Comparison of bronchopulmonary collaterals and collateral blood flow in patients with chronic thromboembolic and primary pulmonary hypertension

Pulmonary Hypertension in Adult Congenital Heart Disease-Related Heart Failure

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

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.

Modification of pulmonary endarterectomy to prevent neurologic adverse events

PURPOSE

Neurologic adverse events (NAEs) are a major complication after pulmonary endarterectomy (PEA) performed under periods of deep hypothermic circulatory arrest (HCA) for chronic thromboembolic pulmonary hypertension. We modified the PEA strategy to prevent NAEs and evaluated the effectiveness of these modifications.

METHODS

We reviewed the surgical outcomes of 87 patients divided into the following three groups based on the surgical strategy used: group S (n = 49), periods of deep HCA with alpha-stat strategy; group M1 (n = 19), deep HCA with modifications of slower cooling and rewarming rates and the pH-stat strategy for cooling: and group M2 (n = 13), multiple short periods of moderate HCA.

RESULTS

PEA provided significant improvement of pulmonary hemodynamics in each group. Sixteen (29%) of the 49 group S patients suffered NAEs, associated with total circulatory arrest time (cutoff, 57 min) and Jamieson type I disease. The Group M1 and M2 patients did not suffer NAEs, although the group M1 patients had prolonged cardiopulmonary bypass (CPB) and more frequent respiratory failure.

CONCLUSIONS

NAEs were common after PEA performed under periods of deep HCA. The modified surgical strategy could decrease the risk of NAEs but increase the risk of respiratory failure. Multiple short periods of moderate HCA may be useful for patients at risk of NAEs.

Lung Dual-Energy CT Perfusion Blood Volume as a Marker of Severity in Chronic Thromboembolic Pulmonary Hypertension

In chronic thromboembolic pulmonary hypertension (CTEPH), assessment of severity requires right heart catheterization (RHC) through cardiac index (CI). Previous studies have shown that dual-energy CT allows a quantitative assessment of the lung perfusion blood volume (PBV). Therefore, the objective was to evaluate the quantitative PBV as a marker of severity in CTEPH. In the present study, thirty-three patients with CTEPH (22 women, 68.2 ± 14.8 years) were included from May 2017 to September 2021. Mean quantitative PBV was 7.6% ± 3.1 and correlated with CI (r = 0.519, p = 0.002). Mean qualitative PBV was 41.1 ± 13.4 and did not correlate with CI. Quantitative PBV AUC values were 0.795 (95% CI: 0.637-0.953, p = 0.013) for a CI ≥ 2 L/min/m² and 0.752 (95% CI: 0.575-0.929, p = 0.020) for a CI ≥ 2.5 L/min/m². In conclusion, quantitative lung PBV outperformed qualitative PBV for its correlation with the cardiac index and may be used as a non-invasive marker of severity in CTPEH patients.

Systemic artery to pulmonary artery aneurysm malformations associated with variants at MCF2L

Arteriovenous malformations (AVM) are characterized by abnormal vessels connecting arteries and veins resulting in a disruption of normal blood flow. Hereditary hemorrhagic telangiectasia (HHT) is the most common cause of pulmonary AVM characterized by a right to left shunt. Here we describe a distinct malformation where the flow of blood was from a systemic artery to the pulmonary artery (PA) resulting in a left to right shunt instead of the right to left shunt seen in individuals with HHT. This distinct malformation was identified in seven probands, one from a multiplex family containing 10 affected individuals from five generations. To identify the molecular basis of this distinct malformation, we performed exome sequencing (ES) on the seven probands and the affected paternal female cousin from the multiplex family. PhenoDB was used to prioritize candidate causative variants along with burden analysis. We describe the clinical and radiological details of the new systemic artery to PA malformation with or without pulmonary artery aneurysm (SA-PA(A)) and recommend distinct treatment techniques. Moreover, ES analysis revealed possible causative variants identified in three families with variants in a novel candidate disease gene, MCF2L. Further functional studies will be necessary to better understand the molecular mechanisms involved on SA-PA(A) malformation, however our findings suggest that MCF2L is a novel disease gene associated with SA-PA(A).

Evaluating cardiopulmonary function following acute pulmonary embolism

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Systemic-pulmonary collateral supply associated with clinical severity of chronic thromboembolic pulmonary hypertension: a study using intra-aortic computed tomography angiography

OBJECTIVES

To assess whether systemic-pulmonary collaterals are associated with clinical severity and extent of pulmonary perfusion defects in chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS

This prospective study was approved by a local ethics committee. Twenty-four patients diagnosed with inoperable CTEPH were enrolled between July 2014 and February 2017. Systemic-pulmonary collaterals were detected using pulmonary vascular enhancement on intra-aortic computed tomography (CT) angiography. The pulmonary enhancement parameters were calculated, including (1) Hounsfield unit differences (HUdiff) between pulmonary trunks and pulmonary arteries (PAs) or veins (PVs), namely HUdiff-PA and HUdiff-PV, on the segmental base; (2) the mean HUdiff-PA, mean HUdiff-PV, numbers of significantly enhanced PAs and PVs, on the patient base. Pulmonary perfusion defects were recorded and scored using the lung perfused blood volume (PBV) based on intravenous dual-energy CT (DECT) angiography. Pearson's or Spearman's correlation coefficients were used to evaluate correlations between the following: (1) segment-based intra-aortic CT and intravenous DECT parameters (2) patient-based intra-aortic CT parameters and clinical severity parameters or lung PBV scores. Statistical significance was set at p < 0.05.

RESULTS

Segmental HUdiff-PV was correlated with the segmental perfusion defect score (r = 0.45, p < 0.01). The mean HUdiff-PV was correlated with the mean pulmonary arterial pressure (PAP) (r = 0.52, p < 0.01), cardiac output (rho = - 0.41, p = 0.05), and lung PBV score (rho = 0.43, p = 0.04). And the number of significantly enhanced PVs was correlated with the mean PAP (r = 0.54, p < 0.01), pulmonary vascular resistance (r = 0.54, p < 0.01), and lung PBV score (rho = 0.50, p = 0.01).

CONCLUSIONS

PV enhancement measured by intra-aortic CT angiography reflects clinical severity and pulmonary perfusion defects in CTEPH.

KEY POINTS

• Intra-aortic CT angiography demonstrated heterogeneous enhancement within the pulmonary vasculature, showing collaterals from the systemic arteries to the pulmonary circulation in CTEPH. • The degree of systemic-pulmonary collateral development was significantly correlated with the clinical severity of CTEPH and may be used to evaluate disease progression. • The distribution of systemic-pulmonary collaterals is positively correlated with perfusion defects in the lung segments in CTEPH.

A 51-year-old man with chronic cough and left hilar prominence

A 51-year-old male in good overall health presented with a dry cough of 5 months' duration. He was working as a long-distance truck driver and was a life-long nonsmoker. He had no associated dyspnoea, wheezing, rhinosinusitis, haemoptysis or syncope, nor constitutional symptoms such as weight loss or fevers. Physical examination and vital signs were normal on presentation. Chest radiographs with posterior–anterior and lateral views are shown in figure 1.

What is the diagnosis of this man with a chronic dry cough and left hilar prominence on chest radiography?https://bit.ly/3fL7QMx

Chronic Thromboembolic Pulmonary Hypertension: JACC Focus Seminar

Chronic thromboembolic pulmonary hypertension (CTEPH) is the result of pulmonary arterial obstruction by organized thrombotic material stemming from incompletely resolved acute pulmonary embolism. The exact incidence of CTEPH is unknown but appears to approximate 2.3% among survivors of acute pulmonary embolism. Although ventilation/perfusion scintigraphy has been supplanted by computed tomographic pulmonary angiography in the diagnostic approach to acute pulmonary embolism, it has a major role in the evaluation of patients with suspected CTEPH, the presence of mismatched segmental defects being consistent with the diagnosis. Diagnostic confirmation of CTEPH is provided by digital subtraction pulmonary angiography, preferably performed at a center familiar with the procedure and its interpretation. Operability assessment is then undertaken to determine if the patient is a candidate for potentially curative pulmonary endarterectomy surgery. When pulmonary endarterectomy is not an option, pulmonary arterial hypertension-targeted pharmacotherapy and balloon pulmonary angioplasty represent potential therapeutic alternatives.

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

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

Chronic thromboembolic pulmonary hypertension - still evolving

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

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

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

Imaging of Chronic Thromboembolic Disease

Acute pulmonary embolism (PE) is a leading cause of cardiovascular morbidity. The most common long-term complication of acute PE is chronic thromboembolic disease, a heterogenous entity which ranges from asymptomatic imaging sequelae to persistent symptoms. Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease that can develop in this population and represents the only treatable type of pulmonary hypertension. Recognition of the characteristic findings of chronic pulmonary embolism and CTEPH provides not only diagnostic information, but is also crucial for guiding therapy. The present state-of-the-art review focuses on the multimodality imaging features of chronic pulmonary embolism. Detailed description and illustrations of relevant imaging findings will be demonstrated for ventilation/perfusion (V/Q) scan, CT scan and Dual-Energy CT and MRI and features that distinguish chronic PE from common imaging mimics.

Efficacy and Safety of Bronchial Artery Embolization on Hemoptysis in Chronic Thromboembolic Pulmonary Hypertension: A Pilot Prospective Cohort Study

Supplemental Digital Content is available in the text.

Objectives:

Managing hemoptysis in chronic thromboembolic pulmonary hypertension can be challenging due to the difficulties in maintaining coagulation homeostasis in affected patients. In this study, we evaluated the efficacy and safety of bronchial artery embolization in treating hemoptysis in chronic thromboembolic pulmonary hypertension patients.

Design:

Pilot, prospective cohort study.

Setting:

A large respiratory medical institute.

Patients:

From January 1, 2012, to December 31, 2017, hospitalized chronic thromboembolic pulmonary hypertension patients were eligible for inclusion. Patients with pulmonary hypertension caused by other conditions, or who failed to participate in the follow-up were excluded.

Interventions:

Hemoptysis in chronic thromboembolic pulmonary hypertension patients was treated with or without bronchial artery embolization based on whether the bleeding could be stopped with medication alone and patient willingness for bronchial artery embolization treatment.

Measurements and Main Results:

A total of 328 patients diagnosed with chronic thromboembolic pulmonary hypertension were consecutively collected, 317 patients were completed the follow-up. There were 15 chronic thromboembolic pulmonary hypertension patients with hemoptysis in total, and the occurrence rate of hemoptysis in chronic thromboembolic pulmonary hypertension patients was 4.7%. Among the hemoptysis chronic thromboembolic pulmonary hypertension patients, 10 (67%) underwent bronchial artery embolization, and five (33%) were treated with medication only. The median follow-up period for hemoptysis patients was 7.6 months. In patients underwent bronchial artery embolization treatment, oxygenation index and right heart function showed no significant difference between pre bronchial artery embolization and post bronchial artery embolization. Hemoptysis relapse (20% vs 80%; p = 0.025) and hemoptysis-related mortality (0% vs 40%; p = 0.032) were significantly lower, whereas the overall survival (90% vs 40%; p = 0.040) was higher in patients treated with bronchial artery embolization than in patients treated without bronchial artery embolization.

Conclusions:

Bronchial artery embolization procedure demonstrated effectiveness and safety to treat hemoptysis in chronic thromboembolic pulmonary hypertension patients at our center, but further controlled studies are needed before it can be considered as an effective therapy for these patients.

3'-Deoxy-3'-[18F]Fluorothymidine Positron Emission Tomography Depicts Heterogeneous Proliferation Pathology in Idiopathic Pulmonary Arterial Hypertension Patient Lung

BACKGROUND

Pulmonary vascular cell hyperproliferation is characteristic of pulmonary vascular remodeling in pulmonary arterial hypertension. A noninvasive imaging biomarker is needed to track the pathology and assess the response to novel treatments targeted at resolving the structural changes. Here, we evaluated the application of radioligand 3'-deoxy-3'-[18F]-fluorothymidine (¹⁸FLT) using positron emission tomography.

METHODS AND RESULTS

We performed dynamic ¹⁸FLT positron emission tomography in 8 patients with idiopathic pulmonary arterial hypertension (IPAH) and applied in-depth kinetic analysis with a reversible 2-compartment 4k model. Our results show significantly increased lung ¹⁸FLT phosphorylation (k₃) in patients with IPAH compared with nonpulmonary arterial hypertension controls (0.086±0.034 versus 0.054±0.009 min^-1; P<0.05). There was heterogeneity in the lung ¹⁸FLT signal both between patients with IPAH and within the lungs of each patient, compatible with histopathologic reports of lungs from patients with IPAH. Consistent with ¹⁸FLT positron emission tomographic data, TK1 (thymidine kinase 1) expression was evident in the remodeled vessels in IPAH patient lung. In addition, hyperproliferative pulmonary vascular fibroblasts isolated from patients with IPAH exhibited upregulated expression of TK1 and the thymidine transporter, ENT1 (equilibrative nucleoside transporter 1). In the monocrotaline and SuHx (Sugen hypoxia) rat pulmonary arterial hypertension models, increased lung ¹⁸FLT uptake was strongly associated with peripheral pulmonary vascular muscularization and the proliferation marker, Ki-67 score, together with prominent TK1 expression in remodeled vessels. Importantly, lung ¹⁸FLT uptake was attenuated by 2 antiproliferative treatments: dichloroacetate and the tyrosine kinase inhibitor, imatinib.

CONCLUSIONS

Dynamic ¹⁸FLT positron emission tomography imaging can be used to report hyperproliferation in pulmonary hypertension and merits further study to evaluate response to treatment in patients with IPAH.

Involvement of pulmonary arteriopathy in the development and severity of reperfusion pulmonary edema after pulmonary endarterectomy

Reperfusion pulmonary edema (RPE) is a common complication after pulmonary endarterectomy (PEA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, the precise mechanisms underlying the development of RPE remain unclear. To evaluate the effects of pulmonary vasculopathy on RPE, the severity of the pulmonary arteriopathies and venopathies of lung tissues biopsied during PEA were pathologically quantified in 33 CTEPH patients. The severity of RPE was classified from grade 0 (no RPE) to 4 (death due to RPE) based on the arterial oxygen tension/inspiratory oxygen fraction (P/F ratio) and necessity of respiratory management. Among the 33 patients (27 women; mean age = 63.3 years), 17 (51.5%) patients developed RPE. The severity of pulmonary arteriopathy (obstruction ratio) correlated with the grade of RPE (r = 0.576, P = 0.0005). The obstruction ratio also correlated with the P/F ratio (r = −0.543, P = 0.001) and the perioperative mean pulmonary arterial pressure (r = 0.445, P = 0.009). Multivariate logistic regression analysis revealed that the obstruction ratio was a significant independent determinant for the development of RPE (odds ratio = 15.7; 95% confidence interval = 2.29–108.00, P = 0.005). In conclusion, pulmonary arteriopathy could be a determinant of the development and severity of RPE after PEA.

An Interventionalist's Guide to Hemoptysis in Cystic Fibrosis

Massive hemoptysis occurs in a minority of patients with cystic fibrosis, with an annual incidence of 1%. Although rare, massive hemoptysis can be a severe and potentially fatal complication of this disease. Beyond the acute life-threatening event, hemoptysis in patients with cystic fibrosis has been associated with faster decline in lung function, accelerated need for lung transplant, and increased mortality. The bronchial arteries are the culprit vessels in over 90% of cases of hemoptysis. This normally quiescent vascular system undergoes remarkable hypertrophy, collateralization, and angiogenesis before the onset of hemoptysis, introducing numerous pitfalls for the interventionalist. However, in experienced hands, bronchial artery embolization is a safe and potentially lifesaving therapy. Preprocedural noninvasive imaging, specifically computed tomographic angiography, has been repeatedly validated for helping to localize the likely site of bleeding, characterizing pertinent arterial anatomy, and promoting efficient and effective intervention; it has been recommended for all stable patients with hemoptysis. Success in the angiographic suite requires a thorough understanding of normal and variant bronchial arterial anatomy, appropriate patient selection, and a meticulous embolization technique. A meticulous approach to imaging and intervention, conscientious of both visualized and nonvisualized collateral pathways and nontarget vessels, can minimize potentially devastating complications. This review summarizes the current literature, modern procedural techniques, and emerging controversies, serving to guide an evolving approach to management of patients with cystic fibrosis and hemoptysis. ^©RSNA, 2018.

Angiogenesis in the lung

Both systemic (tracheal and bronchial) and pulmonary circulations perfuse the lung. However, documentation of angiogenesis of either is complicated by the presence of the other. Well-documented angiogenesis of the systemic circulations have been identified in asthma, cystic fibrosis, chronic thromboembolism and primary carcinomas. Angiogenesis of the vasa vasorum, which are branches of bronchial arteries, is seen in the walls of large pulmonary vessels after a period of chronic hypoxia. Documentation of increased pulmonary capillaries has been shown in models of chronic hypoxia, after pneumonectomy and in some carcinomas. Although endothelial cell proliferation may occur as part of the repair process in several pulmonary diseases, it is separate from the unique establishment of new functional perfusing networks defined as angiogenesis. Identification of the mechanisms driving the expansion of new vascular beds in the adult needs further investigation. Yet the growth factors and molecular mechanisms of lung angiogenesis remain difficult to separate from underlying disease sequelae.

Poor Subpleural Perfusion Predicts Failure After Balloon Pulmonary Angioplasty for Nonoperable Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

Poor subpleural perfusion (PSP) in the capillary phase of pulmonary angiography predicts worse outcomes following pulmonary endarterectomy in operable chronic thromboembolic pulmonary hypertension (CTEPH). Balloon pulmonary angioplasty (BPA) has emerged as a treatment for nonoperable CTEPH. The goal of the present article was to assess the association between PSP and BPA failure.

METHODS

Subpleural perfusion was classified as poor (defined as subpleural spaces either not perfused or minimally perfused in all segments) or normal. We retrospectively reviewed PSP and hemodynamic variables of 101 consecutive patients who underwent BPA from February 2014 to August 2016. The total cross-sectional area of bronchial arteries was also measured by using CT scanning. Patients were categorized according to hemodynamic results after the last BPA: a failure group (defined as mean pulmonary arterial pressure > 30 mm Hg and a decrease in pulmonary vascular resistance < 30% [n = 15]) or a success group (n = 86).

RESULTS

Although baseline hemodynamic variables were similar between the two groups, PSP was observed in 46.7% of patients in the failure group vs 13.9% in the success group (P = .003). Multivariate analysis revealed that PSP was the only predictor of BPA failure (OR, 4.02 [95% CI, 1.17-13.89]; P = .028). Patients with PSP exhibited poorly developed bronchial arteries compared with patients with normal perfusion (7.0 [5.8-9.6] mm² vs 8.7 [6.9-11.3] mm²; P = .032).

CONCLUSIONS

PSP in the capillary phase, suggesting the presence of small vessel disease with diffuse distal thrombosis, is a predictor of BPA failure. PSP was also associated with less developed bronchial arteries, which suggests a key role of bronchial-pulmonary anastomoses in maintaining the pulmonary capillary bed open downstream of the pulmonary arterial obstruction. PSP affected approximately 15% of patients with nonoperable CTEPH who underwent BPA.

Diagnostic Evaluation of Chronic Thromboembolic Pulmonary Hypertension

Pulmonary hypertension is defined by a mean pulmonary artery pressure greater than 25 mm Hg. Chronic thromboembolic pulmonary hypertension (CTEPH) is defined as pulmonary hypertension in the presence of an organized thrombus within the pulmonary vascular bed that persists at least 3 months after the onset of anticoagulant therapy. Because CTEPH is potentially curable by surgical endarterectomy, correct identification of patients with this form of pulmonary hypertension and an accurate assessment of surgical candidacy are essential to provide optimal care. Patients most commonly present with symptoms of exertional dyspnea and otherwise unexplained decline in exercise capacity. Atypical chest pain, a nonproductive cough, and episodic hemoptysis are observed less frequently. With more advanced disease, patients often develop symptoms suggestive of right ventricular compromise. Physical examination findings are minimal early in the course of this disease, but as pulmonary hypertension progresses, may include nonspecific finding of right ventricular failure, such as a tricuspid regurgitation murmur, pedal edema, and jugular venous distention. Chest radiographs may suggest pulmonary hypertension, but are neither sensitive nor specific for the diagnosis. Radioisotopic ventilation-perfusion scanning is sensitive for detecting CTEPH, making it a valuable screening study. Conventional catheter-based pulmonary angiography retains an important role in establishing the presence and extent of chronic thromboembolic disease. However, computed tomographic and magnetic resonance imaging are playing a growing diagnostic role. Innovative technologies such as dual-energy computed tomography, dynamic contrast-enhanced magnetic resonance imaging, and optical coherence tomography show promise for contributing diagnostic information and assisting in the preoperative characterization of patients with CTEPH.

Imaging in Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the potentially curable causes of pulmonary hypertension and is definitively treated with pulmonary thromboendartectomy. CTEPH can be overlooked, as its symptoms are nonspecific and can be mimicked by a wide range of diseases that can cause pulmonary hypertension. Early diagnosis of CTEPH and prompt evaluation for surgical candidacy are paramount factors in determining future outcomes. Imaging plays a central role in the diagnosis of CTEPH and patient selection for pulmonary thromboendartectomy and balloon pulmonary angioplasty. Currently, various imaging tools are used in concert, with techniques such as computed tomography (CT) and conventional pulmonary angiography providing detailed structural information, tests such as ventilation-perfusion (V/Q) scanning providing functional data, and magnetic resonance imaging providing a combination of morphologic and functional information. Emerging techniques such as dual-energy CT and single photon emission computed tomography-CT V/Q scanning promise to provide both anatomic and functional information in a single test and may change the way we image these patients in the near future. In this review, we discuss the roles of various imaging techniques and discuss their merits, limitations, and relative strengths in depicting the structural and functional changes of CTEPH. We also explore newer imaging techniques and the potential value they may offer.

Feline Cardiogenic Arterial Thromboembolism: Prevention and Therapy

Feline cardiogenic arterial thromboembolism (CATE) is a devastating disease whereby 33% of cats survive their initial event, although approximately 50% of mortality is from euthanasia. Short-term management focuses on inducing a hypocoagulable state, improving blood flow, and providing supportive care. Ideally, all cats should be given 72 hours of treatment to determine the acute clinical course. Preventive protocols include antiplatelet and/or anticoagulant drugs, with the only prospective clinical trial demonstrating that clopidogrel is superior to aspirin with a lower CATE recurrence rate and longer time to recurrent CATE. Newer anticoagulant drugs hold great promise in the future of managing this disease.

Imaging of acute and chronic thromboembolic disease: state of the art

Acute pulmonary embolism (PE) is a life-threatening condition that requires prompt diagnosis and treatment. Recent advances in imaging allow acute and rapid recognition even by the non-specialist radiologist. Most acute emboli resolve on anticoagulation without sequelae; however, some emboli fail to fully resolve becoming endothelialised with the development of chronic thromboembolic disease (CTED). Increased pulmonary vascular resistance arising from CTED may lead to chronic thromboembolic pulmonary hypertension (CTEPH) a debilitating disease affecting up to 5% of survivors of acute PE. Diagnostic evaluation is more complex in CTEPH/CTED than acute PE with subtle imaging features often being overlooked or misinterpreted. Differentiation of acute from chronic PE and from other forms of pulmonary hypertension has profound therapeutic implications. Diverse imaging techniques are available to diagnose and monitor PEs both in the acute and chronic setting. Broadly they include techniques that provide data on lung parenchymal perfusion (ventilation-perfusion [VQ] scintigraphy), angiographic techniques (computed tomography [CT], magnetic resonance imaging [MRI], and invasive angiography) or a combination of both (MR angiography and time-resolved angiography or dual-energy CT angiography). This review aims to describe state of the art imaging highlighting the strength and weaknesses of individual techniques in the diagnosis of acute and chronic PE.

BMPR2 mutation status influences bronchial vascular changes in pulmonary arterial hypertension

The impact of bone morphogenetic protein receptor 2 (BMPR2) gene mutations on vascular remodelling in pulmonary arterial hypertension (PAH) is unknown. We sought to identify a histological profile of BMPR2 mutation carriers.Clinical data and lung histology from 44 PAH patients were subjected to systematic analysis and morphometry.Bronchial artery hypertrophy/dilatation and bronchial angiogenesis, as well as muscular remodelling of septal veins were significantly increased in PAH lungs carrying BMPR2 mutations. We found that patients displaying increased bronchial artery remodelling and bronchial microvessel density, irrespective of the mutation status, were more likely to suffer from severe haemoptysis. History of substantial haemoptysis (>50 mL) was significantly more frequent in BMPR2 mutation carriers. 43.5% of BMPR2 mutation carriers, as opposed to 9.5% of noncarriers, displayed singular large fibrovascular lesions, which appear to be closely related to the systemic lung vasculature.Our analysis provides evidence for the involvement of the pulmonary systemic circulation in BMPR2 mutation-related PAH. We show that BMPR2 mutation carriers are more prone to haemoptysis and that haemoptysis is closely correlated to bronchial arterial remodelling and angiogenesis; in turn, pronounced changes in the systemic vasculature correlate with increased pulmonary venous remodelling, creating a distinctive profile in PAH patients harbouring a BMPR2 mutation.

Effector T Cells and Ischemia-Induced Systemic Angiogenesis in the Lung

Lymphocytes have been shown to modulate angiogenesis. Our previous work showed that T regulatory (Treg) cell depletion prevented angiogenesis. In the present study, we sought to examine T-cell populations during lung angiogenesis and subsequent angiostasis. In a mouse model of ischemia-induced systemic angiogenesis in the lung, we examined the time course (0-35 d) of neovascularization and T-cell phenotypes within the lung after left pulmonary artery ligation (LPAL). T cells increased and reached a maximum by 10 days after LPAL and then progressively decreased, suggestive of a modulatory role during the early phase of new vessel growth. Because others have shown IFN-γ to be angiostatic in tumor models, we focused on this effector T-cell cytokine to control the magnitude of angiogenesis. Results showed that IFN-γ protein is secreted at low levels after LPAL and that mice required Treg depletion to see the full effect of effector T cells. Using Foxp3(DTR) and diphtheria toxin to deplete T regulatory cells, increased numbers of effector T cells (CD8(+)) and/or increased capacity to secrete the prominent angiostatic cytokine IFN-γ (CD4(+)) were seen. In vitro culture of mouse systemic and pulmonary microvascular endothelial cells with IFN-γ showed increased endothelial cell apoptosis. CD8(-/-) mice and IFN-γR(-/-) mice showed enhanced angiogenesis compared with wild-type mice, confirming that, in this model, IFN-γ limits the extent of systemic neovascularization in the lung.

Bronchial arteries: anatomy, function, hypertrophy, and anomalies

The two main sources of blood supply to the lungs and their supporting structures are the pulmonary and bronchial arteries. The bronchial arteries account for 1% of the cardiac output but can be recruited to provide additional systemic circulation to the lungs in various acquired and congenital thoracic disorders. An understanding of bronchial artery anatomy and function is important in the identification of bronchial artery dilatation and anomalies and the formulation of an appropriate differential diagnosis. Visualization of dilated bronchial arteries at imaging should alert the radiologist to obstructive disorders that affect the pulmonary circulation and prompt the exclusion of diseases that produce or are associated with pulmonary artery obstruction, including chronic infectious and/or inflammatory processes, chronic thromboembolic disease, and congenital anomalies of the thorax (eg, proximal interruption of the pulmonary artery). Conotruncal abnormalities, such as pulmonary atresia with ventricular septal defect, are associated with systemic pulmonary supply provided by aortic branches known as major aortopulmonary collaterals, which originate in the region of the bronchial arteries. Bronchial artery malformation is a rare left-to-right or left-to-left shunt characterized by an anomalous connection between a bronchial artery and a pulmonary artery or a pulmonary vein, respectively. Bronchial artery interventions can be used successfully in the treatment of hemoptysis, with a low risk of adverse events. Multidetector computed tomography helps provide a vascular road map for the interventional radiologist before bronchial artery embolization.

Bronchial artery embolization in chronic pulmonary thromboembolism: A therapeutic dilemma

Bronchial artery embolization is the treatment of choice for the management of life-threatening massive hemoptysis. Chronic pulmonary thromboembolism (PTE) is one of the rare causes of hemoptysis. Management of hemoptysis in chronic PTE is a point of debate. In this article, we have reported one case of hemoptysis in chronic PTE managed successfully with bronchial artery embolization.

Lung Angiogenesis Requires CD4(+) Forkhead Homeobox Protein-3(+) Regulatory T Cells

Angiogenesis in ischemic organs is modulated by immune cells. Systemic neovascularization of the ischemic lung requires macrophages, with chemokines playing a central role in new vessel growth. Because regulatory T (Treg) cells modulate tumor-induced neovascularization, we questioned whether this CD4(+) lymphocyte subset impacts blood vessel growth during ischemia. In a model of left lung ischemia, an increase in CD4(+) CD25(+) forkhead homeobox protein-3 (Foxp3)(+) cells was observed 3-5 days after the onset of ischemia in wild-type C57Bl/6 mice. Using transgenic mice where Foxp3(+) Treg cells can be depleted with diphtheria toxin (DT; Foxp3(DTR)), we unexpectedly found that Foxp3(+) Treg depletion led to markedly reduced lung angiogenesis (90% reduction from Foxp3(gfp) controls). Adoptive transfer studies using CD4(+) CD25(+) splenocytes from congenic CD45.1 mice into Foxp3(+) Treg-depleted mice showed an almost complete recovery of the angiogenic phenotype (80% of Foxp3(gfp) controls). A survey of lung gene expression of angiogenic (lipopolysaccharide-induced CXC chemokine [LIX], IL-6, IL-17) and angiostatic (IFN-γ, transforming growth factor-β, IL-10) cytokines showed Treg-dependent differences only in LIX (CXCL5) and IL-6. Protein confirmation demonstrated a significant reduction in LIX in Treg-deficient mice compared with controls 5 days after the onset of ischemia. Phenotyping other inflammatory cells in the lung by multicolor flow cytometry demonstrated a significantly reduced number of macrophages (major histocombatibility complex class II [MHCII](int), CD11C(+)) in Treg-deficient lungs compared with Treg-sufficient lungs. Treg cells are essential for maximal systemic angiogenesis after pulmonary ischemia. One likely mechanism responsible for the decrease in angiogenesis in Treg-depleted mice was the decline in the essential CXC chemokine, LIX.

Prevalence of coronary artery-pulmonary artery collaterals in patients with chronic thromboembolic pulmonary hypertension

This study sought to determine the prevalence of coronary artery-pulmonary artery collaterals in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and to correlate their presence with the degree of clot burden. CTEPH is a treatable cause of severe pulmonary hypertension and right heart failure. Bronchopulmonary collateral vessels have been used as a supplementary diagnostic and prognostic tool for this disease. Coronary artery-pulmonary artery collaterals in this population have not been described. The coronary angiograms of 300 consecutive patients with CTEPH evaluated for pulmonary thromboendarterectomy (PTE) between January 1, 2007, and May 1, 2014, were examined. Of these patients, 259 (50% male; mean age, 58.3 ± 10.6 years) had cineangiographic images deemed adequate to definitively assess for the presence of coronary artery-pulmonary artery collaterals and were included in the final analyses. Pulmonary angiogram reports were reviewed for extent of pulmonary artery obstruction. The coronary angiograms of 259 age- and sex-matched control patients were also examined. Among 259 CTEPH patients with definitive imaging, 34 coronary artery-pulmonary artery collaterals were found in 28 patients (10.8%), versus 1 coronary artery-pulmonary artery collateral among control subjects (0.4%; P < 0.001). Compared with CTEPH patients without collaterals, patients with collaterals had a significantly higher prevalence of total occlusion of their right or left main pulmonary artery (P < 0.001) or lobar arteries (P < 0.001). In conclusion, the prevalence of coronary artery-pulmonary artery collaterals in CTEPH patients undergoing coronary angiography for possible PTE is approximately 11%. These vessels are associated with more severe pulmonary artery occlusion.

Physiological and pathological angiogenesis in the adult pulmonary circulation

Angiogenesis occurs during growth and physiological adaptation in many systemic organs, for example, exercise-induced skeletal and cardiac muscle hypertrophy, ovulation, and tissue repair. Disordered angiogenesis contributes to chronic inflammatory disease processes and to tumor growth and metastasis. Although it was previously thought that the adult pulmonary circulation was incapable of supporting new vessel growth, over that past 10 years new data have shown that angiogenesis within this circulation occurs both during physiological adaptive processes and as part of the pathogenic mechanisms of lung diseases. Here we review the expression of vascular growth factors in the adult lung, their essential role in pulmonary vascular homeostasis and the changes in their expression that occur in response to physiological challenges and in disease. We consider the evidence for adaptive neovascularization in the pulmonary circulation in response to alveolar hypoxia and during lung growth following pneumonectomy in the adult lung. In addition, we review the role of disordered angiogenesis in specific lung diseases including idiopathic pulmonary fibrosis, acute adult distress syndrome and both primary and metastatic tumors of the lung. Finally, we examine recent experimental data showing that therapeutic enhancement of pulmonary angiogenesis has the potential to treat lung diseases characterized by vessel loss.

Risk factors for hemoptysis in idiopathic and hereditary pulmonary arterial hypertension

Introduction

When hemoptysis complicates pulmonary arterial hypertension (PAH), it is assumed to result from bronchial artery hypertrophy. In heritable PAH, the most common mutation is in the BMPR2 gene, which regulates growth, differentiation and apoptosis of mesenchymal cells. The aim of this study is to determine the relationship in PAH between the occurrence of hemoptysis, and disease progression, bronchial artery hypertrophy, pulmonary artery dilation and BMPR2 mutations.

Methods

129 IPAH patients underwent baseline pulmonary imaging (CT angio or MRI) and repeated right-sided heart catheterization. Gene mutations were assessed in a subset of patients.

Results

Hemoptysis was associated with a greater presence of hypertrophic bronchial arteries and more rapid hemodynamic deterioration. The presence of a BMPR2 mutation did not predispose to the development of hemoptysis, but was associated with a greater number of hypertrophic bronchial arteries and a worse baseline hemodynamic profile.

Conclusion

Hemoptysis in PAH is associated with bronchial artery hypertrophy and faster disease progression. Although the presence of a BMPR2 mutation did not correlate with a greater incidence of hemoptysis in our patient cohort, its association with worse hemodynamics and a trend of greater bronchial arterial hypertrophy may increase the risk of hemoptysis.

Chemokine localization in bronchial angiogenesis

Angiogenesis in the lung involves the systemic bronchial vasculature and becomes prominent when chronic inflammation prevails. Mechanisms for neovascularization following pulmonary ischemia include growth factor transit from ischemic parenchyma to upstream bronchial arteries, inflammatory cell migration/recruitment through the perfusing artery, and paracrine effects of lung cells within the left bronchus, the niche where arteriogenesis takes place. We analyzed left lung bronchoalveolar lavage (BAL) fluid and left bronchus homogenates after left pulmonary artery ligation (LPAL) in rats, immediately after the onset of ischemia (0 h), 6 h and 24 h later. Additionally, we tested the effectiveness of dexamethasone on decreasing inflammation (0–24 h LPAL) and angiogenesis at early (3 d LPAL; bronchial endothelial proliferation) and late (14 d LPAL; blood flow) stages. After LPAL (6 h), BAL protein, total inflammatory cells, macrophages, and polymorphonuclear cells increased significantly. In parallel, pro-angiogenic CXC chemokines increased in BAL and the left main-stem bronchus (CXCL1) or only within the bronchus (CXCL2). Dexamethasone treatment reduced total BAL protein, inflammatory cells (total and polymorphonuclear cells), and CXCL1 but not CXCL2 in BAL. By contrast, no decrease was seen in either chemokine within the bronchial tissue, in proliferating bronchial endothelial cells, or in systemic perfusion of the left lung. Our results confirm the presence of CXC chemokines within BAL fluid as well as within the left mainstem bronchus. Despite significant reduction in lung injury and inflammation with dexamethasone treatment, chemokine expression within the bronchial tissue as well as angiogenesis were not affected. Our results suggest that early changes within the bronchial niche contribute to subsequent neovascularization during pulmonary ischemia.

Chronic pulmonary emboli and radiologic mimics on CT pulmonary angiography: a diagnostic challenge

Chronic pulmonary thromboembolism (CPE) is a challenging diagnosis for clinicians. It is an often-forgotten diagnosis and can be difficult to detect and easily misdiagnosed. The radiologic features on CT pulmonary angiography are subtle and can be further compounded by pathologic mimics and unusual findings observed with disease progression. Diagnosis is important because CPE can lead to progressive pulmonary hypertension, morbidity, and mortality. Moreover, chronic thromboembolic pulmonary hypertension is the only category of pulmonary hypertension with an effective curative treatment in the form of pulmonary endarterectomy. Therefore, CPE must be considered and recognized early. The features of chronic pulmonary emboli on CT scans can be categorized into vascular or parenchymal findings. Endoluminal signs include totally or partially occlusive thrombi and webs and bands. Parenchymal features such as mosaic attenuation and pulmonary infarction are also noted, in addition to features of pulmonary artery hypertension. Additional findings have been noted, including cavitation of infarcts, microbial colonization of cavities, and bronchopleural fistulae. As CPE can be diagnosed at different stages of its disease pathway, such findings may not necessarily arouse suspicion toward a causative diagnosis of chronic embolism. To aid diagnosis for clinicians, this article describes the characteristic vascular and parenchymal CT scan features of chronic emboli, as well as important ancillary findings. We also provide an illustrative case series focusing on CT pulmonary angiography specifically as an imaging modality to highlight the progressive nature of CPE and its sequelae, as well as important radiologic mimics to consider in the differential diagnosis.

Angiogenesis in the ischemic rat lung

The adult lung is perfused by both the systemic bronchial artery and the entire venous return flowing through the pulmonary arteries. In most lung pathologies, it is the smaller systemic vasculature that responds to a need for enhanced lung perfusion and shows robust neovascularization. Pulmonary vascular ischemia induced by pulmonary artery obstruction has been shown to result in rapid systemic arterial angiogenesis in man as well as in several animal models. Although the histologic assessment of the time course of bronchial artery proliferation in rats was carefully described by Weibel , mechanisms responsible for this organized growth of new vessels are not clear. We provide surgical details of inducing left pulmonary artery ischemia in the rat that leads to bronchial neovascularization. Quantification of the extent of angiogenesis presents an additional challenge due to the presence of the two vascular beds within the lung. Methods to determine functional angiogenesis based on labeled microsphere injections are provided.

Effects of ischemia on lung macrophages

Angiogenesis after pulmonary ischemia is initiated by reactive O(2) species and is dependent on CXC chemokine growth factors, and its magnitude is correlated with the number of lavaged macrophages. After complete obstruction of the left pulmonary artery in mice, the left lung is isolated from the peripheral circulation until 5-7 days later, when a new systemic vasculature invades the lung parenchyma. Consequently, this model offers a unique opportunity to study the differentiation and/or proliferation of monocyte-derived cells within the lung. In this study, we questioned whether macrophage subpopulations were differentially expressed and which subset contributed to growth factor release. We characterized the change in number of all macrophages (MHCII(int), CD11C+), alveolar macrophages (MHCII(int), CD11C+, CD11B-) and mature lung macrophages (MHCII(int), CD11C+, CD11B+) in left lungs from mice immediately (0 h) or 24 h after left pulmonary artery ligation (LPAL). In left lung homogenates, only lung macrophages increased 24 h after LPAL (vs. 0 h; p<0.05). No changes in proliferation were seen in any subset by PCNA expression (0 h vs. 24 h lungs). When the number of monocytic cells was reduced with clodronate liposomes, systemic blood flow to the left lung 14 days after LPAL decreased by 42% (p<0.01) compared to vehicle controls. Furthermore, when alveolar macrophages and lung macrophages were sorted and studied in vitro, only lung macrophages secreted the chemokine MIP-2α (ELISA). These data suggest that ischemic stress within the lung contributes to the differentiation of immature monocytes to lung macrophages within the first 24 h after LPAL. Lung macrophages but not alveolar macrophages increase and secrete the proangiogenic chemokine MIP-2α. Overall, an increase in the number of lung macrophages appears to be critical for neovascularization in the lung, since clodronate treatment decreased their number and attenuated functional angiogenesis.

Are pulmonary artery pulsatility indexes able to differentiate chronic pulmonary thromboembolism from pulmonary arterial hypertension? An echocardiographic and catheterization study

The differentiation between chronic pulmonary thromboembolic hypertension (CTEPH) and pulmonary arterial hypertension (PAH) remains a clinical challenge. The aim of our study was to evaluate the usefulness of both echocardiographically and invasively derived pulmonary artery pulsatility indexes in the etiologic differentiation of patients with CTEPH and PAH. We retrospectively analyzed the results of echocardiographic and invasive hemodynamic examinations in 125 patients with either CTEPH (n = 62) or PAH (n = 63). Invasive data were obtained in 52 patients with CTEPH and 43 PAH patients. Using echocardiography, pulmonary artery systolic (PASP), diastolic (PADP) and mean (PAMP) pressures were estimated from velocities of tricuspid regurgitation and pulmonary regurgitation, respectively. Pulse pressure (PP) was calculated as the difference between PASP and PADP. To obtain pulmonary artery pulsatility indexes, we normalized PP by PASP (PP/PASP), by PAMP (PP/PAMP) and by PADP (PP/PADP). Pulsatility indexes assessed by echocardiography did not differ between CTEPH and PAH patients except for PP/PAMP [PP/PAMP (1.82 ± 0.33 vs. 1.40 ± 0.3, p < 0.001)]. Invasively derived pulsatility indexes were significantly higher in subjects with CTEPH (0.60 ± 0.08 vs. 0.53 ± 0.09 for PP/PASP; 0.98 ± 0.21 vs. 0.81 ± 0.21 for PP/PAMP; 1.58 ± 0.52 vs. 1.21 ± 0.41 for PP/PADP; all p < 0.001). The areas under the receiver-operating characteristic curves analysis showed that no cutoff value allowed discriminating between CTEPH and PAH by using echocardiographically or invasively derived pulsatility indices. Invasively derived pulmonary artery pulsatility indexes as well as echocardiographically determined PP/PAMP indexes are higher in CTEPH compared to PAH. However, due to the important overlap no optimal threshold values of these parameters can be given to allow satisfactory discrimination of the two diseases in clinical practice.

Hemoptysis requiring bronchial artery embolization in pulmonary arterial hypertension

OBJECTIVES

Hemoptysis is an uncommon complication in patients with pulmonary arterial hypertension (PAH). Although the mechanism of hemoptysis is unknown, treatment with bronchial artery embolization (BAE) is proposed to be a safe and reliable method of treatment. We report our experience in treating PAH patients presenting with acute hemoptysis that required multiple BAEs.

METHODS

Three female and one male PAH patients, ages 45 + or - 9 years (mean + or - standard deviation [SD]) presented with acute hemoptysis. Right ventricular systolic pressure and cardiac index at the time of the first episode of hemoptysis were 85 + or - 17 mm Hg and 2.7 + or - 0.7 L/min/m, respectively. Two of the four patients had recurrent episodes of hemoptysis, requiring multiple BAEs. All four were on intravenous prostacyclin analogue. None were receiving warfarin or endothelin receptor antagonists at the time of the episode. During each episode of hemoptysis, international normalized ratio (INR) was 1.09 + or - 0.11 units, and platelet count was 124,000 + or - 47,000 per microliter.

RESULTS

Each episode of hemoptysis was acutely terminated with BAE. In the majority of cases, patients had multiple aberrant bronchial arteries embolized, and an average of 2.3 arteries was embolized per session (1-4 embolized arteries). Each BAE was performed utilizing polyvinyl alcohol particles, ranging from 250-500 microns. There were no reported complications of the 14 BAE procedures performed.

CONCLUSION

Although the incidence of hemoptysis is unknown and likely underreported, we report our experience in which recurrent hemoptysis was treated with multiple BAE procedures. This report emphasizes the efficacy and safety of BAE in terminating episodes of recurrent hemoptysis in patients with severe PAH.