Pulmonary Endarterectomy. Patient Selection, Technical Challenges, and Outcomes

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.

Current strategies for managing chronic thromboembolic pulmonary hypertension: results of the worldwide prospective CTEPH Registry

Background

Pulmonary endarterectomy (PEA), pulmonary arterial hypertension (PAH) therapy and balloon pulmonary angioplasty (BPA) are currently accepted therapies for chronic thromboembolic pulmonary hypertension (CTEPH). This international CTEPH Registry identifies clinical characteristics of patients, diagnostic algorithms and treatment decisions in a global context.

Methods

1010 newly diagnosed consecutive patients were included in the registry between February 2015 and September 2016. Diagnosis was confirmed by right heart catheterisation, ventilation–perfusion lung scan, computerised pulmonary angiography and/or invasive pulmonary angiography after at least 3 months on anticoagulation.

Results

Overall, 649 patients (64.3%) were considered for PEA, 193 (19.1%) for BPA, 20 (2.0%) for both PEA and BPA, and 148 (14.7%) for PAH therapy only. Reasons for PEA inoperability were technical inaccessibility (n=235), comorbidities (n=63) and patient refusal (n=44). In Europe and America and other countries (AAO), 72% of patients were deemed suitable for PEA, whereas in Japan, 70% of patients were offered BPA as first choice. Sex was evenly balanced, except in Japan where 75% of patients were female. A history of acute pulmonary embolism was reported for 65.6% of patients. At least one PAH therapy was initiated in 35.8% of patients (26.2% of PEA candidates, 54.5% of BPA candidates and 54.1% of those not eligible for either PEA or BPA). At the time of analysis, 39 patients (3.9%) had died of pulmonary hypertension-related causes (3.5% after PEA and 1.8% after BPA).

Conclusions

The registry revealed noticeable differences in patient characteristics (rates of pulmonary embolism and sex) and therapeutic approaches in Japan compared with Europe and AAO.

There are distinct regional differences in the management of CTEPH patients but globally, the proportion of patients managed by PEA remains stable, independently of the new established treatment options of PAH therapies and BPAhttps://bit.ly/3zEXxkv

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

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

Advanced Surgical and Percutaneous Approaches to Pulmonary Vascular Disease

Despite progress in modern medical therapy, pulmonary hypertension remains an unremitting disease. Once severe or refractory to medical therapy, advanced percutaneous and surgical interventions can palliate right ventricular overload, bridge to transplantation, and overall extend a patient's course. These approaches include atrial septostomy, Potts shunt, and extracorporeal life support. Bilateral lung transplantation is the ultimate treatment for eligible patients, although the need for suitable lungs continues to outpace availability. Measures such as ex vivo lung perfusion are ongoing to expand donor lung availability, increase rates of transplant, and decrease waitlist mortality.

Raising the bar to ultradisciplinary collaborations in management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension is an underdiagnosed and potentially fatal subgroup of pulmonary hypertension, if left untreated. Clinical signs include exertional dyspnea and non-specific symptoms. Diagnosis requires multimodality imaging and heart catheterization. Pulmonary endarterectomy, an open heart surgery, is the gold standard treatment of choice in selected patients in specialized centers. Targeted medical therapy and balloon pulmonary angioplasty can be effective in high-risk patients with significant comorbidities, distal pulmonary vascular obstructions, or recurrent/persistent pulmonary hypertension after pulmonary endarterectomy. Currently, there is a limited number of data regarding novel coronavirus-2019 infection in patients with chronic thromboembolic pulmonary hypertension and the changing spectrum of the disease during the pandemic. Challenging times during this outbreak due to healthcare crisis and relatively higher case-fatality rates require convergence; that is an ultradisciplinary collaboration, which crosses disciplinary and sectorial boundaries to develop integrated knowledge and new paradigms. Management strategies for the "new normal" such as virtual care, preparedness for further threats, redesigned standards and working conditions, reevaluation of specific recommendations, and online collaborations for optimal decisions for chronic thromboembolic pulmonary hypertension patients may change the poor outcomes.

Risk Factors for Prolonged Mechanical Ventilation After Pulmonary Endarterectomy: 7 Years' Experience From an Experienced Hospital in China

Background: Prolonged mechanical ventilation (PMV) is common after cardiothoracic surgery, whereas the mechanical ventilation strategy after pulmonary endarterectomy (PEA) has not yet been reported. We aim to identify the incidence and risk factors for PMV and the relationship between PMV and short-term outcomes.

Methods: We studied a retrospective cohort of 171 who undergoing PEA surgery from 2014 to 2020. Cox regression with restricted cubic splines was performed to identify the cutoff value for PMV. The Least absolute shrinkage and selection operator regression and logistic regressions were applied to identify risk factors for PMV. The impacts of PMV on the short-term outcomes were evaluated.

Results: PMV was defined as the duration of mechanical ventilation exceeding 48 h. Independent risk factors for PMV included female sex (OR 2.911; 95% CI 1.303–6.501; P = 0.009), prolonged deep hypothermic circulatory arrest (DHCA) time (OR 1.027; 95% CI 1.002–1.053; P = 0.036), increased postoperative blood product use (OR 3.542; 95% CI 1.203–10.423; P = 0.022), elevated postoperative total bilirubin levels (OR 1.021; 95% CI 1.007–1.034; P = 0.002), increased preoperative pulmonary artery pressure (PAP) (OR 1.031; 95% CI 1.014–1.048; P < 0.001) and elongated postoperative right ventricular anteroposterior dimension (RVAD) (OR 1.119; 95% CI 1.026–1.221; P = 0.011). Patients with PMV had longer intensive care unit stays, higher incidences of postoperative complications, and higher in-hospital medical expenses.

Conclusions: Female sex, prolonged DHCA time, increased postoperative blood product use, elevated postoperative total bilirubin levels, increased preoperative PAP, and elongated postoperative RVAD were independent risk factors for PMV. Identification of risk factors associated with PMV in patients undergoing PEA may facilitate timely diagnosis and re-intervention for some of these modifiable factors to decrease ventilation time and improve patient outcomes.

Balloon Pulmonary Angioplasty in Technically Operable and Technically Inoperable Chronic Thromboembolic Pulmonary Hypertension

Background: In this study, we aimed to assess the efficacy and safety of balloon pulmonary angioplasty (BPA) in patients with technically inoperable distal-type chronic thromboembolic pulmonary hypertension (d-CTEPH) and technically operable proximal-type disease (p-CTEPH) by analyzing the results of BPA treatment in two collaborating CTEPH referral centers. Methods and results: We assessed hemodynamic results, functional efficacy, complication and survival rate after BPA treatment in 70 CTEPH patients (median age 64 years; (interquartile range (IQR): 52–73 years)), of whom 16 (median age 73 years; (QR 62–82 years)) were in the p-CTEPH subgroup. Altogether, 377 BPA procedures were performed, resulting in significant (p < 0.001) improvement in mean pulmonary artery pressure (mPAP 48.6 ± 10 vs. 31.3 ± 8.6 mmHg), pulmonary vascular resistance (694 ± 296 vs. 333 ± 162 dynes*s*cm⁻⁵), six-minute walk test (365 ± 142 vs. 433 ± 120 metres) and N-terminal pro B-type natriuretic peptide (1307 (510–3294) vs. 206 (83–531) pg/mL). The rate of improvement did not differ between the sub-groups. Lung injury episodes and severe hemoptysis were similarly infrequent in d-CTEPH and p-CTEPH (6.4% vs. 5%; p = 0.55 and 1.0% vs. 2.5; p = 0.24, respectively). There was no significant difference between the sub-groups regarding survival (p = 0.53 by log-rank test). Conclusion: BPA may be beneficial in patients with p-CTEPH who cannot undergo pulmonary endarterectomy (PEA). Larger long-term studies are needed to better define the efficacy, safety, and optimal BPA procedural standards in this population.

Intimal Sarcoma of the Great Vessels

Intimal sarcomas of the pulmonary artery and aorta are rare entities with a poor prognosis. In many instances, pulmonary artery sarcomas are misinterpreted as acute or chronic pulmonary thromboembolism, whereas aortic intimal sarcomas are often misdiagnosed as protuberant atherosclerotic disease or intimal thrombus. Discernment of intimal sarcomas from these and other common benign entities is essential for the timely initiation of aggressive therapy. The most useful imaging modalities for assessment of a suspected intimal sarcoma include CT angiography, fluorine 18-fluorodeoxyglucose PET, and MRI. The authors discuss the clinical features, current treatment options, characteristic imaging findings, and underlying pathologic features of intimal sarcomas. The authors emphasize imaging discernment of intimal sarcomas and how their differential diagnosis is informed by knowledge of radiologic-pathologic correlation. The most reliable distinguishing imaging features are also emphasized to improve accurate and timely diagnosis. Online supplemental material is available for this article. ^©RSNA, 2021.

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.

Interventional and pharmacological management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is caused by obstruction of the pulmonary vasculature, leading to increased pulmonary vascular resistance and ultimately right ventricular failure, the leading cause of death in non-operated patients. This article reviews the current management of CTEPH. The standard of care in CTEPH is pulmonary endarterectomy (PEA). However, up to 40% of patients with CTEPH are ineligible for PEA, and up to 51% develop persistent/recurrent PH after PEA. Riociguat is currently the only medical therapy licensed for treatment of inoperable or persistent/recurrent CTEPH after PEA based on the results of the Phase III CHEST-1 study. Studies of balloon pulmonary angioplasty (BPA) have shown benefits in patients with inoperable or persistent/recurrent CTEPH after PEA; however, data are lacking from large, prospective, controlled studies. Studies of macitentan in patients with inoperable CTEPH and treprostinil in patients with inoperable or persistent/recurrent CTEPH showed positive results. Combination therapy is under evaluation in CTEPH, and long-term data are not available. In the future, CTEPH may be managed by PEA, medical therapy or BPA - alone or in combination, according to individual patient needs. Patients should be referred to experienced centers capable of assessing and delivering all options.

Surgical treatment of pulmonary artery sarcoma: a report of 17 cases

Pulmonary artery sarcoma (PAS) is a rare and devastating disease. The diagnosis is often delayed, and optimal treatment remains unclear. The aim of this study is to report our experience in the surgical management of this disease. Between 2000 and 2018, 17 patients underwent operations for PAS at our center. The medical records were retrospectively reviewed to evaluate the clinical characteristics, operative findings, the postoperative outcomes, and the long-term results. The mean age at operation was 46.0 ± 12.4 years (range, 26–79 years), and eight (47.1%) patients were male. Six patients underwent tumor resection alone, whereas the other 11 patients received pulmonary endarterectomy (PEA). There were two perioperative deaths. Follow-up was completed for all patients with a mean duration of 23.5 ± 17.6 months (1–52 months). For all 17 patients, the median postoperative survival was 36 months, and estimated cumulative survival rates at 1, 2, 3, and 4 years were 60.0%, 51.4%, 42.9%, and 21.4%, respectively. The mean survival was 37.0 months after PEA and 14.6 months after tumor resection only (p = 0.046). Patients who had no pulmonary hypertension (PH) postoperatively were associated with improved median survival (48 vs. 5 months, p = 0.023). In conclusion, PAS is often mistaken for chronic pulmonary thromboembolism. The prognosis of this very infrequent disease remains poor. Early detection is essential for prompt and best surgical approach, superior to tumor resection alone, and PEA surgery with PH relieved can provide better chance of survival.

Imaging of pulmonary hypertension in adults: a position paper from the Fleischner Society

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure greater than 20 mmHg and classified into five different groups sharing similar pathophysiologic mechanisms, haemodynamic characteristics, and therapeutic management. Radiologists play a key role in the multidisciplinary assessment and management of PH. A working group was formed from within the Fleischner Society based on expertise in the imaging and/or management of patients with PH, as well as experience with methodologies of systematic reviews. The working group identified key questions focusing on the utility of CT, MRI, and nuclear medicine in the evaluation of PH: a) Is noninvasive imaging capable of identifying PH? b) What is the role of imaging in establishing the cause of PH? c) How does imaging determine the severity and complications of PH? d) How should imaging be used to assess chronic thromboembolic PH before treatment? e) Should imaging be performed after treatment of PH? This systematic review and position paper highlights the key role of imaging in the recognition, work-up, treatment planning, and follow-up of PH.

Imaging of Pulmonary Hypertension in Adults: A Position Paper from the Fleischner Society

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure greater than 20 mm Hg and classified into five different groups sharing similar pathophysiologic mechanisms, hemodynamic characteristics, and therapeutic management. Radiologists play a key role in the multidisciplinary assessment and management of PH. A working group was formed from within the Fleischner Society based on expertise in the imaging and/or management of patients with PH, as well as experience with methodologies of systematic reviews. The working group identified key questions focusing on the utility of CT, MRI, and nuclear medicine in the evaluation of PH: (a) Is noninvasive imaging capable of identifying PH? (b) What is the role of imaging in establishing the cause of PH? (c) How does imaging determine the severity and complications of PH? (d) How should imaging be used to assess chronic thromboembolic PH before treatment? (e) Should imaging be performed after treatment of PH? This systematic review and position paper highlights the key role of imaging in the recognition, work-up, treatment planning, and follow-up of PH. This article is a simultaneous joint publication in Radiology and European Respiratory Journal. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article. © 2021 RSNA and the European Respiratory Society. Online supplemental material is available for this article.

Chronic Thromboembolic Pulmonary Hypertension: the Bedside

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Monitoring Microcirculation: Utility and Barriers - A Point-of-View Review

Microcirculation is a particular organ of the cardiovascular system. The goal of this narrative review is a critical reappraisal of the present knowledge of microcirculation monitoring, mainly focused on the videomicroscopic evaluation of sublingual microcirculation in critically ill patients. We discuss the technological developments in handheld videomicroscopy, which have resulted in adequate tools for the bedside monitoring of microcirculation. By means of these techniques, a large body of evidence has been acquired about the role of microcirculation in the pathophysiological mechanisms of shock, especially septic shock. We review the characteristics of sublingual microcirculation in septic shock, which mainly consist in a decrease in the perfused vascular density secondary to a reduction in the proportion of perfused vessels along with a high heterogeneity in perfusion. Even in patients with high cardiac output, red blood cell velocity is decreased. Thus, hyperdynamic flow is absent in the septic microcirculation. We also discuss the dissociation between microcirculation and systemic hemodynamics, particularly after shock resuscitation, and the different behavior among microvascular beds. In addition, we briefly comment the effects of some treatments on microcirculation. Despite the fact that sublingual microcirculation arises as a valuable goal for the resuscitation in critically ill patients, significant barriers remain present for its clinical application. Most of them are related to difficulties in video acquisition and analysis. We comprehensively analyzed these shortcomings. Unfortunately, a simpler approach, such as the central venous minus arterial PCO₂ difference, is a misleading surrogate for sublingual microcirculation. As conclusion, the monitoring of sublingual microcirculation is an appealing method for monitoring critically ill patients. Nevertheless, the lack of controlled studies showing benefits in terms of outcome, as well as technical limitations for its clinical implementation, render this technique mainly as a research tool.

A successful case of heart transplantation concurrent with pulmonary thromboendarterectomy

INTRODUCTION

Pre-transplant irreversible pulmonary hypertension and high pulmonary vascular resistance are generally considered as contraindications for orthotopic heart transplantation due to the high risk of right ventricular dysfunction after transplantation. However, there is no consensus on whether reversible pulmonary hypertension increases the incidence of post-transplant complications and mortality.

CASE REPORT

A patient with acute heart failure and pulmonary artery occlusion successfully underwent heart transplantation concurrent with pulmonary thromboendarterectomy.

DISCUSSION AND CONCLUSION

This case illustrates that heart transplantation concurrent with pulmonary thromboendarterectomy can be performed successfully with meticulous operability assessment, superb surgical technique and careful perioperative management.

Novel Balloon Pulmonary Angioplasty Technique for Chronic Thromboembolic Pulmonary Hypertension

This study aimed to clarify the usefulness of the Ikari-curve left (IL) guiding catheter for balloon pulmonary angioplasty (BPA).The current BPA strategy for chronic thromboembolic pulmonary hypertension is dilation of as many branches as possible to normalize hemodynamics and oxygenation. The shape of the guiding catheter is a major factor in achieving this. However, conventional guiding catheters are difficult to introduce into particular branches. The IL guiding catheter may be suitable; however, its utility remains unclear.We retrospectively analyzed 202 consecutive BPA sessions of 40 patients from November 2016 to October 2019 and divided these sessions into two groups: the IL group where the IL guiding catheter was used and the non-IL group where other catheters were utilized. The occurrence of lung injury was determined by the presence of bloody sputum. We compared the rates of successful introduction into target vessels and assessed for the occurrence of lung injury.The average age of enrolled patients was 60.3 ± 14.4 years, with females comprising 65%. There were 99 sessions in the IL group. The median treated branches per session differed between the 2 groups (IL group: 15 versus non-IL group: 10, P < 0.05). The occurrence of lung injury was lower in the IL group (4.0% versus 11.7%, P = 0.07). The IL group had more successful vessel insertions than the non-IL group (78.8% versus 42.7%, P < 0.01).The IL guiding catheter may be introduced into branches that cannot be accessed by conventional guiding catheters.

Evaluation of Routine Coronary Angiography Before Pulmonary Thromboendarterectomy

BACKGROUND

At the University of California, San Diego, routine coronary angiography has generally been performed in men 40 years of age and older and women 45 years of age and older before pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension (CTEPH). The prevalence of significant coronary artery disease (CAD) in this population has not been evaluated, however, and the optimal screening strategy has not been established. This study sought to evaluate whether the current approach may be better optimized on the basis of cardiac risk factors.

METHODS

This study included 462 consecutive patients with CTEPH who were undergoing preoperative coronary angiography for pulmonary thromboendarterectomy. Baseline demographic and medical information was recorded. Major cardiac risk factors included: diabetes, hypertension, hyperlipidemia, body mass index 25 kg/m² or greater, tobacco use, and family history of CAD. Charts were then reviewed for presence of significant CAD and revascularization.

RESULTS

Significant CAD was found in 13.4% of patients who underwent routine preoperative coronary angiography; it was present in only 5% of patients younger than 50 years of age, compared with 16% of patients 50 years old and older. No patient younger than 50 years of age without cardiac risk factors was found to have significant CAD. Furthermore, in patients younger than 50 years of age, significant CAD was found only among those with 3 or more major risk factors.

CONCLUSIONS

In patients younger than 50 years of age with CTEPH, the prevalence of significant CAD was low. Omitting preoperative coronary angiography in this subset of patients is reasonable when no coronary risk factors are present. Preoperative coronary angiography is warranted in individuals 50 years of age and older, as well as in those younger than 50 years who have significant risk factors for CAD.

Pulmonary thromboendarterectomy in Portugal: Initial experience

INTRODUCTION

Surgical treatment for chronic thromboembolic pulmonary hypertension (CTEPH) is challenging. Most Portuguese patients with CTEPH have been referred to foreign institutions for treatment, with significant social and economic costs. To meet this emerging need, the cardiothoracic surgery department of Hospital de Santa Marta, Lisbon, has developed a dedicated program for pulmonary thromboendarterectomy (PTE). We hereby present the results for the first 19 patients treated.

METHODS

We conducted a retrospective analysis of all 19 patients who underwent PTE at Hospital de Santa Marta between 2008 and April 2019.

RESULTS

Since 2008, a total of 19 patients have undergone PTE in our department. The procedure was performed with good outcomes in both survival and functional recovery. At the very beginning of the series two patients died perioperatively, before all the team underwent formal training at the Royal Papworth Hospital, UK, with no early deaths since. Postoperative complications were similar to other published series. During 11 years of follow-up, there were three late deaths, all in patients with residual pulmonary arterial hypertension. At the latest follow-up (October 2019), all surviving patients showed significant functional recovery, all in NYHA class I or II, with only one patient on vasodilator therapy with sildenafil (the first in the series, operated in 2008).

CONCLUSIONS

PTE is a demanding procedure, in which outcomes are related to volume and accumulated experience, however it can be performed safely and with reproducible results by a properly prepared dedicated team with a well-controlled learning curve. More patients and multidisciplinary experience will be needed to further improve and streamline results.

Speckle tracking for predicting outcomes of balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

BACKGROUND

Right ventricular (RV) function is a prognostic marker of chronic thromboembolic pulmonary hypertension (CTEPH). We used two-dimensional (2D) speckle-tracking echocardiography (STE) to evaluate the therapeutic effects of balloon pulmonary angioplasty (BPA) in CTEPH patients.

METHODS

A total of 46 CTEPH patients who underwent 2D STE before and after BPA were enrolled in this retrospective study. The following RV functional parameters were measured: tricuspid annular plane systolic excursion (TAPSE), right ventricular fractional area change (RVFAC), RV index of myocardial performance (RIMP), and free wall longitudinal strain (RVFWLS). Satisfactory BPA was defined as mean pulmonary arterial pressure (mPAP) <25 mm Hg or improvement in mPAP > 10 mm Hg after BPA. Patients were divided into two groups according to mPAP values: group I had satisfactory BPA outcomes; group Ⅱ had unsatisfactory BPA outcomes. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to determine the optimal cutoff values and the ability of RVFWLS to predict successful BPA outcomes.

RESULTS

After BPA, SPAP measured by echocardiography (SPAP_echo ) and RIMP decreased, but TAPSE, RVFAC, and RVFWLS increased. Before BPA, group Ⅰ had significantly better RV function than group Ⅱ. Multifactor logistic regression analysis identified RVFWLS as an independent factor associated with satisfactory BPA outcomes. The optimal cutoff value for RVFWLS in predicting satisfactory BPA outcomes was -12.2%.

CONCLUSIONS

Balloon pulmonary angioplasty improves RV function in CTEPH patients. RVFWLS is a valuable noninvasive tool with which to assess the treatment effects of BPA. CTEPH patients with lower RVFWLS may have limited benefit from BPA.

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.

Life expectancy after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: a Swedish single-center study

Pulmonary endarterectomy is the guideline recommended treatment for chronic thromboembolic pulmonary hypertension, in addition to life-long anticoagulation therapy. The aim was to analyze long-term relative survival after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension. We included all patients who underwent pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension at Karolinska University Hospital between 1997 and 2018 (n = 100). We obtained baseline characteristics and vital status from patient charts and national health-data registers. The expected survival from the general Swedish population matched by age, sex, and year of surgery was obtained from the Human Mortality Database. The relative survival was used as an estimate of cause-specific mortality. The mean age of the patients was 62 years and 39% were women. Most patients were severely symptomatic (95% in New York Heart Association functional class III-IV), and mean preoperative systolic/diastolic (mean) pulmonary artery pressure was 78/27 (45) mmHg. The mean and maximum follow-up time was 7.2 and 22.1 years, respectively. Early (30-day) mortality was 7%. The 15-year observed, expected, and relative survival was 55% (95% confidence interval, 40%-68%), 71%, and 77% (95% confidence interval, 56%-95%), respectively. The 15-year relative survival conditional on 30-day survival was 83% (95% confidence interval, 60%-100%). Although the life expectancy following pulmonary endarterectomy was shorter compared to the general population, the difference was small in those who survived the operation and the early postoperative period. Patients with chronic thromboembolic pulmonary hypertension who are surgical candidates should undergo pulmonary endarterectomy to improve prognosis.

Is microcirculatory assessment ready for regular use in clinical practice?

PURPOSE OF REVIEW

The present review discusses the current role of microcirculatory assessment in the hemodynamic monitoring of critically ill patients.

RECENT FINDINGS

Videomicroscopic techniques have demonstrated that microvascular perfusion is altered in critically ill patients, and especially in sepsis. These alterations are associated with organ dysfunction and poor outcome. Handheld microscopes can easily be applied on the sublingual area of critically ill patients. Among the specific limitations of these techniques, the most important is that these can mostly investigate the sublingual microcirculation. The representativity of the sublingual area may be questioned, especially as some areas may sometimes be more affected than the sublingual area. Also, evaluation of the sublingual area may be difficult in nonintubated hypoxemic patients. Alternative techniques include vasoreactivity tests using either transient occlusion or performing a thermal challenge. These techniques evaluate the maximal dilatory properties of the microcirculation but do not really evaluate the actual microvascular perfusion. Focusing on the glycocalyx may be another option, especially with biomarkers of glycocalyx degradation and shedding. Evaluation of the glycocalyx is still largely experimental, with different tools still in investigation and lack of therapeutic target. Venoarterial differences in PCO2 are inversely related with microvascular perfusion, and can thus be used as surrogate for microcirculation assessment. Several limitations prevent the regular use in clinical practice. The first is the difficult use of some of these techniques outside research teams, whereas nurse-driven measurements are probably desired. The second important limitation for daily practice use is the lack of uniformly defined endpoint. The final limitation is that therapeutic interventions affecting the microcirculation are not straightforward.

SUMMARY

Clinical and biological surrogates of microcirculatory assessment can be used at bedside. The role of microvideoscopic techniques is still hampered by the lack of clearly defined targets as well as interventions specifically targeting the microcirculation.

Surgical and Percutaneous Interventions for Chronic Thromboembolic Pulmonary Hypertension

The treatment of chronic thromboembolic pulmonary hypertension has expanded considerably. The ability to endarterectomize chronic thromboembolic material, the availability of pulmonary hypertension medical therapy to treat inoperable chronic thromboembolic pulmonary hypertension and/or residual pulmonary hypertension, and the rebirth of pulmonary balloon angioplasty have changed the management landscape. Patient selection requires a multidisciplinary evaluation at an experienced center. What is inoperable chronic thromboembolic pulmonary hypertension to one group may be operable chronic thromboembolic pulmonary hypertension to another. The ultimate challenge then becomes which intervention provides the optimal long-term outcome for any individual patient.

Balloon pulmonary angioplasty for inoperable chronic thromboembolic pulmonary hypertension: the UK experience

Objective

Inoperable chronic thromboembolic pulmonary hypertension (CTEPH) managed medically has a poor prognosis. Balloon pulmonary angioplasty (BPA) offers a new treatment for inoperable patients. The national BPA service for the UK opened in October 2015 and we now describe the treatment of our initial patient cohort.

Methods

Thirty consecutive, inoperable, anatomically suitable, symptomatic patients on stable medical therapy for CTEPH were identified and offered BPA. They initially underwent baseline investigations including Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) quality of life (QoL) questionnaire, cardiopulmonary exercise test, 6 min walk distance (6MWD), transthoracic echocardiography, N-terminal probrain natriuretic peptide (NT pro-BNP) and right heart catheterisation. Serial BPA sessions were then performed and after completion, the treatment effect was gauged by comparing the same investigations at 3 months follow-up.

Results

A median of 3 (IQR 1-6) BPA sessions per patient resulted in a significant improvement in functional status (WHO functional class ≥3: 24 vs 4, p<0.0001) and QoL (CAMPHOR symptom score: 8.7±5.4 vs 5.6±6.1, p=0.0005) with reductions in pulmonary pressures (mean pulmonary artery pressure: 44.7±11.0 vs 34.4±8.3 mm Hg, p<0.0001) and resistance (pulmonary vascular resistance: 663±281 vs 436±196 dyn.s.cm-5, p<0.0001). Exercise capacity improved (minute ventilation/carbon dioxide production: 55.3±12.2 vs 45.0±7.8, p=0.03 and 6MWD: 366±107 vs 440±94 m, p<0.0001) and there was reduction in right ventricular (RV) stretch (NT pro-BNP: 442 (IQR 168-1607) vs 202 (IQR 105-447) pg/mL, p<0.0001) and dimensions (mid RV diameter: 4.4±1.0 vs 3.8±0.7 cm, p=0.002). There were no deaths or life-threatening complications and the mild-moderate per-procedure complication rate was 10.5%.

Conclusions

BPA is safe and improves the functional status, QoL, pulmonary haemodynamics and RV dimensions of patients with inoperable CTEPH.

Preoperative platelet count, preoperative hemoglobin concentration and deep hypothermic circulatory arrest duration are risk factors for acute kidney injury after pulmonary endarterectomy: a retrospective cohort study

Background

Acute kidney injury (AKI) is a major postoperative morbidity of patients undergoing cardiac surgery and has a negative effect on prognosis. The kidney outcomes after pulmonary endarterectomy (PEA) have not yet been reported; However, several perioperative characteristics of PEA may induce postoperative AKI. The objective of our study was to identify the incidence and risk factors for postoperative AKI and its association with short-term outcomes.

Methods

This was a single-center, retrospective, observational, cohort study. Assessments of AKI diagnosis was executed based on the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

Results

A total of 123 consecutive patients who underwent PEA between 2014 and 2018 were included.

The incidence of postoperative AKI was 45% in the study population. Stage 3 AKI was associated with worse short-term outcomes and 90-day mortality (p < 0.001, p = 0.002, respectively). The independent predictors of postoperative AKI were the preoperative platelet count (OR 0.992; 95%CI 0.984–0.999; P = 0.022), preoperative hemoglobin concentration (OR 0.969; 95%CI 0.946–0.993; P = 0.01) and deep hypothermic circulatory arrest (DHCA) time (OR 1.197; 95%CI 1.052–1.362; P = 0.006) in the multivariate analysis.

Conclusion

The incidence of postoperative AKI was relatively high after PEA compared with other types of cardiothoracic surgeries. The preoperative platelet count, preoperative hemoglobin concentration and DHCA duration were modifiable predictors of AKI, and patients may benefit from some low-risk, low-cost perioperative measures.

Pulmonary endarterectomy in a 12-year-old boy with multiple comorbidities

A 10-year-old boy, with multiple comorbidities presented with fever, exertional dyspnea, fatigue and an obliterated brachiocephalic and inferior caval vein. Chronic thromboembolic pulmonary hypertension (CTEPH) was diagnosed. Nadroparine, antibiotics and supplemental oxygen were successfully started. Aged 12 years, supplemental oxygen was permanently needed with progressive exertional dyspnea and fatigue. In the country of residence the patient was considered as inoperable. The right ventricle was severely dilated, hypocontractile and hypertrophic. Mean pulmonary artery pressure (mPAP) was 79 mmHg and cardiac output 2.2 L/min. Pulmonary endarterectomy was uneventful. Four days later, mPAP was 33 mmHg and cardiac output 6.4 L/min. Three months later the boy restarted his education without supplemental oxygen. Six months after surgery right ventricular size and function and mPAP (14 mmHg) were normal. We demonstrated that pulmonary endarterectomy in young aged children is feasible and well-tolerated, even in the presence of severe co-morbidities. CTEPH should be an important diagnostic consideration in symptomatic children with a known hypercoaguable state, a history of thrombo-embolism or venous catheter placement, and/or a diagnosis of pulmonary hypertension. Hesitating to refer children for surgical consideration, or attempting to treat them by medication, only postpones the single potentially curable treatment and may worsen their prognosis.

Effectiveness of balloon pulmonary angioplasty in patients with inoperable chronic thromboembolic pulmonary hypertension despite having lesion types suitable for surgical treatment

BACKGROUND

Balloon pulmonary angioplasty (BPA) has been performed in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). However, some patients have inoperable CTEPH despite having lesions suitable for surgical treatment. The effectiveness of BPA in such cases is unclear. The aim of this study was to clarify the effectiveness of BPA in these cases.

METHODS

We retrospectively investigated patients with inoperable CTEPH and divided them into two groups: BPA-suitable and BPA-unsuitable groups based on the findings of pulmonary angiography, computed tomography, and perfusion scintigraphy. The BPA-unsuitable group included patients whose lesions are suitable for surgical treatment but who did not undergo the procedure for any specified reason. We analyzed the hemodynamic, respiratory, and functional status of the patients before and after BPA.

RESULTS

Forty-three consecutive patients with inoperable CTEPH (age, 62.6 ± 13.5 years; 31 women) were included; all of them underwent BPA. There were 10 patients in the BPA-unsuitable group. In all patients, the mean pulmonary artery pressure, pulmonary vascular resistance, arterial oxygen saturation level, and 6-min walking distance significantly improved after BPA (mean pulmonary artery pressure, from 43.3 ± 7.8 mmHg to 23.9 ± 4.7 mmHg; pulmonary vascular resistance, from 924.1 ± 462.2 dynes/s/cm^-5 to 319.7 ± 163.8 dynes/s/cm^-5; arterial oxygen saturation level, from 89.3 ± 4.3% to 93.4 ± 3.3%; 6-min walking distance, from 370.0 ± 107.4 m to 443.8 ± 101.4 m). Notably, none of the parameters significantly differed between the groups after BPA. Importantly, the amount of lung bleeding did not differ between them. However, several sessions were required in the BPA-unsuitable group (BPA-unsuitable group: six sessions vs. BPA-suitable group: four sessions).

CONCLUSIONS

BPA safely improved the hemodynamic and functional statuses of the patients with CTEPH who are judged as inoperable for any reason despite lesion being suitable for surgical treatment. However, numerous BPA sessions were required in these patients.

ICAM-1 promotes the abnormal endothelial cell phenotype in chronic thromboembolic pulmonary hypertension

BACKGROUND

Pulmonary endothelial cells play a key role in the pathogenesis of Chronic Thromboembolic Pulmonary Hypertension (CTEPH). Increased synthesis and/or the release of intercellular adhesion molecule-1 (ICAM-1) by pulmonary endothelial cells of patients with CTEPH has been recently reported, suggesting a potential role for ICAM-1 in CTEPH.

METHODS

We studied pulmonary endarterectomy specimens from 172 patients with CTEPH and pulmonary artery specimens from 97 controls undergoing lobectomy for low-stage cancer without metastasis.

RESULTS

ICAM-1 was overexpressed in vitro in isolated and cultured endothelial cells from endarterectomy specimens. Endothelial cell growth and apoptosis resistance were significantly higher in CTEPH specimens than in the controls (p < 0.001). Both abnormalities were abolished by pharmacological inhibition of ICAM-1 synthesis or activity. The overexpression of ICAM-1 contributed to the acquisition and maintenance of abnormal EC growth and apoptosis resistance via the phosphorylation of SRC, p38 and ERK1/2 and the overproduction of survivin. Regarding the ICAM-1 E469K polymorphism, the KE heterozygote genotype was significantly more frequent in CTEPH than in the controls, but it was not associated with disease severity among patients with CTEPH.

CONCLUSIONS

ICAM-1 contributes to maintaining the abnormal endothelial cell phenotype in CTEPH.

Chronic Thromboembolic Pulmonary Hypertension: An Update

Chronic thromboembolic pulmonary hypertension (CTEPH) is a progressive pulmonary vascular disease with significant morbidity. It is a result of an alternate natural history in which there is limited resolution of thromboemboli with pulmonary artery obstruction leading to pulmonary hypertension (PH). CTEPH requires a thorough clinical assessment including pulmonary hemodynamics and radiologic evaluation in addition to consultation with an expert center. Surgical intervention remains the optimal management strategy. Select patients may be candidates for catheter-based intervention with balloon pulmonary angioplasty in centers with clinical expertise. Inoperable patients or those with post-intervention PH are treated with pulmonary hypertension-targeted medical therapy.

Surgical Management of Acute and Chronic Pulmonary Embolism

Surgical pulmonary embolectomy and pulmonary thromboendarterectomy are well-established treatment strategies for patients with acute and chronic pulmonary embolism, respectively. For both procedures, techniques and outcomes have evolved considerably over the past decades. Patients with massive and submassive acute pulmonary embolism are at risk for rapid decline owing to right ventricular failure and shock. When thrombus is proximal, embolectomy can rapidly restore cardiac function. Chronic thromboembolic pulmonary hypertension is a more complex disease that requires skilled, careful dissection of the arterial wall, including vascular intima. When successful, surgery leads to clinical cure of the associated pulmonary hypertension, with excellent long-term outcomes.

Monitoring peripheral perfusion and microcirculation

PURPOSE OF REVIEW

Microcirculatory alterations play a major role in the pathogenesis of shock. Monitoring tissue perfusion might be a relevant goal for shock resuscitation. The goal of this review was to revise the evidence supporting the monitoring of peripheral perfusion and microcirculation as goals of resuscitation. For this purpose, we mainly focused on skin perfusion and sublingual microcirculation.

RECENT FINDINGS

Although there are controversies about the reproducibility of capillary refill time in monitoring peripheral perfusion, it is a sound physiological variable and suitable for the ICU settings. In addition, observational studies showed its strong ability to predict outcome. Moreover, a preliminary study suggested that it might be a valuable goal for resuscitation. These results should be confirmed by the ongoing ANDROMEDA-SHOCK randomized controlled trial. On the other hand, the monitoring of sublingual microcirculation might also provide relevant physiological and prognostic information. On the contrary, methodological drawbacks mainly related to video assessment hamper its clinical implementation at the present time.

SUMMARY

Measurements of peripheral perfusion might be useful as goal of resuscitation. The results of the ANDROMEDA-SHOCK will clarify the role of skin perfusion as a guide for the treatment of shock. In contrast, the assessment of sublingual microcirculation mainly remains as a research tool.

Critical Care of Patients After Pulmonary Thromboendarterectomy

Pulmonary thromboendarterectomy (PTE) remains the only curative surgery for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Postoperative intensive care unit care challenges providers with unique disease physiology, operative sequelae, and the potential for detrimental complications. Central concerns in patients with CTEPH immediately after PTE relate to neurologic, pulmonary, hemodynamic, and hematologic aspects. Institutional experience in critical care for the CTEPH population, a multidisciplinary team approach, patient risk assessment, and integration of current concepts in critical care determine outcomes after PTE surgery. In this review, the authors will focus on specific aspects unique to this population, with integration of current available evidence and future directions. The goal of this review is to provide the cardiac anesthesiologist and intensivist with a comprehensive understanding of postoperative physiology, potential complications, and contemporary intensive care unit management immediately after pulmonary endarterectomy.

Outcomes of Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension at a Single Center in Taiwan

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is classified as group IV pulmonary hypertension. This study aimed to report our institutional experience in managing CTEPH.

METHODS

We prospectively collected the data of 23 patients diagnosed with CTEPH between August 2001 and August 2017 in Linkou Chang Gung Memorial Hospital. Baseline characteristics including functional class (FC), 6-minute walk distance (6MWD), comorbidities, hematological and biochemical data, echocardiography, cardiac catheterization, and selective pulmonary angiography were recorded at diagnosis. All patients were referred to a cardiac surgeon for pulmonary endarterectomy (PEA) assessment.

RESULTS

The mean age at diagnosis was 48.4 ± 16.1 years. Nineteen patients (83%) underwent PEA with mean postoperative follow-up of 37.7 ± 42.8 months. The in-hospital mortality rate of PEA was 11%. The 1-, 2-, 3- and 5-year overall survival rates were 89%, 89%, 81%, and 50%, respectively. After 3 months of PEA, all patients had improvements in FC, 6MWD (from 326 ± 62 to 420 ± 63 m), B-type natriuretic peptide level (from 602 ± 599 to 268 ± 565 pg/mL), and systolic pulmonary artery pressure (from 79 ± 19 to 48 ± 19 mmHg). The patients with proximal disease (Jamieson type 1 or 2) had better survival than those with distal disease (Jamieson type 3 or 4), but there was no significant difference in mortality between FC III and IV. All of the four patients who did not undergo PEA survived for more than 3 years.

CONCLUSIONS

Significant improvements in symptoms, functional capacity, and hemodynamics were achieved in the CTEPH patients after PEA. However, the overall survival was still unsatisfactory.

Meta-analysis of use of balloon pulmonary angioplasty in patients with inoperable chronic thromboembolic pulmonary hypertension

BACKGROUND

Current guidelines give balloon pulmonary angioplasty (BPA) a Class IIb recommendation for use in inoperable chronic thromboembolic pulmonary hypertension (CTEPH), as its safety and efficacy remain poorly defined. We conducted a systematic review and meta-analysis to evaluate BPA effectiveness.

METHODS

Medline, Cochrane Library and Scopus were searched for original studies from database inception dates until 24th May 2018. Prospective studies reporting outcomes before and after BPA in inoperable CTEPH patients were included. Studies with <20 patients were excluded. Data were pooled using a random effects model represented as weighted mean differences with 95% confidence intervals (CIs).

RESULTS

Seventeen noncomparative studies comprising 670 CTEPH patients (mean age 62 years; 68% women) were included. Meta-analysis showed significantly decreased mean pulmonary artery pressure (-14.2 mm Hg [95% CI -18.9, -9.5]), pulmonary vascular resistance (-303.5 dyn·s/cm⁵ [95% CI -377.6, -229.4]) and mean right atrial pressure (-2.7 mm Hg [95% CI -4.1, -1.3]) after BPA. Six-minute walk distance (67.3 m [95% CI 53.8, 80.8]) and cardiac output (0.2 l/min [95% CI 0.0, 0.3]) were significantly increased following BPA. From 12 studies reporting mortality with median follow-up of 9 months after BPA (range, 1-51 months), pooled incidence of short (≤1 month) and long-term mortality (>1 month) was 1.9% and 5.7%, respectively.

CONCLUSION

This systematic review and meta-analysis suggests mildly improved hemodynamics and overall low mortality rates following BPA in inoperable CTEPH patients. This non-comparative evidence can be used to facilitate decision making until the results of larger, controlled studies become available.

Chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of pulmonary embolism and a major cause of chronic PH leading to right heart failure and death. Lung ventilation/perfusion scintigraphy is the screening test of choice; a normal scan rules out CTEPH. In the case of an abnormal perfusion scan, a high-quality pulmonary angiogram is necessary to confirm and define the pulmonary vascular involvement and prior to making a treatment decision. PH is confirmed with right heart catheterisation, which is also necessary for treatment determination. In addition to chronic anticoagulation therapy, each patient with CTEPH should receive treatment assessment starting with evaluation for pulmonary endarterectomy, which is the guideline recommended treatment. For technically inoperable cases, PH-targeted medical therapy is recommended (currently riociguat based on the CHEST studies), and balloon pulmonary angioplasty should be considered at a centre experienced with this challenging but potentially effective and complementary intervention.