Chronic Thromboembolic Pulmonary Hypertension

Differential effects of balloon pulmonary angioplasty on chronic thromboembolic pulmonary disease

BACKGROUND

Decreased diffusing capacity of the lungs for carbon monoxide (DLco) is associated with microvascular damage in chronic thromboembolic pulmonary hypertension (CTEPH). Balloon pulmonary angioplasty (BPA) is an effective treatment for CTEPH, but the efficacy of BPA in patients with CTEPH with low DLco remains unclear because BPA does not directly address microvascular damage. This study investigates the influence of microvasculopathy on BPA in CTEPH according to DLco.

METHODS

We retrospectively analysed data from patients with inoperable CTEPH who underwent BPA at the University of Tokyo Hospital from July 2011 to August 2023. The patients were classified into two groups based on their preprocedural DLco (normal DLco (ND) and low DLco (LD) groups), with a DLco cut-off value of 80%. We compared the patient characteristics and effectiveness of BPA between the groups.

RESULTS

Among the 75 patients, 36 were in the LD group. The LD group had a shorter 6-minute walking distance (324±91 vs 427±114 m) than the ND group but the mean pulmonary artery pressure (mPAP) was similar (38.9±7.3 vs 41.1±9.2 mm Hg) before BPA. BPA improved the haemodynamic status and exercise tolerance in both groups. The LD group exhibited a higher mPAP (25.1±7.4 vs 21.5±5.6 mm Hg) and required more sessions of BPA (median 6 vs 4). Based on the analysis of covariance adjusted for baseline values, low DLco significantly correlated with mPAP (sβ=-0.304, 95% CI -7.015 to -1.132, p=0.007) and pulmonary vascular resistance (sβ=-0.324, 95% CI -141.0 to -29.81, p=0.003).

CONCLUSIONS

BPA was associated with an improvement in the haemodynamic status and exercise tolerance in patients with CTEPH even with low DLco. However, low DLco may attenuate the effect of BPA on mPAP and pulmonary vascular resistance and require more treatment sessions.

Development and web deployment of prediction model for pulmonary arterial pressure in chronic thromboembolic pulmonary hypertension using machine learning

BACKGROUND AND PURPOSE

Mean pulmonary artery pressure (mPAP) is a key index for chronic thromboembolic pulmonary hypertension (CTEPH). Using machine learning, we attempted to construct an accurate prediction model for mPAP in patients with CTEPH.

METHODS

A total of 136 patients diagnosed with CTEPH were included, for whom mPAP was measured. The following patient data were used as explanatory variables in the model: basic patient information (age and sex), blood tests (brain natriuretic peptide (BNP)), echocardiography (tricuspid valve pressure gradient (TRPG)), and chest radiography (cardiothoracic ratio (CTR), right second arc ratio, and presence of avascular area). Seven machine learning methods including linear regression were used for the multivariable prediction models. Additionally, prediction models were constructed using the AutoML software. Among the 136 patients, 2/3 and 1/3 were used as training and validation sets, respectively. The average of R squared was obtained from 10 different data splittings of the training and validation sets.

RESULTS

The optimal machine learning model was linear regression (averaged R squared, 0.360). The optimal combination of explanatory variables with linear regression was age, BNP level, TRPG level, and CTR (averaged R squared, 0.388). The R squared of the optimal multivariable linear regression model was higher than that of the univariable linear regression model with only TRPG.

CONCLUSION

We constructed a more accurate prediction model for mPAP in patients with CTEPH than a model of TRPG only. The prediction performance of our model was improved by selecting the optimal machine learning method and combination of explanatory variables.

Pulmonary Hypertension in Adult Congenital Heart Disease-Related Heart Failure

Already a challenging condition to define, adult congenital heart disease (ACHD) -associated heart failure (HF) often incorporates specific anatomies, including intracardiac and extracardiac shunts, which require rigorous diagnostic characterization and heighten the importance of clinicians proactively considering overall hemodynamic impacts of using specific therapies. The presence of elevated pulmonary vascular resistance dramatically increases the complexity of managing patients with ACHD-HF. Total circulatory management in patients with ACHD-HF requires input from multidisciplinary care teams and thoughtful and careful utilization of medical, interventional, and surgical approaches.

Efficacy of balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension patients with pulmonary comorbidity

Background

Balloon pulmonary angioplasty (BPA) is an established treatment for inoperable chronic thromboembolic pulmonary hypertension (CTEPH), but its efficacy in CTEPH patients with a pulmonary comorbidity has not been well-studied. Here, we compared post-BPA outcomes between CTEPH patients with and without chronic pulmonary disease at baseline and analyzed predictors of BPA success.

Methods

From August 2017 to October 2022, 62 patients with inoperable CTEPH who underwent BPA were consecutively enrolled and grouped based on the presence of a pulmonary comorbidity at baseline. All patients underwent transthoracic echocardiography, pulmonary function tests, and right heart catheterization. Pre- and post-BPA data were evaluated to identify factors that influence the success of BPA.

Results

Among the 62 CTEPH patients, BPA was considered successful in 50 patients and unsuccessful in 12 patients. Responders to BPA had better exercise capacity and right heart function at baseline, but no differences in hemodynamic or respiratory function were detected between the groups. In CTEPH patients with chronic pulmonary disease (n = 14), BPA significantly improved mean pulmonary arterial pressure, pulmonary vascular resistance and right heart function parameters. Only CTEPH patients without chronic pulmonary disease (n = 48) exhibited significant improvement in 6-minute walk distance and respiratory function. Multivariate logistic regression analysis showed that pulmonary comorbidity at baseline was independently associated with the efficacy of BPA.

Conclusions

BPA provided significantly improvements in hemodynamics and right heart function in CTEPH patients, independent of pulmonary comorbidity at baseline. However, pulmonary comorbidity can negatively impact post-BPA outcomes.

Gender differences in the incidence of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism: A meta-analysis

BACKGROUND

To explore the role of gender in the incidence of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism.

METHODS

Two researchers search the PubMed Database, Embase Database and Cochrane Library Database from their establishment to October 2022, using Endnote software for document management and RevMan5.3 software for the meta-analysis of the included literature. A total of 11 studies are selected, including 5788 acute pulmonary embolism events and 391 patients (179 males and 212 females) with chronic thromboembolic pulmonary hypertension (CTEPH) under the stated conditions. The results show that there is no statistically significant difference in the incidence of CTEPH between males and females after PE (P = .28), with combined OR of 0.89 and 95% CI 0.72-1.10.

RESULTS AND CONCLUSIONS

Gender is found to be absent as a factor in the incidence of CTEPH after acute pulmonary embolism. This may indicate that gender is not a risk factor for CTEPH and that female patients are not necessarily more likely to have a higher incidence than male patients. As such, accurate judgments should be made on the possible complications of all patients after acute pulmonary embolism, which will be conducive to early detection and intervention in the treatment of CTEPH.

Chronic Thromboembolic Pulmonary Hypertension: A Review of the Multifaceted Pathobiology

Chronic thromboembolic pulmonary disease results from the incomplete resolution of thrombi, leading to fibrotic obstructions. These vascular obstructions and additional microvasculopathy may lead to chronic thromboembolic pulmonary hypertension (CTEPH) with increased pulmonary arterial pressure and pulmonary vascular resistance, which, if left untreated, can lead to right heart failure and death. The pathobiology of CTEPH has been challenging to unravel due to its rarity, possible interference of results with anticoagulation, difficulty in selecting the most relevant study time point in relation to presentation with acute pulmonary embolism (PE), and lack of animal models. In this article, we review the most relevant multifaceted cross-talking pathogenic mechanisms and advances in understanding the pathobiology in CTEPH, as well as its challenges and future direction. There appears to be a genetic background affecting the relevant pathological pathways. This includes genetic associations with dysfibrinogenemia resulting in fibrinolysis resistance, defective angiogenesis affecting thrombus resolution, and inflammatory mediators driving chronic inflammation in CTEPH. However, these are not necessarily specific to CTEPH and some of the pathways are also described in acute PE or deep vein thrombosis. In addition, there is a complex interplay between angiogenic and inflammatory mediators driving thrombus non-resolution, endothelial dysfunction, and vascular remodeling. Furthermore, there are data to suggest that infection, the microbiome, circulating microparticles, and the plasma metabolome are contributing to the pathobiology of CTEPH.

Modulating NO-GC Pathway in Pulmonary Arterial Hypertension

The pathogenesis of complex diseases such as pulmonary arterial hypertension (PAH) is entirely rooted in changes in the expression of some vasoactive factors. These play a significant role in the onset and progression of the disease. Indeed, PAH has been associated with pathophysiologic alterations in vascular function. These are often dictated by increased oxidative stress and impaired modulation of the nitric oxide (NO) pathway. NO reduces the uncontrolled proliferation of vascular smooth muscle cells that leads to occlusion of vessels and an increase in pulmonary vascular resistances, which is the mainstay of PAH development. To date, two classes of NO-pathway modulating drugs are approved for the treatment of PAH: the phosphodiesterase-5 inhibitors (PD5i), sildenafil and tadalafil, and the soluble guanylate cyclase activator (sGC), riociguat. Both drugs provide considerable improvement in exercise capacity and pulmonary hemodynamics. PD5i are the recommended drugs for first-line PAH treatment, whereas sGCs are also the only drug approved for the treatment of resistant or inoperable chronic thromboembolic pulmonary hypertension. In this review, we will focus on the current information regarding the nitric oxide pathway and its modulation in PAH.

Prevalence and predictors of chronic thromboembolic pulmonary hypertension following severe forms of acute pulmonary embolism

INTRODUCTION AND OBJECTIVES

The true prevalence of chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism (PE) in the Portuguese population remains unknown. We aimed to assess the prevalence and predictors of CTEPH two years after a symptomatic high- (HR) or intermediate-high risk (IHR) PE.

METHODS

We conducted a retrospective cohort study of patients admitted with PE between 2014 and 2019 to a Portuguese referral center for pulmonary hypertension.

RESULTS

In this single-center registry of 969 patients admitted with PE (annual incidence of 46/100000 population), 194 had HR (5.4%) and IHR (14.7%) PE. After excluding patients who died or had no follow-up in the first three months, 129 patients were included in the analysis. The overall prevalence of suspected CTEPH by clinical assessment, Doppler echocardiography and V/Q lung scan was 6.2% (eight patients). CTEPH was confirmed by right heart catheterization in four of these (3.1%). Increased pulmonary artery systolic pressure (PASP) at admission (OR 1.12; 95% CI 1.04-1.22; p=0.005) and the presence of varicose veins in the lower limbs (OR 7.47; 95% CI 1.53-36.41; p=0.013) were predictors of CTEPH. PASP >60 mmHg at admission identified patients with CTEPH at follow-up with sensitivity and specificity of 83.3% and 76.3%, respectively. All patients diagnosed with CTEPH had at least two radiological findings suggestive of CTEPH at the index event.

CONCLUSIONS

In our cohort, the prevalence of CTEPH in survivors of severe forms of acute PE was 6.2%. PASP above 60 mmHg and supporting radiological findings on the index computed tomography scan are highly suggestive of acute-on-chronic CTEPH.

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.

New Drugs and Therapies in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension is a chronic, progressive disorder of the pulmonary vasculature with associated pulmonary and cardiac remodeling. PAH was a uniformly fatal disease until the late 1970s, but with the advent of targeted therapies, the life expectancy of patients with PAH has now considerably improved. Despite these advances, PAH inevitably remains a progressive disease with significant morbidity and mortality. Thus, there is still an unmet need for the development of new drugs and other interventional therapies for the treatment of PAH. One shortcoming of currently approved vasodilator therapies is that they do not target or reverse the underlying pathogenesis of the disease process itself. A large body of evidence has evolved in the past two decades clarifying the role of genetics, dysregulation of growth factors, inflammatory pathways, mitochondrial dysfunction, DNA damage, sex hormones, neurohormonal pathways, and iron deficiency in the pathogenesis of PAH. This review focuses on newer targets and drugs that modify these pathways as well as novel interventional therapies in PAH.

The angiogenic gene profile of pulmonary endarterectomy specimens: Initial study

Objectives

The underlying mechanisms for the development of chronic thromboembolic pulmonary hypertension and prognostic biomarkers are not clear yet. Thus, our aim is to assess and identify new biomarkers for the expression of 84 key genes linked to angiogenesis.

Methods

Patients who had levels more than 1000 dynes·sec·cm^-5 were included in the test group, and the other patients were included in the control group. Twelve specimens were taken from the patients. RT² Profiler PCR Array (Qiagen) was used to quantify the expression of the 84 key genes.

Results

Eight patients (6 male, 2 female, median age 54.4 ± 13.1 years) who underwent pulmonary endarterectomy were included. Pulmonary vascular resistance improved significantly from 811 ± 390 dyn/s/cm^-5 to 413.3 ± 144.9 dyn/s/cm^-5 (P < .005). A difference was also detected in median mean pulmonary arterial pressure, which decreased from 49.8 ± 9 mm Hg to 32.62 ± 2.50 mm Hg (P > .005) after surgery. Median length of hospital stay was 11.62 ± 2.97 days. The test group had a distinct pattern of impaired angiogenic and antiangiogenic genes. The expression levels of TGFA, TGFB1, THBS2, THBS1, TGFBR1, SERPINE1, SERPINF1, TGFB2, TIMP2, VEGFC, IFNA1, TNF, CXCL10, NOS3, IGF1, and MMP14 were downregulated in the specimens from the patients who had higher pulmonary vascular resistance values, whereas some genes, including PDGFA, showed upregulation that was statistically nonsignificant in the same group.

Conclusions

These results can lead to the development of new markers that could predict adverse outcomes of patients with CTEPH. Identification of new markers that are related to worse outcomes would enable screening patients for early diagnosis and treatment.

Utility of cardiac magnetic resonance feature tracking strain assessment in chronic thromboembolic pulmonary hypertension for prediction of REVEAL 2.0 high risk status

Chronic thromboembolic pulmonary hypertension may be cured by pulmonary endarterectomy (PEA). Thromboembolic disease distribution/PEA success primarily determines prognosis but risk scoring criteria may be adjunctive. Right ventriculoarterial (RV-PA) and ventriculoatrial (RV-right atrium [RA]) coupling may be evaluated by cardiac MRI (CMR) feature tracking deformation/strain assessment. We characterized biatrial and biventricular CMR feature tracking (FT) strain parameters following PEA and tested the ability of CMR FT to identify REVEAL 2.0 high-risk status. We undertook a retrospective single-center cross-sectional study of patients (n = 57) who underwent PEA (2015-2020). All underwent pre and postoperative catheterization and CMR. Pulmonary arterial hypertension validated risk scores were calculated. Significant postoperative improvements were observed in mean pulmonary artery pressure (mPAP) (pre-op 45 ± 11 mmHg vs. post-op 26 ± 11 mmHg; p < 0.001) and PVR however a large proportion had residual pulmonary hypertension (45%; mPAP ≥25 mmHg). PEA augmented left heart filling with left ventricular end diastolic volume index and left atrial volume index increment. Left ventricular ejection fraction was unchanged postoperatively but LV global longitudinal strain improved (pre-op median -14.2% vs. post-op -16.0%; p < 0.001). Right ventricular (RV) geometry and function also improved with reduction in RV mass. Most had uncoupled RV-PA relationships which recovered (pre-op right ventricular free wall longitudinal strain -13.2 ± 4.8%, RV stroke volume/right ventricular end systolic volume ratio 0.78 ± 0.53 vs. post-op -16.8 ± 4.2%, 1.32 ± 0.55; both p < 0.001). Postoperatively, there were six REVEAL 2.0 high-risk patients, best predicted by impaired RA strain which was superior to traditional volumetric parameters (area under the curve [AUC] 0.99 vs. RVEF AUC 0.88). CMR deformation/strain evaluation can offer insights into coupling recovery; RA strain may be an expeditious surrogate for the more laborious REVEAL 2.0 score.

Efficacy and Safety of Balloon Pulmonary Angioplasty for Patients With Chronic Thromboembolic Pulmonary Hypertension and Comorbid Chronic Obstructive Pulmonary Disease

Background Balloon pulmonary angioplasty (BPA) is a promising treatment modality for nonoperable chronic thromboembolic pulmonary hypertension (CTEPH). However, BPA for atypical CTEPH with concurrent chronic obstructive pulmonary disease (COPD) remains controversial owing to the risk of exacerbation of ventilation-perfusion mismatch. We aimed to evaluate the efficacy and safety of BPA for CTEPH with moderate or severe COPD. Methods and Results Data from 149 patients with CTEPH, who underwent BPA from March 2011 to June 2021, were retrospectively analyzed. Patients were divided based on COPD comorbidity: the COPD group (n=32, defined as forced expiratory volume in 1 second/forced vital capacity <70% and forced expiratory volume in 1 second <80% predicted) and the non-COPD group (n=101); patients with mild COPD (n=16) were excluded. Hemodynamic and respiratory parameters were compared between the groups. Hemodynamics improved similarly in both groups (reduction in pulmonary vascular resistance): -55.6±29.0% (COPD group) and -58.9±21.4% (non-COPD group); P=nonsignificant. Respiratory function and oxygenation improved in the COPD group (forced expiratory volume in 1 second/forced vital capacity [61.8±7.0% to 66.5±10.2%, P=0.02] and arterial oxygen partial pressure [60.9±10.6 mm Hg to 69.3±13.6 mm Hg, P<0.01]). Higher vital capacity (P=0.024) and higher diffusing capacity for lung carbon monoxide (P=0.028) at baseline were associated with greater improvement in oxygenation in the multivariable linear analysis. Lung injury per BPA session was 1.6% in the COPD group. Conclusions The efficacy and safety of BPA for nonoperable CTEPH in patients with comorbid COPD were similar to those in patients without COPD. Oxygenation and forced expiratory volume in 1 second/forced vital capacity improved in patients with COPD. BPA should be considered in patients with CTEPH with concurrent COPD.

Clinicopathological Correlation of Chronic Thromboembolic Pulmonary Hypertension: A Retrospective Study

The pathophysiology of chronic thromboembolic pulmonary hypertension (CTEPH) is largely unknown. Although pulmonary endarterectomy (PEA) is potentially curative, inoperable patients and persistent pulmonary hypertension (PH) following surgery remain a significant problem. In this study, we aim to describe the histopathological characteristics of CTEPH and explore the potential relationship between pulmonary arterial lesions, radiological parameters, and clinical manifestations. Endarterectomized tissues from 81 consecutive patients of CTEPH were carefully collected, sectioned, and examined by experienced pathologists. Pertinent clinical and radiological data were obtained from medical records and operative reports. Neointima, fresh/organized thrombi, recanalized regions, and atherosclerotic lesions were microscopically examined as previously described. Thrombi and atherosclerosis were dominant in UCSD classification level I PEA materials, while recanalized neo-vessels were more frequently observed in UCSD classification level III cases. Degenerative changes of the extracellular matrix were also noticed in the vascular bed. Atherosclerotic lesions were more frequently observed in cases with higher ratio of the pulmonary artery diameter to ascending aorta diameter (PA/AA) reflected by computed tomographic pulmonary arterial scanning. Furthermore, the removal of pulmonary artery complex lesions (with the combination of three to four types of lesions) by PEA was associated with lower postoperative mean pulmonary arterial pressure (mPAP) and decreased incidences of persistent PH. Our study demonstrates that the histopathological features of CTEPH are strongly linked with clinical manifestations and the postoperative outcome after PEA. These data may provide possible evidence for further studies in searching for appropriate causal factors underlying this disease.

Balloon Pulmonary Angioplasty for Takayasu Arteritis and Peripheral Pulmonary Artery Stenosis Mimicking Chronic Thromboembolic Pulmonary Hypertension

Balloon pulmonary angioplasty (BPA) has been reported to be effective and safe to an acceptable level in patients with distal-type, inoperable chronic thromboembolic pulmonary hypertension (CTEPH), resulting in improved long-term survival. However, evidenced treatment options and strategy including medical therapy of antithrombotic therapy, glucocorticoids, immunosuppressants, and pulmonary hypertension (PH)-specific therapies are scarce in patients with significant PH and right heart failure associated with Takayasu arteritis and peripheral pulmonary artery stenosis, both of which mimic CTEPH. Moreover, there has been still concern on safety and lack of established methodology in performing BPA for these conditions. In this report, we would like to review recent publications including several case reports and discuss the efficacy, safety, and suitable methods of BPA in this population.

Quantitative CT Evaluation of Small Pulmonary Vessels Has Functional and Prognostic Value in Pulmonary Hypertension

Background The in vivo relationship between peel pulmonary vessels, small pulmonary vessels, and pulmonary hypertension (PH) is not fully understood. Purpose To quantitatively assess peel pulmonary vessel volumes (PPVVs) and small pulmonary vessel volumes (SPVVs) as estimated from CT pulmonary angiography (CTPA) in different subtypes of PH compared with controls, their relationship to pulmonary function and right heart catheter metrics, and their prognostic value. Materials and Methods In this retrospective single-center study performed from January 2008 to February 2018, quantitative CTPA analysis of total SPVV (TSPVV) (0.4- to 2-mm vessel diameter) and PPVV (within 15, 30, and 45 mm from the lung surface) was performed. Results A total of 1823 patients (mean age, 69 years ± 13 [SD]; 1192 women [65%]) were retrospectively analyzed; 1593 patients with PH (mean pulmonary arterial pressure [mPAP], 43 mmHg ± 13 [SD]) were compared with 230 patient controls (mPAP, 19 mm Hg ± 3). The mean vessel volumes in pulmonary peels at 15-, 30-, and 45-mm depths were higher in pulmonary arterial hypertension (PAH) and PH secondary to lung disease compared with chronic thromboembolic PH (45-mm peel, mean difference: 6.4 mL [95% CI: 1, 11] [P < .001] vs 6.8 mL [95% CI: 1, 12] [P = .01]). Mean small vessel volumes at a diameter of less than 2 mm were lower in PAH and PH associated with left heart disease compared with controls (1.6-mm vessels, mean difference: -4.3 mL [95% CI: -8, -0.1] [P = .03] vs -6.8 mL [95% CI: -11, -2] [P < .001]). In patients with PH, the most significant positive correlation was noted with forced vital capacity percentage predicted (r = 0.30-0.40 [all P < .001] for TSPVVs and r = 0.21-0.25 [all P < .001] for PPVVs). Conclusion The volume of pulmonary small vessels is reduced in pulmonary arterial hypertension and pulmonary hypertension (PH) associated with left heart disease, with similar volume of peel vessels compared with controls. For chronic thromboembolic PH, the volume of peel vessels is reduced. In PH, small pulmonary vessel volume is associated with pulmonary function tests. Clinical trial registration no. NCT02565030 Published under a CC BY 4.0 license Online supplemental material is available for this article.

Evaluating cardiopulmonary function following acute pulmonary embolism

INTRODUCTION

Pulmonary embolism is a common cause of cardiopulmonary mortality and morbidity worldwide. Survivors of acute pulmonary embolism may experience dyspnea, report reduced exercise capacity, or develop overt pulmonary hypertension. Clinicians must be alert for these phenomena and appreciate the modalities and investigations available for evaluation.

AREAS COVERED

In this review, the current understanding of available contemporary imaging and physiologic modalities is discussed, based on available literature and professional society guidelines. The purpose of the review is to provide clinicians with an overview of these modalities, their strengths and disadvantages, and how and when these investigations can support the clinical work-up of patients post-pulmonary embolism.

EXPERT OPINION

Echocardiography is a first test in symptomatic patients post-pulmonary embolism, with ventilation/perfusion scanning vital to determination of whether there is chronic residual emboli. The role of computed tomography and magnetic resonance in assessing the pulmonary arterial tree in post-pulmonary embolism patients is evolving. Functional testing, in particular cardiopulmonary exercise testing, is emerging as an important modality to quantify and determine cause of functional limitation. It is possible that future investigations of the post-pulmonary embolism recovery period will better inform treatment decisions for acute pulmonary embolism patients.

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.

The Clinical Problem of Pelvic Venous Disorders

Pelvic venous disorders are inter-related pathologic conditions caused by reflux and obstruction in the pelvic veins. It can present a spectrum of clinical features based on the route of transmission of venous hypertension to either distal or caudal venous reservoirs. Imaging can help to visualize pelvic vascular and visceral structures to rule out other gynecologic, gastrointestinal, and urologic diseases. Endovascular treatment, owing to its low invasive nature and high success rate, has become the mainstay in the management of pelvic venous disorders. This article reviews the pathophysiology, clinical presentations, and diagnostic and therapeutic approaches to pelvic venous disorders.

Increased Morbidity With Diagnosis and Treatment of Pulmonary Embolism After Total Joint Arthroplasty: A Matched Control Analysis of 30,000 Patients

BACKGROUND

Currently, the risks associated with the diagnosis of pulmonary embolism (PE) and subsequent treatment are not well known. The purpose of our study is to quantify the specific in-hospital complications and resource utilization of patients with PE following total joint arthroplasty when compared to a matched cohort.

METHODS

The Nationwide Inpatient Sample database was used to identify patients undergoing primary hip and knee arthroplasty from January 1993 to December 2008. PE was determined using International Classification of Diseases, Ninth Revision, Clinical Modification codes. In-hospital complications, costs, and length of stay for patients with PE were compared to patients without PE, matched on the basis of age, gender, procedure (total hip arthroplasty vs total knee arthroplasty), year of surgery, morbid obesity, and all 28 comorbid-defined elements of the Elixhauser Comorbidity Index.

RESULTS

Of 8,634,038 procedures, 30,281 (0.4%) patients had a PE after total joint arthroplasty. In total, 29,917 (98%) were matched one-to-one with patients without PE. Patients with PE had a substantially higher risk of all postoperative in-hospital complications: deep vein thrombosis (odds ratio [OR] 17), peripheral vascular (OR 34), hematoma (OR 3.7), and gastrointestinal bleeding (OR 7.0) (all P < .001). Mortality was significantly higher in patients with PE compared to patients without PE (3.4% vs 0.1%, OR 30), along with total hospital costs, lengths of stay, and rates of discharge to rehabilitation facilities.

CONCLUSION

After controlling for comorbidities patients with PE have a significantly higher risk for complications including in-hospital mortality and higher hospital costs when compared to patient without PE.

Balloon Pulmonary Angioplasty in Patients with Chronic Thromboembolic Pulmonary Hypertension in Greece: Data from the Hellenic Pulmonary Hypertension Registry

Balloon pulmonary angioplasty (BPA) is a novel and promising treatment option for patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are ineligible for pulmonary endarterectomy (PEA) and for those with persistent or recurrent pulmonary hypertension after PEA. We present the results of BPA procedures in CTEPH patients included in the Greek Pulmonary Hypertension Registry, evaluating the real-life efficacy and safety. We analyzed data from 180 BPA procedures (2−17/patient, mean 8 ± 4/patient, 1248 dilated vessels, 0−18/session). Significant improvements were observed in mean pulmonary arterial pressure (a reduction by 44%, p < 0.001), pulmonary vascular resistance (reduction by 60%, p < 0.001), and NT-proBNP (decrease by >70%, p: 0.003), while cardiac index improved modestly (9% increase, p = 0.143). We had 37 BPA-related non-fatal complications (20.6% in all interventions), predominantly including hemoptysis. Overall survival was 91%, 75% and 62% at 3, 4 and 5 years, respectively. Therefore, BPA may be a promising therapeutic option in patients with CTEPH in Greece.

When right ventricular pressure meets volume: the impact of arrival time of reflected waves on right ventricle load in pulmonary arterial hypertension

Abstract

Right ventricular (RV) wall tension in pulmonary arterial hypertension (PAH) is determined not only by pressure, but also by RV volume. A larger volume at a given pressure generates more wall tension. Return of reflected waves early after the onset of contraction, when RV volume is larger, may augment RV load. We aimed to elucidate: (1) the distribution of arrival times of peak reflected waves in treatment‐naïve PAH patients; (2) the relationship between time of arrival of reflected waves and RV morphology; and (3) the effect of PAH treatment on the arrival time of reflected waves. Wave separation analysis was conducted in 68 treatment‐naïve PAH patients. In the treatment‐naïve condition, 54% of patients had mid‐systolic return of reflected waves (defined as 34–66% of systole). Despite similar pulmonary vascular resistance (PVR), patients with mid‐systolic return had more pronounced RV hypertrophy compared to those with late‐systolic or diastolic return (RV mass/body surface area; mid‐systolic return 54.6 ± 12.6 g m^–2, late‐systolic return 44.4 ± 10.1 g m^–2, diastolic return 42.8 ± 13.1 g m^–2). Out of 68 patients, 43 patients were further examined after initial treatment. At follow‐up, the stiffness of the proximal arteries, given as characteristic impedance, decreased from 0.12 to 0.08 mmHg s mL^–1. Wave speed was attenuated from 13.3 to 9.1 m s^–1, and the return of reflected waves was delayed from 64% to 71% of systole. In conclusion, reflected waves arrive at variable times in PAH. Early return of reflected waves was associated with more RV hypertrophy. PAH treatment not only decreased PVR, but also delayed the timing of reflected waves.

Key points

Right ventricular (RV) wall tension in pulmonary arterial hypertension (PAH) is determined not only by pressure, but also by RV volume. Larger volume at a given pressure causes larger RV wall tension.

Early return of reflected waves adds RV pressure in early systole, when RV volume is relatively large. Thus, early return of reflected waves may increase RV wall tension. Wave reflection can provide a description of RV load.

In PAH, reflected waves arrive back at variable times. In over half of PAH patients, the RV is exposed to mid‐systolic return of reflected waves. Mid‐systolic return of reflected waves is related to RV hypertrophy.

PAH treatment acts favourably on the RV not only by reducing resistance, but also by delaying the return of reflected waves.

Arrival timing of reflected waves is an important parameter for understanding the relationship between RV load and its function in PAH.

Pulmonary thromboendarterectomy in chronic thromboembolic pulmonary hypertension: the Spanish experience

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) can be cured by pulmonary endarterectomy (PEA). It is considered the best and only curable treatment option for patients with accessible lesions evaluated as optimal candidates. We describe the experience of the two reference centers in Spain, in order to reinforce the need for referring CTEPH patients to a specialized center to be assessed by a Multidisciplinary Expert Team.

METHODS

We included a population of 338 patients who met the definition for CTEPH and underwent PEA between January 2007 and December 2019. The surgery was indicated in almost 60% of patients assessed. Demographic, anthropometric, hemodynamic and echocardiographic features are listed for PEA patients. Immediate and one-year postoperative outcomes as well as overall mortality were analyzed.

RESULTS

Mean age was 53.5±15.0 years, 53.8% were men; a total of 68.5% were in WHO functional class III-IV; and most of them were in a preoperative hemodynamic condition: mean pulmonary arterial pressure (mPAP) was 46.5±13.1 mmHg and mean pulmonary vascular resistance (PVR) was 764.5±392.8 dyn·s·cm-5. PEA surgery was performed with cardiopulmonary bypass (CBP) and circulatory arrest, with very few complications [including neurological, postoperative reperfusion edema, extracorporeal membrane oxygenation (ECMO) implant and cardiac failure] and optimal postoperative results, where exercise capacity increased and mPAP and PVR values decreased significantly. Presence of persistent pulmonary hypertension (PH) at the six-month right heart catheterization was evaluated. A 3.3% perioperative mortality was achieved. Overall, one-, three- and five-year survival rates were analyzed by Kaplan-Meier's method (94.8%, 93.3% and 90.5% respectively), as well as for residual PH patients. Mortality risk factors were assessed.

CONCLUSIONS

Outstanding PEA results were seen in the immediate, one-year and long-term outcomes. The incidence of complications, including in-hospital mortality and long-term mortality were also below European rates.

Initiating a Chronic Thromboembolic Pulmonary Hypertension and Pulmonary Endarterectomy Program Based on a Single Center Experience in Lebanon

Purpose

In 2018, the American University of Beirut Medical Center established the first multidisciplinary Chronic Thromboembolic Pulmonary Hypertension and Pulmonary Endarterectomy program in Lebanon. The study describes the challenges faced in establishing the program and in improving patient referral, evaluation, and perioperative care.

Methods

The program establishment including the preparation phase, clinical evaluation, and team education is discussed. The implementation of the flow of patients referred to the program was established. Education regarding diagnosis and referral were provided to physicians in the community. The initial experience is described in a retrospective analysis of 4 consecutive patients who were diagnosed with CTEPH and underwent PEA.

Results

Four patients were diagnosed with CTEPH had PEA performed. The mean age of patients was 64 years. The average CPB and total circulatory arrest times were 244 and 23.9 minutes per side, respectively. No mortalities were encountered perio-operatively. All patients reported significant improvement in functional capacity from NYHA III and IV to a NYHA class of I with an average PASP decrease of 59.5 ± 19.7 mmHg and mPAP drop by 30.2 ± 16.3 mmHg.

Conclusion

The launch of the first CTEPH and PEA program in Lebanon, with a clear framework, coupled with good surgical outcomes is very encouraging. The program offers a curative solution for CTEPH patients in the region. A clear referral process and an increase in disease and treatment awareness in the community are crucial to the future success of the program, offering a definitive treatment, and avoiding delays to surgery.

The Roles of S100A4 and the EGF/EGFR Signaling Axis in Pulmonary Hypertension with Right Ventricular Hypertrophy

Pulmonary hypertension (PH) is characterized by increased pulmonary arterial pressure caused by the accumulation of mesenchymal-like cells in the pulmonary vasculature. PH can lead to right ventricular hypertrophy (RVH) and, ultimately, heart failure and death. In PH etiology, endothelial-to-mesenchymal transition (EndMT) has emerged as a critical process governing the conversion of endothelial cells into mesenchymal cells, and S100A4, EGF, and EGFR are implicated in EndMT. However, a potential role of S100A4, EGF, and EGFR in PH has to date not been elucidated. We therefore quantified S100A4, EGF, and EGFR in patients suffering from chronic thromboembolic pulmonary hypertension (CTEPH) and idiopathic pulmonary arterial hypertension (iPAH). To determine specificity for unilateral heart disease, the EndMT biomarker signature was further compared between PH patients presenting with RVH and patients suffering from aortic valve stenosis (AVS) with left ventricular hypertrophy. Reduced S100A4 concentrations were found in CTEPH and iPAH patients with RVH. Systemic EGF was increased in CTEPH but not in iPAH, while AVS patients displayed slightly diminished EGF levels. EGFR was downregulated in all patient groups when compared to healthy controls. Longitudinal data analysis revealed no effect of surgical therapies on EndMT markers. Pulmonary thrombo-endarterectomized samples were devoid of S100A4, while S100A4 tissue expression positively correlated with higher grades of Heath–Edwards histopathological lesions of iPAH-derived lung tissue. Histologically, EGFR was not detectable in CTEPH lungs or in iPAH lesions. Together, our data suggest an intricate role for S100A4 and EGF/EGFR in PH with right heart pathology.

CMR Measures of Left Atrial Volume Index and Right Ventricular Function Have Prognostic Value in Chronic Thromboembolic Pulmonary Hypertension

Providing prognostic information is important when counseling patients and planning treatment strategies in chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this study was to assess the prognostic value of gold standard imaging of cardiac structure and function using cardiac magnetic resonance imaging (CMR) in CTEPH. Consecutive treatment-naive patients with CTEPH who underwent right heart catheterization and CMR between 2011 and 2017 were identified from the ASPIRE (Assessing-the-Specturm-of-Pulmonary-hypertensIon-at-a-REferral-center) registry. CMR metrics were corrected for age and sex where appropriate. Univariate and multivariate regression models were generated to assess the prognostic ability of CMR metrics in CTEPH. Three hundred and seventy-five patients (mean+/-standard deviation: age 64+/-14 years, 49% female) were identified and 181 (48%) had pulmonary endarterectomy (PEA). For all patients with CTEPH, left-ventricular-stroke-volume-index-%predicted (LVSVI%predicted) (p = 0.040), left-atrial-volume-index (LAVI) (p = 0.030), the presence of comorbidities, incremental shuttle walking test distance (ISWD), mixed venous oxygen saturation and undergoing PEA were independent predictors of mortality at multivariate analysis. In patients undergoing PEA, LAVI (p < 0.010), ISWD and comorbidities and in patients not undergoing surgery, right-ventricular-ejection-fraction-%predicted (RVEF%pred) (p = 0.040), age and ISWD were independent predictors of mortality. CMR metrics reflecting cardiac function and left heart disease have prognostic value in CTEPH. In those undergoing PEA, LAVI predicts outcome whereas in patients not undergoing PEA RVEF%pred predicts outcome. This study highlights the prognostic value of imaging cardiac structure and function in CTEPH and the importance of considering left heart disease in patients considered for PEA.

Prevalence of Mental Disorders in Patients With Chronic Thromboembolic Pulmonary Hypertension

OBJECTIVE

Pulmonary hypertension (PH) is a chronic and progressive pulmonary vascular disease resulting in symptoms such as shortness of breath and fatigue and leading to death from right heart failure if not adequately treated. Chronic thromboembolic pulmonary hypertension (CTEPH) is a subgroup of PH characterized by obstruction or occlusion of pulmonary arteries by post-embolic fibrotic material. To date, few studies examined symptoms of depression and anxiety in patients with CTEPH, showing depression levels as high as 37.5%. However, none of the former studies used structured expert interviews.

METHODS

Mental disorders were diagnosed using the Structured Clinical Interview for DSM-5 (SCID). The prevalence of mental disorders in patients with CTEPH were compared to the prevalence in patients with pulmonary arterial hypertension (PAH) and the general German population. Quality of life (QoL) was measured with World Health Organization (WHO) Quality of Life questionnaire (short form). Factors associated with QoL were analyzed with linear regression and the diagnostic value of the Hospital Anxiety and Depression Scale (HADS) was evaluated using receiver operating characteristics (ROC) curve analysis.

RESULTS

Hundred and seven patients with CTEPH were included. Almost one-third of the patients (31.8%) had current psychological disorders. Panic disorder (8.4%), specific phobia (8.4%), and major depressive disorder (6.5%) were the most prevalent mental illnesses. The prevalence of panic disorders was higher in CTEPH compared to the German population while major depressive disorder was fewer in CTEPH compared to PAH. The presence of mental disorders had a major impact on QoL. Hospital Anxiety and Depression Scale discriminated depression and panic disorder reliably.

CONCLUSION

Mental disorders are common in patients with CTEPH and associated with an impaired QoL. The HADS may be a useful screening tool for panic and depression disorders in patients with CTEPH. Further research on therapeutic strategies targeting mental disorders in patients with CTEPH is needed.

Incidence and predictors of chronic thromboembolic pulmonary hypertension following acute pulmonary embolism: An echocardiography guided approach

There is significant variability in the worldwide epidemiology of chronic thromboembolic pulmonary hypertension (CTEPH). We thereby aim to determine the incidence and predictors of CTEPH, following an episode of acute pulmonary embolism (PE), using non-invasive modalities. Patients with acute PE were prospectively followed-up and after receiving at least 3 months of effective anticoagulation, persistently symptomatic patients with echocardiographic evidence of persistent pulmonary hypertension, were investigated further for CTEPH. Incidence of CTEPH was 8.19%. Delayed presentation, higher pulmonary artery pressures at presentation and discharge, and greater thrombotic burden were significant predictors for the development of CTEPH following acute PE.

Interventricular septal curvature as an additional echocardiographic parameter for evaluating chronic thromboembolic pulmonary hypertension: a single-center retrospective study

BACKGROUND

Noninvasive estimation of the actual systolic pulmonary artery pressure measured via right-sided heart catheterization (sPAP_RHC) is vital for the management of pulmonary hypertension, including chronic thromboembolic pulmonary hypertension (CTEPH). Evaluation related to the interventricular septum (IVS) is generally performed with only visual assessment and has been rarely assessed quantitatively in the field of echocardiography. Thus, this study aimed to investigate the utility of echocardiographic IVS curvature to estimate sPAP_RHC in patients with CTEPH.

METHODS

Medical records of 72 patients with CTEPH were studied retrospectively. We estimated sPAP_RHC using echocardiographic IVS curvature (esPAP_curv) and left ventricular eccentricity index (esPAP_LVEI), and compared their ability to predict sPAP_RHC with estimated sPAP_RHC using tricuspid regurgitant pressure gradient (esPAP_TRPG).

RESULTS

IVS curvature and LVEI were significantly correlated with sPAP_RHC (r = - 0.52 and r = 0.49, respectively). Moreover, the IVS curvature was effective in estimating the sPAP_RHC of patients with trivial tricuspid regurgitation (r = - 0.56) and in determining patients with sPAP_RHC ≥ 70 mmHg with higher sensitivity (77.0%) compared to those with esPAP_TRPG and esPAP_LVEI.

CONCLUSION

Our results indicate that the echocardiographic IVS curvature could be a useful additional tool for estimating sPAP_RHC in CTEPH patients for whom accurate estimation of sPAP_RHC using tricuspid regurgitant pressure gradient is challenging.

Surgical results of chronic thromboembolic pulmonary endarterectomy in our recently developed program

Background

In this case series, we aimed to present our diagnostic workup, surgical management, and results of the patients who underwent pulmonary endarterectomy.

Methods

In this case series, a total of 26 patients (8 males, 18 females; median age: 58 years; range, 34 to 67 years) who were evaluated by a multidisciplinary team and were diagnosed with chronic thromboembolic pulmonary hypertension who underwent pulmonary endarterectomy in our clinic between November 2015 and December 2019 were included. Pulmonary endarterectomy procedure was performed in all cases under cardiopulmonary bypass and total circulatory arrest. The results of the procedures were analyzed retrospectively.

Results

Perioperative complications were observed in seven patients (26.9%) and in-hospital mortality rate caused by perioperative complications was 15.38%. At one-year of postoperative follow-up, the mean systolic pulmonary artery pressure decreased from 78±22 mmHg to 41±20 mmHg, pulmonary vascular resistance decreased from 698±10 dyn·s·cm-5 to 235±10 dyn·s·cm-5, 6-min walk distance increased from 345±10 m to 460±10 m and, arterial oxygen saturation increased from 85±3.5% to 95±4%. New York Heart Association functional class improvement from Class III-IV to Class I-II was observed in most patients, and one-year mortality rate was 19.23%.

Conclusion

We suggest that patients diagnosed chronic thromboembolic pulmonary hypertension should be referred to cardiac surgery centers for pulmonary thromboendarterectomy, early before irreversible arteriopathy occurs.

Epidemiology and Management of Chronic Thromboembolic Pulmonary Hypertension in Greece. Real-World Data from the Hellenic Pulmonary Hypertension Registry (HOPE)

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) is a rare disease with poor prognosis if left untreated, characterized by pulmonary vascular bed obstruction due to unresolving thromboembolic material. The Hellenic pulmonary hypertension registry (HOPE) was launched in Greece in early 2015 and enrolls patients from all pulmonary hypertension subgroups in Greece. In total, 98 patients with CTEPH were enrolled from January 2015 until November 2019. Of these patients, 55.1% represented incident population, 50% were classified in the World Health Organization functional class II and 49% had a history of acute pulmonary embolism. The median values of pulmonary vascular resistance (PVR) and cardiac index were 7.4 (4.8) WU and 2.4 (1.0) L/min/m², respectively, the mean diffusing capacity for carbon monoxide was 74.8 ± 20.6%, the median 6-minute walk distance was 347 (220) meters and the median value of N Terminal-pro brain natriuretic peptide was 506.0 (1450.0) pg/mL. In total, 60.2% of the patients were under pulmonary arterial hypertension-targeted therapy at the time of enrolment; specifically, riociguat was received by 35.7% of the patients and combination therapy was the preferred strategy for 16% of the patients. In total, 74 patients were evaluated for pulmonary endarterectomy (PEA), 34 (45.9%) were assessed as operable but only 23 of those (31.1%) finally underwent PEA. The remaining 40 patients were ineligible for PEA according to the operability assessment and 13 (17.6%) of them underwent balloon pulmonary angioplasty. The age of the non-operable patients was significantly higher than the operable patients (p < 0.001), while there was no significant difference with regard to the history of coagulopathies between the operable and non-operable patients (p = 0.33).

Performance of a 3D convolutional neural network in the detection of hypoperfusion at CT pulmonary angiography in patients with chronic pulmonary embolism: a feasibility study

BACKGROUND

Chronic pulmonary embolism (CPE) is a life-threatening disease easily misdiagnosed on computed tomography. We investigated a three-dimensional convolutional neural network (CNN) algorithm for detecting hypoperfusion in CPE from computed tomography pulmonary angiography (CTPA).

METHODS

Preoperative CTPA of 25 patients with CPE and 25 without pulmonary embolism were selected. We applied a 48%-12%-40% training-validation-testing split (12 positive and 12 negative CTPA volumes for training, 3 positives and 3 negatives for validation, 10 positives and 10 negatives for testing). The median number of axial images per CTPA was 335 (min-max, 111-570). Expert manual segmentations were used as training and testing targets. The CNN output was compared to a method in which a Hounsfield unit (HU) threshold was used to detect hypoperfusion. Receiver operating characteristic area under the curve (AUC) and Matthew correlation coefficient (MCC) were calculated with their 95% confidence interval (CI).

RESULTS

The predicted segmentations of CNN showed AUC 0.87 (95% CI 0.82-0.91), those of HU-threshold method 0.79 (95% CI 0.74-0.84). The optimal global threshold values were CNN output probability ≥ 0.37 and ≤ -850 HU. Using these values, MCC was 0.46 (95% CI 0.29-0.59) for CNN and 0.35 (95% CI 0.18-0.48) for HU-threshold method (average difference in MCC in the bootstrap samples 0.11 (95% CI 0.05-0.16). A high CNN prediction probability was a strong predictor of CPE.

CONCLUSIONS

We proposed a deep learning method for detecting hypoperfusion in CPE from CTPA. This model may help evaluating disease extent and supporting treatment planning.

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

Characteristics of patients with chronic thromboembolic pulmonary hypertension according to the Russian National Registry

Aim. To assess demographic and clinical characteristics, to describe of the functional and hemodynamic status, profile of concomitant pathology, data of instrumental examination in chronic thromboembolic pulmonary hypertension (CTEPH) patients; to study the features of specific and supportive therapy according to the data of the Russian national registry. Materials and methods. From 2012 till 2020 a multicenter, prospective study in 15 regional expert centers of the Russian Federation (www.medibase.pro) included 404 newly diagnosed CTEPH patients over the age of 18 years in the Russian registry of patients with pulmonary arterial hypertension and CTEPH (NCT03707561). The diagnosis was established by European and Russian clinical guidelines for the diagnosis and management of pulmonary hypertension. 154 inoperable CTEPH patients an additional analysis of specific and supportive therapy was performed. Results. The study included 404 patients (55.6% women and 44.3% men) at the age of 58.6 [48.6; 69.3] years. Median time from symptom onset to the diagnosis verification waswas 2.4 years (from 0.1 to 2.9 years). 79.1% of patients were in the III and IV functional class (World Health Organization) at the time of diagnosis and in 44.1% with RHF (right heart failure). In assessing the profile of concomitant pathology, it was noted that CTEPH patients were more often with arterial hypertension (39.1%), erosive-ulcerative lesions of the stomach/duodenum (16.1%), atrial fibrillation (13.8%), obesity (13.1%). Distance in 6MWD (6-min walk distance) was 337.2 [250; 422] m, Borg dyspnea index scale 4.1 [3.0; 5.0] points. Hemodynamic parameters according to right heart catheterization were: Mean PAP (pulmonary arterial pressure) (51.114.04) mmHg, CO (cardiac output) (3.50.98) l/min, CI (cardiac index) (2.00.48) l/min/m2, PVR (2008528) dyns/cm5. Conclusion. According to the Russian registry, inoperable CTEPH patients had precapillary PH (pulmonary hypertension) with severe functional status, in combination with frequent concomitant pathology (arterial hypertension, erosive-ulcerative lesions of the stomach/duodenum, atrial fibrillation, obesity, right heart failure). 66% of inoperable CTEPH patients received specific drug therapy.

Exercise tolerance and quality of life in hemodynamically partially improved patients with chronic thromboembolic pulmonary hypertension treated with balloon pulmonary angioplasty

The efficacy of extensive balloon pulmonary angioplasty (BPA) beyond hemodynamic improvement in chronic thromboembolic pulmonary hypertension (CTEPH) patients has been verified. However, the relationship between extensive BPA in CTEPH patients after partial hemodynamic improvement and exercise tolerance or quality of life (QOL) remains unclear. We prospectively enrolled 22 CTEPH patients (66±10 years, females: 59%) when their mean pulmonary artery pressure initially decreased to <30 mmHg during BPA sessions. Hemodynamic and echocardiographic data, cardiopulmonary exercise testing, and QOL scores using the 36-item short form questionnaire (SF-36) were evaluated at enrollment (entry), just after the final BPA session (finish), and at the 6-month follow-up (follow-up). We analyzed whether extensive BPA improves exercise capacity and QOL scores over time. Moreover, the clinical characteristics leading to improvement were elucidated. The peak oxygen uptake (VO₂) showed significant improvement at entry, finish, and follow-up (17.3±5.5, 18.4±5.9, and 18.9±5.3 mL/kg/min, respectively; P<0.001). Regarding the QOL, the physical component summary (PCS) scores significantly improved (32±11, 38±13, and 43±13, respectively; P<0.001), but the mental component summary scores remained unchanged. Linear regression analysis revealed that age and a low peak VO2 at entry were predictors of improvement in peak VO2, while low PCS scores and low TAPSE at entry were predictors of improvement in PCS scores. In conclusion, extensive BPA led to improved exercise tolerance and physical QOL scores, even in CTEPH patients with partially improved hemodynamics.

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.

Evaluation of Asymmetric Dimethylarginine Levels in Patients With Chronic Thromboembolic Pulmonary Hypertension Undergoing Pulmonary Endarterectomy

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is a form of pulmonary embolism, and pulmonary endarterectomy (PEA) is the surgical treatment. Asymmetric dimethylarginine (ADMA) levels are increased in pulmonary hypertension. This study aimed to investigate serum ADMA levels in patients with CTEPH, the effect of PEA on ADMA, and its prognostic value in long-term mortality.

METHOD

Eighty (80) patients with CTEPH and 32 healthy controls were included. Preoperative serum ADMA levels, determined using an enzyme-linked immunosorbent assay, were compared between patients with CTEPH and controls. Of 80 patients, 64 had PEA. Pre- and 6-month postoperative serum ADMA levels, 6-minute walk distance (6MWD), and haemodynamic parameters were collected from patients undergoing PEA. Patients were followed-up for survival analysis.

RESULTS

Mean ± standard deviation serum ADMA levels were significantly higher in patients with CTEPH compared with controls (0.79±0.32 μmol/L vs 0.52±0.12 μmol/L; p=0.0001). Statistically significant differences were observed between preoperative and postoperative serum ADMA levels (0.78±0.30 μmol/L vs 0.62±0.22 μmol/L; p=0.0001), 6MWD (p=0.0001), and pulmonary vascular resistance (p=0.0001) in 60 patients who underwent and survived PEA. The decrease in serum ADMA levels and increase in 6MWD were significantly correlated (r=-0.286, p=0.027). No other correlation was found. Perioperative mortality was 6.3%, and the survival rate with a mean follow-up of 34.57±8.20 months was 93.3%. Patients with serum ADMA levels >0.8 μmol/L had a significantly lower survival rate (logrank: 5.86; p=0.015).

CONCLUSIONS

Levels of circulating ADMA might add diagnostic and prognostic information in CTEPH. Pulmonary endarterectomy is associated with an improvement in serum ADMA levels. Preoperative serum ADMA levels may be useful for estimating the outcome of PEA.

Assessment of oxygenation after balloon pulmonary angioplasty for patients with inoperable chronic thromboembolic pulmonary hypertension

BACKGROUND

The efficacy of balloon pulmonary angioplasty (BPA) in patients with inoperable chronic thromboembolic pulmonary hypertension would be promising. However, some patients showed residual dyspnea or symptoms, despite normalized hemodynamics. We aimed to clarify the clinical impact of oxygenation parameters on BPA outcome.

METHOD

Ninety-nine consecutive patients who underwent BPA from September 2011 to December 2019 were enrolled. We evaluated hemodynamics with right heart catheterization, arterial blood gas examination, New York Heart Association functional class (NYHA-FC), respiratory function tests, nocturnal oximetry, and exercise capacity (6-min walk test and cardiopulmonary exercise testing) at baseline and after BPA.

RESULT

Nearly normal hemodynamics was achieved after BPA (mean pulmonary artery pressure (PAP): 37.5 ± 10.0 to 20.6 ± 4.9 mmHg, p < 0.01). Oxygenation slightly improved (partial pressure of arterial oxygen; 61.5 ± 12.3 to 67.7 ± 12.7 mmHg, p < 0.01). Exertional desaturation remained unchanged (-8.1 ± 4.8 to -7.8 ± 5.1, p = 0.59), and this was associated with residual symptom (NYHA-FC ≥ 2) after BPA (OR 0.591, 95% CI 0.416-0.840, p = 0.003) in multivariate regression analyses. Lower vital capacity (r² = 0.03, p = 0.01), higher mean PAP (r² = 0.08, p = 0.02), and higher minute ventilation/carbon dioxide production (VE/VCO₂) slope (r² = 0.18, p < 0.01), the marker of ventilatory inefficiency, were correlated with exertional desaturation after BPA in multivariate linear analyses.

CONCLUSION

Although hemodynamics nearly normalized, oxygenation did not. Moreover, exertional desaturation remained unchanged. This might cause residual symptom after BPA. Residual pulmonary hypertension suggesting incurable arteriopathy, and higher VE/VCO₂ slope suggesting ventilation-perfusion mismatch might be related to exertional desaturation. Domiciliary oxygen therapy should be continued, if necessary.

CLINICAL IMPLICATIONS OF BODY COMPOSITION AND EXERCISE CAPACITY FOLLOWING PULMONARY ENDARTERECTOMY

BACKGROUND

Pulmonary endarterectomy (PEA) is a curative procedure for patients with chronic thromboembolic pulmonary hypertension. Body composition and exercise capacity have been associated with adverse outcomes in patients undergoing cardiothoracic surgeries, but their significance with PEA is unclear. We evaluated the association of body composition and 6-minute walk distance (6MWD) with disease severity, hospital length of stay, discharge disposition and post-operative functional recovery.

METHODS

Retrospective, single-center cohort study of patients who underwent PEA (Jan/2014-Dec/2017). Body composition (skeletal muscle mass and adiposity cross sectional area, body mass index) was quantified using thoracic computed tomography with Slice-O-Matic software. Association of body composition measures and 6MWD with clinical outcomes was evaluated using multivariable regression models.

RESULTS

127 patients (58±14 years; 42% males, Body Mass Index: 31±7 kg/m², 6MWD: 361±165 m) were included. Muscle and 6MWD were associated with disease severity measures. Of those surviving hospitalization (n=125), a greater 6MWD was associated with a shorter hospital stay (1.9 median days per 100m, p<0.001) and higher likelihood of being discharged directly home from hospital (OR: 2.1 per 100m, p= 0.004), independent of age, sex and body mass index. Those with a lower pre-operative 6MWD (per 100m) had a greater increase in their post-operative 6MWD (52m, p< 0.0001), independent of age, sex, and body mass index. Body composition measures were not associated with hospital outcomes or exercise capacity in the first-year post-operatively.

CONCLUSIONS

Exercise capacity was a more prognositc marker of PEA outcomes compared to body composition. Future research is needed to explore pre-PEA rehabilitation strategies.

Parasympathetic modulation withdrawal improves functional capacity in pulmonary arterial hypertension

In 15 pulmonary arterial hypertension patients, the relation of functional capacity to their peripheral endothelial function and sympathaovagal modulation was studied by carrying out brachial artery ultrasound and electrocardiogram spectral analysis, respectively. The functional capacity was assessed by cardiopulmonary exercise testing and six-minute walking test. The sympathovagal modulation was correlated with the predicted peak oxygen consumption (peak VO₂ %; r = 0.692, P < 0.05), peak O₂ pulse (mL/beat; r = 0.661, P < 0.05), VE, minute ventilation, VCO₂ carbon dioxide production (VE/VCO₂ slope; r=-0.806, P < 0.01) and distance walked predicted (%6MWT; r = 0.694, P < 0.05). Moreover, there were negative correlations between parasympathetic modulation with peak VO₂ (r = 0.755, P < 0.01), peak VO₂% (r=-0.727, P < 0.01) and peak O₂ pulse (r = 0.615, P < 0.05), %6MWT (r=-0.834, P < 0.01). Collectively these correlations indicate that parasympathetic withdrawal is crucial for improving functional capacity. This conclusion is supported by both positive and negative correlations of parasympathetic modulation with the functional capacity parameters. The sympathetic modulation predominance, although increases the cardiovascular risk, is probably crucial to facilitate the bronchodilation and the oxygen uptake.

Pulmonary angioplasty: A step further in the continuously changing landscape of chronic thromboembolic pulmonary hypertension management

Chronic thromboembolic pulmonary hypertension (CTEPH) is a potentially fatal and frequently undiagnosed form of pulmonary hypertension (PH), classified within group 4 by the World Health Organization (WHO). It is a type of precapillary PH, which uncommonly develops as a peculiar sequel of acute pulmonary embolism due to the partial resolution of the mechanically obstructing thrombus with a coexisting inflammatory response from pulmonary vessels. CTEPH is one of the potentially treatable forms of PH whose current standard of care is surgical pulmonary endarterectomy. Medical therapy with few drugs in non-operable disease is approved and has shown improvement in patients' hemodynamic condition and functional ability. Recently, balloon pulmonary angioplasty (BPA) has shown promising results as a treatment option for technically inoperable patients, those with unacceptable risk-to-benefit ratio and in a case of residual PH after endarterectomy. Lack of meticulous CTEPH screening programs in post-pulmonary embolism patients leading to underdiagnosis of this condition, complex operability assessment, and diversity in BPA techniques among different institutions are still the issues that need to be addressed. In this paper, we review the recent achievements in the management of non-operable CTEPH, their outcome and safety, based on available data.

Evaluation of microvasculopathy using dual-energy computed tomography in patients with chronic thromboembolic pulmonary hypertension

The existence of microvasculopathy in patients with chronic thromboembolic pulmonary hypertension has been suggested. Recently, dual-energy computed tomography has been used to produce a sensitive iodine distribution map in lung fields to indicate microvasculopathy according to poor subpleural perfusion. Our aim was to evaluate the impact of microvasculopathy on pathophysiology in chronic thromboembolic pulmonary hypertension. According to the extent of poor subpleural perfusion, ninety-three interventional treatment-naïve patients were divided into poorly perfused (n = 49) or normally perfused group (n = 44). We assessed cardiopulmonary exercise test, right heart catheterization, and dual-energy computed tomography parameters for quantitative evaluation of lung perfusion of blood volume score. Lung perfusion of blood volume score in normally perfused group was significantly inversely correlated with pulmonary vascular resistance (pulmonary vascular resistance = 6816.1 × lung perfusion of blood volume score^−0.793, R² = 0.225, p < 0.01), but lung perfusion of blood volume score in poorly perfused group was not. Poorly perfused group had higher pulmonary vascular resistance (879 ± 409 dynes-s/cm⁵ vs. 574 ± 279 dynes-s/cm⁵, p < 0.01) and lower lung perfusion of blood volume score (22.1 ± 5.4 vs. 26.4 ± 6.6, p < 0.01) and % diffusing capacity for carbon monoxide divided by the alveolar volume (59.9 ± 15.4% vs. 78.8 ± 14.2%, p < 0.01). Perfusion of blood volume score in the normally perfused group showed an inverse correlation with pulmonary vascular resistance; however, that in poorly perfused group did not. Microvasculopathy might contribute to severe hemodynamics, apart from pulmonary vascular obstruction. In our experience, more than half of treatment-naïve chronic thromboembolic pulmonary hypertension patients have microvasculopathy.

Pulmonary manifestations of antiphospholipid syndrome: a retrospective analysis of 67 patients

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by arterial and/ or venous thrombosis accompanied by persistently elevated levels of antiphospholipid antibodies (aPLs). The aim of this study is to evaluate the pulmonary manifestations of APS and compare the levels of aPLs in patients with and without pulmonary involvement. We retrospectively reviewed the files of patients with the diagnosis of APS between October 2010 and May 2017. Demographic data, clinical, radiological and laboratory findings were recorded. The study included 67 patients (56 female/11 male) with a mean age of 39 ± 13 years. Pulmonary manifestations such as parenchymal and/or vascular involvement were seen in 12 (17.9%) patients. The patients with and without pulmonary manifestations were not significantly different in terms of age (p = 0.46), comorbidities (p = 0.48) and APS duration (p = 0.66). Acute pulmonary thromboembolism (PE) was determined in 11 (16.4%), alveolar hemorrhage in 2 (3%) patients. Four patients with acute PE (36%) developed chronic thromboembolic pulmonary hypertension (CTEPH). One patient developed both CTEPH and diffuse alveolar hemorrhage after acute PE during follow up. Antiphosholipid antibody IgM was highly positive in patients with PE compared to patients without PE (p = 0.005). Other antibodies and lupus anticoagulant were not significantly different in patients with and without PE. None of the patients were deceased due to pulmonary manifestations of APS. PE was the most common pulmonary manifestation of APS. The development of CTEPH was high among APS patients. Patients with APS should be closely followed for the onset of PE and CTEPH.

Chronic Thromboembolic Pulmonary Hypertension: the Bedside

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Melo E, B. C. T. Coimbra L, Lapa MS, Acencio MMP, Freitas-Filho O, Capelozzi VL, Teixeira LR, Fernandes CJCS, Jatene FB, Laurindo FRM, Terra-Filho M. Shear stress-exposed pulmonary artery endothelial cells fail to upregulate HSP70 in chronic thromboembolic pulmonary hypertension

The pathophysiological mechanisms underlying chronic thromboembolic pulmonary hypertension (CTEPH) are still unclear. Endothelial cell (EC) remodeling is believed to contribute to this pulmonary disease triggered by thrombus and hemodynamic forces disbalance. Recently, we showed that HSP70 levels decrease by proatherogenic shear stress. Molecular chaperones play a major role in proteostasis in neurological, cancer and inflammatory/ infectious diseases. To shed light on microvascular responses in CTEPH, we characterized the expression of molecular chaperones and annexin A2, a component of the fibrinolytic system. There is no animal model that reproduces microvascular changes in CTEPH, and this fact led us to isolated endothelial cells from patients with CTEPH undergoing pulmonary endarterectomy (PEA). We exposed CTEPH-EC and control human pulmonary endothelial cells (HPAEC) to high- (15 dynes/cm2) or low- (5 dynes/cm2) shear stress. After high-magnitude shear stress HPAEC upregulated heat shock protein 70kDa (HSP70) and the HSP ER paralogs 78 and 94kDa glucose-regulated protein (GRP78 and 94), whereas CTEPH-ECs failed to exhibit this response. At static conditions, both HSP70 and HSP90 families in CTEPH-EC are decreased. Importantly, immunohistochemistry analysis showed that HSP70 expression was downregulated in vivo, and annexin A2 was upregulated. Interestingly, wound healing and angiogenesis assays revealed that HSP70 inhibition with VER-155008 further impaired CTEPH-EC migratory responses. These results implicate HSP70 as a novel master regulator of endothelial dysfunction in type 4 PH. Overall, we first show that global failure of HSP upregulation is a hallmark of CTEPH pathogenesis and propose HSP70 as a potential biomarker of this condition.

Overview of Riociguat and Its Role in the Treatment of Pulmonary Hypertension

Pulmonary hypertension (PH), which includes pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), is a progressive condition with significant morbidity and mortality due to right heart failure if left untreated. Riociguat is a soluble guanylate cyclase (sGC) stimulator and is the only treatment approved for both PAH and CTEPH. The objectives of this review are to describe the epidemiology and pathophysiology of PAH and CTEPH; synthesize the pharmacology, efficacy, safety, and utilization of riociguat; and discuss the role of the pharmacist in managing patients with these conditions. Data presented in this review is supported by peer reviewed literature, using PubMed and key words including pulmonary hypertension, pulmonary arterial hypertension, chronic thromboembolic pulmonary hypertension, and riociguat. The review draws on key studies and review articles that discuss the pathophysiology of PAH and CTEPH, as well as articles discussing the safety and efficacy of riociguat. The overall goal in the treatment of PAH and CTEPH is to improve long-term survival. Treatment planning depends on the type of PH, treatment goals, comorbidities, and risk profiles. Pharmacists serve a valuable role as part of the multidisciplinary team in the care of patients with PH, many of whom may have comorbidities that contribute to high costs and resource utilization. Riociguat is a first-in-class medication and the only approved treatment for both PAH and CTEPH. In clinical trials, riociguat has demonstrated favorable efficacy and tolerability. Riociguat is a valuable addition to the armamentarium of options for treating patients with PH.