Chronic thromboembolic pulmonary hypertension

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

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

Review of Advances on Management of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension is rare, underdiagnosed form of pulmonary hypertension. It is caused by intravascular obstruction of pulmonary arteries due to fibrotic transformation of thromboembolic material and microvasculopathy. It is important to diagnose this variant as potentially curative treatment in the form of pulmonary endarterectomy is available. Last two decades have seen rapid advances in targeted medical management and refinement in balloon pulmonary angioplasty technique, which have provided a viable therapeutic option for patients who deemed to be inoperable.

Research progress on the pathogenesis of CTEPH

Chronic thromboembolic pulmonary hypertension (CTEPH) is an established long-term complication of pulmonary thromboembolism (PTE). However, studies have shown that many patients with a definitive CTEPH diagnosis have no history of symptomatic PTE, suggesting that PTE is not the only cause of CTEPH. Despite extensive progress in research on pulmonary hypertension in recent years, due to a lack of relevant studies on the pathophysiology of CTEPH, implementing pulmonary endarterectomy (PEA) in patients has many challenges, and the prognosis of patients with CTEPH is still not optimistic. Therefore, revealing the pathogenesis of CTEPH would be of great significance for understanding the occurrence and development of CTEPH, developing relevant drug treatment studies and formulating intervention strategies, and may provide new preventive measures. This article summarizes the current research progress in CTEPH pathogenesis from the perspective of risk factors related to medical history, abnormal coagulation and fibrinolytic mechanisms, inflammatory mechanisms, genetic susceptibility factors, angiogenesis, in situ thrombosis, vascular remodeling, and other aspects.

Chronic Thromboembolic Pulmonary Hypertension: Pearls and Pitfalls of Diagnosis

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by chronic obstruction of major pulmonary arteries by organized thromboembolic material. Untreated CTEPH can result in pulmonary hypertension and eventually right heart failure, yet it is the only form of pulmonary hypertension that is potentially curable with surgical or catheter-based intervention. While early diagnosis is key to increasing the likelihood of successful treatment, CTEPH remains largely underdiagnosed. This article reviews the role of echocardiogram, ventilation/perfusion scan, and other available modalities in the diagnosis of CTEPH.

Diagnostic accuracy of lung subtraction iodine mapping CT for the evaluation of pulmonary perfusion in patients with chronic thromboembolic pulmonary hypertension: Correlation with perfusion SPECT/CT

BACKGROUND

For treatment of chronic thromboembolic pulmonary hypertension (CTEPH), the evaluation of segmental pulmonary perfusion is important. There are no previous reports about lung subtraction iodine mapping (LSIM) computed tomography (CT) for evaluation of segmental pulmonary perfusion in patients with CTEPH, using lung perfusion SPECT/CT (LPS) as the reference.

METHODS

50 patients (age, 60.7±16.7years) with known or suspected CTEPH were enrolled in this study. Non-contrast chest CT and CT pulmonary angiography (CTPA) were performed on a 320-detector row CT system. Then, based on a non-rigid registration followed by subtraction of non-contrast images from contrast-enhanced images, color-coded LSIM images were generated. LPS was performed using a SPECT/CT system within a period of 2months, and served as the reference standard. LSIM and CTPA images were evaluated in a blinded manner for the detection of pulmonary perfusion defects on a segment-by-segment basis.

RESULTS

The sensitivity, specificity, accuracy, and positive and negative predictive values of LSIM for the detection of segmental perfusion defects were 95% (734/773), 84% (107/127), 93% (841/900), 97% (734/754) and 73% (107/146), respectively, while the corresponding values for CTPA were 65% (505/773), 61% (78/127), 65% (583/900), 91% (505/554) and 23% (78/346). Generalized estimating equations analyses revealed a significantly better performance of LSIM than that of CTPA regarding the sensitivity, accuracy, and positive and negative predictive values (all P<0.0001).

CONCLUSIONS

LSIM is a feasible technique for segment-based evaluation of pulmonary perfusion in patients with CTEPH, and it provides a significantly higher diagnostic accuracy compared with CTPA.

ANMCO Position Paper: long-term follow-up of patients with pulmonary thromboembolism

Venous thromboembolism (VTE), including pulmonary embolism and deep venous thrombosis, is the third most common cause of cardiovascular death. The management of the acute phase of VTE has already been described in several guidelines. However, the management of the follow-up (FU) of these patients has been poorly defined. This consensus document, created by the Italian cardiologists, wants to clarify this issue using the currently available evidence in VTE. Clinical and instrumental data acquired during the acute phase of the disease are the cornerstone for planning the FU. Acquired or congenital thrombophilic disorders could be identified in apparently unprovoked VTE during the FU. In other cases, an occult cancer could be discovered after a VTE. The main targets of the post-acute management are to prevent recurrence of VTE and to identify the patients who can develop a chronic thromboembolic pulmonary hypertension. Knowledge of pathophysiology and therapeutic approaches is fundamental to decide the most appropriate long-term treatment. Moreover, prognostic stratification during the FU should be constantly updated on the basis of the new evidence acquired. Currently, the cornerstone of VTE treatment is represented by both the oral and the parenteral anticoagulation. Novel oral anticoagulants should be an interesting alternative in the long-term treatment.

Lung perfusion: MRI vs. SPECT for screening in suspected chronic thromboembolic pulmonary hypertension

Purpose

To assess the diagnostic accuracy of magnetic resonance imaging (MRI) perfusion against perfusion single photon emission tomography (SPECT) screening for chronic thromboembolic pulmonary hypertension (CTEPH). Ventilation/perfusion (V/Q) scintigraphy is recommended to screen for suspected CTEPH. It has previously been shown that 3D dynamic contrast‐enhanced (DCE) lung perfusion MRI has a similar sensitivity for diagnosing CTEPH in comparison to planar perfusion scintigraphy; however, planar scintigraphy has now been largely replaced by SPECT, due to higher spatial resolution and sensitivity.

Materials and Methods

Consecutive patients with suspected CTEPH or unexplained pulmonary hypertension attending a referral center, who underwent lung DCE perfusion MRI at 1.5T, perfusion SPECT, and computed tomography pulmonary angiography (CTPA) within 14 days of right heart catheterization, from April 2013 to April 2014, were included. DCE‐MR, SPECT, and CTPA were independently analyzed by two blinded radiologists. Disagreements were corrected by consensus. The gold standard reference for the diagnosis of chronic thromboemboli was based on a review of multimodality imaging and clinical findings.

Results

In all, 74 patients with suspected CTEPH underwent all three modalities. Forty‐six were diagnosed with CTEPH (36) or chronic thromboembolic disease (CTED) (10). 3D DCE perfusion MRI correctly identified all patients (sensitivity of 100%), compared with a 97% sensitivity for SPECT.

Conclusion

DCE lung perfusion MRI has increased sensitivity when compared with perfusion scintigraphy in screening for CTEPH. As MRI does not use ionizing radiation, it should be considered as a first‐line imaging modality in suspected CTEPH.

Level of Evidence: 3

Technical Efficacy: Stage 3

J. Magn. Reson. Imaging 2017;46:1693–1697.

Pulmonary endarterectomy in the management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a type of pulmonary hypertension, resulting from fibrotic transformation of pulmonary artery clots causing chronic obstruction in macroscopic pulmonary arteries and associated vascular remodelling in the microvasculature.

Pulmonary endarterectomy (PEA) offers the best chance of symptomatic and prognostic improvement in eligible patients; in expert centres, it has excellent results. Current in-hospital mortality rates are <5% and survival is >90% at 1 year and >70% at 10 years. However, PEA, is a complex procedure and relies on a multidisciplinary CTEPH team led by an experienced surgeon to decide on an individual's operability, which is determined primarily by lesion location and the haemodynamic parameters. Therefore, treatment of patients with CTEPH depends largely on subjective judgements of eligibility for surgery by the CTEPH team.

Other controversies discussed in this article include eligibility for PEA versus balloon pulmonary angioplasty, the new treatment algorithm in the European Society of Cardiology/European Respiratory Society guidelines and the definition of an “expert centre” for the management of this condition.

Impact of CT perfusion imaging on the assessment of peripheral chronic pulmonary thromboembolism: clinical experience in 62 patients

PURPOSE

To evaluate the impact of CT perfusion imaging on the detection of peripheral chronic pulmonary embolisms (CPE).

MATERIALS AND METHODS

62 patients underwent a dual-energy chest CT angiographic examination with (a) reconstruction of diagnostic and perfusion images; (b) enabling depiction of vascular features of peripheral CPE on diagnostic images and perfusion defects (20 segments/patient; total: 1240 segments examined). The interpretation of diagnostic images was of two types: (a) standard (i.e., based on cross-sectional images alone) or (b) detailed (i.e., based on cross-sectional images and MIPs).

RESULTS

The segment-based analysis showed (a) 1179 segments analyzable on both imaging modalities and 61 segments rated as nonanalyzable on perfusion images; (b) the percentage of diseased segments was increased by 7.2 % when perfusion imaging was compared to the detailed reading of diagnostic images, and by 26.6 % when compared to the standard reading of images. At a patient level, the extent of peripheral CPE was higher on perfusion imaging, with a greater impact when compared to the standard reading of diagnostic images (number of patients with a greater number of diseased segments: n = 45; 72.6 % of the study population).

CONCLUSION

Perfusion imaging allows recognition of a greater extent of peripheral CPE compared to diagnostic imaging.

KEY POINTS

• Dual-energy computed tomography generates standard diagnostic imaging and lung perfusion analysis. • Depiction of CPE on central arteries relies on standard diagnostic imaging. • Detection of peripheral CPE is improved by perfusion imaging.

Advances in the management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH), a potentially curable form of pulmonary hypertension with pulmonary thromboendarterectomy surgery, has been the focus of significant medical advances. In addition to new imaging modalities that are now used to help recognize and diagnose CTEPH, additional treatment options have emerged for inoperable cases. These include a newly approved medical therapy for inoperable disease or persistent/recurrent CTEPH as well as percutaneous balloon angioplasty of the pulmonary arteries. In this article, we summarize these recent advances in the field and review the related literature.

Diagnostic advances and opportunities in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterised by the presence of thromboembolic material in the pulmonary circulation, and patients have a poor prognosis without treatment. Patients present with nonspecific symptoms, such as breathlessness and syncope, which means that other more common conditions are sometimes suspected before CTEPH, leading to delayed diagnosis and treatment. This is problematic because CTEPH is potentially curable with surgical pulmonary endarterectomy (PEA); indeed, CTEPH should always be considered in any patient with unexplained pulmonary hypertension (PH).

Several key evaluations are necessary and complementary to confirm a diagnosis of CTEPH and assess operability. Echocardiography is initially used to confirm a general diagnosis of PH. Ventilation/perfusion scanning is then essential in the first stage of CTEPH diagnosis, with a wedge-shaped perfusion deficit indicative of CTEPH. This should be followed by right heart catheterisation (RHC) which is mandatory in confirming the diagnosis and providing haemodynamic parameters that are key predictors of the risk associated with PEA and subsequent prognosis. RHC is ideally coupled with conventional pulmonary angiography, the gold-standard technique for confirming the location and extent of disease, and thus whether the obstruction is surgically accessible. Computed tomographic pulmonary angiography is also now routinely used as a complementary technique to aid diagnosis and operability assessment.

Recent improvements in the resolution of other noninvasive techniques, such as cardiac magnetic resonance imaging, allow for detailed reconstructions of the vascular tree and imaging of vessel defects, and interest in their use is increasing.

Chronic thromboembolic pulmonary hypertension in young woman with history of caesarian section

Chronic thromboembolic pulmonary hypertension (CTEPH) is one of subgroups of pulmonary hypertension. This is a serious medical condition that severely under diagnosed. CTEPH is commonly underdiagnosed due to non specific symptoms and lack of diagnostic tools. The aim of this presentation is to discuss the etiology, risk factors, diagnosis and management of CTEPH. A 36-year-old woman presented with easily fatigue and dyspneu on effort since two years ago. The symptom occured about three months after she gave birth with caesarian section due to preeclampsia. Further history taking, physical examination, electrocardiography (ECG) and echocardiography were highly suggestive of pulmonary hypertension. No deep vein thrombosis (DVT) was found on vascular femoral sonography. It was found after the lung perfusion scintigraphy performed that she actually had CTEPH. This patient was categorized as inoperable because CT pulmonary angiography showed no thrombus. The patient got pulmonary vasodilator and oral anticoagulant for lifelong.

Additional percutaneous transluminal pulmonary angioplasty for residual or recurrent pulmonary hypertension after pulmonary endarterectomy

BACKGROUND

Pulmonary endarterectomy (PEA) has been the most effective therapy for chronic thromboembolic pulmonary hypertension (CTEPH). However, residual or recurrent pulmonary hypertension often persists after PEA. Recently, catheter-based angioplasty, called percutaneous transluminal pulmonary angioplasty (PTPA) or balloon pulmonary angioplasty, has been developed as a promising strategy for CTEPH. Therefore, the usefulness of PTPA for residual or recurrent pulmonary hypertension after PEA was investigated.

METHODS

Thirty-nine patients underwent PEA from January 2000, and a total of 423 consecutive PTPA sessions in 110 patients were performed from January 2009 to May 2014. Of them, 9 patients (23.0% of 39 patients undergoing PEA and 8.2% of 110 patients undergoing PTPA) had undergone previous PEA and additional PTPA.

RESULTS

In these 9 patients, pulmonary vascular resistance (PVR) was 15.6 (7.8-18.9) wood units at baseline, and significantly improved after PEA [5.6 (3.5-6.5) wood units] (p<0.05). However, PVR gradually deteriorated before PTPA [8.1 (6.1-12.3) wood units] compared to after PEA, suggesting that these 9 patients had residual or recurrent pulmonary hypertension after PEA. PTPA was performed at 4.1 (2.7-7.9) years after PEA. Follow-up catheterization at 1.9 (1.3-3.3) years after PTPA revealed significant improvement of PVR [4.2 (2.8-4.8) wood units] (p<0.05).

CONCLUSIONS

A hybrid approach combining PEA and additional PTPA may be reasonable for patients with both proximal and very distal lesions not easily approachable by PEA. PTPA could be a promising alternative therapeutic strategy for residual or recurrent pulmonary hypertension after PEA.

Safety and efficacy of percutaneous transluminal pulmonary angioplasty in elderly patients

BACKGROUND

Percutaneous transluminal pulmonary angioplasty (PTPA) is a recently developed catheter-based therapy for chronic thromboembolic pulmonary hypertension (CTEPH). The aim of the present study was to investigate the safety and efficacy of PTPA in elderly patients with CTEPH.

METHODS

In all, 257 PTPA sessions in 70 patients (median age 63 years) were analyzed. Patients were divided into two groups according to age: (i) a younger group (<65 years; n=39); and (ii) an elderly group (≥65 years; n=31).

RESULTS

Hemodynamic improvements were comparable between the younger and elderly groups (63.1% vs. 68.2% decrease in pulmonary vascular resistance, respectively; P>0.05). The median length of stay in the intensive care unit after each session (1.0 vs. 1.0 days) and in hospital per session (9.2 vs. 9.4 days) was similar between the two groups (P>0.05 for all). The prevalence of reperfusion pulmonary edema (23.4% vs. 26.3% across all sessions) and other complications, such as contrast dye-induced nephropathy (0% vs. 2.0%), infection (0% vs. 0%), and neurological complications (0% vs. 1.0%), was comparable in the younger vs. elderly groups (P>0.05 for all). One-year all-cause mortality was similar in the younger and elderly groups (0% vs. 3.2%, respectively; P>0.05).

CONCLUSIONS

PTPA can be performed safely and effectively, even in elderly patients, and could be considered as an alternative therapeutic strategy for elderly patients who are too fragile for pulmonary endarterectomy (PEA) or who are treated in institutions without highly experienced PEA surgeons.

Pulmonary Thromboendarterectomy for Chronic Thromboembolic Pulmonary Hypertension

Pulmonary thromboendarterectomy is the most effective therapy for chronic thromboembolic pulmonary hypertension. The pathophysiology, anesthetic management, and perioperative outcomes of patients with chronic thromboembolic pulmonary hypertension undergoing pulmonary thromboendarterectomy are reviewed.

A new era of therapeutic strategies for chronic thromboembolic pulmonary hypertension by two different interventional therapies; pulmonary endarterectomy and percutaneous transluminal pulmonary angioplasty

BACKGROUND

Pulmonary endarterectomy (PEA) is established for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH). Recently, percutaneous transluminal pulmonary angioplasty (PTPA) has been added for peripheral-type CTEPH, whose lesions exist in segmental, subsegmental, and more distal pulmonary arteries. A shift in clinical practice of interventional therapies occurred in 2009 (first mainly PEA, later PTPA). We examined the latest clinical outcomes of patients with CTEPH.

METHODS AND RESULTS

This study retrospectively included 136 patients with CTEPH. Twenty-nine were treated only with drug (Drug-group), and the other 107 underwent interventional therapies (Interventions-group) (39 underwent PEA [PEA-group] and 68 underwent PTPA [PTPA-group]). Total 213 PTPA sessions (failures, 0%; mortality rate, 1.47%) was performed in the PTPA-group (complications: reperfusion pulmonary edema, 7.0%; hemosputum or hemoptysis, 5.6%; vessel dissection, 2.3%; wiring perforation, 0.9%). Although baseline hemodynamic parameters were significantly more severe in the Interventions-group, the outcome after the diagnosis was much better in the Interventions-group than in the Drug-group (98% vs. 64% 5-year survival, p<0.0001). Hemodynamic improvement in the PEA-group was a 46% decrease in mean pulmonary arterial pressure (PAP) and a 49% decrease in total pulmonary resistance (TPR) (follow-up period; 74.7 ± 32.3 months), while those in the PTPA-group were a 40% decrease in mean PAP and a 49% decrease in TPR (follow-up period; 17.4 ± 9.3 months). The 2-year survival rate in the Drug-group was 82.0%, and the 2-year survival rate, occurrence of right heart failure, and re-vascularization rate in the PEA-group were 97.4%, 2.6%, and 2.8%, and those in the PTPA-group were 98.5%, 2.9%, and 2.9%, respectively.

CONCLUSION

The patients who underwent interventional therapies had better results than those treated only with drugs. The availability of both of these operative and catheter-based interventional therapies leads us to expect the dawn of a new era of therapeutic strategies for CTEPH.

Pulmonary edema predictive scoring index (PEPSI), a new index to predict risk of reperfusion pulmonary edema and improvement of hemodynamics in percutaneous transluminal pulmonary angioplasty

OBJECTIVES

This study sought to identify useful predictors for hemodynamic improvement and risk of reperfusion pulmonary edema (RPE), a major complication of this procedure.

BACKGROUND

Percutaneous transluminal pulmonary angioplasty (PTPA) has been reported to be effective for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH). PTPA has not been widespread because RPE has not been well predicted.

METHODS

We included 140 consecutive procedures in 54 patients with CTEPH. The flow appearance of the target vessels was graded into 4 groups (Pulmonary Flow Grade), and we proposed PEPSI (Pulmonary Edema Predictive Scoring Index) = (sum total change of Pulmonary Flow Grade scores) × (baseline pulmonary vascular resistance). Correlations between occurrence of RPE and 11 variables, including hemodynamic parameters, number of target vessels, and PEPSI, were analyzed.

RESULTS

Hemodynamic parameters significantly improved after median observation period of 6.4 months, and the sum total changes in Pulmonary Flow Grade scores were significantly correlated with the improvement in hemodynamics. Multivariate analysis revealed that PEPSI was the strongest factor correlated with the occurrence of RPE (p < 0.0001). Receiver-operating characteristic curve analysis demonstrated PEPSI to be a useful marker of the risk of RPE (cutoff value 35.4, negative predictive value 92.3%).

CONCLUSIONS

Pulmonary Flow Grade score is useful in determining therapeutic efficacy, and PEPSI is highly supportive to reduce the risk of RPE after PTPA. Using these 2 indexes, PTPA could become a safe and common therapeutic strategy for CTEPH.

Pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension: How can patients be better selected?

Chronic thromboembolic pulmonary hypertension (CTEPH) comprises organizing thrombotic obstructions in the pulmonary arteries by nonresolving thromboemboli, formation of fibrosis and remodeling of pulmonary blood vessels. Surgical pulmonary endarterectomy (PEA) is the therapy of choice for patients with surgically accessible CTEPH, which leads to a profound improvement in hemodynamics, functional class and survival. Selecting the candidates that will benefit from surgery is still a challenging task. Criteria for surgical suitability have been described but the decision-making for or against surgical intervention remains still subjective. The optimal characterization of the reciprocal contribution of large vessel and small vessel disease in the elevation of pulmonary vascular resistance is crucial for the indication and outcome of PEA. Recently, Toshner et al intended to validate the partition resistance into small and large vessels compartments (upstream resistance: Rup) by the occlusion technique in the preoperative assessment of PEA. We discuss the advantages and disadvantages of Rup and compare it with other hemodynamic predictor to evaluate operative risk in CTEPH patients.

Percutaneous transluminal pulmonary angioplasty for the treatment of chronic thromboembolic pulmonary hypertension

BACKGROUND

Chronic thromboembolic pulmonary hypertension leads to pulmonary hypertension and right-sided heart failure. The purpose of this study was to investigate the efficacy of percutaneous transluminal pulmonary angioplasty (PTPA) for the treatment of chronic thromboembolic pulmonary hypertension.

METHODS AND RESULTS

Twenty-nine patients with chronic thromboembolic pulmonary hypertension underwent PTPA. One patient had a wiring perforation as a complication of PTPA and died 2 days after the procedure. In the remaining 28 patients, PTPA did not produce immediate hemodynamic improvement at the time of the procedure. However, after follow-up (6.0 ± 6.9 months), New York Heart Association functional classifications and levels of plasma B-type natriuretic peptide significantly improved (both P<0.01). Hemodynamic parameters also significantly improved (mean pulmonary arterial pressure, 45.3 ± 9.8 versus 31.8 ± 10.0 mm Hg; cardiac output, 3.6 ± 1.2 versus 4.6 ± 1.7 L/min, baseline versus follow-up, respectively; both P<0.01). Twenty-seven of 51 procedures in total (53%), and 19 of 28 first procedures (68%), had reperfusion pulmonary edema as the chief complication. Patients with severe clinical signs and/or severe hemodynamics at baseline had a high risk of reperfusion pulmonary edema.

CONCLUSIONS

PTPA improved subjective symptoms and objective variables, including pulmonary hemodynamics. PTPA may be a promising therapeutic strategy for the treatment of chronic thromboembolic pulmonary hypertension.

CLINICAL TRIAL REGISTRATION

URL: http://www.umin.ac.jp. Unique identifier: UMIN000001572.

CT evaluation of chronic thromboembolic pulmonary hypertension

The educational objectives of this article are to provide an overview of the computed tomography (CT) findings in chronic thromboembolic pulmonary hypertension. This article reviews the key imaging findings at CT in patients with chronic thromboembolic pulmonary hypertension. After reading this article, the reader should have an improved awareness of the condition, its imaging features, and the CT imaging features associated with surgically accessible disease.