Factors associated with diagnosis and operability of chronic thromboembolic pulmonary hypertension

Clinical and radiologic characteristics of chronic thromboembolic pulmonary hypertension patients without a history of acute venous thromboembolism

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is thought to result from incomplete resolution of vascular obstruction following acute pulmonary embolism. However, at least 25% of patients with CTEPH do not have a documented episode of acute venous thromboembolism (VTE).

OBJECTIVES

We hypothesized that patients without a VTE in their past medical history have different clinical and radiologic characteristics compared with patients with CTEPH with previous acute VTE.

METHODS

Baseline data and the history of VTE were retrospectively retrieved from the charts of all patients with CTEPH included between 2014 and 2022 in the Amsterdam University Medical Center CTEPH registry. Computed tomography pulmonary angiography, right heart catheterization, and pulmonary function tests were performed in all patients. Subsegmental disease was defined by the presence of a contrast defect in the pulmonary arterial vessels after the first arterial branch division.

RESULTS

A total of 262 patients with CTEPH were included; 47 patients (18%) did not have previous acute VTE. Baseline radiologic assessment showed that subsegmental disease was more frequent in patients without previous VTE (n = 16/43; 35%, 95% CI: 22-49) than in patients with previous VTE (n = 27/214; 13% [95% CI: 9.0-18], OR: 2.6 [95% CI: 1.2-5.7]). The patients without previous VTE were less frequently assigned to pulmonary endarterectomy than patients with acute VTE (30% [95% CI: 18-44] vs 56% [95% CI: 49-62]; OR: 0.5 [95% CI: 0.2-0.9]). Comorbidities, pulmonary function, and hemodynamics were not different.

CONCLUSION

Patients with CTEPH without previous VTE had more distally located disease on imaging than patients with CTEPH with previous VTE and were less often subjected to pulmonary endarterectomy.

Enhanced lung endothelial glycolysis is implicated in the development of severe pulmonary hypertension in type 2 diabetes

Metabolic abnormalities in pulmonary endothelial cells are implicated in pulmonary hypertension (PH) while increasing evidence shows the influence of diabetes on progressing PH. In this study, we examined the effect of type 2 diabetes on hypoxia-induced PH and investigated its molecular mechanisms using hypoxia-induced diabetic male mice. Chronic hypoxia led to a more severe PH in type 2 diabetic mice than in control mice. Next, we compared gene expression patterns in isolated pulmonary endothelial cells (MPECs) from control mice in normoxia (CN), diabetic mice in normoxia (DN), control mice exposed to hypoxia (CH), and diabetic mice exposed to hypoxia (DH). The results showed that expression levels of 27 mRNAs, out of 92 mRNAs, were significantly different among the four groups. Two glycolysis-related proteins, GAPDH and HK2, were increased in MPECs of DH mice compared with those in DN or CH mice. In addition, the levels of pyruvate and lactate (glycolysis end products) were significantly increased in MPECs of DH mice, but not in CH mice, compared with MPECs of CN mice. Augmentation of glycolysis by terazosin exacerbated hypoxia-induced PH in CH mice but not in DH mice. On the contrary, inhibiting GAPDH (a key enzyme of the glycolytic pathway) by koningic acid ameliorated hypoxia-induced PH in DH mice but had no effect in CH mice. These data suggest that enhanced glycolysis in diabetic mice is involved in severe hypoxia-induced PH, and glycolysis inhibition is a potential target to reduce the severe progression of PH in patients with diabetes.NEW & NOTEWORTHY Increasing evidence shows that diabetes exacerbates the progression of pulmonary hypertension; however, its molecular mechanisms are understudied. In this study, we revealed that augmented glycolysis in diabetic pulmonary endothelial cells is involved in the development of severe PH in diabetes. Inhibition of glycolysis could be a therapeutic strategy for treating pulmonary hypertension in patients with diabetes.

Chronic thromboembolic pulmonary hypertension treatment and sex: Systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of pulmonary embolism and a major cause of chronic pulmonary hypertension leading to right heart failure and death. While pulmonary endarterectomy is the treatment of choice, some patients might benefit from medical therapy or balloon pulmonary angioplasty. Sex differences in outcomes of these therapies are not well characterized.

MATERIAL AND METHODS

We conducted a systematic review and meta-analysis to investigate sex differences in outcomes of various therapies for CTEPH. We searched MEDLINE, PubMed, Embase, CINAHL and the Cochrane Library databases between January 1, 2010 and April 30, 2021, published in English. We pooled incidence estimates using random-effects meta-analyses. We evaluated heterogeneity using the I2 statistic. We assessed publication bias using Begg's and Egger's tests. This study is registered in PROSPERO, CRD42021268504.

RESULTS

A total of 19 studies met the eligibility criteria, but only 3 trials provided separate outcomes for women and men. Two studies evaluated the efficacy of BPA, and one study evaluated the efficacy of riociguat (129 patients). Overall, 57.3% of patients were women and 62.6% were in functional class III. Mean time of follow-up was 55.5 (SD 26.1) weeks. Women showed a significantly better response in cardiac index (mean difference [MD], 0.10L/min/m2; 95% confidence interval [CI], 0.04-0.16; I2=0%; P=0.001). Alternatively, the reduction of pulmonary vascular resistances was significantly higher for men than for women (MD, 161.17dynscm-5; 95% CI, 67.99-254.35; I2=0%; P=0.0007).

CONCLUSIONS

Women and men might show different hemodynamic responses to riociguat or BPA for CTEPH.

Hyperglycemia and Venous Thromboembolism

Patients with diabetes mellitus (DM) have chronically increased blood glucose and multiple physiologic alterations that place them at elevated risk for vascular disease. Traditionally, this vascular risk has mainly referred to chronic atherosclerosis and embolic arterial disease. Retrospective studies have suggested an increased risk of a pulmonary embolism (PE) and deep vein thrombosis (DVT), collectively termed venous thromboembolism (VTE), in patients with DM, but this association has been difficult to demonstrate with comorbidities such as obesity in meta-analysis. Clinical studies have demonstrated worse outcomes for patients with DM who suffer from VTE. In vitro studies show multiple physiologic abnormalities with chronic inflammation, endothelial dysfunction, dysfunction in the coagulation cascade, as well as other changes that drive a vicious cycle of hypercoagulability. Aggressive medical management of DM can improve vascular outcomes, and some anti-hyperglycemic therapies may modify VTE risk as well. Anticoagulation strategies are similar for patients with DM, but with some added considerations, such as high rates of comorbid renal dysfunction. More research is needed to definitively categorize DM as a risk factor for VTE and elucidate specific therapeutic strategies.

Balloon pulmonary angioplasty for proximal chronic thromboembolic pulmonary hypertension in patients ineligible for pulmonary endarterectomy

Balloon pulmonary angioplasty (BPA) to treat chronic thromboembolic pulmonary hypertension (CTEPH) is generally reserved for distal obstruction precluding pulmonary endarterectomy (PEA) but can be used in patients with proximal disease who are at high surgical risk or refuse surgery. This single-center retrospective study compared BPA efficacy in patients with proximal versus distal CTEPH. Of the 478 patients, 36 had proximal disease, follow-up was 11.6 months and mean number of BPA 6. After BPA, PVR, and mean pulmonary artery pressure decreased significantly in the proximal and distal groups (from 6.5 to 4.0 WU and 39 to 31 mmHg and from 7.6 to 3.8 WU and 44 to 31 mmHg, respectively, p < 0.001 for all comparisons). NYHA class also improved significantly in both groups, from 3 to 2, whereas the 6-min walk distance, cardiac output, and serum NT pro-BNP showed significant improvements only in the distal group. Thus, when PEA for CTEPH is technically feasible but not performed due to severe comorbidities or patient refusal, BPA can produce significant hemodynamic improvements, albeit less marked than in patients with distal disease. Better patient selection to BPA might improve outcomes in patients with proximal disease who are ineligible for PEA.

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.

Chronic thromboembolic pulmonary hypertension: realising the potential of multimodal management

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. Important advances have enabled better understanding, characterisation, and treatment of this condition. Guidelines recommending systematic follow-up after acute pulmonary embolism, and the insight that CTEPH can mimic acute pulmonary embolism on initial presentation, have led to the definition of CTEPH imaging characteristics, the introduction of artificial intelligence diagnosis pathways, and thus the prospect of easier and earlier CTEPH diagnosis. In this Series paper, we show how the understanding of CTEPH as a sequela of inflammatory thrombosis has driven successful multidisciplinary management that integrates surgical, interventional, and medical treatments. We provide imaging examples of classical major vessel targets, describe microvascular targets, define available tools, and depict an algorithm facilitating the initial treatment strategy in people with newly diagnosed CTEPH based on a multidisciplinary team discussion at a CTEPH centre. Further work is needed to optimise the use and combination of multimodal therapeutic options in CTEPH to improve long-term outcomes for patients.

[Update on Pulmonary Embolism: Guideline-Based Diagnosis and Therapy of an Exemplary Case]

Update on Pulmonary Embolism: Guideline-Based Diagnosis and Therapy of an Exemplary Case Abstract. In the evaluation of acute pulmonary embolism, a swift and focused diagnostic process is crucial and has an impact on prognosis. An initial clinical assessment is done in haemodynamically stable patients, followed by determination of D-dimer or immediate imaging by computer tomography if the clinical (pre-test) probability is high. After confirming the diagnosis of pulmonary embolism, the most appropriate anticoagulant regiment should be selected and patients should be candidate for a structured follow-up plan. The initial anticoagulant therapy regime is determined by a number of factors, including haemodynamic stability (or potential need for reperfusion treatments), demographic characteristics and comorbidities. While anticoagulation is usually recommended for the first 3-6 months, re-evaluation of therapy after acute therapy is mandatory. In addition, the possibility of chronic thrombo-embolic pulmonary hypertension (CTEPH) or a post-PE syndrome should be considered if symptoms persist after 3-6 months.

Right ventricle remodeling in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is an underdiagnosed, but potentially curable pulmonary vascular disease. The increased pulmonary vascular resistance in CTEPH is caused by unresolved proximal thrombus and secondary microvasculopathy in the pulmonary vasculature, leading to adaptive and maladaptive remodeling of the right ventricle (RV), eventual right heart failure, and death. Knowledge on the RV remodeling process in CTEPH is limited. The progression to RV failure in CTEPH is a markedly slower process. A detailed understanding of the pathophysiology and underlying mechanisms of RV remodeling may facilitate early diagnosis and the development of targeted therapy. While ultrasound, magnetic resonance imaging, right heart catheterization, and serum biomarkers have been used to assess cardiac function, the current treatment strategies reduce the afterload of the right heart, but are less effective in improving the maladaptive remodeling of the right heart. This review systematically summarizes the current knowledge on adaptive and maladaptive remodeling of the right heart in CTEPH from molecular mechanisms to clinical practice.

Brazilian Thoracic Society recommendations for the diagnosis and treatment of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious and debilitating disease caused by occlusion of the pulmonary arterial bed by hematic emboli and by the resulting fibrous material. Such occlusion increases vascular resistance and, consequently, the pressure in the region of the pulmonary artery, which is the definition of pulmonary hypertension. The increased load imposed on the right ventricle leads to its progressive dysfunction and, finally, to death. However, CTEPH has a highly significant feature that distinguishes it from other forms of pulmonary hypertension: the fact that it can be cured through treatment with pulmonary thromboendarterectomy. Therefore, the primary objective of the management of CTEPH should be the assessment of patient fitness for surgery at a referral center, given that not all patients are good candidates. For the patients who are not good candidates for pulmonary thromboendarterectomy, the viable therapeutic alternatives include pulmonary artery angioplasty and pharmacological treatment. In these recommendations, the pathophysiological bases for the onset of CTEPH, such as acute pulmonary embolism and the clinical condition of the patient, will be discussed, as will the diagnostic algorithm to be followed and the therapeutic alternatives currently available.

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.

May-Thurner Anatomy in Patients With Chronic Thromboembolic Pulmonary Hypertension: An Important Clinical Association

OBJECTIVES

The aim of this study was to investigate the incidence of May-Thurner anatomy (MTA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and identify its predictors.

BACKGROUND

MTA is an anatomical variant characterized by compression of left common iliac vein by the overlying right iliac artery. Over time, this leads to venous intimal scarring, blood flow stasis, and the development of deep vein thrombosis (DVT). DVT is a known risk factor for the development of CTEPH. The prevalence of this anatomical variation in patients with CTEPH is unknown.

METHODS

A retrospective chart review was conducted in patients referred to Temple University Hospital's cardiac catheterization laboratory for the evaluation of CTEPH between January 2016 and June 2020. Among these patients, those who underwent invasive venography were evaluated for the presence of angiographic MTA. Multivariate regression was used to identify factors associated with presence of MTA.

RESULTS

A total of 193 patients with CTEPH were referred for pulmonary angiography, of whom 148 patients underwent invasive venography. MTA was identified in 44 patients (29.7%). Factors associated with the presence of MTA were lower extremity DVT (odds ratio: 3.5; 95% confidence interval: 1.58-7.8; P = 0.002), and left lower extremity post-thrombotic syndrome (odds ratio: 2.0; 95% confidence interval: 0.98-4.1; P = 0.05). Patients with MTA were more likely to undergo pulmonary thromboendarterectomy than patients without MTA (79.5% vs 58.7%; P = 0.015).

CONCLUSIONS

MTA is very common in patients with CTEPH. History of lower extremity DVT and or left lower extremity post-thrombotic syndrome was associated with the presence of MTA.

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.

Chronic thromboembolic pulmonary hypertension: a review

Chronic thromboembolic pulmonary hypertension (CTEPH) is a unique form of pulmonary hypertension resulting from obstruction of the pulmonary artery by fibrotic thromboembolic material, usually initiated by recurrent or incomplete resolution of pulmonary embolism. This distinct form of pulmonary hypertension is classified under Group 4 of the World Health Organization classification. Further investigations are usually initiated, with transthoracic echocardiography followed by right heart catheterisation and pulmonary angiography as the gold standard. Definitive treatment is usually in the form of surgical pulmonary endarterectomy. Inoperable CTEPH is medically treated with pharmacological agents such as phosphodiesterase Type 5 inhibitors, endothelin receptor antagonists, soluble guanylate cyclase stimulators and prostacyclin. Recent developments have made balloon pulmonary angioplasty a viable option as well.

ERS statement on chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism, either symptomatic or not. The occlusion of proximal pulmonary arteries by fibrotic intravascular material, in combination with a secondary microvasculopathy of vessels <500 µm, leads to increased pulmonary vascular resistance and progressive right heart failure. The mechanism responsible for the transformation of red clots into fibrotic material remnants has not yet been elucidated. In patients with pulmonary hypertension, the diagnosis is suspected when a ventilation/perfusion lung scan shows mismatched perfusion defects, and confirmed by right heart catheterisation and vascular imaging. Today, in addition to lifelong anticoagulation, treatment modalities include surgery, angioplasty and medical treatment according to the localisation and characteristics of the lesions.This statement outlines a review of the literature and current practice concerning diagnosis and management of CTEPH. It covers the definitions, diagnosis, epidemiology, follow-up after acute pulmonary embolism, pathophysiology, treatment by pulmonary endarterectomy, balloon pulmonary angioplasty, drugs and their combination, rehabilitation and new lines of research in CTEPH.It represents the first collaboration of the European Respiratory Society, the International CTEPH Association and the European Reference Network-Lung in the pulmonary hypertension domain. The statement summarises current knowledge, but does not make formal recommendations for clinical practice.

Chronic thromboembolic pulmonary hypertension risk score evaluation and validation (CTEPH Solution): proposal of a study protocol aimed to realize a validated risk score for early diagnosis

BACKGROUND

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) is the most serious long-term complication of acute pulmonary embolism (PE) though it is the only potentially reversible form of Pulmonary Hypertension (PH). Its incidence is mainly limited to the first 2 years following the embolic event, however it is often underdiagnosed or misdiagnosed.

METHODS

This is a multicenter observational cross-sectional and prospective study. Patients with a prior diagnosis of PE will be enrolled and undergo baseline evaluation for prevalent PH detection through a clinical examination and an echocardiogram as first screening exam. All cases of intermediate-high echocardiographic probability of PH will be confirmed by right heart catheterization and then identified as CTEPH through appropriate imaging and functional examinations in order to exclude other causes of PH. A CTEPH Risk Score will be created using retrospective data from this prevalent cohort of patients and will be then validated on an incident cohort of patients with acute PE.

RESULTS

1000 retrospective and 218 prospective patients are expected to be enrolled and the study is expected to be completed by the end of 2021. Up to now 841 patients (620 retrospective and 221 prospective) have been enrolled.

CONCLUSIONS

This study is the first large prospective study for the prediction of CTEPH development in patients with PE. It aims to create a comprehensive scoring tool that includes echocardiographic data which may allow early detection of CTEPH and the application of targeted follow up screening programs in patients with PE.

Association between splenectomy and chronic thromboembolic pulmonary hypertension: a systematic review and meta-analysis

OBJECTIVE

Whether splenectomy increases the risk of chronic thromboembolic pulmonary hypertension (CTEPH) remains unclear. We conducted a systematic review and meta-analysis to explore the association between splenectomy and CTEPH.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase and Cochrane Library databases.

METHODS

Two authors independently searched and extracted the data. The Newcastle-Ottawa Scale and the Strengthening the Reporting of Observational Studies in Epidemiology guidelines were used to assess the quality of the included studies, and each quality item was graded as low risk or high risk. A random-effects model was used to calculate different effective values.

RESULTS

In total, 8 trials involving 6183 participants fulfilled the inclusion criteria. The overall pooled crude prevalence of splenectomy was 4.0% (95% CI 0.03 to 0.06, I²=71.5%, p<0.001) in patients with CTEPH. Subgroup analysis showed a statistically significant high incidence of splenectomy in patients with CTEPH (OR=2.94, 95% CI 1.62 to 5.33, I²=0.0%, p<0.001) compared with patients with pulmonary arterial hypertension. There was a significantly high incidence of splenectomy in patients with CTEPH (OR=5.59, 95% CI 2.12 to 14.74, I²=0.0%, p<0.001) compared with patients with thromboembolism disease (venous thromboembolism or pulmonary embolism).

CONCLUSION

The prevalence of splenectomy in patients with CTEPH was 4.0% and CTEPH might be associated with splenectomy. However, high-quality prospective trials are needed.

PROSPERO REGISTRATION NUMBER

CRD42020137591.

ERS International Congress, Madrid, 2019: highlights from the Pulmonary Vascular Diseases Assembly

The 2019 European Respiratory Society (ERS) International Congress, held in Madrid, Spain, had exciting sessions regarding the field of pulmonary vascular disease. The symposia related to the new ERS/European Society of Cardiology (ESC) Guidelines for the diagnosis and management of acute pulmonary embolism were well received, as were sessions on pulmonary hypertension related to lung disease, demonstrating the concept of pulmonary hypertension not being the rarity that it was previously thought to be. The use of risk stratification in relation to pulmonary arterial hypertension (PAH) was heavily featured and the scientific sessions informing the respiratory community of potential biomarkers and targets for future therapies were thought-provoking. This article discusses highlights of the 2019 pulmonary vascular disease sessions as a summary of current knowledge and practice. We have summarised the key points from the sessions pertaining to the new ERS/ESC Guidelines for the management of acute pulmonary embolism. We have also focused on prognostic factors and potential therapies in pulmonary hypertension related to interstitial lung disease. Relating to PAH, we have reviewed the symposia on risk stratification, along with the use of noninvasive measures and the sessions relating to biomarkers in PAH.

Diagnosis of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism

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

Clinical and Instrumental Characteristics of Newly Diagnosed Patients with Various Forms of Pulmonary Hypertension according to the Russian National Registry

Aim

To study demographic and clinical characteristics and to give a comparative description of the functional and hemodynamic status, profile of concomitant pathology in patients with various forms of pulmonary arterial hypertension (PAH), and chronic thromboembolic pulmonary hypertension (CTEPH) according to the Russian National Registry.

Methods

During the period from January 01, 2012, till January 01, 2019, 1105 patients aged >18 years with verified diagnosis of PAH and CTEPH, who were subsequently observed at 15 PH expert centers of the Russian Federation in the 52 provinces, are included in the Russian registry on the basis of the Federal State Budgetary Institution of Cardiology of the Ministry of Healthcare of Russia. All newly diagnosed patients (n = 727) were entered into the registry database (NCT03707561). A comparative analysis of demographic and clinical characteristics, profile of concomitant pathology, and parameters of a comprehensive examination of patients was performed.

Results

Among newly diagnosed patients, 67% had PAH and 28.3% had CTEPH. In the PAH group, 40.9% of patients had idiopathic arterial PAH (IPAH), 36.6% had PAH associated with simple congenital heart disease (PAH-CHD), 19.3% had PAH associated with systemic connective tissue disease (PAH-CTD), 1.8% had portal pulmonary hypertension (PoPH), 0.6% had PAH associated with HIV infection (PAH-HIV), 0.4% had heritable PAH (HPAH), and 0.4% had drug/toxin-induced PAH. At the time of diagnosis, PAH patients were younger than patients with CTEPH (45.2 ± 14.9; 52.6 ± 15.3 years, respectively) (p < 0.05). At the time of diagnosis, 71% PAH and 77% CTEPH patients had WHO FC III/IV. Mean (±SD) 6MWD was significantly less in CTEPH vs. the PAH group 331.3 ± 110.3 vs. 361.8 ± 135.7 m (p = 0.0006). Echo data showed a comparable sPAP between groups; CTEPH population had a more pronounced increase in the area of the right atrium (S_RA) (24 [20; 32] cm² and 19 [15; 26] cm², respectively), and a significant decrease in FAC (24.7 [22, 4; 29.0] and 29.0 [23.0; 31.0] %, respectively) as compared to the PAH group. RHC showed a comparable increase of sPAP and mPAP in PAH and CTEPH groups. 15.2% of patients with IPAH and HPAH demonstrated positive results in the acute vasoreactivity testing. CTEPH patients were more often obese and suffered from arterial hypertension and right heart failure. Deep venous thrombosis was significantly more often observed in patients with CTEPH (53%). The most common concomitant pathology was erosive-ulcerative lesion of the stomach/duodenum, less often of the esophagus (23.5% and 44.5%, respectively).

Conclusion

According to the Russian registry in patients with PAH and IPAH, the diagnosis is established at a younger age in comparison with the European registries. CTEPH patients are characterized by more severe functional status, pronounced signs of right heart failure taking into account the older age and the spectrum of comorbid pathology, which limits the possibility of surgical treatment. An increase in the number of expert centers participating in the registry is the key to improving early diagnosis of PH and optimal follow-up according to common standards in order to timely optimize therapy and reduce mortality of patients.

Chronic thromboembolic pulmonary hypertension - still evolving

Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the leading causes of severe pulmonary hypertension (PH). The disease is still underdiagnosed, and the true prevalence is unknown. CTEPH is characterized by intraluminal non-resolving thrombus organization and fibrous stenosis, or complete obliteration of pulmonary arteries, promoted by progressive remodeling of the pulmonary vasculature. One consequence of this is an increase in pulmonary vascular resistance and pressure, resulting in PH and progressive right heart failure, leading to death if left untreated.

Endovascular disobliteration by pulmonary endarterectomy (PEA) is the preferred treatment for CTEPH patients. PEA surgery is the only technique that can potentially cure CTEPH disease, especially in patients with fresh or organized thrombi of the proximal branches of pulmonary arteries. However, not all patients are eligible for PEA surgery. Recent research has provided evidence suggesting balloon pulmonary angioplasty (BPA) and targeted medical therapy as additional promising available treatments options for inoperable CTEPH and recurrent/persistent PH after PEA surgery.

Studies on BPA have shown it to improve pulmonary hemodynamics, symptoms, exercise capacity and RV function in inoperable CTEPH. Subsequently, BPA has developed into an essential component of the modern era of CTEPH treatment. Large randomized controlled trials have demonstrated varying significant improvements with targeted medical therapy in technically inoperable CTEPH patients. Thus, treatment of CTEPH requires a comprehensive multidisciplinary assessment, including an experienced PEA surgeon, PH specialist, BPA interventionist and CTEPH-trained radiologist at expert centers. In this comprehensive review, we address the latest developments in the fast-evolving field of CTEPH. These include advancements in imaging modalities and developments in operative and interventional techniques, which have widened the range of patients who may benefit from these procedures. The efficacy and safety of targeted medical therapies in CTEPH patients are also discussed. As the treatment options for CTEPH improve, hybrid management involving multiple treatments in the same patient may become a viable option in the near future.

Dyspnea in antiphospholipid syndrome: Beyond pulmonary embolism

Pulmonary embolism due to primary antiphospholipid syndrome is rarely associated with chronic thromboembolic pulmonary hypertension, and therefore according to the latest guidelines on pulmonary hypertension, routine screening is not recommended. We describe a young patient with a late diagnosis of chronic thromboembolic pulmonary hypertension in the context of pulmonary embolism, primary antiphospholipid syndrome and suboptimal anticoagulation. Of note, mild cardiopulmonary symptoms were consistently misattributed to a depressive disorder because physical examination was normal, serial Doppler echocardiography failed to show pulmonary hypertension, and all other diagnostic tests were normal. Once symptoms became severe, positive screening tests led to the correct diagnosis and surgical referral, and bilateral pulmonary endarterectomy was successfully performed. This case demonstrates the need for extra awareness in patients with antiphospholipid syndrome and pulmonary embolism.

Sex-specific differences in chronic thromboembolic pulmonary hypertension. Results from the European CTEPH registry

BACKGROUND

Women are more susceptible than men to several forms of pulmonary hypertension, but have better survival. Sparse data are available on chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS

We investigated sex-specific differences in the clinical presentation of CTEPH, performance of pulmonary endarterectomy (PEA), and survival.

RESULTS

Women constituted one-half of the study population of the European CTEPH registry (N = 679) and were characterized by a lower prevalence of some cardiovascular risk factors, including prior acute coronary syndrome, smoking habit, and chronic obstructive pulmonary disease, but more prevalent obesity, cancer, and thyroid diseases. The median age was 62 (interquartile ratio, 50-73) years in women and 63 (interquartile ratio, 53-70) in men. Women underwent PEA less often than men (54% vs 65%), especially at low-volume centers (48% vs 61%), and were exposed to fewer additional cardiac procedures, notably coronary artery bypass graft surgery (0.5% vs 9.5%). The prevalence of specific reasons for not being operated, including patient's refusal and the proportion of proximal vs distal lesions, did not differ between sexes. A total of 57 (17.0%) deaths in women and 70 (20.7%) in men were recorded over long-term follow-up. Female sex was positively associated with long-term survival (adjusted hazard ratio, 0.66; 95% confidence interval, 0.46-0.94). Short-term mortality was identical in the two groups.

CONCLUSIONS

Women with CTEPH underwent PEA less frequently than men, especially at low-volume centers. Furthermore, they had a lower prevalence of cardiovascular risk factors and were less often exposed to additional cardiac surgery procedures. Women had better long-term survival.

Treprostinil for the treatment of chronic thromboembolic pulmonary hypertension

Introduction: Parenteral treprostinil for patients with pulmonary arterial hypertension has resulted in improvement of exercise capacity, functional class, hemodynamics, and survival. Recently, a first randomized trial performed in patients with chronic thromboembolic pulmonary hypertension confirmed the efficacy of subcutaneous treprostinil in this subset of pulmonary hypertension. Areas covered: Treprostinil sodium is a prostacyclin analog produced synthetically. Drug characteristics include potent systemic and pulmonary vasodilatory effects. Local side-effects of subcutaneous treprostinil have been an obstacle for its use. However, in contrast to other prostacyclins, treprostinil has favorable features. We performed a literature survey by searching PubMed for clinical trials published in any language, investigating medicinal treatments for CTEPH. We used the search terms 'inoperable', and 'chronic thromboembolic pulmonary hypertension' with 'randomized clinical trial', and have put treprostinil for CTEPH in the contest of published literature. Expert opinion: Drugs approved for PAH have recently shown excellent efficacy in patients with non-operable CTEPH. Rather than head-to-head comparisons of drugs, combination treatments are to be expected in the near future. Furthermore, drugs will have to be tested alongside with pulmonary endarterectomy (PEA), and alongside balloon pulmonary angioplasty, a promising percutaneous mechanical treatment for CTEPH that is not suited for PEA.

Chronic thromboembolic pulmonary hypertension suspicion after pulmonary embolism in cancer patients

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe condition which should be screened in patient with persistent dyspnea after pulmonary embolism (PE). After PE, CTEPH incidence was estimated between 0.1 and 9.1% in overall patients. Although cancer is associated with an increased risk of CTEPH, CTEPH incidence is still unknown in cancer patients with PE. We aimed to estimate the frequency CTEPH-likely patients after PE, in cancer patients.

MATERIALS

We individualized cancer patients of a monocentric prospective registry including consecutive patients with symptomatic PE. The primary outcome was the frequency of "CTEPH-likely" patients defined by the European Respiratory Society (ERS) guidelines (an accelerated tricuspid regurgitation more than 2.8m/s and at least 1-2 segmental or larger-sized defects, after more than 3 months of therapeutic anticoagulation).

RESULTS

We included 129 cancer patients with PE. Colorectal cancer (19%), breast cancer (17%) and prostate cancer (15%) were the most frequent cancers. PE occurred after surgery or medical immobilization in 17% of patients, while 26% of patients had history of venous thromboembolism. During the follow-up, 2 patients (1.5%) had a clinical suspicion of CTEPH and only 1 patient with ovarian cancer (0.75% 95%CI [0.0%-2.2%]) was classified as "CTEPH-likely", 6 months after PE.

CONCLUSION

The frequency of screening for CTEPH seems negligible in PE patients with cancer. Concomitant cancer may affect the clinical suspicion of CTEPH.

[Features of clinical, functional and hemodynamics profile, medical treatment and prognosis evaluation in patients with inoperable chronic thromboembolic pulmonary hypertension and idiopathic pulmonary arterial hypertension according to the Russian registry]

AIM

to perform the complex analysis of clinical, functional, hemodynamics profile in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) compared to the idiopathic pulmonary arterial hypertension (IPAH) group at the time of diagnosis verification according to the Russian registry, and to evaluate the features of medical therapy and it's influence on prognosis in these patients.

MATERIALS AND METHODS

In the retrospective study 193 patients with IPAH and 130 patients with inoperable CTEPH older than 18 years were included. All included patients were the participants of Russian registry (www.medibase.pro) in 15 Russian expert centers during the period from 01.01.2012 to 31.12.2018 year. The diagnosis was verified according to the algorithm, reflected in the Russian guidelines on diagnosis and treatment of PH and CTEPH (2016 year). The comparison analysis of clinical, functional, hemodynamics parameters in patients with IPAH and inoperable CTEPH was made.

RESULTS

The status of 193 patients with IPAH (32 male and 162 female) and 130 patients with inoperable CTEPH - (40 male and 90 female) was analyzed during the study. The CTEPH patients were older compared to the IPAH patients: 52.2 [41.1; 60.6] and 36.5 [26.8; 36.5] years, respectively. The median period since symptom occurrence till CTEPH verification was 1.08 [0.2; 3.1] years, in IPAH patients - 2.01 [0.6; 4.2] years. More than 80% of inoperable CTEPH patients had III and IV functional class (FC) according to the World Health Organization classification at the time of diagnosis verification versus 61% of IPAH patients. According to echocardiography the level of mean pulmonary arterial pressure was comparable in two groups of PH patients. However in inoperable CTEPH patients the right atrial area was larger. The significantly higher value of mean pulmonary arterial pressure and lower value oxygen saturation of arterial blood according to the right heart catheterization were revealed. The 5-year survival in CTEPH patients, receiving initial dual combination therapy in 75% cases (in 40% - combination of riociguat and iloprost ) was 93% versus 86.5% in patients with IPAH.

CONCLUSION

It was revealed, that inoperable CTEPH patients were significantly older with severe functional and hemodynamics status at the time of diagnosis verification, although with higher level of 5-year survival compared to the IPAH patients according to the Russian registry.

Chronic thromboembolic pulmonary hypertension following long-term peripherally inserted central venous catheter use

A 36-year-old woman presented with recurrent pulmonary emboli (PE) despite oral anticoagulation. She was a type I diabetic with severe gastroparesis requiring insertion of multiple long-term peripherally inserted central catheters (PICC) over a 10-year period. Imaging at presentation demonstrated a PICC-associated mobile mass in the right atrium and signs of pulmonary hypertension (PH). She was thrombolyzed and fully anticoagulated, and diabetic management without PICC strongly recommended. PH persisted, however, and she developed chronic thromboembolic pulmonary hypertension (CTEPH), for which successful pulmonary endarterectomy (PEA) surgery led to symptomatic and hemodynamic improvement. This was the first case of CTEPH reported related to long-term PICC use outside the setting of malignant disease, and a novel observation that the PEA specimen contained multiple plastic fragments. Long-term PICC placement increases the risk of CTEPH, a life-threatening, albeit treatable, complication.

Proximal pressure reducing effect of wave reflection in the pulmonary circulation disappear in obstructive disease: insight from a rabbit model

Locating the site of increased resistance within the vascular tree in pulmonary arterial hypertension could assist in both patient diagnosis and tailoring treatment. Wave intensity analysis (WIA) is a wave analysis method that may be capable of localizing the major site of reflection within a vascular system. We investigated the contribution of WIA to the analysis of the pulmonary circulation in a rabbit model with animals subjected to variable occlusive pulmonary disease. Animals were embolized with different sized microspheres for 6 wk ( n = 10) or underwent pulmonary artery (PA) ligation for 6 wk ( n = 3). These animals were compared with a control group ( n = 6) and acutely embolized animals ( n = 4). WIA was performed and compared with impedance-based methods to analyze wave reflections. The control group showed a relatively high extent of reflected waves (15.7 ± 10.6%); reflections had a net effect of pressure reduction during systole, suggesting an open-end reflector. The pattern of wave reflection was not different in the group with partial PA ligation (12.4 ± 4.1%). In the chronically embolized group, wave reflection was not observed (3.6 ± 1.5%). In the acute embolization group, wave reflection was more prominent (37.3 ± 12.6%), with the appearance of a novel wave increasing pressure, suggesting the appearance of a closed-end reflector. Wave reflections of an open-end type are present in the normal rabbit pulmonary circulation. However, the pattern and nature of reflections vary according to the extent of pulmonary vascular occlusion.

NEW & NOTEWORTHY The study proposes an original framework of a complementary analysis of wave reflections in the time domain and in the frequency domain. The methodology was used in the pulmonary circulation with different forms of chronic obstructions. The results suggest that the pulmonary vascular tree generates a reflection pattern that could actually assist the heart during ejection, and chronic obstruction significantly modifies the pattern.

Diabetes and Lung Disease: A Neglected Relationship

BACKGROUND

Diabetes mellitus is a systemic disorder associated with inflammation and oxidative stress which may target many organs such as the kidney, retina, and the vascular system. The pathophysiology, mechanisms, and consequences of diabetes on these organs have been studied widely. However, no work has been done on the concept of the lung as a target organ for diabetes and its implications for lung diseases.

AIM

In this review, we aimed to investigate the effects of diabetes and hypoglycemic agent on lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, pulmonary hypertension, and lung cancer. We also reviewed the potential mechanisms by which these effects may affect lung disease patients.

RESULTS

Our results suggest that diabetes can affect the severity and clinical course of several lung diseases.

CONCLUSIONS

Although the diabetes-lung association is epidemiologically and clinically well-established, especially in asthma, the underlying mechanism and pathophysiology are not been fully understood. Several mechanisms have been suggested, mainly associated with the pro-inflammatory and proliferative properties of diabetes, but also in relation to micro- and macrovascular effects of diabetes on the pulmonary vasculature. Also, hypoglycemic drugs may influence lung diseases in different ways. For example, metformin was considered a potential therapeutic agent in lung diseases, while insulin was shown to exacerbate lung diseases; this suggests that their effects extend beyond their hypoglycemic properties.

Subcutaneous treprostinil for the treatment of severe non-operable chronic thromboembolic pulmonary hypertension (CTREPH): a double-blind, phase 3, randomised controlled trial

BACKGROUND

Treprostinil, a prostacyclin analogue, is effective for the treatment of pulmonary arterial hypertension. However, information is scarce regarding treprostinil for treatment of chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this study was to examine the efficacy and safety of subcutaneous treprostinil in this setting.

METHODS

In this 24-week, randomised, double-blind controlled trial, we enrolled patients with CTEPH, classified as non-operable, or with persistent or recurrent pulmonary hypertension after pulmonary endarterectomy, in six European expert centres in Austria, Czech Republic, Germany, and Poland. Patients in WHO functional class III or IV with a 6-min walk distance of 150-400 m were randomly assigned at a 1:1 allocation ratio to continuous high-dose subcutaneous treprostinil (target dose around 30 ng/kg per min at week 12) or low-dose subcutaneous treprostinil (target dose around 3 ng/kg per min at week 12). The primary endpoint was the change from baseline in 6-min walk distance at week 24. All patients who received at least one dose of the study drug were included in the intention-to-treat efficacy and safety analyses based on assessment of adverse events. The trial was registered at ClinicalTrialsRegister.eu EudraCT number 2008-006441-10 and ClinicalTrials.gov, number NCT01416636.

FINDINGS

From March 9, 2009, to June 9, 2016, 105 patients were enrolled with 53 (50%) patients randomly assigned to high-dose and 52 (50%) patients to low-dose subcutaneous treprostinil. At week 24, marginal mean 6-min walk distance improved by 44·98 m (95% CI 27·52 to 62·45) in the high-dose group, and by 4·29 m (95% CI -13·34 to 21·92) in the low-dose group (treatment effect 40·69 m, 95% CI 15·86 to 65·53, p=0·0016). 12 serious adverse events were reported in ten (19%) of 52 patients from the low-dose group and 16 serious adverse events were reported in nine (17%) of 53 patients from the high-dose group. The most common treatment-related adverse events in both groups were infusion site pain and other infusion site reactions.

INTERPRETATION

Treatment with subcutaneous treprostinil was safe, and improved exercise capacity in patients with severe CTEPH. Subcutaneous treprostinil provides a parenteral treatment option for patients of WHO functional class III or IV and those who do not tolerate other therapies or need combination treatment.

FUNDING

SciPharm Sàrl.

The impact of patient choice on survival in chronic thromboembolic pulmonary hypertension

Pulmonary endarterectomy (PEA) is the gold standard treatment for operable chronic thromboembolic pulmonary hypertension (CTEPH). However, a proportion of patients with operable disease decline surgery. There are currently no published data on this patient group. The aim of this study was to identify outcomes and prognostic factors in a large cohort of consecutive patients with CTEPH.Data were collected for consecutive, treatment-naive CTEPH patients at the Pulmonary Vascular Disease Unit of the Royal Hallamshire Hospital (Sheffield, UK) between 2001 and 2014.Of 550 CTEPH patients (mean±sd age 63±15 years, follow-up 4±3 years), 49% underwent surgery, 32% had technically operable disease and did not undergo surgery (including patient choice n=72 and unfit for surgery n=63), and 19% had inoperable disease due to disease distribution. The 5-year survival was superior in patients undergoing PEA (83%) versus technically operable disease who did not undergo surgery (53%) and inoperable due to disease distribution (59%) (p<0.001). Survival was superior in patients following PEA compared with those offered but declining surgery (55%) (p<0.001). In patients offered PEA, independent prognostic factors included mixed venous oxygen saturation, gas transfer and patient decision to proceed to surgery.Outcomes in CTEPH following PEA are excellent and superior to patients declining surgery, and strongly favour consideration of a surgical intervention in eligible patients.

Incidence and risk factors of chronic thromboembolic pulmonary hypertension following venous thromboembolism, a population-based cohort study in England

Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of unresolved organised pulmonary emboli/thrombi obstructing the major pulmonary arteries. The aim of this study was to estimate the incidence and risk factors of CTEPH in a cohort with first venous thromboembolism (VTE). This was a population-based cohort study of patients with first VTE and no active cancer in England between 2001 and 2012. CTEPH was assessed using a rigorous case-ascertainment algorithm. Risk factors for CTEPH were studied using a nested case-control approach by matching CTEPH cases to VTE patients without CTEPH. Adjusted odds ratios (OR) of comorbidities were estimated from conditional logistic regression. During 81,413 person-years of follow-up among 23,329 patients with first VTE (mean follow-up 3.5 years; maximum 11.0 years) 283 patients were diagnosed with CTEPH (incidence rate 3.5 per 1000 person-years); cumulative incidence was 1.3% and 3.3% at 2 and 10 years after pulmonary embolism, and 0.3% and 1.3% following deep vein thrombosis (DVT), respectively. Risk factors for CTEPH included age over 70, OR 2.04 (95% CI 1.23 to 3.38), female gender, 1.44 (1.06 to 1.94), pulmonary embolism at first VTE, 3.11 (2.23 to 4.35), subsequent pulmonary embolism and DVT, 3.17 (2.02 to 4.96) and 2.46 (1.34 to 4.51) respectively, chronic obstructive pulmonary disease 3.17 (2.13 to 4.73), heart failure 2.52 (1.76 to 3.63) and atrial fibrillation, 2.42 (1.71 to 3.42). CTEPH develops most commonly after pulmonary embolism and less frequently after DVT. Awareness of risk factors may increase referrals to specialised centres for confirmation of CTEPH and initiation of specific treatment.

Chronic thromboembolic pulmonary hypertension from the perspective of patients with pulmonary embolism

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but feared long-term complication of acute pulmonary embolism (PE), although CTEPH may occur in patients with no history of symptomatic venous thromboembolism. It represents the most severe presentation of the so-called 'post-PE syndrome', a phenomenon of permanent functional limitations after PE caused by deconditioning after PE or ventilatory or circulatory impairment as a result of unresolved pulmonary artery thrombi. Because the post-PE syndrome may occur in up to 50% of PE survivors, and CTEPH tends to have an insidious and non-specific clinical presentation, CTEPH is often not diagnosed or diagnosed after a very long delay. Once the diagnosis is confirmed, the treatment of choice is pulmonary endarterectomy which effectively lowers the pulmonary vascular resistance and normalizes resting pulmonary artery pressures, leading to recovery of the right ventricle. When pulmonary endarterectomy is not technically feasible, balloon pulmonary angioplasty may be a potential acceptable alternative. Also, medical treatment may help to improve patient's symptoms and hemodynamics. Current studies are focusing on strategies for earlier CTEPH diagnosis after acute PE, as well as the most optimal treatment of inoperable patients. This review will focus on the epidemiology, risk factors, diagnosis and treatment of CTEPH from the perspective of the PE patient.

Sex-specific cardiopulmonary exercise testing indices to estimate the severity of inoperable chronic thromboembolic pulmonary hypertension

Background

Sex differences in chronic thromboembolic pulmonary hypertension (CTEPH) have been revealed in few studies. Although right heart catheterization (RHC) is the gold standard for clinical diagnosis and assessment of prognosis in pulmonary hypertension (PH), cardiopulmonary exercise testing (CPET) has been a more widely used assessment of functional capacity, disease severity, prognosis, and treatment response in PH. We hypothesized that the “sex-specific” CPET indices could estimate the severity of inoperable CTEPH.

Methods

Data were retrieved for 33 male (age, mean ± standard deviation [SD] =62.5±13.4 years) and 40 female (age, mean ± SD =56.3±11.8 years) patients with stable CTEPH who underwent both RHC and CPET at Shanghai Pulmonary Hospital from February 2010 to February 2016. Univariate and forward/backward multiple stepwise regression analysis was performed to assess the predictive value of CPET indices to hemodynamic parameters. Event-free survival was estimated using the Kaplan–Meier method and analyzed with the log-rank test. Cox proportional hazards models were performed to determine the independent event-free survival predictors.

Results

Numerous CPET parameters were different between male and female patients with CTEPH and the control group. There were no significant differences in both clinical variables and RHC parameters between male and female patients with CTEPH. O₂ pulse, workload, minute ventilation (VE), and end-tidal partial pressure of O₂ (P_ETO₂) at anaerobic threshold, as well as peak O₂ pulse, workload, VE, and nadir VE/CO₂ were significantly higher in male patients than in female patients (P<0.05). Only oxygen uptake efficiency plateau (OUEP) showed a significantly higher difference in female than male patients (P<0.05). In addition, several CPET indices correlated with hemodynamic parameters, especially pulmonary vascular resistance (PVR), which was distinctly different between the sexes. Nadir VE/CO₂ was an independent predictor of PVR in male patients with CTEPH, whereas OUEP was an independent predictor of PVR in female patients with CTEPH.

Conclusion

Even after confounding for age and body mass index, different CPET measurements of gas exchange efficiency correlated with PVR differently between male and female patients. This potentially could be used to estimate the severity of CTEPH.

Chronic Thromboembolic Pulmonary Hypertension: Epidemiology, Diagnosis, and Management

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

Prevalence of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism

Chronic thromboembolic pulmonary hypertension (CTEPH) has been estimated to occur in 0.1–0.5% of patients who survive a pulmonary embolism (PE), but more recent prospective studies suggest that its incidence may be much higher. The absence of initial haemodynamic evaluation at the time of PE should explain this discrepancy. We performed a prospective multicentre study including patients with PE in order to assess the prevalence and to describe risk factors of CTEPH. Follow-up every year included an evaluation of dyspnea and echocardiography using a predefined algorithm. In case of suspected CTEPH, the diagnosis was confirmed using right heart catheterisation (RHC). Signs of CTEPH were searched on the multidetector computed tomography (CT) and echocardiography performed at the time of PE. Of the 146 patients analysed, eight patients (5.4%) had suspected CTEPH during a median follow-up of 26 months. CTEPH was confirmed using RHC in seven cases (4.8%; 95%CI, 2.3 – 9.6) and ruled-out in one. Patients with CTEPH were older, had more frequently previous venous thromboembolic events and more proximal PE than those without CTEPH. At the time of PE diagnosis, patients with CTEPH had a higher systolic pulmonary artery pressure and at least two signs of CTEPH on the initial CT. After acute PE, the prevalence of CTEPH appears high. However, initial echocardiography and CT data at the time of the index PE suggest that a majority of patients with CTEPH had previously unknown pulmonary hypertension, indicating that a first clinical presentation of CTEPH may mimic acute PE.

The role of computed tomography in the diagnosis of acute and chronic pulmonary embolism

Pulmonary embolism (PE) is a potentially life threatening condition requiring adequate diagnosis and treatment. Computed tomography pulmonary angiography (CTPA) is excellent for including and excluding PE, therefore CT is the first-choice diagnostic imaging technique in patients suspected of having acute PE. Due to its wide availability and low invasiveness, CTPA tends to be overused. Correct implementation of clinical decision rules in diagnostic workup for PE improves adequate use of CT. Also, CT adds prognostic value by evaluating right ventricular (RV) function. CT-assessed RV dysfunction and to lesser extent central emboli location predicts PE-related mortality in normotensive and hypotensive patients, while PE embolic obstruction index has limited prognostic value. Simple RV/left ventricular (LV) diameter ratio measures >1.0 already predict risk for adverse outcome, whereas ratios <1.0 can safely exclude adverse outcome. Consequently, assessing the RV/LV diameter ratio may help identify patients who are potential candidates for treatment at home instead of treatment in the hospital. A minority of patients develop chronic thromboembolic pulmonary hypertension (CTEPH) following acute PE, which is a life-threatening condition that can be diagnosed by CT. In proximal CTEPH, involving the more central pulmonary arteries, thrombectomy usually results in good outcome in terms of both functional status and long-term survival rate. CT is becoming the imaging method of choice for diagnosing CTEPH as it can identify patients who may benefit from thrombectomy. New CT developments such as distensibility measurements and dual-energy or subtraction techniques may further refine diagnosis and prognosis for improved patient care.

[Clinical guidelines for the diagnosis and treatment of chronic thromboembolic pulmonary hypertension (Part 1)]

Chronic thromboembolic pulmonary hypertension (CTEPH) is precapillary pulmonary hypertension, in which chronic obstruction of large and middle branches of pulmonary arteries (PAs) and secondary changes in the lung microcirculatory bed result in a progressive increase in pulmonary vascular resistance and PA pressure with the development of severe right cardiac dysfunction and heart failure. CTEPH is a unique form of pulmonary hypertension since it is potentially curable by surgical treatment. The diagnostic criteria for CTEPH are a mean PA pressure of ≥25 mm Hg, as evidenced by right heart catheterization; a PA wedge pressure of ≤15 mm Hg; a pulmonary vascular resistance of >2 Wood units; the presence of chronic/organized thrombi/emboli in the elastic PAs (pulmonary trunk, lobular, segmental, subsegmental PAs); effective anticoagulant therapy at therapeutic dosages over at least 3 months. Up to now, our country has had no guidelines for the diagnosis and treatment of this rare severe disease that, when appropriately untreated, has an extremely poor prognosis. The main task in the preparation of this document was to generalize and analyze the data of current registries, multicenter randomized clinical trials, national and international guidelines, and consensus documents recently published on this problem in order to optimize a diagnostic process and treatment in this category of patients. Part 1 gives a definition of CTEPH, its place in the clinical classification, epidemiology and prognosis, risk factors, pathogenesis and morphology, diagnostic approaches and determination of operability in patients, and specific features of differential diagnosis.

Innate Effector-Memory T-Cell Activation Regulates Post-Thrombotic Vein Wall Inflammation and Thrombus Resolution

RATIONALE

Immune cells play an important role during the generation and resolution of thrombosis. T cells are powerful regulators of immune and nonimmune cell function, however, their role in sterile inflammation in venous thrombosis has not been systematically examined.

OBJECTIVE

This study investigated the recruitment, activation, and inflammatory activity of T cells in deep vein thrombosis and its consequences for venous thrombus resolution.

METHODS AND RESULTS

CD4⁺ and CD8⁺ T cells infiltrate the thrombus and vein wall rapidly on deep vein thrombosis induction and remain in the tissue throughout the thrombus resolution. In the vein wall, recruited T cells largely consist of effector-memory T (T_EM) cells. Using T-cell receptor transgenic reporter mice, we demonstrate that deep vein thrombosis-recruited T_EM receive an immediate antigen-independent activation and produce IFN-γ (interferon) in situ. Mapping inflammatory conditions in the thrombotic vein, we identify a set of deep vein thrombosis upregulated cytokines and chemokines that synergize to induce antigen-independent IFN-γ production in CD4⁺ and CD8⁺ T_EM cells. Reducing the number of T_EM cells through a depletion recovery procedure, we show that intravenous T_EM activation determines neutrophil and monocyte recruitment and delays thrombus neovascularization and resolution. Examining T-cell recruitment in human venous stasis, we show that superficial varicose veins preferentially contain activated memory T cells.

CONCLUSIONS

T_EM orchestrate the inflammatory response in venous thrombosis affecting thrombus resolution.