPA in the detection of CTEPH were 0.98, 0.99, 0.94, 1.00, 0.96, 0.96, and 292. Evaluation of perfusion changes yielded pooled estimates for sensitivity, specificity, PPV, NPV, accuracy, and DOR of 0.99, 0.84, 0.79, 0.98, 0.89, 0.89, and 98 across four studies with 278 patients. Scintigraphy, SPECT, digital subtraction angiography, right heart catheterization, pulmonary endarterectomy, and international guidelines were used to establish the diagnosis.

CONCLUSION

CTPA has high sensitivity and specificity in the detection of CTEPH when the examination is evaluated by expert radiologists. Evaluation of parenchymal perfusion alone is associated with slightly lower specificity. Further research is needed to determine the diagnostic performance of CTPA in excluding CTEPH in general radiology departments.

KEY POINTS

• CT pulmonary angiography (CTPA) is recommended in the diagnostic workup of chronic thromboembolic pulmonary hypertension (CTEPH). • CTPA has high sensitivity and specificity in the detection of CTEPH when evaluated by an expert radiologist. • Evaluation of changes in parenchymal perfusion alone is associated with slightly lower specificity. • Little is known about the diagnostic performance of CTPA in the detection of CTEPH in general radiology departments.

Prognostic Relevance of Cardiopulmonary Exercise Testing for Patients with Chronic Thromboembolic Pulmonary Hypertension

Background: Following acute pulmonary embolism (PE), a relevant number of patients experience decreased exercise capacity which can be associated with disturbed pulmonary perfusion. Cardiopulmonary exercise testing (CPET) shows several patterns typical for disturbed pulmonary perfusion. Research question: We aimed to examine whether CPET can also provide prognostic information in chronic thromboembolic pulmonary hypertension (CTEPH). Study Design and Methods: We performed a multicenter retrospective chart review in Germany between 2002 and 2020. Patients with CTEPH were included if they had ≥6 months of follow-up and complete CPET and hemodynamic data. Symptom-limited CPET was performed using a cycle ergometer (ramp or Jones protocol). The association of anthropometric data, comorbidities, symptoms, lung function, and echocardiographic, hemodynamic, and CPET parameters with survival was examined. Mortality prediction models were calculated by Cox regression with backward selection. Results: 345 patients (1532 person-years) were included; 138 underwent surgical treatment (pulmonary endarterectomy or balloon pulmonary angioplasty) and 207 received only non-surgical treatment. During follow-up (median 3.5 years), 78 patients died. The death rate per 1000 person-years was 24.9 and 74.2 in the surgical and non-surgical groups, respectively (p < 0.001). In age- and sex-adjusted Cox regression analyses, CPET parameters including peak oxygen uptake (VO2peak, reflecting cardiopulmonary exercise capacity) were prognostic in the non-surgical group but not in the surgical group. In mortality prediction models, age, sex, VO2peak (% predicted), and carbon monoxide transfer coefficient (% predicted) showed significant prognostic relevance in both the overall cohort and the non-surgical group. In the non-surgical group, Kaplan−Meier analysis showed that patients with VO2peak below 53.4% predicted (threshold identified by receiver operating characteristic analysis) had increased mortality (p = 0.007). Interpretation: The additional measurement of cardiopulmonary exercise capacity by CPET allows a more precise prognostic evaluation in patients with CTEPH. CPET might therefore be helpful for risk-adapted treatment of CTEPH.

Molecular imaging as a tool for evaluation of COVID-19 sequelae – A review of literature

Coronavirus disease 2019 (COVID-19) is caused by the novel viral pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 primarily involves the lungs. Nucleic acid testing based on reverse-transcription polymerase chain reaction of respiratory samples is the current gold standard for the diagnosis of SARS-CoV-2 infection. Imaging modalities have an established role in triaging, diagnosis, evaluation of disease severity, monitoring disease progression, extra-pulmonary involvement, and complications. As our understanding of the disease improves, there has been substantial evidence to highlight its potential for multi-systemic involvement and development of long-term sequelae. Molecular imaging techniques are highly sensitive, allowing non-invasive visualization of physiological or pathological processes at a cellular or molecular level with potential for detection of functional changes earlier than conventional radiological imaging. The purpose of this review article is to highlight the evolving role of molecular imaging in evaluation of COVID-19 sequelae. Though not ideal for diagnosis, the various modalities of molecular imaging play an important role in assessing pulmonary and extra-pulmonary sequelae of COVID-19. Perfusion imaging using single photon emission computed tomography fused with computed tomography (CT) can be utilized as a first-line imaging modality for COVID-19 related pulmonary embolism. ¹⁸F-fluorodeoxyglucose positron emission tomography (PET)/CT is a sensitive tool to detect multi-systemic inflammation, including myocardial and vascular inflammation. PET in conjunction with magnetic resonance imaging helps in better characterization of neurological sequelae of COVID-19. Despite the fact that the majority of published literature is retrospective in nature with limited sample sizes, it is clear that molecular imaging provides additional valuable information (complimentary to anatomical imaging) with semi-quantitative or quantitative parameters to define inflammatory burden and can be used to guide therapeutic strategies and assess response. However, widespread clinical applicability remains a challenge owing to longer image acquisition times and the need for adoption of infection control protocols.

The alterations in molecular markers and signaling pathways in chronic thromboembolic pulmonary hypertension, a study with transcriptome sequencing and bioinformatic analysis

Background

At present, the alterations in molecular markers and signaling pathways in chronic thromboembolic pulmonary hypertension (CTEPH) remain unclear. We aimed to compare the difference of molecular markers and signaling pathways in patients with CTEPH and healthy people with transcriptome sequencing and bioinformatic analysis.

Methods

We prospectively included 26 patients with CTEPH and 35 sex- and age-matched healthy volunteers as control. We extracted RNA from whole blood samples to construct the library. Then, qualified libraries were sequenced using PE100 strategy on BGIseq platform. Subsequently, the DESeq2 package in R was used to screen differentially expressed mRNAs (DEmRNAs) and differentially expressed long non-coding RNAs (DElncRNAs) of 7 patients with CTEPH and 5 healthy volunteers. Afterwards, we performed functional enrichment and protein–protein interaction analysis of DEmRNAs. We also performed lncRNA-mRNA co-expression analysis and lncRNA-miRNA-mRNA network construction. In addition, we performed diagnostic analysis on the GSE130391 dataset. Finally, we performed reverse transcription polymerase chain reaction (RT-PCR) of genes in 19 patients with CTEPH and 30 healthy volunteers.

Results

Gender and age between patients with CTEPH and healthy controls, between sequencing group and in vitro validation group, were comparable. A total of 437 DEmRNAs and 192 DElncRNAs were obtained. Subsequently, 205 pairs of interacting DEmRNAs and 232 pairs of lncRNA-mRNA relationship were obtained. DEmRNAs were significantly enriched in chemokine signaling pathway, metabolic pathways, arachidonic acid metabolism, and MAPK signaling pathway. Only one regulation pathway of SOBP-hsa-miR-320b-LINC00472 was found through ceRNA network construction. In diagnostic analysis, the area under curve (AUC) values of LINC00472, PIK3R6, SCN3A, and TCL6, respectively, were 0.964, 0.893, 0.750, and 0.732.

Conclusion

The identification of alterations in molecules and pathways may provide further research directions on pathogenesis of CTEPH. Additionally, LINC00472, PIK3R6, SCN3A, and TCL6 may act as the potential gene markers in CTEPH.

Acute on Chronic Thromboembolic Pulmonary Hypertension: Case Series and Review of Management

Chronic thromboembolic pulmonary hypertension (CTEPH) is a distinct form of precapillary pulmonary hypertension classified as group 4 by the World Symposium on Pulmonary Hypertension (WSPH) and should be excluded during an episode of acute pulmonary embolism (PE). Patients presenting to emergency departments with sudden onset of signs and symptoms of acute PE may already have a pre-existing CTEPH condition decompensated by the new PE episode. Identifying an underlying and undiagnosed CTEPH during acute PE, while challenging, is an important consideration as it will alter the patients’ acute and long-term management. Differential diagnosis and evaluation require an interdisciplinary expert team. Analysis of the clinical condition, the CT angiogram, and the hemodynamic situation are important considerations; patients with CTEPH usually have significantly higher sPAP at the time of index PE, which is unusual and unattainable in the context of acute PE and a naïve right ventricle. The imaging may reveal signs of chronic disease such as right ventricle hypertrophy bronchial collaterals and atypical morphology of the thrombus. There is no standard for the management of acute on chronic CTEPH. Herein, we provide a diagnostic and management algorithm informed by several case descriptions and a review of the literature.

Pulmonary thromboembolic events in COVID‐19 – a systematic literature review

Pulmonary thromboembolic events have been linked to coronavirus disease 2019 (COVID‐19), but their incidence and long‐term sequelae remain unclear. We performed a systematic literature review to investigate the incidence of pulmonary embolism (PE), microthrombi, thrombosis in situ (thromboinflammatory disease), and chronic thromboembolic pulmonary hypertension (CTEPH) during and after COVID‐19. PubMed and the World Health Organization Global Research Database were searched on May 7, 2021. Hospital cohort and database studies reporting data for ≥1000 patients and autopsy studies reporting data for ≥20 patients were included. Results were summarized descriptively. We screened 1438 records and included 41 references (32 hospital/database studies and 9 autopsy studies). The hospital/database studies reported the incidence of PE but not CTEPH, microthrombi, or thromboinflammatory disease. PE incidence varied widely (0%–1.1% of outpatients, 0.9%–8.2% of hospitalized patients, and 1.8%–18.9% of patients in intensive care). One study reported PE events occurring within 45 days after hospital discharge (incidence in discharged patients: 0.2%). Segmental arteries were generally the most common location for PE. In autopsy studies, PE, thromboinflammatory disease, and microthrombi were reported in 6%–23%, 43%–100%, and 45%–84% of deceased patients, respectively. Overall, the included studies mostly focused on PE during the acute phase of COVID‐19. The results demonstrate the challenges of identifying and characterizing vascular abnormalities using current protocols (e.g., visual computed tomography reads). Further research is needed to detect subtle pulmonary vascular abnormalities, distinguish thromboinflammatory disease from PE, optimize treatment, and assess the incidence of long‐term sequelae after COVID‐19.

Diagnosis of Chronic Thromboembolic Pulmonary Hypertension Using Quantitative Lung Perfusion Parameters Extracted From Dual-energy Computed Tomography Images

PURPOSE

To evaluate quantified iodine mapping parameters in dual-energy computed tomography in normal patients versus those with chronic thromboembolic pulmonary hypertension (CTEPH) with and without pulmonary thromboembolism.

MATERIALS AND METHODS

Using automatically quantified iodine mapping in dual-energy computed tomography, we evaluated lung relative average enhancement, standard deviation (SD), and the SD/lung relative average enhancement ratio. We compared the values for these parameters in normal patients versus those with CTEPH. We also performed a receiver operating characteristic curve analysis to determine the diagnostic cutoffs for the parameters.

RESULTS

Patients constituted 41 patients (10 male [24.4%] and 31 female [75.6%]; mean age [SD]: 70.0 y [13.3]) with CTEPH and 237 (92 male [38.8%] and 145 female [61.2%]; mean age [SD]: 65.9 y [15.9]) normal patients. We found significant differences in lung relative average enhancement (34.9±6.3 vs. 26.9±6.3; P <0.0001), SD (11.6±1.9 vs. 14.7±3.3; P <0.001), and the SD/lung relative average enhancement ratio (33.7±5.0 vs. 55.7±10.4; P <0.001) between the normal and CTEPH groups, respectively. The ROC analyses demonstrated high discriminatory power (area under the curve=0.99) for using the SD/lung relative average enhancement ratio to differentiate between patients in the normal group and CTEPH group. At a threshold for the area under the curve of 44.2, diagnostic sensitivity, specificity, positive predictive value, and negative predictive value for the ratio were 92.7%, 97.5%, 86.5%, and 98.7%, respectively.

CONCLUSIONS

Patients with CTEPH were well-discriminated from normal patients using the SD/lung relative average enhancement ratio.

Prognostic implication of noninvasive right ventricle-to-pulmonary artery coupling in chronic thromboembolic pulmonary hypertension

Aims:

Impairment of right ventricle-to-pulmonary artery coupling (RV-PA coupling) is a major determinant of poor prognosis in patients with pulmonary hypertension. This study sought to evaluate the ability of an echo-derived metric of RV-PA coupling, the ratio between tricuspid annular plane systolic excursion (TAPSE), and pulmonary artery systolic pressure (PASP) and to predict adverse clinical outcomes in chronic thromboembolic pulmonary hypertension (CTEPH).

Methods and results:

A total of 205 consecutive patients with confirmed CTEPH were retrospectively recruited from Fuwai Hospital between February 2016 and November 2020. Baseline echocardiography, right heart catheterization, and cardiopulmonary exercise testing were analyzed. Patients with lower TAPSE/PASP had a significantly compromised echocardiographic and hemodynamic status and exercise capacity at baseline. The TAPSE/PASP ratio correlated significantly with hemodynamic parameters, including pulmonary vascular resistance (r = −0.48, p < 0.001) and pulmonary arterial compliance (r = 0.45, p < 0.001). During a median period of 1-year follow-up, 63 (30.7%) patients experienced clinical worsening. The relationship between TAPSE/PASP and clinical worsening was assessed using different multivariate Cox regression models. After adjustment for a series of previously screened independent predictors, TAPSE/PASP remained significantly associated with outcomes, and the hazard ratio (per standard deviation increase) of the final model was 0.402.

Conclusion:

In patients with CTEPH, baseline RV-PA coupling measured as the TAPSE/PASP ratio is associated with disease severity and adverse outcomes. A low TAPSE/PASP identifies patients with a high risk of clinical deterioration, and this novel metric could be applicable for risk stratification in CTEPH.

Precapillary pulmonary arterial hypertension in a patient with Proteus syndrome

Proteus syndrome is a rare progressive multisystem disorder characterized by asymmetric, disproportionate overgrowth of bone, skin, and other tissue types. Molecular pathogenesis has been identified as somatic activating mutations of the AKT1 gene. The presentation of Proteus syndrome is exceptionally variable. Respiratory complications include emphysematous lung disease and predisposition to pulmonary emboli, the latter of which is a significant source of mortality. Pulmonary hypertension due to longstanding hypoxic lung disease as well as chronic thromboembolic events has been observed in this population. In contrast, precapillary pulmonary arterial hypertension in the absence of chronic pulmonary emboli and parenchymal lung disease has not been described in the literature on patients with Proteus syndrome. We report such a case in a young patient with Proteus syndrome, reviewing subsequent management and emphasizing the need for a detailed investigation of dyspnea.

Lung Ventilation/Perfusion Scintigraphy for the Screening of Chronic Thromboembolic Pulmonary Hypertension (CTEPH): Which Criteria to Use?

Objective

The diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) is a major challenge as it is a curable cause of pulmonary hypertension (PH). Ventilation/Perfusion (V/Q) lung scintigraphy is the imaging modality of choice for the screening of CTEPH. However, there is no consensus on the criteria to use for interpretation. The aim of this study was to assess the accuracy of various interpretation criteria of planar V/Q scintigraphy for the screening of CTEPH in patients with PH.

Methods

The eligible study population consisted of consecutive patients with newly diagnosed PH in the Brest University Hospital, France. Final diagnosis (CTEPH or non-CTEPH) was established in a referential center on the management of PH, based on the ESC/ERS guidelines and a minimum follow-up of 3 years. A retrospective central review of planar V/Q scintigraphy was performed by three nuclear physicians blinded to clinical findings and to final diagnosis. The number, extent (sub-segmental or segmental) and type (matched or mismatched) of perfusion defects were reported. Sensitivity and specificity were evaluated for various criteria based on the number of mismatched perfusion defects and the number of perfusion defects (regardless of ventilation). Receiver operating characteristic (ROC) curves were generated and areas under the curve (AUC) were calculated for both.

Results

A total of 226 patients with newly diagnosed PH were analyzed. Fifty six (24.8%) were diagnosed with CTEPH while 170 patients (75.2%) were diagnosed with non-CTEPH. The optimal threshold was 2.5 segmental mismatched perfusion defects, providing a sensitivity of 100 % (95% CI 93.6–100%) and a specificity of 94.7% (95%CI 90.3–97.2%). Lower diagnostic cut-offs of mismatched perfusion defects provided similar sensitivity but lower specificity. Ninety five percent of patients with CTEPH had more than 4 segmental mismatched defects. An interpretation only based on perfusion provided similar sensitivity but a specificity of 81.8% (95%CI 75.3–86.9%).

Conclusion

Our study confirmed the high diagnostic performance of planar V/Q scintigraphy for the screening of CTEPH in patients with PH. The optimal diagnostic cut-off for interpretation was 2.5 segmental mismatched perfusion defects. An interpretation only based on perfusion defects provided similar sensitivity but lower specificity.

Resveratrol attenuates chronic pulmonary embolism-related endothelial cell injury by modulating oxidative stress, inflammation, and autophagy

OBJECTIVES

Due to Pulmonary Artery Endothelial Cell (PAEC) dysfunction, Pulmonary Hypertension (PH) persists even after the Pulmonary Embolism (PE) has been relieved. However, the mechanism behind this remains unclear.

METHOD

Here, the authors incubated Human PAECs (HPAECs) with thrombin to simulate the process of arterial thrombosis.

RESULTS

CCK8 results showed a decrease in the viability of HPAECs after thrombin incubation. In addition, the expression of Tissue Factor (TF), Monocyte Chemoattractant Protein 1 (MCP-1), VCAM-1, ICAM-1, cleaved caspase 3, cleaved caspase 9, and Bax protein were all increased after thrombin incubation, while Bcl-2 was decreased. The effects of 3-MA treatment further suggested that autophagy might mediate the partial protective effects of Resveratrol on HPAECs. To observe the effects of Resveratrol in vivo, the authors established a Chronic Thromboembolic Pulmonary Hypertension (CTEPH) model by repeatedly injecting autologous blood clots into a rat's left jugular vein. The results exhibited that Mean Pulmonary Arterial Pressure (mPAP) and vessel Wall Area/Total Area (WA/TA) ratio were both decreased after Resveratrol treatment. Moreover, Resveratrol could reduce the concentration and activity of TF, vWF, P-selectin, and promote these Superoxide Dismutase (SOD) in plasma. Western blot analysis of inflammation, platelet activation, autophagy, and apoptosis-associated proteins in pulmonary artery tissue validated the results in PHAECs.

CONCLUSIONS

These findings suggested that reduced autophagy, increased oxidative stress, increased platelet activation, and increased inflammation were involved in CTEPH-induced HPAEC dysfunction and the development of PH, while Resveratrol could improve PAEC dysfunction and PH.

Modulation of soluble guanylate cyclase ameliorates pulmonary hypertension in a rat model of chronic thromboembolic pulmonary hypertension by stimulating angiogenesis

Acute pulmonary embolism (PE) does not always resolve after treatment and can progress to chronic thromboembolic disease (CTED) or the more severe chronic thromboembolic pulmonary hypertension (CTEPH). The mechanisms surrounding the likelihood of PE resolution or progress to CTED/CTEPH remain largely unknown. We have developed a rat model of CTEPH that closely resembles the human disease in terms of hemodynamics and cardiac manifestations. Embolization of rats with polystyrene microspheres followed by suppression of angiogenesis with the inhibitor of vascular endothelial growth factor receptor 2 (VEGF-R2) SU5416 results in transient, acute pulmonary hypertension that progresses into chronic PE with PH with sustained right ventricular systolic pressures exceeding 70 mmHg (chronic pulmonary embolism [CPE] model). This model is similar to the widely utilized hypoxia/SU5416 model with the exception that the "first hit" is PE. Rats with CPE have impaired right heart function characterized by reduced VO2 Max, reduced cardiac output, and increased Fulton index. None of these metrics are adversely affected by PE alone. Contrast-mediated CT imaging of lungs from rats with PE minus SU5416 show large increases in pulmonary vascular volume, presumably due to an angiogenic response to acute PE/PH. Co-treatment with SU5416 suppresses angiogenesis and produces the CTEPH-like phenotype. We report here that treatment of CPE rats with agonists for soluble guanylate cyclase, a source of cGMP which is in turn a signal for angiogenesis, markedly increases angiogenesis in lungs, and ameliorates the cardiac deficiencies in the CPE model. These results have implications for future development of therapies for human CTEPH.

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.

A Feasibility Study on Using Single-Photon Emission Computed Tomography Pulmonary Perfusion/Ventilation Imaging for the Diagnosis of Chronic Thromboembolic Pulmonary Hypertension and Patient Risk Assessment

Objective

The study is designed to evaluate the diagnostic ability of single-photon emission computed tomography (SPECT) pulmonary ventilation/perfusion (V/Q) imaging in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and investigate its feasibility in assessing patient risk.

Methods

A total of 83 patients suspected of having CTEPH who received V/Q tomography were retrospectively analyzed. The consistency between SPECT V/Q imaging and pulmonary angiography was compared to investigate the correlation between the percentage of pulmonary perfusion defect score (PPDs%) and the hemodynamic indices. Patients were grouped according to the pulmonary arterial hypertension risk stratification, and the V/Q imaging results were compared between different groups.

Results

For the 1494 pulmonary segments of the 83 patients, the sensitivity, specificity, and accuracy of identifying pulmonary segments with defects using V/Q imaging was 87.05%, 82.78% (668/807), and 84.74% (1266/1494), respectively. The average PPDs% (58.8 ± 12.6%) was positively correlated with the mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), and right ventricular pressure (RVP; r =0.316, 0.318, and 0.432, respectively; P < 0.05) and negatively correlated with the six-minute walk distance (6MWD; r = −0.309; P < 0.05). There were 37 patients in the low-risk group and 46 in the medium-high-risk group. The number of pulmonary segments with perfusion defects (NPSPDs) and PPDs% were higher in the medium-high risk than in the low-risk group (t = −6.721, −5.032; P < 0.05). In the low- and medium-high-risk groups, the cut-off values for the NPSPDs (7.2 ± 2.1 and 10.2 ± 2.0) and PPDs% (51.9 ± 11.1% and 64.3 ± 11.1%,) were 8.5 and 61.25%, respectively.

Conclusion

SPECT V/Q imaging achieved an accurate diagnosis of CTEPH. The semi-quantitative analysis index (PPDs%) was correlated with the hemodynamic indices and 6MWD. SPECT V/Q could be used for the preoperative risk assessment of patients with CTEPH.

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.

Higher Incidence of Chronic Thromboembolic Pulmonary Hypertension After Acute Pulmonary Embolism in Asians Than in Europeans: A Meta-Analysis

Aim: To summarize the incidence of right heart catheter diagnosed chronic thromboembolic pulmonary hypertension (CTEPH) after acute pulmonary embolism (PE) in a meta-analysis. Methods: Cohort studies reporting the incidence of CTEPH after acute PE were identified via search of Medline, Embase, China National Knowledge Infrastructure and WanFang databases. Results: Twenty-two cohort studies with 5,834 acute PE patients were included. Pooled results showed that the overall incidence of CTEPH was 2.82% (95% CI: 2.11-3.53%). Subgroup analyses showed higher incidence of CTEPH in Asians than Europeans (5.08 vs. 1.96%, p = 0.01), in retrospective cohorts than prospective cohorts (4.75 vs. 2.47%, p = 0.02), and in studies with smaller sample size than those with larger sample size (4.57 vs. 1.71%, p < 0.001). Stratified analyses showed previous venous thromboembolic events and unprovoked PE were both significantly associated with increased risk of CTEPH (OR = 2.57 and 2.71, respectively; both p < 0.01). Conclusions: The incidence of CTEPH after acute PE is ~3% and the incidence is higher in Asians than Europeans. Efforts should be made for the early diagnosis and treatment of CTEPH in PE patients, particularly for high-risk population.

Cardiopulmonary exercise testing and pulmonary function testing for predicting the severity of CTEPH

Background

Cardiopulmonary exercise testing (CPET) and pulmonary function testing (PFT) are noninvasive methods to evaluate the respiratory and circulatory systems. This research aims to evaluate and monitor chronic thromboembolic pulmonary hypertension (CTEPH) noninvasively and effectively by these two methods. Moreover, the research assesses the predictive value of CPET and PFT parameters for severe CTEPH.

Methods

We used data from 86 patients with CTEPH (55 for test set, and 31 for validation set) at the Shanghai Pulmonary Hospital Affiliated to Tongji University. The clinical, PFT and CPET data of CTEPH patients of different severity classified according to pulmonary artery pressure (PAP) (mm Hg) were collected and compared. Logistic regression analysis was performed to appraise the predictive value of each PFT and CPET parameter for severe CTEPH. The performance of CPET parameters for predicting severe CTEPH was determined by receiver operating characteristic (ROC) curves and calibration curves.

Results

Data showed that minute ventilation at anaerobic threshold (VE @ AT) (L/min) and oxygen uptake at peak (VO₂ @ peak) (mL/kg/min) were independent predictors for severe CTEPH classified according to PAP (mm Hg). Additionally, the efficacy of VE @ AT (L/min) and VO₂ @ peak (mL/kg/min) in identifying severe CTEPH was found to be moderate with the area under ROC curve (AUC) of 0.769 and 0.740, respectively. Furthermore, the combination of VE @ AT (L/min) and VO₂ @ peak (mL/kg/min) had a moderate utility value in identifying severe CTEPH with the AUC of 0.843.

Conclusion

Our research suggests that CPET and PFT can noninvasively and effectively evaluate, monitor and predict the severity of CTEPH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01668-3.

Chronic Thromboembolic Pulmonary Hypertension Mimicking Acute Pulmonary Embolism: A Case Report

Patient: Female, 68-year-old

Final Diagnosis: Chronic thromboembolic pulmonary hypertension (CTEPH)

Symptoms: Dsypnea

Medication:—

Clinical Procedure: —

Specialty: Cardiology

Chronic thromboembolic pulmonary hypertension: the impact of advances in perioperative techniques in patient outcomes

Objectives

Pulmonary endarterectomy (PEA) is the gold standard treatment for chronic thromboembolic pulmonary hypertension (CTEPH). This study aimed at reporting outcomes of CTEPH patients undergoing PEA within 10 years, focusing on advances in anesthetic and surgical techniques.

Methods

We evaluated 102 patients who underwent PEA between January 2007 and May 2016 at the Instituto do Coração do Hospital das Clínicas da Universidade de São Paulo. Changes in techniques included longer cardiopulmonary bypass, heating, and cooling times and mean time of deep hypothermic circulatory arrest and shortened reperfusion time. Patients were stratified according to temporal changes in anesthetic and surgical techniques: group 1 (January 2007–December 2012), group 2 (January 2013–March 2015), and group 3 (April 2015–May 2016). Clinical outcomes were any occurrence of complications during hospitalization.

Results

Groups 1, 2, and 3 included 38, 35, and 29 patients, respectively. Overall, 62.8% were women (mean age, 49.1 years), and 65.7% were in New York Heart Association functional class III–IV. Postoperative complications were less frequent in group 3 than in groups 1 and 2: surgical complications (10.3% vs. 34.2% vs. 31.4%, p=0.035), bleeding (10.3% vs. 31.5% vs. 25.7%, p=0.047), and stroke (0 vs. 13.2% vs. 0, p=0.01). Between 3 and 6 months post-discharge, 85% were in NYHA class I–II.

Conclusion

Improvements in anesthetic and surgical procedures were associated with better outcomes in CTEPH patients undergoing PEA during the 10-year period.

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.

WNT5B promotes vascular smooth muscle cell dedifferentiation via mitochondrial dynamics regulation in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by proliferative vascular remodeling. Abnormal vascular smooth muscle cell (VSMC) phenotype switching is crucial to this process, highlighting the need for VSMC metabolic changes to cover cellular energy demand in CTEPH. We report that elevated Wnt family member 5B (WNT5B) expression is associated with vascular remodeling and promotes VSMC phenotype switching via mitochondrial dynamics regulation in CTEPH. Using primary culture of pulmonary artery smooth muscle cells, we show that high WNT5B expression activates VSMC proliferation and migration and results in mitochondrial fission via noncanonical Wnt signaling in CTEPH. Abnormal VSMC proliferation and migration were abolished by mitochondrial division inhibitor 1, an inhibitor of mitochondrial fission. Secreted frizzled-related protein 2, a soluble scavenger of Wnt signaling, attenuates VSMC proliferation and migration by accelerating mitochondrial fusion. These findings indicate that WNT5B is an essential regulator of mitochondrial dynamics, contributing to VSMC phenotype switching in CTEPH.

Selective Segmental Pulmonary Angiography: Anatomical, Technical and Safety Aspects of a Must-Learn Technique in Times of Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension

With the advent of balloon pulmonary angioplasty (BPA) for non-surgical chronic thromboembolic pulmonary hypertension (CTEPH) patients, there is renewed interest in the pulmonary angiography technique. This technique is still the standard imaging modality to confirm CTEPH, which, in addition, helps to determine the most appropriate treatment. Furthermore, learning this technique fulfills two main purposes: to identify BPA candidates and to provide the operator with the catheter handling needed to perform BPA. Operators interested in performing BPA must learn not only the pulmonary arteries’ anatomy, but also which are the best angiographic projections and the most suitable catheters to canalize and display each segmental branch. Unfortunately, this information is scarce in the literature. With this goal, learning the diagnostic pulmonary angiography technique can be a first step on the way to perform BPA. Although there are descriptions on how to perform a pulmonary angiography with balloon-tipped catheters and the digital subtraction technique, this technique does not provide operators with the catheter knowledge and manual skill needed to cannulate each segmental branch. In contrast, learning the conventional selective segmental pulmonary angiography (SSPA) technique provides the operator with this knowledge and skills. In this review, based on the experience of the authors, we describe the pulmonary arteries’ anatomy and detail the practical aspects of the SSPA procedure, with the aim of providing operators with the anatomical and technical knowledge needed to perform BPA. We also summarize the contemporary complications of SSPA in CTEPH patients at a reference center.

Peripheral Arterial Stiffness in Acute Pulmonary Embolism and Pulmonary Hypertension at Short-Term Follow-Up

Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe and under-recognized complication of acute pulmonary embolism (PE). Forty consecutive patients with acute PE (Group 1), predominantly female (22, 55%) with a mean age of 69 ± 15 years, were matched for demographic data with 40 healthy subjects (Group 2), 40 systemic hypertension patients (Group 3) and 45 prevalent idiopathic pulmonary arterial hypertension (IPAH) patients (Group 4). The baseline evaluation included physical examination, NYHA/WHO functional class, right heart catheterization (RHC) limited to IPAH patients, echocardiographic assessment and systemic arterial stiffness measurement by cardio-ankle vascular index (CAVI). Patients with PE underwent an echocardiographic evaluation within 1 month from hospital discharge (median 27 days; IQR 21–30) to assess the echo-derived probability of PH. The CAVI values were significantly higher in the PE and IPAH groups compared with the others (Group 1 vs. Group 2, p < 0.001; Group 1 vs. Group 3, p < 0.001; Group 1 vs. Group 4, p = ns; Group 4 vs. Group 2, p < 0.001; Group 4 vs. Group 3, p < 0.001; Group 2 vs. Group 3, p = ns). The predicted probability of echocardiography-derived high-risk criteria of PH increases for any unit increase of CAVI (OR 9.0; C.I.3.9–20.5; p = 0.0001). The PE patients with CAVI ≥ 9.0 at the time of hospital discharge presented an increased probability of PH. This study highlights a possible positive predictive role of CAVI as an early marker for the development of CTEPH.

Frequency of computed tomography abnormalities in patients with chronic thromboembolic pulmonary hypertension: a comparative study between lung perfusion scan and computed tomography pulmonary angiography

Introduction

Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the leading causes of pulmonary hypertension. Diagnosis of CTEPH can be established using various imaging techniques, including ventilation-perfusion scintigraphy (VQ) and multidetector computed tomography pulmonary angiography (CTPA). The aim of this study was to determine the frequency of direct pulmonary vascular, parenchymal lung, and cardiac abnormalities on CTPA in patients with CTEPH and to compare the diagnostic accuracy of both VQ scan CTPA in detecting CTEPH.

Methods

We retrospectively included 54 patients who had been referred for pulmonary hypertension service (20 males, 34 females). All patients had VQ scan and CTPA within 15 days and underwent pulmonary artery endarterectomy (PEA) thereafter. VQ scans were reported according to modified PIOPED (Prospective Investigation of Pulmonary Embolism Diagnosis) criteria. CTPA was considered as diagnostic for CTEPH if it showed presence of thrombus, webs, stenosis, or perfusion lung abnormalities.

Results

The mean age of the study population was 41±10 years. The mean pulmonary artery pressure was 53±13 mmHg. Fifty-three out of 54 patients in the study population had high probability VQ scan and one patient had intermediate probability. CTPA was suggestive of CTEPH in all patients. The most frequent CTPA findings in the central pulmonary arteries and peripheral arteries were presence of thrombotic materials, abnormal vessel tapering and abrupt vessels-cut off (76% vs 65%, 67% vs 48%, and 48% vs 22%), respectively. The mosaic lung perfusion was present in 78% of the patients, and various cardiac morphology abnormalities were present and most common was abnormal right to left ventricle ratio (69%).

Conclusion

Our findings indicate that both VQ scan and CTPA are highly sensitive for the detection of CTEPH confirmed by PEA. Most CTEPH patients had several pulmonary vascular, parenchymal lung and cardiac abnormalities. There was no sign with 100% sensitivity on CTPA for CTEPH detection.

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.