Pulmonary Endarterectomy. Patient Selection, Technical Challenges, and Outcomes

Clinical outcome of lung transplantation for chronic thromboembolic pulmonary hypertension

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is a type of pulmonary hypertension with a low incidence. Despite pulmonary endarterectomy(PEA) being the preferred treatment for CTEPH, for patients who failed medical therapy and who are not suitable candidates for PEA, lung transplantation (LT) is still the only effective treatment for end-stage CTEPH; however, there are currently very few reports on the efficacy of LT for CTEPH.

METHODS

We retrospectively analyzed the clinical data of seven patients diagnosed with CTEPH between July 2019 and July 2021. The follow-up deadline was March, 2022.

RESULTS

The mean age at admission was 54 ± 12 years. The average value of mean pulmonary artery pressure (mPAP) was 40 ± 5 mmHg. The mean preoperative oxygenation index(PaO2/FiO2) was 203 ± 56 mm Hg. After evaluation, one patient underwent left LT and the rest underwent bilateral LT. Three patients received intraoperative veno-venous extracorporeal membrane oxygenation (ECMO) support, and four patients received intraoperative veno-arterial ECMO support. The average postoperative mPAP was 19 ± 4 mmHg. The mean postoperative oxygenation index(PaO2/FiO2) was 388 ± 83 mmHg. There was a significant difference between the preoperative and postoperative mPAP and oxygenation index(PaO2/FiO2). All patients recovered well and were discharged 37 ± 19 days postoperatively. The mean follow-up duration was 19 ± 8 months. There was no recurrence of CTEPH.

CONCLUSIONS

LT is an effective treatment for end-stage CTEPH, which can improve cardiopulmonary function and quality of life and prolong survival. Patients who are unable to tolerate PEA should be considered for LT as early as possible when internal medicine failed.

Chronic Thromboembolic Pulmonary Hypertension: the therapeutic assessment

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) is a severe and complex condition that evolves from unresolved pulmonary embolism, leading to fibrotic obstruction of pulmonary arteries, pulmonary hypertension, and potential right heart failure. The cornerstone of CTEPH management lies in a multifaceted therapeutic approach tailored to individual patient profiles, reflecting the disease's heterogeneity. This review delves into the current therapeutic strategies for CTEPH, including surgical pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA), and targeted pharmacological treatments such as PDE5 inhibitors, endothelin receptor antagonists, sGC stimulators, and prostanoids. Lifelong anticoagulation is also highlighted as a preventive strategy against recurrent thromboembolism. Special emphasis is placed on the interdisciplinary nature of CTEPH care, necessitating collaboration among PEA surgeons, BPA interventionists, PH specialists, and thoracic radiologists to ensure comprehensive treatment planning and execution. The review underscores the importance of selecting an appropriate treatment modality based on the patient's specific disease characteristics and the evolving landscape of CTEPH treatment, aiming to improve patient outcomes through integrated care strategies.

Chronic thromboembolic pulmonary hypertension: A comprehensive review of pathogenesis, diagnosis, and treatment strategies

Chronic thromboembolic pulmonary hypertension (CTEPH) is part of group 4 of the pulmonary hypertension (PH) classification and generally affects more than a third of patients referred to PH centers. It is a three-compartment disease involving proximal (lobar-to-segmental) and distal (subsegmental) pulmonary arteries that are obstructed by persistent fibrothrombotic material, and precapillary pulmonary arteries that can be affected as in pulmonary arterial hypertension. It is a rare complication of pulmonary embolism (PE), with an incidence of around 3% in PE survivors. The observed incidence of CTEPH in the general population is around six cases per million but could be three times higher than this, as estimated from PE incidence. However, a previous venous thromboembolic episode is not always documented. With advances in multimodality imaging and therapeutic management, survival for CTEPH has improved for both operable and inoperable patients. Advanced imaging with pulmonary angiography helps distinguish proximal from distal obstructive disease. However, right heart catheterization is of utmost importance to establish the diagnosis and hemodynamic severity of PH. The therapeutic strategy relies on a stepwise approach, starting with an operability assessment. Pulmonary endarterectomy (PEA), also known as pulmonary thromboendarterectomy, is the first-line treatment for operable patients. Growing experience and advances in surgical technique have enabled expansion of the distal limits of PEA and significant improvements in perioperative and mid- to long-term mortality. In patients who are inoperable or who have persistent/recurrent PH after PEA, medical therapy and/or balloon pulmonary angioplasty (BPA) are effective treatment options with favorable outcomes that are increasingly used. All treatment decisions should be made with a multidisciplinary team that includes a PEA surgeon, a BPA expert, and a chest radiologist.

Notch ratio in pulmonary flow predicts long-term survival after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

BACKGROUND

Assessment of the pattern of the RV outflow tract Doppler provides insights into the hemodynamics of chronic thromboembolic pulmonary hypertension (CTEPH). We studied whether pre-operative assessment of timing of the pulmonary flow systolic notch by Doppler echocardiography is associated with long-term survival after pulmonary endarterectomy (PEA) for CTEPH.

METHODS

Fifty-nine out of 61 consecutive CETPH patients (mean age 53 ± 14 years, 34% male) whom underwent PEA between June 2002 and June 2005 were studied. Clinical, echocardiographic and hemodynamic variables were assessed pre-operatively and repeat echocardiography was performed 3 months after PEA. Notch ratio (NR) was assessed with pulsed Doppler and calculated as the time from onset of pulmonary flow until notch divided by the time from notch until end of pulmonary flow. Long-term follow-up was obtained between May 2021 and February 2022.

RESULTS

Pre-operative mean pulmonary artery pressure (mPAP) was 45 ± 15 mmHg and pulmonary vascular resistance (PVR) was 646 ± 454 dynes.s.cm-5. Echocardiography before PEA showed that 7 patients had no notch, 33 had a NR < 1.0 and 19 had a NR > 1.0. Three months after PEA, echocardiography revealed a significant decrease in sPAP in long-term survivors with a NR < 1.0 and a NR > 1.0, while a significant increase in TAPSE/sPAP was only observed in the NR < 1.0 group. Mean long-term clinical follow-up was 14 ± 6 years. NR was significantly different between survivors and non-survivors (0.73 ± 0.25 vs. 1.1 ± 0.44, p < 0.001) but no significant differences were observed in mPAP or PVR. Long-term survival at 14 years was significantly better in patients with a NR < 1.0 compared to patients with a NR > 1.0 (83% vs. 37%, p =  < 0.001).

CONCLUSION

Pre-operative assessment of NR is a predictor of long-term survival in CTEPH patients undergoing PEA, with low mortality risk in patients with NR < 1.0. Long-term survivors with a NR < 1.0 and NR > 1.0 had a significant decrease in sPAP after PEA. However, the TAPSE/sPAP only significantly increased in the NR < 1.0 group. In the NR < 1.0 group, the 6-min walk test increased significantly between pre-operative and at 1-year post-operative follow-up. NR is a simple echocardiographic parameter that can be used in clinical decision-making for PEA.

Chronic Thromboembolic Pulmonary Hypertension: Clinical and Imaging Evaluation

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

Imaging of chronic thromboembolic pulmonary hypertension before, during and after balloon pulmonary angioplasty

Balloon pulmonary angioplasty (BPA) has recently been elevated as a class I recommendation for the treatment of inoperable or residual chronic thromboembolic pulmonary hypertension (CTEPH). Proper patient selection, procedural safety, and post-procedural evaluation are crucial in the management of these patients, with imaging work-up playing a pivotal role. Understanding the diagnostic and therapeutic imaging algorithms of CTEPH, the imaging features of patients amenable to BPA, all imaging findings observed during and immediately after the procedure and the changes observed during the follow-up is crucial for all interventional radiologists involved in the care of patients with CTEPH. This article illustrates the imaging work-up of patients with CTEPH amenable to BPA, the imaging findings observed before, during and after BPA, and provides a detailed description of all imaging modalities available for CTEPH evaluation.

The Initial Experience of Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension in Latvia

Background: Treatment options for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or persistent pulmonary hypertension after pulmonary endarterectomy (PEA) include targeted medical therapy and balloon pulmonary angioplasty (BPA). BPA is an emerging treatment modality that has been reported to improve functional capacity, pulmonary hemodynamics, and right ventricular function. Reports from expert centers are promising, but more data are needed to make the results more generalizable. Materials and Methods: We conducted a prospective analysis of nine consecutive CTEPH patients who underwent balloon pulmonary angioplasty (BPA) sessions at Pauls Stradins Clinical University Hospital in Riga, Latvia between 1 April 2022 and 1 July 2023. We assessed World Health Organization (WHO) functional class, 6 min walk distance (6MWD), blood oxygen saturation (SpO2), brain natriuretic peptide (BNP) level at baseline and 3 months after the first BPA session. For two patients on whom repeated BPA sessions were performed, we additionally assessed cardiac output (CO), pulmonary vascular resistance (PVR), and mean pulmonary artery pressure (mPAP). Results: A total of 12 BPA procedures for nine patients were performed; repeated BPA sessions were performed for two patients. Our results show a reduction in BNP levels and improvement in WHO functional class, 6MWD, and SpO2 after the first BPA session. Improvement in 6MWD was statistically significant. Additionally, an improvement in pulmonary hemodynamic parameters was observed. Conclusions: Our data show that BPA is an effective interventional treatment modality, improving both the pulmonary hemodynamics and functional status. Moreover, BPA is safe and excellently tolerated.

Endothelial Overexpression of TGF-β-Induced Protein Impairs Venous Thrombus Resolution: Possible Role in CTEPH

Endothelial cells play a critical role during venous thrombus remodeling, and unresolved, fibrotic thrombi with irregular vessels obstruct the pulmonary artery in patients with chronic thromboembolic pulmonary hypertension (CTEPH). This study sought to identify endothelial mediators of impaired venous thrombus resolution and to determine their role in the pathogenesis of the vascular obstructions in patients with CTEPH. Endothelial cells outgrown from pulmonary endarterectomy specimens (PEA) were processed for mRNA profiling, and nCounter gene expression and immunohistochemistry analysis of PEA tissue microarrays and immunoassays of plasma were used to validate the expression in CTEPH. Lentiviral overexpression in human pulmonary artery endothelial cells (HPAECs) and exogenous administration of the recombinant protein into C57BL/6J mice after inferior Vena cava ligation were employed to assess their role for venous thrombus resolution. RT2 PCR profiler analysis demonstrated the significant overexpression of factors downstream of transforming growth factor beta (TGFβ), that is TGFβ-Induced Protein (TGFBI or BIGH3) and transgelin (TAGLN), or involved in TGFβ signaling, that is follistatin-like 3 (FSTL3) and stanniocalcin-2 (STC2). Gene expression and immunohistochemistry analysis of tissue microarrays localized potential disease candidates to vessel-rich regions. Lentiviral overexpression of TGFBI in HPAECs increased fibrotic remodeling of human blood clots in vitro, and exogenous administration of recombinant TGFBI in mice delayed venous thrombus resolution. Significantly elevated plasma TGFBI levels were observed in patients with CTEPH and decreased after PEA. Our findings suggest that overexpression of TGFBI in endothelial promotes venous thrombus non-resolution and fibrosis and is causally involved in the pathophysiology of CTEPH.

Clinical-radiological-pathological correlation in chronic thromboembolic pulmonary hypertension

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

Semi-automatic quantification of mosaic perfusion of lung parenchyma and its correlation with haemodynamic parameters in patients with chronic thromboembolic pulmonary hypertension

AIM

To investigate the feasibility of semiautomatic quantification of mosaic perfusion and the associations between mosaic perfusion on computed tomography (CT; the ratio of hypoperfused parenchyma to the whole lung volume) and haemodynamic parameters through linear regression analysis.

MATERIALS AND METHODS

Fifty-eight consecutive patients (mean age 66 years, 28 females) diagnosed with chronic thromboembolic pulmonary hypertension (CTEPH) in General University Hospital, Prague, in 2021 were evaluated retrospectively and underwent both right heart catheterisation and CT pulmonary angiography. The parameters derived from the CT examinations were correlated with the recorded haemodynamic parameters.

RESULTS

A method was developed for semiautomatic detection of hypoperfused tissue from CT using widely available software and a statistically significant correlation was found between the proportion of hypoperfused parenchyma and the mean pulmonary artery pressure (mPAP; R2 0.22; p<0.01) and pulmonary vascular resistance (PVR; R2 0.09; p<0.05).

CONCLUSIONS

The developed method facilitates the quantification of mosaic perfusion, which is associated with important haemodynamic parameters (mPAP and PVR) in patients with CTEPH.

Predictors of procedural complications in balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

BACKGROUND

Balloon pulmonary angioplasty (BPA) is an effective treatment for inoperable chronic thromboembolic pulmonary hypertension, with good results reported for residual pulmonary hypertension (PH) after pulmonary endarterectomy (PEA). However, BPA is associated with complications, such as pulmonary artery perforation and vascular injury, which can lead to critical pulmonary hemorrhage requiring embolization and mechanical ventilation. Furthermore, the risk factors for occurrence of complications in BPA are unclear; therefore, this study aimed to evaluate predictors of procedural complications in BPA.

METHODS

In this retrospective study, we collected clinical data (patient characteristics, details of medical therapy, hemodynamic parameters, and details of the BPA procedure) from 321 consecutive sessions involving 81 patients who underwent BPA. Procedural complications were evaluated as endpoints.

RESULTS

BPA for residual PH after PEA was performed in 141 sessions (43.9 %), which involved 37 patients. Procedural complications were observed in 79 sessions (24.6 %), including severe pulmonary hemorrhage requiring embolization in 29 sessions (9.0 % of all sessions). No patients experienced severe complications requiring intubation with mechanical ventilation or extracorporeal membrane oxygenation. Age ≥ 75 years and mean pulmonary artery pressure ≥ 30 mmHg were independent predictors of procedural complications. Residual PH after PEA was a significant predictor of severe pulmonary hemorrhage requiring embolization (adjusted odds ratio, 3.048; 95 % confidence interval, 1.042-8.914, p = 0.042).

CONCLUSIONS

Older age, high pulmonary artery pressure, and residual PH after PEA increase the risk of severe pulmonary hemorrhage requiring embolization in BPA.

Impact of sex on outcome after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

BACKGROUND

The impact of sex on long-term outcomes after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (PH) remains unclear. We therefore examined the early and long-term outcome after PEA to determine whether sex had an impact on the risk of residual PH and need for targeted PH medical therapy.

METHODS

Retrospective study of 401 consecutive patients undergoing PEA at our institution between August 2005 and March 2020 was performed. Primary outcome was the need for targeted PH medical therapy postoperatively. Secondary outcomes included survival and measures of hemodynamic improvement.

RESULTS

Females (N = 203, 51%) were more likely to have preoperative home oxygen therapy (29.6% vs 11.6%, p < 0.01), and to present with segmental and subsegmental disease compared to males (49.2% vs 21.2%, p < 0.01). Despite similar preoperative values, females had higher postoperative pulmonary vascular resistance (final total pulmonary vascular resistance after PEA, 437 Dynes∙s∙cm-5 vs 324 Dynes∙s∙cm-5 in males, p < 0.01). Although survival at 10 years was not significantly different between sexes (73% in females vs 84% in males, p = 0.08), freedom from targeted PH medical therapy was lower in females (72.9% vs 89.9% in males at 5 years, p < 0.001). Female sex remained an independent factor affecting the need for targeted PH medical therapy after PEA in multivariate analysis (HR 2.03, 95%CI 1.03-3.98, p = 0.04).

CONCLUSIONS

Although outcomes are excellent for both sexes, females had greater need for targeted PH medical therapy in the long-term. Early reassessment and long-term follow-up of these patients are important. Further investigations into possible mechanisms to explain the differences are warranted.

[Chronic thromboembolic pulmonary hypertension]

Chronic thromboembolic pulmonary disease (CTEPD) is an important late complication of acute pulmonary embolism, in which the thrombi transform into fibrous tissue, become integrated into the vessel wall, and lead to chronic obstructions. CTEPD is differentiated into cases without pulmonary hypertension (PH), characterized by a mean pulmonary arterial pressure up to 20 mmHg and a form with PH. Then, it is still referred to as chronic thromboembolic pulmonary hypertension (CTEPH).When there is suspicion of CTEPH, initial diagnostic tests should include echocardiography and ventilation/perfusion scan to detect perfusion defects. Subsequently, referral to a CTEPH center is recommended, where further imaging diagnostics and right heart catheterization are performed to determine the appropriate treatment.Currently, three treatment modalities are available. The treatment of choice is pulmonary endarterectomy (PEA). For non-operable patients or patients with residual PH after PEA, PH-targeted medical therapy, and the interventional procedure of balloon pulmonary angioplasty (BPA) are available. Increasingly, PEA, BPA, and pharmacological therapy are combined in multimodal concepts.Patients require post-treatment follow-up, preferably at (CTE)PH centers. These centers are required to perform a minimum number of PEA surgeries (50/year) and BPA interventions (100/year).

Computed Tomography Pulmonary Angiography Prediction of Adverse Long-Term Outcomes in Chronic Thromboembolic Pulmonary Hypertension: Correlation with Hemodynamic Measurements Pre- and Post-Pulmonary Endarterectomy

CT pulmonary angiography is commonly used in diagnosing chronic thromboembolic pulmonary hypertension (CTEPH). This work was conducted to determine if cardiac chamber size on CTPA may also be useful for predicting the outcome of CTEPH treatment. A retrospective analysis of paired CTPA and right heart hemodynamics in 33 consecutive CTEPH cases before and after pulmonary thromboendarterectomy (PTE) was performed. Semiautomated and manual CT biatrial and biventricular size quantifications were correlated with mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR) and cardiac output. The baseline indexed right atrioventricular volumes were twice the left atrioventricular volumes, with significant (p < 0.001) augmentation of left heart filling following PTE. Except for the left atrial volume to cardiac index, all other chamber ratios significantly correlated with hemodynamics. Left to right ventricular ratio cut point <0.82 has high sensitivity (91% and 97%) and specificity (88% and 85%) for identifying significant elevations of mPAP and PVR, respectively (AUC 0.90 and 0.95), outperforming atrial ratios (sensitivity 78% and 79%, specificity 82% and 92%, and AUC 0.86 and 0.91). Manual LV:RV basal dimension ratio correlates strongly with semiautomated volume ratio (r 0.77, 95% CI 0.64-0.85) and is an expeditious alternative with comparable prognostic utility (AUC 0.90 and 0.95). LV:RV dimension ratio of <1.03 and ≤0.99 (alternatively expressed as RV:LV ratio of >0.97 and ≥1.01) is a simple metric that can be used for CTEPH outcome prediction.

Chronic thromboembolic pulmonary hypertension: More options, more awareness

-

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.

Distribution of thrombus predicts severe reperfusion pulmonary edema after pulmonary endarterectomy

OBJECTIVES

Patients underwent pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH). This study aimed to investigate the effect of thrombus distribution on the occurrence of severe reperfusion pulmonary edema (RPE) and identify specific parameters for predicting severe RPE.

METHODS

Patients with CTEPH who underwent PEA surgery were retrospectively analyzed. The thrombus in pulmonary arteries were evaluated through computed tomography pulmonary angiography. Based on presence of prolonged artificial ventilation, extracorporeal membrane oxygenation required, or perioperative death due to RPE, the patients were divided into the severe RPE and without severe RPE groups.

MAIN RESULTS

Among the 77 patients (29 women), 16 (20.8%) patients developed severe RPE. The right major pulmonary artery (RPA) (0.64[0.58, 0.73] vs 0.58[0.49, 0.64]; p = 0.008) and pulmonary artery trunk (PAT) thrombus ratios (0.48[0.44, 0.61] vs 0.42[0.39, 0.50]; p = 0.009) (the PAT ratio is expressed as the sum of the right middle lobe clot burden and right lower lobe clot burden divided by the total clot burden multiplied by 100) of the severe RPE group was significantly higher than that of the without severe RPE group. Receiver operator characteristics curve identified a PAT ratio of 43.4% as the threshold with areas under the curve = 0.71(95%CI 0.582; 0.841) for the development of severe RPE (sensitivity 0.875, specificity 0.541). The logistic regression analysis demonstrated that age, period from symptom onset to PEA, NT-pro BNP, preoperative mPAP, preoperative PVR, RPA ratio, and PAT ratio were associated with the development of severe RPE. Multivariable logistic regression analysis revealed PAT ratio (odds ratio = 10.2; 95% confidence interval 1.87, 55.53, P = 0.007) and period from symptom onset to PEA (OR = 1.01; 95% CI = 1.00-1.02, P = 0.015) as independent risk factors for the development of severe RPE.

CONCLUSIONS

The thrombus distribution could be a key factor in the severity of RPE. PAT ratio and medical history could predict the development of severe RPE.

Mapping the Spatial Extent of Hypoperfusion in Chronic Thromboembolic Pulmonary Hypertension Using Multienergy CT

Purpose

To assess if a novel automated method to spatially delineate and quantify the extent of hypoperfusion on multienergy CT angiograms can aid the evaluation of chronic thromboembolic pulmonary hypertension (CTEPH) disease severity.

Materials and Methods

Multienergy CT angiograms obtained between January 2018 and December 2020 in 51 patients with CTEPH (mean age, 47 years ± 17 [SD]; 27 women) were retrospectively compared with those in 110 controls with no imaging findings suggestive of pulmonary vascular abnormalities (mean age, 51 years ± 16; 81 women). Parenchymal iodine values were automatically isolated using deep learning lobar lung segmentations. Low iodine concentration was used to delineate areas of hypoperfusion and calculate hypoperfused lung volume (HLV). Receiver operating characteristic curves, correlations with preoperative and postoperative changes in invasive hemodynamics, and comparison with visual assessment of lobar hypoperfusion by two expert readers were evaluated.

Results

Global HLV correctly separated patients with CTEPH from controls (area under the receiver operating characteristic curve = 0.84; 10% HLV cutoff: 90% sensitivity, 72% accuracy, and 64% specificity) and correlated moderately with hemodynamic severity at time of imaging (pulmonary vascular resistance [PVR], ρ = 0.67; P < .001) and change after surgical treatment (∆PVR, ρ = -0.61; P < .001). In patients surgically classified as having segmental disease, global HLV correlated with preoperative PVR (ρ = 0.81) and postoperative ∆PVR (ρ = -0.70). Lobar HLV correlated moderately with expert reader lobar assessment (ρHLV = 0.71 for reader 1; ρHLV = 0.67 for reader 2).

Conclusion

Automated quantification of hypoperfused areas in patients with CTEPH can be performed from clinical multienergy CT examinations and may aid clinical evaluation, particularly in patients with segmental-level disease.Keywords: CT-Spectral Imaging (Multienergy), Pulmonary, Pulmonary Arteries, Embolism/Thrombosis, Chronic Thromboembolic Pulmonary Hypertension, Multienergy CT, Hypoperfusion© RSNA, 2023.

Distal vessel pulmonary thromboendarterectomy: Results from a single institution

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is primarily managed by pulmonary thromboendarterectomy (PTE). As advanced surgical techniques permit resection at the segmental and subsegmental level, PTE can now be curative for CTEPH mostly involving the distal pulmonary arteries.

METHODS

Between January 2017 and June 2021, consecutive patients undergoing PTE were categorized according to the most proximal level of chronic thrombus resection: Level I (main pulmonary artery), Level II (lobar), Level III (segmental) and Level IV (subsegmental). Proximal disease patients (any Level I or II) were compared to distal disease (Level III or IV bilaterally) patients. Demographics, medical history, preoperative pulmonary hemodynamics, and immediate postoperative outcomes were obtained for each group.

RESULTS

During the study period, 794 patients underwent PTE, 563 with proximal disease and 231 with distal disease. Patients with distal disease more frequently had a history of an indwelling intravenous device, splenectomy, upper extremity thrombosis or use thyroid replacement and less often had prior lower extremity thrombosis or hypercoagulable state. Despite more use of PAH-targeted medications in the distal disease group (63.2% vs 50.1%, p < 0.001), preoperative hemodynamics were similar. Both patient groups exhibited significant improvements in pulmonary hemodynamics postoperatively with comparable in-hospital mortality rates. Compared to proximal disease, a lower percentage of patients with distal disease showed residual pulmonary hypertension (3.1% vs 6.9%, p = 0.039) and airway hemorrhage (3.0% vs 6.6%, p = 0.047) postoperatively.

CONCLUSIONS

Thromboendarterectomy for distal (segmental and subsegmental) CTEPH is technically feasible and may result in favorable pulmonary hemodynamic outcomes, without increased mortality or morbidity.

Pulmonary artery blood flow dynamics in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension is caused by incomplete resolution and organization of thrombi. Blood flow dynamics are involved in thrombus formation; however, only a few studies have reported on pulmonary artery blood flow dynamics in patients with chronic thromboembolic pulmonary hypertension. Furthermore, the effects of treatment interventions on pulmonary artery blood flow dynamics are not fully understood. The aim of the study was to evaluate pulmonary artery blood flow dynamics in patients with chronic thromboembolic pulmonary hypertension before and after pulmonary endarterectomy and balloon pulmonary angioplasty, using computational fluid dynamics. We analyzed patient-specific pulmonary artery models of 10 patients with chronic thromboembolic pulmonary hypertension and three controls using computational fluid dynamics. In patients with chronic thromboembolic pulmonary hypertension, flow velocity and wall shear stress in the pulmonary arteries were significantly decreased, and the oscillatory shear index and blood stagnation volume were significantly increased than in controls. Pulmonary endarterectomy induced redistribution of pulmonary blood flow and improved blood flow dynamics in the pulmonary artery. Balloon pulmonary angioplasty improved pulmonary blood flow disturbance, decreased blood flow stagnation, and increased wall shear stress, leading to vasodilatation of the distal portion of the pulmonary artery following balloon pulmonary angioplasty treatment.

Pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension: Relationship between treated branches and outcome

BACKGROUND

In patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing pulmonary endarterectomy (PEA) it is important to minimize residual obstructions, in order to achieve low postoperative pulmonary vascular resistances and better clinical results. The aim of the study was to test the hypothesis that the greater the number of pulmonary artery branches treated at surgery, the better the hemodynamic and clinical outcome after PEA.

METHODS

In 564 consecutive CTEPH patients undergoing PEA the count of the number of treated branches was performed directly on the surgical specimens. Post-operative follow-up visits were scheduled at 3 months and 12 months after surgery including right heart catheterization and modified Bruce test.

RESULTS

The population was divided into tertiles based on the number of treated branches: Group 1 (from 4 to 30 treated branches, n = 194 patients); Group 2 (from 31 to 43 treated branches, n = 190 patients); Group 3 (from 44 to 100 treated branches, n = 180 patients). At 3 and at 12 months after PEA, after adjustment for confounders, patients in the highest tertile of treated branches had significantly lower values of pulmonary vascular resistance and higher values of pulmonary arterial compliance as compared to the other two groups (p < 0.002). Hospital mortality was 3% in Group 3, 6% in Group 2 and 10% in Group 1 (overall p = 0.035).

CONCLUSIONS

In CTEPH patients undergoing PEA, a higher number of treated pulmonary artery branches is associated with a better hemodynamic and a better clinical outcome at 3 months and 12 months after surgery.

Hydrodissection in chronic pulmonary endarterectomy

In our series of surgical pulmonary endarterectomies done for chronic thromboembolic pulmonary hypertension, we have incorporated the principle of hydrodissection with the aid of a carbon dioxide (CO2) mist blower which is routinely used for off-pump coronary artery bypass (OPCAB) surgeries. This added method of endarterectomy will help to achieve optimum clearance of thrombic load with basic cardiac surgical instruments.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01476-w.

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

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

Comparison of the safety and efficacy of balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension patients with surgically accessible and inaccessible lesions

BACKGROUND

Although pulmonary endarterectomy is the treatment of choice for chronic thromboembolic pulmonary hypertension, not all patients are eligible. While balloon pulmonary angioplasty is an alternative for such patients, its efficacy and safety may differ between patients with and without surgically accessible lesions.

METHODS

This study involved 344 patients treated with balloon pulmonary angioplasty who were ineligible for pulmonary endarterectomy. Based on the angiographical lesion location, patients were divided into the surgically accessible (Group 1) and inaccessible (Group 2) groups, and percent changes in hemodynamics and clinical parameters before and after balloon pulmonary angioplasty were investigated. We also conducted survival analyses using Kaplan-Meier analysis.

RESULTS

While no differences in baseline characteristics were identified between the groups, balloon pulmonary angioplasty significantly improved hemodynamics in both groups, without any difference regarding the incidence of complications. Meanwhile, the percent changes in the mean pulmonary arterial pressure, pulmonary vascular resistance, 6-min walk distance, right ventricular area index on echocardiography, and the achievement rate of World Health Organization functional class I after balloon pulmonary angioplasty were significantly lower in Group 1 than in Group 2. The cumulative survival rates at 1, 5, and 10 years after balloon pulmonary angioplasty were not significantly different between the two groups (Group 1: 92.5%, 86.1%, 84.3%; and Group 2: 96.5%, 92.9%, 90.1%, respectively).

CONCLUSIONS

The outcome of balloon pulmonary angioplasty in inoperable patients with surgically accessible proximal lesions was acceptable; however, further investigations are necessary to clarify the optimal treatment for such patients.

[Pulmonary Endarterectomy and Treatment for Chronic Thromboembolic Pulmonary Hypertension]

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

Long-term outcome prediction for chronic thromboembolic pulmonary hypertension after pulmonary endarterectomy

BACKGROUND

The definitive treatment for chronic thromboembolic pulmonary hypertension (CTEPH) is pulmonary endarterectomy (PEA), which has good long-term outcomes. However, after surgery, a quarter of the patients still have residual pulmonary hypertension (RPH). In pulmonary hemodynamics, there are no unified criteria for RPH, even though the level may affect long-term survival.

METHODS

Between March 1997 and December 2021, 253 CTEPH patients were treated at our center with PEA. Patients were evaluated retrospectively and classified into early (1997-2014) and late (2015-2021) groups. The clinical characteristics and perioperative outcomes of the two groups were compared, and risk factor analysis for RPH and long-term survival for all cases was performed.

RESULTS

There was no statistically significant difference in demographics between the two groups. However, the Early Group had a significantly higher rate of perioperative death (9.8% vs. 1.2%, p = .001), RPH (48.8% vs. 14.0%, p < .001), and reperfusion pulmonary edema (18.3% vs. 2.9%, p < .001). The median follow-up time was 66.0 months, and overall survival rates at 5, 10, 15, and 18 years after PEA were 91.2%, 83.9%, 64.5%, and 46.0%, respectively. Age and postoperative systolic pulmonary artery pressure (sPAP) were independently related to long-term outcomes in the multivariate Cox analyses. Patients with postoperative sPAP less than 46 mm Hg had a higher chance of survival.

CONCLUSIONS

PEA improved CTEPH hemodynamics immediately and had a positive effect on long-term survival. Patients with postoperative sPAP ≥ 46 mm Hg indicate clinically significant RPH and have a lower long-term survival rate.

Pulmonary artery intimal sarcoma: A rare cause of filling defects in pulmonary arteries

Pulmonary artery intimal sarcomas are very rare and arise from primitive pluripotent mesenchymal cells. They are often misdiagnosed as pulmonary thromboembolism, leading to futile anticoagulation treatment and delayed diagnosis. We present a case of a patient who showed nonspecific pulmonary symptoms and characteristic imaging manifestation. Progressive symptoms and additional imaging led to the suspicion of a pulmonary artery intimal sarcoma, which was finally confirmed by pathological biopsy. This case serves as a reminder to consider pulmonary artery intimal sarcomas in the differential diagnosis of patients with dyspnea and filling defects on computed tomography pulmonary angiography or contrast-enhanced computed tomography.

Catheter-directed therapies for the treatment of high risk (massive) and intermediate risk (submassive) acute pulmonary embolism

BACKGROUND

Acute pulmonary embolism (APE) is a major cause of acute morbidity and mortality. APE results in long-term morbidity in up to 50% of survivors, known as post-pulmonary embolism (post-PE) syndrome.  APE can be classified according to the short-term (30-day) risk of mortality, based on a variety of clinical, imaging and laboratory findings. Most mortality and morbidity is concentrated in high-risk (massive) and intermediate-risk (submassive) APE. The first-line treatment for APE is systemic anticoagulation.  High-risk (massive) APE accounts for less than 10% of APE cases and is a life-threatening medical emergency, requiring immediate reperfusion treatment to prevent death. Systemic thrombolysis is the recommended treatment for high-risk (massive) APE. However, only a minority of the people affected receive systemic thrombolysis, due to comorbidities or the 10% risk of major haemorrhagic side effects. Of those who do receive systemic thrombolysis, 8% do not respond in a timely manner. Surgical pulmonary embolectomy is an alternative reperfusion treatment, but is not widely available.  Intermediate-risk (submassive) APE represents 45% to 65% of APE cases, with a short-term mortality rate of around 3%. Systemic thrombolysis is not recommended for this group, as major haemorrhagic complications outweigh the benefit. However, the people at higher risk within this group have a short-term mortality of around 12%, suggesting that anticoagulation alone is not an adequate treatment. Identification and more aggressive treatment of people at intermediate to high risk, who have a more favourable risk profile for reperfusion treatments, could reduce short-term mortality and potentially reduce post-PE syndrome. Catheter-directed treatments (catheter-directed thrombolysis and catheter embolectomy) are minimally invasive reperfusion treatments for high- and intermediate-risk APE. Catheter-directed treatments can be used either as the primary treatment or as salvage treatment after failure of systemic thrombolysis. Catheter-directed thrombolysis administers 10% to 20% of the systemic thrombolysis dose directly into the thrombus in the lungs, potentially reducing the risks of haemorrhagic side effects. Catheter embolectomy mechanically removes the thrombus without the need for thrombolysis, and may be useful for people with contraindications for thrombolysis.  Currently, the benefits of catheter-based APE treatments compared with existing medical and surgical treatment are unclear despite increasing adoption of catheter treatments by PE response teams. This review examines the evidence for the use of catheter-directed treatments in high- and intermediate-risk APE. This evidence could help guide the optimal treatment strategy for people affected by this common and life-threatening condition.

OBJECTIVES

To assess the effects of catheter-directed therapies versus alternative treatments for high-risk (massive) and intermediate-risk (submassive) APE.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was 15 March 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of catheter-directed therapies for the treatment of high-risk (massive) and intermediate-risk (submassive) APE. We excluded catheter-directed treatments for non-PE. We applied no restrictions on participant age or on the date, language or publication status of RCTs.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. The main outcomes were all-cause mortality, treatment-associated major and minor haemorrhage rates based on two established clinical definitions, recurrent APE requiring retreatment or change to a different APE treatment, length of hospital stay, and quality of life. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We identified one RCT (59 participants) of (ultrasound-augmented) catheter-directed thrombolysis for intermediate-risk (submassive) APE. We found no trials of any catheter-directed treatments (thrombectomy or thrombolysis) in people with high-risk (massive) APE or of catheter-based embolectomy in people with intermediate-risk (submassive) APE. The included trial compared ultrasound-augmented catheter-directed thrombolysis with alteplase and systemic heparinisation versus systemic heparinisation alone. In the treatment group, each participant received an infusion of alteplase 10 mg or 20 mg over 15 hours. We identified a high risk of selection and performance bias, low risk of detection and reporting bias, and unclear risk of attrition and other bias. Certainty of evidence was very low because of risk of bias and imprecision.  By 90 days, there was no clear difference in all-cause mortality between the treatment group and control group. A single death occurred in the control group at 20 days after randomisation, but it was unrelated to the treatment or to APE (odds ratio (OR) 0.31, 95% confidence interval (CI) 0.01 to 7.96; 59 participants). By 90 days, there were no episodes of treatment-associated major haemorrhage in either the treatment or control group. There was no clear difference in treatment-associated minor haemorrhage between the treatment and control group by 90 days (OR 3.11, 95% CI 0.30 to 31.79; 59 participants). By 90 days, there were no episodes of recurrent APE requiring retreatment or change to a different APE treatment in the treatment or control group. There was no clear difference in the length of mean total hospital stay between the treatment and control groups. Mean stay was 8.9 (standard deviation (SD) 3.4) days in the treatment group versus 8.6 (SD 3.9) days in the control group (mean difference 0.30, 95% CI -1.57 to 2.17; 59 participants). The included trial did not investigate quality of life measures.  AUTHORS' CONCLUSIONS: There is a lack of evidence to support widespread adoption of catheter-based interventional therapies for APE. We identified one small trial showing no clear differences between ultrasound-augmented catheter-directed thrombolysis with alteplase plus systemic heparinisation versus systemic heparinisation alone in all-cause mortality, major and minor haemorrhage rates, recurrent APE and length of hospital stay. Quality of life was not assessed.  Multiple small retrospective case series, prospective patient registries and single-arm studies suggest potential benefits of catheter-based treatments, but they provide insufficient evidence to recommend this approach over other evidence-based treatments. Researchers should consider clinically relevant primary outcomes (e.g. mortality and exercise tolerance), rather than surrogate markers (e.g. right ventricular to left ventricular (RV:LV) ratio or thrombus burden), which have limited clinical utility. Trials must include a control group to determine if the effects are specific to the treatment.

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.

Cardiopulmonary exercise testing for treatment effect assessment in chronic thromboembolic pulmonary hypertension patients

Aim      To determine possibilities of the cardiopulmonary stress test (CPST) as an unbiassed, noninvasive method for evaluation of the effect of managing patients with chronic thromboembolic pulmonary hypertension (CTEPH).Material and methods  This study included 37 patients with CTEPH, 24 men (mean age, 53±15 years) and 13 women (mean age, 58±8.5 years). The diagnosis was verified and theCoperability was assessed according to 2015 European Society of Cardiology Clinical Guidelines for the Diagnosis and Treatment of Pulmonary Hypertension (PH). The surgical treatment was used in 65 % (n=24) of CTEPH patients: the group with pulmonary thromboendarterectomy constituted 35 % (n=13); the group with balloon pulmonary angioplasty 30% (n=11); and the conservative tactics was used in 27 % (n=10) of patients.Results Baseline CPST parameters significantly correlated with parameters of right heart catheterization (RHC): mixed venous oxygen saturation (SvO2) significantly positively correlated with V´O2peak (r=0.640, p&lt;0.05), V´O2 / heart rate (HR) (r=0.557; p&lt;0.001), PETCO2 peak (r=0.598, p&lt;0.05), and V´E / V´CO2 (r=0.587; p&lt;0.001); cardiac output (CO) correlated with V´O2 / HR (r=0.555, p&lt;0.001), PETCO2peak (r= -0.476; p&lt;0.05 and r=0.555, p&lt;0.001 for ´E / V´CO2). In repeated testing, the physical working capacity (V´O2peak) increased only in patients after the surgical treatment of CTEPH. Importantly in this process, significant correlations remained between a number of CPST and RHC parameters: SvO2 correlated with V´O2peak (r=0.743; p&lt;0.05), V´O2 /HR (r=0.627; p&lt;0.001), PETCO2peak (r=0.538; p&lt;0.05), and V´E / V´CO2 (r=0.597; p&lt;0.001); V´O2 / HR, PETCO2peak, and V´E / V´CO2 significantly correlated with CO (r=0.645, p&lt;0.001; r= -0.516, p&lt;0.001, and r=0.555, p&lt;0.001, respectively.Conclusion      CPST can be used as a noninvasive instrument for evaluation of the effect of CTEPH treatment, particularly in the absence of echocardiographic data for residual PH.

Therapeutic alternatives in chronic thromboembolic pulmonary hypertension: from pulmonary endarterectomy to balloon pulmonary angioplasty to medical therapy. State of the art from a multidisciplinary team

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease with a very complex pathophysiology differing from other causes of pulmonary hypertension (PH). It is an infrequent consequence of acute pulmonary embolism that is frequently misdiagnosed. Pathogenesis has been related to coagulation abnormalities, infection or inflammation, although these disturbances can be absent in many cases. The hallmarks of CTEPH are thrombotic occlusion of pulmonary vessels, variable degree of ventricular dysfunction and secondary microvascular arteriopathy. The definition of CTEPH also includes an increase in mean pulmonary arterial pressure of more than 25 mmHg with a normal pulmonary capillary wedge of less than 15 mmHg. It is classified as World Health Organization group 4 PH, and is the only type that can be surgically cured by pulmonary endarterectomy (PEA). This operation needs to be carried out by a team with strong expertise, from the diagnostic and decisional pathway to the operation itself. However, because the disease has a very heterogeneous phenotype in terms of anatomy, degree of PH and the lack of a standard patient profile, not all cases of CTEPH can be treated by PEA. As a result, PH-directed medical therapy traditionally used for the other types of PH has been proposed and is utilized in CTEPH patients. Since 2015, we have been witnessing the rebirth of balloon pulmonary angioplasty, a technique first performed in 2001 but has since fallen out fashion due to major complications. The refinement of such techniques has allowed its safe utilization as a salvage therapy in inoperable patients. In the present keynote lecture, we will describe these therapeutic approaches and results.

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

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

Surgical Management of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension is a progressive disease, which may lead to severe right ventricular dysfunction and debilitating symptoms. Pulmonary thromboendarterectomy (PTE) provides the best opportunity for complete resolution of obstructing thromboembolic disease and functional improvement in appropriately selected patients. In this article, the authors review preoperative workup, patient selection, operative technique, postoperative care, and outcomes after PTE.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Dual-Energy CT Pulmonary Angiography for the Assessment of Surgical Accessibility in Patients with Chronic Thromboembolic Pulmonary Hypertension

We assessed the value of dual-energy CT pulmonary angiography (CTPA) for classification of the level of disease in chronic thromboembolic pulmonary hypertension (CTEPH) patients compared to the surgical Jamieson classification and prediction of hemodynamic changes after pulmonary endarterectomy. Forty-three CTEPH patients (mean age, 57 ± 16 years; 18 females) undergoing CTPA prior to surgery were retrospectively included. “Proximal” and “distal disease” were defined as L1 and 2a (main and lobar pulmonary artery [PA]) and L2b-4 (lower lobe basal trunk to subsegmental PA), respectively. Three radiologists had a moderate interobserver agreement for the radiological classification of disease (k = 0.55). Sensitivity was 92–100% and specificity was 24–53% to predict proximal disease according to the Jamieson classification. A median of 9 segments/patient had CTPA perfusion defects (range, 2–18 segments). L1 disease had a greater decrease in the mean pulmonary artery pressure (p = 0.029) and pulmonary vascular resistance (p = 0.011) after surgery compared to patients with L2a to L3 disease. The extent of perfusion defects was not associated with the level of disease or hemodynamic changes after surgery (p > 0.05 for all). CTPA is highly sensitive for predicting the level of disease in CTEPH patients with a moderate interobserver agreement. The radiological level of disease is associated with hemodynamic improvement after surgery.

Dynamic tracking of microvascular hemoglobin content for continuous perfusion monitoring in the intensive care unit: pilot feasibility study

PURPOSE

There is a need for bedside methods to monitor oxygen delivery in the microcirculation. Near-infrared spectroscopy commonly measures tissue oxygen saturation, but does not reflect the time-dependent variability of microvascular hemoglobin content (MHC) that attempts to match oxygen supply with demand. The objective of this study is to determine the feasibility of MHC monitoring in critically ill patients using high-resolution near-infrared spectroscopy to assess perfusion in the peripheral microcirculation.

METHODS

Prospective observational cohort of 36 patients admitted within 48 h at a tertiary intensive care unit. Perfusion was measured on the quadriceps, biceps, and/or deltoid, using the temporal change in optical density at the isosbestic wavelength of hemoglobin (798 nm). Continuous wavelet transform was applied to the hemoglobin signal to delineate frequency ranges corresponding to physiological oscillations in the cardiovascular system.

RESULTS

31/36 patients had adequate signal quality for analysis, most commonly affected by motion artifacts. MHC signal demonstrates inter-subject heterogeneity in the cohort, indicated by different patterns of variability and frequency composition. Signal characteristics were concordant between muscle groups in the same patient, and correlated with systemic hemoglobin levels and oxygen saturation. Signal power was lower for patients receiving vasopressors, but not correlated with mean arterial pressure. Mechanical ventilation directly impacts MHC in peripheral tissue.

CONCLUSION

MHC can be measured continuously in the ICU with high-resolution near-infrared spectroscopy, and reflects the dynamic variability of hemoglobin distribution in the microcirculation. Results suggest this novel hemodynamic metric should be further evaluated for diagnosing microvascular dysfunction and monitoring peripheral perfusion.

Pulmonary endarterectomy

Chronic thromboembolic pulmonary hypertension is an underdiagnosed condition. Patients typically present with the symptoms of right heart failure. Diagnosis is usually done by radionuclide ventilation/perfusion (VQ) scan, high-quality multidetector computed tomography (CT) or pulmonary angiography at expert centers. Pulmonary endarterectomy remains the corner stone in management of chronic thromboembolic pulmonary hypertension. Deep hypothermic circulatory arrest is commonly used for the operation at most centers. In-hospital mortality ranges from 1.7 to 14.2%. Pulmonary hemorrhage, reperfusion lung injury, and right ventricular failure remain major early post-operative concerns. Five-year survival is reported to be 76 to 89%. Long-term outcome depends on residual pulmonary hypertension. Balloon pulmonary angioplasty and medical management play an adjunctive role. Here, we provide a comprehensive review on surgical management of chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension anno 2021

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Chronic thromboembolic pulmonary hypertension in Australia and New Zealand: An analysis of the PHSANZ registry

BACKGROUND AND OBJECTIVE

Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious condition occurring in 2%-4% of patients after acute pulmonary embolism. Pulmonary endarterectomy (PEA) is a potential cure for technically operable disease. The epidemiology and long-term outcomes of CTEPH have not been previously described in Australia and New Zealand.

METHODS

Data were extracted from the Pulmonary Hypertension Society of Australia and New Zealand (PHSANZ) registry for patients diagnosed with CTEPH between January 2004 and March 2020. Baseline characteristics, treatment strategies, outcome data and long-term survival are reported.

RESULTS

A total of 386 patients were included with 146 (37.8%) undergoing PEA and 240 (62.2%) in the non-PEA group. PEA patients were younger (55 ± 16 vs. 62 ± 16 years, p < 0.001) with higher baseline 6-min walk distance (6MWD; 405 ± 122 vs. 323 ± 146 m, p = 0.021), whilst both groups had similar baseline pulmonary haemodynamics. Pulmonary hypertension-specific therapy was used in 54% of patients post-PEA and 88% in the non-PEA group. The 1-, 3- and 5-year survival rates were 93%, 87% and 84% for the PEA group compared to 86%, 73% and 62%, respectively, for the non-PEA group (p < 0.001). Multivariate survival analysis showed baseline 6MWD was an independent predictor of survival in both operated and medically managed patients.

CONCLUSION

In this first multicentre report of CTEPH in Australia and New Zealand, long-term survival is comparable to that in other contemporary CTEPH registries. However, PEA was only performed in a minority of CTEPH patients (37.8%) and significantly less than overseas reports. Greater awareness of PEA and improved patient access to experienced CTEPH centres are important priorities.

Sex Differences in Chronic Thromboembolic Pulmonary Hypertension. Treatment Options over Time in a National Referral Center

(1) Background: Clinical presentation, disease distribution, or treatment received may provide insights into the reasons contributing to sex differences in chronic thromboembolic pulmonary hypertension (CTEPH). (2) Methods: We evaluated 453 patients (56% women) between 2007-2019. Data was collected from REHAP (Registro Español de Hipertensión Arterial Pulmonar) registry. Two time periods were selected to evaluate the influence of new treatments over time. (3) Results: Women were older. Baseline functional class was worse, and distance walked shorter in women compared with men. Women had higher pulmonary vascular resistances. Despite this, pulmonary endarterectomy (PEA) was carried out in more men, and women received more frequently pulmonary vasodilators exclusively. The 2014-2019 interval was associated with a better survival only among women. Interestingly, women had a more distal disease during this second period of time. (4) Conclusions: Even though women were older, and received invasive treatments less frequently, mortality was similar in both sexes. The introduction of balloon pulmonary angioplasty and the improvement of pulmonary endarterectomy, especially during the last years, could be associated with a survival benefit among women.

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

Objectives

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

Methods

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

Results

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

Conclusion

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

Experience with pulmonary endarterectomy: Lessons learned across 17 years

BACKGROUND

Pulmonary endarterectomy is potential curative therapy for chronic thromboembolic pulmonary hypertension patients. Here, we present our experience with pulmonary endarterectomy spanning 17 years and detail our management strategy.

METHODS

This is a single-centre retrospective study conducted on chronic thromboembolic pulmonary hypertension patients who underwent pulmonary endarterectomy at our centre across 17 years.

RESULTS

Between 2004 and 2020, 591 patients underwent pulmonary endarterectomy. Amongst them 429 (72.4%) were males with a male to female ratio of 2.6:1, the median age was 38 (range, 14-73) years. The median length of hospital stay was 11 days (IQR, 8-16). Extra corporeal membranous oxygenation was used in 82 (13.9%) patients during/after surgery, out of whom 28 (34.1%) survived. There were 70 (11.8%) in-hospital deaths. Female gender (p < 0.01), pulmonary artery systolic pressure >100 mmHg (p < 0.05) and use of extra corporeal membrane oxygenation (p < 0.001) were significant risk factors for in-hospital mortality. The mortality in the first period (2004-2012) was 15.7% which reduced to 9.1% in the later period (2013-2020). The reduction in mortality rate was 42% (p < 0.05). Following pulmonary endarterectomy, there was a significant reduction in pulmonary artery systolic pressure (86.68 ± 24.38 vs. 39.71 ± 13.13 mmHg; p < 0.001) and improvement in median walk distance as measured by 6-min walk test on follow-up (300 vs. 450 meters; p < 0.001). The median duration of follow-up was 8 months (inter-quartile range: 2-24).

CONCLUSIONS

pulmonary endarterectomy has a learning curve, high pulmonary vascular resistance alone is not a contraindication for surgery. Patients following surgery have improved survival and quality of life.

Multimodal Approach of Isolated Pulmonary Vasculitis: A Single-Institution Experience

BACKGROUND

Isolated pulmonary vasculitis (IPV) is a single-organ vasculitis of unknown etiology and may mimic chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this study was to review our clinical experience with pulmonary endarterectomy in patients with CTEPH secondary to IPV.

METHODS

Data were collected prospectively for consecutive patients who underwent pulmonary endarterectomy and had a diagnosis of IPV at or after surgery.

RESULTS

We identified nine patients (six female, median age 48 (23-55) years) with IPV. The diagnosis was confirmed after histopathological examination of all surgical materials. The mean duration of disease before surgery was 88.0 ±70.2 months. Exercise-induced dyspnea was the presenting symptom in all patients. Pulmonary endarterectomy was bilateral in six patients and unilateral in three. No mortality was observed, however, one patient had pulmonary artery stenosis and stent implantation was performed. All patients received immunosuppressive therapies after surgery. Mean pulmonary artery pressure decreased significantly from 30(19-67) mm Hg to 21(15-49) mm Hg after surgery (p <0.05). Pulmonary vascular resistance also improved significantly from 270 (160-1600) to 153 (94-548) dyn/s/cm^-5 (p<0.05). After a median follow-up of 41 months, all but one patient had improved to the New York Heart Association functional class I.

CONCLUSIONS

Isolated pulmonary vasculitis can mimic CTEPH, and these patients can be diagnosed with pulmonary endarterectomy. Furthermore, surgery has not only diagnostic but also therapeutic value for IPV when stenotic and/or thrombotic lesions are surgically accessible. A multidisciplinary experienced CTEPH team is critical for management of these unique patients.

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.