Chronic Thromboembolic Pulmonary Hypertension

How Would I Treat My Own Chronic Thromboembolic Pulmonary Hypertension in the Perioperative Period?

Chronic thromboembolic pulmonary hypertension (CTEPH) results from an incomplete resolution of acute pulmonary embolism, leading to occlusive organized thrombi, vascular remodeling, and associated microvasculopathy with pulmonary hypertension (PH). A definitive CTEPH diagnosis requires PH confirmation by right-heart catheterization and evidence of chronic thromboembolic pulmonary disease on imaging studies. Surgical removal of the organized fibrotic material by pulmonary endarterectomy (PEA) under deep hypothermic circulatory arrest represents the treatment of choice. One-third of patients with CTEPH are not deemed suitable for surgical treatment, and medical therapy or interventional balloon pulmonary angioplasty presents alternative treatment options. Pulmonary endarterectomy in patients with technically operable disease significantly improves symptoms, functional capacity, hemodynamics, and quality of life. Perioperative mortality is <2.5% in expert centers where a CTEPH multidisciplinary team optimizes patient selection and ensures the best preoperative optimization according to individualized risk assessment. Despite adequate pulmonary artery clearance, patients might be prone to perioperative complications, such as right ventricular maladaptation, airway bleeding, or pulmonary reperfusion injury. These complications can be treated conventionally, but extracorporeal membrane oxygenation has been included in their management recently. Patients with residual PH post-PEA should be considered for medical or percutaneous interventional therapy.

Macitentan for the treatment of inoperable chronic thromboembolic pulmonary hypertension (MERIT-1): results from the multicentre, phase 2, randomised, double-blind, placebo-controlled study

BACKGROUND

Macitentan is beneficial for long-term treatment of pulmonary arterial hypertension. The microvasculopathy of chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary arterial hypertension are similar.

METHODS

The phase 2, double-blind, randomised, placebo-controlled MERIT-1 trial assessed macitentan in 80 patients with CTEPH adjudicated as inoperable. Patients identified as WHO functional class II-IV with a pulmonary vascular resistance (PVR) of at least 400 dyn·s/cm5 and a walk distance of 150-450 m in 6 min were randomly assigned (1:1), via an interactive voice/web response system, to receive oral macitentan (10 mg once a day) or placebo. Treatment with phosphodiesterase type-5 inhibitors and oral or inhaled prostanoids was permitted for WHO functional class III/IV patients. The primary endpoint was resting PVR at week 16, expressed as percentage of PVR measured at baseline. Analyses were done in all patients who were randomly assigned to treatment; safety analyses were done in all patients who received at least one dose of the study drug. This study is registered with ClinicalTrials.gov, number NCT02021292.

FINDINGS

Between April 3, 2014, and March 17, 2016, we screened 186 patients for eligibility at 48 hospitals across 20 countries. Of these, 80 patients in 36 hospitals were randomly assigned to treatment (40 patients to macitentan, 40 patients to placebo). At week 16, geometric mean PVR decreased to 71·5% of baseline in the macitentan group and to 87·6% in the placebo group (geometric means ratio 0·81, 95% CI 0·70-0·95, p=0·0098). The most common adverse events in the macitentan group were peripheral oedema (9 [23%] of 40 patients) and decreased haemoglobin (6 [15%]).

INTERPRETATION

In MERIT-1, macitentan significantly improved PVR in patients with inoperable CTEPH and was well tolerated.

FUNDING

Actelion Pharmaceuticals Ltd.

Recent advances in the potential effects of natural products from traditional Chinese medicine against respiratory diseases targeting ferroptosis

Respiratory diseases, marked by structural changes in the airways and lung tissues, can lead to reduced respiratory function and, in severe cases, respiratory failure. The side effects of current treatments, such as hormone therapy, drugs, and radiotherapy, highlight the need for new therapeutic strategies. Traditional Chinese Medicine (TCM) offers a promising alternative, leveraging its ability to target multiple pathways and mechanisms. Active compounds from Chinese herbs and other natural sources exhibit anti-inflammatory, antioxidant, antitumor, and immunomodulatory effects, making them valuable in preventing and treating respiratory conditions. Ferroptosis, a unique form of programmed cell death (PCD) distinct from apoptosis, necrosis, and others, has emerged as a key area of interest. However, comprehensive reviews on how natural products influence ferroptosis in respiratory diseases are lacking. This review will explore the therapeutic potential and mechanisms of natural products from TCM in modulating ferroptosis for respiratory diseases like acute lung injury (ALI), asthma, pulmonary fibrosis (PF), chronic obstructive pulmonary disease (COPD), lung ischemia-reperfusion injury (LIRI), pulmonary hypertension (PH), and lung cancer, aiming to provide new insights for research and clinical application in TCM for respiratory health.

Challenging in pulmonary thromboembolism diagnosis in patients with disproportionate pulmonary hypertension and severe mitral stenosis: Report of two cases

Key Clinical Message

Before valvular interventions, echocardiography, especially the TEE or the ventilation/perfusion scan, should be performed to detect silent PTE and set a more accurate treatment and surgical plan.

Abstract

Pulmonary hypertension (PH) is a progressive and critical disease that can be caused by mitral stenosis (MS). Some of these patients present with disproportionate PH, which is an uncommon phenomenon and is considered a challenging diagnostic and treatment process. In these patients, other causes may also play a role in developing PH. This report presented two cases with disproportionate PH and severe MS who were scheduled for percutaneous mitral valvuloplasty (PMV). The pre-procedural echocardiography revealed systolic pulmonary artery pressure (sPAP) of 90 and 120 mmHg, mitral valve area of 0.80 and 0.55 cm2 by three-dimensional (3D) planimetry, and diastolic pressure gradient (DPG) of 13 and 18.8 mmHg, respectively. Furthermore, in the first patient, 3D transesophageal echocardiography (TEE) revealed multiple saddle-type organized thrombi in the proximal parts of the right and left pulmonary arteries, extending to the distal branches. In the second patient, 3D TEE revealed a large, relatively fresh, flow-limiting thrombosis in the proximal part of the right pulmonary artery. The diagnosis of pulmonary thromboembolism (PTE) in both patients was confirmed by CT angiography. In both patients, the valves were surgically repaired, while all thrombi were removed from the cardiac chambers and pulmonary vessels during surgery. In addition, patients underwent warfarin therapy orally. They were followed up 6 months after the intervention, and their clinical symptoms had improved significantly.

Circulating miR-let7a levels predict future diagnosis of chronic thromboembolic pulmonary hypertension

Distinct patterns of circulating microRNAs (miRNAs) were found to be involved in misguided thrombus resolution. Thus, we aimed to investigate dysregulated miRNA signatures during the acute phase of pulmonary embolism (PE) and test their diagnostic and predictive value for future diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH). Microarray screening and subsequent validation in a large patient cohort (n = 177) identified three dysregulated miRNAs as potential biomarkers: circulating miR-29a and miR-720 were significantly upregulated and miR-let7a was significantly downregulated in plasma of patients with PE. In a second validation study equal expression patterns for miR-29a and miR-let7a regarding an acute event of recurrent venous thromboembolism (VTE) or deaths were found. MiR-let7a concentrations significantly correlated with echocardiographic and laboratory parameters indicating right ventricular (RV) dysfunction. Additionally, circulating miR-let7a levels were associated with diagnosis of CTEPH during follow-up. Regarding CTEPH diagnosis, ROC analysis illustrated an AUC of 0.767 (95% CI 0.54-0.99) for miR-let7a. Using logistic regression analysis, a calculated patient-cohort optimized miR-let7a cut-off value derived from ROC analysis of ≥ 11.92 was associated with a 12.8-fold increased risk for CTEPH. Therefore, miR-let7a might serve as a novel biomarker to identify patients with haemodynamic impairment and as a novel predictor for patients at risk for CTEPH.

Perioperative extracorporeal membrane oxygenation support for pulmonary endarterectomy: A 17-year experience from the UK national cohort

BACKGROUND

Pulmonary endarterectomy (PEA) is the guideline-recommended treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, some patients develop severe cardiopulmonary compromise before surgery, intraoperatively, or early postoperatively. This may result from advanced CTEPH, reperfusion pulmonary edema, massive endobronchial bleeding, or right ventricular (RV) failure secondary to residual pulmonary hypertension. Conventional cardiorespiratory support is ineffective when these complications are severe. Since 2005, we used extracorporeal membrane oxygenation (ECMO) as a rescue therapy for this group. We review our experience with ECMO support in these patients.

METHODS

This study was a retrospective analysis of patients who received perioperative ECMO for PEA from a single national center from August 2005 to July 2022. Data were prospectively collected.

RESULTS

One hundred and ten patients (4.7%) had extreme cardiorespiratory compromise requiring perioperative ECMO. Nine were established on ECMO before PEA. Of those who received ECMO postoperatively, 39 were for refractory reperfusion lung injury, 20 for RV failure, 31 for endobronchial bleeding, and the remaining 11 were for "other" reasons, such as cardiopulmonary resuscitation following late tamponade and aspiration pneumonitis. Sixty-two (56.4%) were successfully weaned from ECMO. Fifty-seven patients left the hospital alive, giving a salvage rate of 51.8%. Distal disease (Jamieson Type III) and significant residual pulmonary hypertension were also predictors of mortality on ECMO support. Overall, 5- and 10-year survival in patients who were discharged alive following ECMO support was 73.9% (SE: 6.1%) and 58.2% (SE: 9.5%), respectively.

CONCLUSIONS

Perioperative ECMO support has an appropriate role as rescue therapy for this group. Over 50% survived to hospital discharge. These patients had satisfactory longer-term survival.

Dynamic chest radiography for pulmonary vascular diseases: clinical applications and correlation with other imaging modalities

Dynamic chest radiography (DCR) is a novel functional radiographic imaging technique that can be used to visualize pulmonary perfusion without using contrast media. Although it has many advantages and clinical utility, most radiologists are unfamiliar with this technique because of its novelty. This review aims to (1) explain the basic principles of lung perfusion assessment using DCR, (2) discuss the advantages of DCR over other imaging modalities, and (3) review multiple specific clinical applications of DCR for pulmonary vascular diseases and compare them with other imaging modalities.

Characteristics and prognostic significance of right heart remodeling and tricuspid regurgitation after pulmonary endarterectomy

OBJECTIVE

Right heart remodeling and tricuspid regurgitation (TR) are common in patients with chronic thromboembolic pulmonary hypertension. This study aimed to investigate the significance of right heart remodeling and TR after pulmonary endarterectomy (PEA) in patients with chronic thromboembolic pulmonary hypertension.

METHODS

Patients who underwent PEA with preoperative and postoperative transthoracic echocardiograms at our center between June 2010 and July 2019 were retrospectively reviewed. The composite end point was defined as death or hospitalization due to worsening heart failure, bleeding, or recurrent pulmonary embolism.

RESULTS

In total, 158 patients were included for analysis. Right ventricular basal (48 [45-52] vs 43 [39-47] mm, P < .001), midcavitary (46 [42-50] vs 38 [34-42] mm, P < .001), and longitudinal dimensions (87 [83-93] vs 80 [75-84] mm, P < .001), along with the right atrial volume index (37 [25-51] vs 24 [18-34] mL/m2, P < .001), significantly decreased, whereas left ventricular and atrial sizes and left ventricular ejection fraction increased after PEA. Overall, 78 patients (49%) showed significant TR on preoperative transthoracic echocardiograms, and 33 (21%) had significant residual TR after PEA. Fourteen patients died, and 24 patients met the composite end point. Residual TR after PEA was independently associated with mortality (P = .005) and the composite end point (P = .003). Patients with residual TR had significantly worse survival (log-rank P < .001) and greater event rates (log-rank P = .003) than those without residual TR.

CONCLUSIONS

Significant improvements in right heart remodeling were seen following PEA. However, residual TR was a poor prognostic marker.

Prevalence and Prognosis of Hypothyroidism in Patients With Chronic Thromboembolic Pulmonary Hypertension: An Updated Review With Description of Case Series

Hypothyroidism has been shown to have several effects on organs, including derangements in the coagulation system, impairing endothelial function, but data on the importance of hypothyroidism in the pathogenesis and development of chronic thromboembolic pulmonary hypertension (CTEPH) are limited. This report presents an updated review of the prevalence and prognosis of hypothyroidism in patients diagnosed with CTEPH, including a detailed retrospective description of the series. The descriptive case series included 34 adult patients diagnosed with CTEPH, of whom 11 patients were diagnosed with hypothyroidism. The prevalence of hypothyroidism in CTEPH was found to be 32.35%. All patients with hypothyroidism had NYHA functional Class II-III. Hemodynamic values obtained through right heart catheterization (RHC) showed that patients with hypothyroidism had significantly higher mean pulmonary arterial pressures (mPAP), with a mean of 56.91 mm Hg vs 43.93 mm Hg (p = 0.026), and the PVR in dynes/sec/cm5 was 932 vs 541 (p = 0.027). Significant differences in PVR were found in wood units (WU) 11.91 vs 7.11 (p = 0.042). The mean level of brain natriuretic peptide (BNP) between both groups was 797.3 pg/mL for patients with hypothyroidism vs 262.02 pg/mL in patients with euthyroidism (p = .032). Hypothyroidism may significantly affect patients' clinical and hemodynamic outcomes in patients with CTEPH. Hypothyroidism as a risk factor in the evaluation and treatment of these patients is vital to optimize outcomes in CTEPH; further research is warranted whether hypothyroidism therapies could alter such outcomes.

Post-Pulmonary Embolism Syndrome and Functional Outcomes after Acute Pulmonary Embolism

Survivors of acute pulmonary embolism (PE) are at risk of developing persistent, sometimes disabling symptoms of dyspnea and/or functional limitations despite adequate anticoagulant treatment, fulfilling the criteria of the post-PE syndrome (PPES). PPES includes chronic thromboembolic pulmonary hypertension (CTEPH), chronic thromboembolic pulmonary disease, post-PE cardiac impairment (characterized as persistent right ventricle impairment after PE), and post-PE functional impairment. To improve the overall health outcomes of patients with acute PE, adequate measures to diagnose PPES and strategies to prevent and treat PPES are essential. Patient-reported outcome measures are very helpful to identify patients with persistent symptoms and functional impairment. The primary concern is to identify and adequately treat patients with CTEPH as early as possible. After CTEPH is ruled out, additional diagnostic tests including cardiopulmonary exercise tests, echocardiography, and imaging of the pulmonary vasculature may be helpful to rule out non-PE-related comorbidities and confirm the ultimate diagnosis. Most PPES patients will show signs of physical deconditioning as main explanation for their clinical presentation. Therefore, cardiopulmonary rehabilitation provides a good potential treatment option for this patient category, which warrants testing in adequately designed and executed randomized trials. In this review, we describe the definition and characteristics of PPES and its diagnosis and management.

Anticoagulation in chronic thromboembolic pulmonary hypertension: A systematic review and meta-analysis

INTRODUCTION

Life-long anticoagulation is the recommended management for chronic thromboembolic pulmonary hypertension (CTEPH). Evidence regarding the use of direct oral anticoagulants (DOAC) for CTEPH is yet to be established. We performed a systematic review and meta-analysis to clarify the outcomes of CTEPH in patients who used DOAC or vitamin K antagonists (VKA).

METHODS

We reviewed literature in PubMed and EMBASE through March 2023. We included studies involving patients with CTEPH where DOAC and VKA were compared. We collected data including intervention history for CTEPH, bleeding events, recurrence of VTE (venous thromboembolism), and mortality. We performed a meta-analysis using the Mantel-Haenszel method with a fixed-effects model.

RESULTS

We included one randomized clinical trial and six observational studies, with a total of 2969 patients. Six studies investigated major bleeding outcomes, and seven investigated all bleeding outcomes. There were no differences in major bleeding (RR 0.59, 95 % CI [0.34-1.02], I2 = 0 %) and all-bleeding (RR 0.87, 95 % CI [0.67-1.13], I2 = 0 %). Based on the five studies we included, DOAC was associated with a lower risk of mortality (RR 0.54, 95 % CI: 0.37-0.79, I2 = 5 %). However, a higher risk of recurrent pulmonary embolism (PE) was seen in three studies (RR 3.80, 95 % CI: [1.93-7.50], I2 = 11 %). No significant differences were noted in terms of VTE.

CONCLUSION

DOAC compared to VKA was associated with a significantly lower mortality and higher risk of recurrent PE. Since most of the included studies are observational, we must consider the existence of multiple biases and confounding factors.

Use of Perioperative Extracorporeal Membranous Oxygenation in Pulmonary Endarterectomy Cases: A Systematic Review and Meta-Analysis

Introduction: Pulmonary endarterectomy (PEA) is known to be a curative intervention for chronic thromboembolic pulmonary hypertension (CTEPH). Its complications include endobronchial bleeding, persistent pulmonary arterial hypertension, right ventricular failure, and reperfusion lung injury. Extracorporeal membranous oxygenation (ECMO) is a perioperative salvage method for PEA. Although risk factors and outcomes have been reported in several studies, overall trends remain unknown. We performed a systematic review and study-level meta-analysis to understand the outcomes of ECMO utilization in the perioperative period of PEA. Methods: We performed a literature search with PubMed and EMBASE on 11/18/2022. We included studies including patients who underwent perioperative ECMO in PEA. We collected data including baseline demographics, hemodynamic measurements, and outcomes such as mortality and weaning of ECMO and performed a study-level meta-analysis. Results: Eleven studies with 2632 patients were included in our review. ECMO insertion rate was 8.7% (225/2,625, 95% CI 5.9-12.5) in total, VV-ECMO was performed as the initial intervention in 1.1% (41/2,625, 95% CI 0.4-1.7) (Figure 3), and VA-ECMO was performed as an initial intervention in 7.1% (184/2,625, 95% CI 4.7-9.9). Preoperative hemodynamic measurements showed higher pulmonary vascular resistance, mean pulmonary arterial pressure, and lower cardiac output in the ECMO group. Mortality rates were 2.8% (32/1238, 95% CI: 1.7-4.5) in the non-ECMO group and 43.5% (115/225, 95% CI: 30.8-56.2) in the ECMO group. The proportion of patients with successful weaning of ECMO was 72.6% (111/188, 95% CI: 53.4-91.7). Regarding complications of ECMO, the incidence of bleeding and multi-organ failure were 12.2% (16/79, 95% CI: 13.0-34.8) and 16.5% (15/99, 95% CI: 9.1-28.1), respectively. Conclusion: Our systematic review showed a higher baseline cardiopulmonary risk in patients with perioperative ECMO in PEA, and its insertion rate was 8.7%. Further studies that compare the use of ECMO in high-risk patients who undergo PEA are anticipated.

A Health State Utility Study to Elicit Societal Values Associated with Pulmonary Hypertension

Aim

Pulmonary hypertension (PH) is a rare, severe, and progressive pulmonary vascular disease, which includes five subgroups with similar presentation. Symptoms include dyspnea, and fatigue, and can significantly impact one's health-related quality of life (HRQL). Although treatments are mainly medical, PH group 4, chronic thromboembolic pulmonary hypertension (CTEPH), can be managed with procedures, ie pulmonary endarterectomy (PEA) and balloon pulmonary angioplasty (BPA). Currently, drugs in Europe are only approved for pulmonary arterial hypertension (PAH), and CTEPH therefore the aim of this study was to elicit novel societal health state utilities in the UK for PAH and CTEPH based on disease severity, functional class (FC), clinical events, and treatment procedures specifically for CTEPH.

Material and Methods

Six health states were defined: World Health Organization (WHO)-FC II, WHO-FC III, and WHO-FC IV [defined by the New York Heart Association (NYHA)]; PH-related hospitalization; and "BPA procedure and recovery" and "PEA surgery and recovery". Health states were based on a targeted literature review and two rounds of interviews with clinical experts (N = 4) and patients (N = 6). Draft health states were validated in cognitive debriefing interviews with clinical experts (N = 3). Health states were valued by the UK general public (n = 200), using a visual analogue scale (VAS) and time trade-off (TTO) assessment with the lead time method.

Results

The mean TTO values/utilities were 0.81 (FC II), 0.80 (BPA), 0.78 (PEA), 0.59 (FC III), 0.28 (FC IV), and 0.25 (PH-related hospitalization). Each progression in FC was associated with worse TTO scores.

Conclusion

This study reports societal utility values for PAH and CTEPH in the UK. It provides first utility estimates for states such as BPA procedure and recovery, PEA surgery and recovery and PH-related hospitalization for this population. The results show important distinctions between FC, treatment procedures, and hospitalization, and the significant burden of disease on HRQL.

Single-Center Experience of Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension: The Results from the Tabriz University Medical Sciences (TUMS) CTEPH Program

INTRODUCTION

Pulmonary endarterectomy (PEA) remains the preferred and potentially curative option for patients with chronic thromboembolic pulmonary hypertension (CTEPH). This study aimed to report the results of PEA for CTEPH in a tertiary center in Tabriz, Iran.

METHODS

We analyzed the results of 42 CTEPH patients undergoing PEA, who were enrolled in the Tabriz University of Medical Sciences (TUMS-CTEPH) from January 2016 to October 2020. The main outcome measures included the New York Heart Association (NYHA) functional classification, the 6-Minute Walk Distance, hemodynamic measures in right heart catheterization, morbidity, and mortality.

RESULTS

There was a significant improvement in the NYHA function class (2.6 ± 0.5 vs 1.1 ± 0.34), mean pulmonary arterial pressure (47.1 ± 13 vs 27.9 ± 8 mm Hg), cardiac output (4.3 ± 1.06 vs 5.9 ± 1.2 L/min), and pulmonary vascular resistance (709.4 ± 297.5 vs 214 ± 77 dyn s/cm5). Fifteen patients (35%) developed complications. The most common complication (10 [23%]) was reperfusion injury. Also, postsurgical mortality was 4% during hospital admission and 1-year follow-up.

CONCLUSION

This is the first single-center report of PEA from Iran. Post-PEA and 1-year survival were acceptable as a referral center. PEA can be performed safe with low mortality. Greater awareness of PEA and patients' access to experienced CTEPH centers are important issues.

Surgical Treatment of Another Sequalae of COVID-19: Post-COVID CTEPH

BACKGROUND

Coronavirus disease 2019 (COVID-19) is still an ongoing entity and every day we face new sequalae of the disease. We hereby present surgical results of patients who are treated for post-COVID chronic thromboembolic pulmonary hypertension.

METHODS

Data were collected among patients who underwent pulmonary endarterectomy and had a diagnosis of post-COVID chronic thromboembolic pulmonary hypertension. All data were retrospectively reviewed from a prospectively conducted database. Operative mortality was described as death in hospital or within 30 days of surgery.

RESULTS

Eleven patients (seven males, four females; median age, 52 [22-63] years) were identified. Pulmonary vascular resistance improved significantly from 572 dyn/s/cm-5 (240-1,192) to 240 (195-377) dyn/s/cm-5 (p < 0.005). Significant difference was also detected in median mPAP, as it decreased from 40 mm Hg (24-54) to 24 mm Hg (15-36) following surgery (p < 0.005). Mortality was observed in one patient due to sepsis on the fifth postoperative day. Median time from COVID-19 disease to surgery was 12 months (6-24). Median length of hospital stay of the survivors was 10 days (8-14).

CONCLUSION

In the new era of chronic thromboembolic pulmonary hypertension, hybrid approach including surgery, balloon pulmonary angioplasty, and medical treatment has been recommended. pulmonary endarterectomy is still the only curative treatment when the disease is surgically accessible. We hereby report the first publication of post-COVID chronic thromboembolic pulmonary hypertension patients who were surgically treated. As we see a lot of long-term symptoms and clinical manifestations in patients who had COVID-19, we should always remember chronic thromboembolic pulmonary hypertension in the differential diagnosis.

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

Purpose

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

Materials and Methods

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

Results

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

Conclusion

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

Feasibility of a screening algorithm for chronic thromboembolic pulmonary hypertension: The OSIRIS study

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a long-term sequel to pulmonary embolism (PE) whose incidence varies according to different published studies. We have carried out this study to determine its incidence within 2 years after index pulmonary embolism and to study limitations to an early diagnosis.

MATERIAL AND METHODS

OSIRIS is a multicentre, longitudinal cohort study. Patients were followed for 3, 6, 12, and 24 months after pulmonary embolism using a structured three-step algorithm. A physician-centered questionnaire at least one positive response in a screening proceeded to the second step, transthoracic echocardiography. The third step consisted of ventilation/perfusion lung scintigraphy and right heart catheterisation. A transthoracic echocardiography was performed in patients without positive response in the screening questionnaire after 2 years. CTEPH diagnosis required haemodynamic confirmation by right heart catheterisation and mismatched perfusion defects on lung scintigraphy.

RESULTS

A total of 1191 patients were enrolled in 18 Spanish hospitals. Cumulative CTEPH incidence after 2-years PE was: 2.49 % (95 % CI: 1.68-3.56) and the incidence rate of CTEPH was 1.1 cases per 1000 person-months (95 % CI: 0.725; 1.60). The CTEPH algorithm presented a lack of adherence of 29 %; patient and physician preferences posed barriers to the triage algorithm The screening questionnaire, in patients who completed the follow-up, shows a specificity of 91.3 % (89.0-93.2 %) and negative predictive value of 99.4 % (98.4-99.8 %)..

CONCLUSIONS

OSIRIS provides practiced clinical based data on the chronic thromboembolic pulmonary hypertension incidence and identified barriers to the implementation of a 3-step triage algorithm for its detection.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT03134898.

Evaluation and Management of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a treatable form of pulmonary hypertension and right heart failure. CTEPH (group 4 pulmonary hypertension) is caused by persistent organized thromboembolic obstruction of the pulmonary arteries from incompletely resolved acute pulmonary embolism. CTEPH also may present without prior VTE history, which can contribute to its underrecognition. The true incidence of CTEPH is unclear, but is estimated to be approximately 3% after acute pulmonary embolism. V˙/Q˙ scintigraphy is the best screening test for CTEPH, with CT scan imaging and other advanced imaging methods now playing a larger role in disease detection and confirmation. Perfusion defects on V˙/Q˙ scintigraphy in the setting of pulmonary hypertension are suggestive of CTEPH, but pulmonary angiography and right heart catheterization are required for confirmation and treatment planning. CTEPH potentially is curative with pulmonary thromboendarterectomy surgery, with mortality rates of approximately 2% at expert centers. Advances in operative techniques are allowing more distal endarterectomies to be performed successfully with favorable outcomes. However, more than one-third of patients may be considered inoperable. Although these patients previously had minimal therapeutic options, effective treatments now are available with pharmacotherapy and balloon pulmonary angioplasty. Diagnosis of CTEPH should be considered in all patients with suspicion of pulmonary hypertension. Treatments for CTEPH have advanced with improvements in outcomes for both operable and inoperable patients. Therapy should be tailored based on multidisciplinary team evaluation to ensure optimal treatment response.

The risk profile change in patients with severe chronic thromboembolic pulmonary hypertension treated with subcutaneous treprostinil

Chronic thromboembolic pulmonary hypertension (CTEPH) is successfully treatable with pulmonary endarterectomy (PEA), balloon pulmonary angioplasty, and medical therapy. Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management risk score (RRS) is able to predict long-term outcome in inoperable patients or in patients with residual PH after surgery. We performed a post hoc analysis of RRS in patients who were enrolled in the CTREPH study (NCT01416636), a randomized, double-blind clinical trial comparing high-dose and low-dose subcutaneous (SC) treprostinil in patients with severe CTEPH that was classified by an interdisciplinary CTEPH team as nonoperable, or as persistent or recurrent pulmonary hypertension after PEA. Baseline mean RRS was similar in both treatment groups (8.7 in high-dose arm vs. 8.6 in low-dose arm), but mean RRS change from baseline to Week 24 was greater in the high-dose treprostinil group than in the low-dose treprostinil group (-0.88 vs. -0.17). The difference in RRS change from baseline to Week 24 between high dose versus low dose was statistically significant with mean difference of -0.70 (95% confidence interval: -1.36 to -0.05, p = 0.0352), and was driven mainly by improvement of World Health Organization functional class and N-terminal pro-brain natriuretic peptide concentration. SC treprostinil therapy administered in standard dose had positive effect on the risk profile measured by RRS in patients with inoperable or persistent/recurrent severe CTEPH. Although our study was limited by the small sample size and post hoc nature, assessment of risk profile is of great importance to this particular patient population with very poor prognosis.

Outpatient Follow-up of Pulmonary Embolism: Putting It all Together

Many patients discharged after an acute pulmonary embolism (PE) admission have inconsistent outpatient follow-up and insufficient workup for chronic complications of PE. A structured outpatient care program is lacking for the different phenotypes of chronic PE, such as chronic thromboembolic disease, chronic thromboembolic pulmonary hypertension, and post-PE syndrome. A dedicated PE follow-up clinic extends the organized, systematic care provided to patients with PE via the PERT (Pulmonary Embolism Response Team) model in the outpatient setting. Such an initiative can standardize follow-up protocols after PE, limit unnecessary testing, and ensure adequate management of chronic complications.

Chronic thromboembolic pulmonary hypertension is associated with a loss of total lung volume on computed tomography

BACKGROUND

Although lung volumes are usually normal in individuals with chronic thromboembolic pulmonary hypertension (CTEPH), approximately 20%-29% of patients exhibit a restrictive pattern on pulmonary function testing.

AIM

To quantify longitudinal changes in lung volume and cardiac cross-sectional area (CSA) in patients with CTEPH.

METHODS

In a retrospective cohort study of patients seen in our hospital between January 2012 and December 2019, we evaluated 15 patients with CTEPH who had chest computed tomography (CT) performed at baseline and after at least 6 mo of therapy. We matched the CTEPH cohort with 45 control patients by age, sex, and observation period. CT-based lung volumes and maximum cardiac CSAs were measured and compared using the Wilcoxon signed-rank test and the Mann-Whitney u test.

RESULTS

Total, right lung, and right lower lobe volumes were significantly reduced in the CTEPH cohort at follow-up vs baseline (total, P = 0.004; right lung, P = 0.003; right lower lobe; P = 0.01). In the CTEPH group, the reduction in lung volume and cardiac CSA was significantly greater than the corresponding changes in the control group (total, P = 0.01; right lung, P = 0.007; right lower lobe, P = 0.01; CSA, P = 0.0002). There was a negative correlation between lung volume change and cardiac CSA change in the control group but not in the CTEPH cohort.

CONCLUSION

After at least 6 mo of treatment, CT showed an unexpected loss of total lung volume in patients with CTEPH that may reflect continued parenchymal remodeling.

Inhibition of heterogeneous nuclear ribonucleoproteins A1 and oxidative stress reduces glycolysis via pyruvate kinase M2 in chronic thromboembolic pulmonary hypertension

Background and Objective

Chronic thromboembolic pulmonary hypertension (CTEPH) is a lethal complication of pulmonary embolism involving pulmonary artery occlusion and microvascular disease. The glucose metabolism and reactive oxygen species (ROS) production may be perturbed in CTEPH, but the precise mechanisms are unclear. This study investigated glucose metabolism in CTEPH employing pulmonary endarterectomy (PEA)-derived pulmonary artery smooth muscle cells (PASMCs) and characterized the roles of pyruvate kinase M2 (PKM2) and its regulation by heterogeneous nuclear ribonucleoproteins A1 (hnRNPA1) and ROS in CTEPH.

Methods

PEA tissues and blood samples of CTEPH patients were collected to study the levels of PKM2. Primary PASMCs were isolated from PEA tissues. We used small interfering RNAs to knock down PKM2 and hnRNPA1, and applied antioxidant N-acetylcysteine (NAC) and mito-TEMPO to reduce ROS production. The expression of glucometabolic genes, ROS production, glycolysis rate and proliferative and migratory activities were analyzed in PEA-derived PASMCs.

Results

PKM2 levels in serum and PEA tissues of CTEPH patients were higher than that of the healthy controls. Compared to the control PASMCs, PEA-derived PASMCs showed increased PKM2 expression and ROS production. The rates of glycolysis, proliferation and migration were increased in PEA-PASMCs and could be mitigated by PKM2 downregulation through hnRNPA1 or ROS inhibition.

Conclusions

Increased glycolysis and PKM2 expression were found in PEA-PASMCs. Inhibition of hnRNPA1 or ROS corrected the aberrant glycolysis, cell proliferation and migration by downregulating PKM2. Regulation of the hnRNPA1/PKM2 axis represents a potential therapeutic target for the treatment of CTEPH.

Treatment Response Evaluation by Computed Tomography Pulmonary Vasculature Analysis in Patients With Chronic Thromboembolic Pulmonary Hypertension

OBJECTIVE

To quantitatively assess the pulmonary vasculature using non-contrast computed tomography (CT) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) pre- and post-treatment and correlate CT-based parameters with right heart catheterization (RHC) hemodynamic and clinical parameters.

MATERIALS AND METHODS

A total of 30 patients with CTEPH (mean age, 57.9 years; 53% female) who received multimodal treatment, including riociguat for ≥ 16 weeks with or without balloon pulmonary angioplasty and underwent both non-contrast CT for pulmonary vasculature analysis and RHC pre- and post-treatment were included. The radiographic analysis included subpleural perfusion parameters, including blood volume in small vessels with a cross-sectional area ≤ 5 mm² (BV5) and total blood vessel volume (TBV) in the lungs. The RHC parameters included mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), and cardiac index (CI). Clinical parameters included the World Health Organization (WHO) functional class and 6-minute walking distance (6MWD).

RESULTS

The number, area, and density of the subpleural small vessels increased after treatment by 35.7% (P < 0.001), 13.3% (P = 0.028), and 39.3% (P < 0.001), respectively. The blood volume shifted from larger to smaller vessels, as indicated by an 11.3% increase in the BV5/TBV ratio (P = 0.042). The BV5/TBV ratio was negatively correlated with PVR (r = -0.26; P = 0.035) and positively correlated with CI (r = 0.33; P = 0.009). The percent change across treatment in the BV5/TBV ratio correlated with the percent change in mPAP (r = -0.56; P = 0.001), PVR (r = -0.64; P < 0.001), and CI (r = 0.28; P = 0.049). Furthermore, the BV5/TBV ratio was inversely associated with the WHO functional classes I-IV (P = 0.004) and positively associated with 6MWD (P = 0.013).

CONCLUSION

Non-contrast CT measures could quantitatively assess changes in the pulmonary vasculature in response to treatment and were correlated with hemodynamic and clinical parameters.

Surgical and Device Interventions in the Treatment of Chronic Thromboembolic Disease

Chronic thromboembolic pulmonary disease (CTEPD) is characterized by unresolved clot burden in large pulmonary arteries, obstructive disease in smaller arteries, and increased downstream clot burden. This occurs in the setting of abnormal fibrinolysis or hematological disorders. Up to 50% of patients in some studies are unaware of a self-history of a deep venous thrombosis or pulmonary embolism. Ultimately, they present with symptoms of pulmonary hypertension (PH), which can result in right heart failure (RHF). Pulmonary endarterectomy (PEA) is curative, though many patients have prohibitive surgical risk or surgically inaccessible disease, warranting other interventions such as balloon pulmonary angioplasty (BPA) and medical therapy. Rarely, other treatment options may be implemented. We focus this review on PEA and BPA, with an overview of the history of CTEPD and the evolution of these procedures. We will briefly discuss other treatment modalities.

Pathophysiology and Treatment of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a condition in which an organic thrombus remains in the pulmonary artery (PA) even after receiving anticoagulation therapy for more than 3 months and is complicated by pulmonary hypertension (PH), leading to right-sided heart failure and death. CTEPH is a progressive pulmonary vascular disease with a poor prognosis if left untreated. The standard treatment for CTEPH is pulmonary endarterectomy (PEA), which is usually performed only in specialized centers. In recent years, balloon pulmonary angioplasty (BPA) and drug therapy for CTEPH have also shown good results. This review discusses the complex pathogenesis of CTEPH and presents the standard of care, PEA, as well as a new device called BPA, which is showing remarkable progress in efficacy and safety. Additionally, several drugs are now demonstrating established evidence of efficacy in treating CTEPH.

Antiphospholipid antibodies in chronic thromboembolic pulmonary hypertension

Acquired thrombophilia and in particular the presence of antiphospholipid antibodies (aPL) may play an important role in the development of chronic thromboembolic pulmonary hypertension (CTEPH). Young patients suffering from an episode of unprovoked pulmonary embolism (PE), or PE provoked by mild risk factors, should be tested for aPL. In case of a positive result, they should be closely followed up and lifelong anticoagulant treatment should be considered. Indeed, aPL-induced thrombophilia may favor PE recurrence with the consequence of possible CTEPH development. The aPL profiles play an important role in this pathway. Patients with PE and triple positivity (lupus anticoagulant, LAC, anti-cardiolipin, aCL, and anti-β2-glycoprotein I, aβ2GPI) are at the highest risk of recurrence and deserve maximum protection by anticoagulant treatment with warfarin.

Pulmonary Hypertension Association's 2022 International Conference Scientific Sessions Overview

The considerable progress made in recent years in the diagnosis, risk stratification, and treatment of pulmonary hypertension was highlighted during the most recent edition of the Pulmonary Hypertension Association Scientific Sessions, which was held in Atlanta, Georgia from June 9 to 11, 2022, with the theme: Vision for the PHuture: The Evolving Science and Management of PH. Content presented over the 3-day conference focused on scientific and management updates since the last sessions were held in 2018 and included didactic talks, debates, and roundtable discussions across a broad spectrum of topics related to pulmonary hypertension. This article aims to summarize the key messages from each of the session talks.

The Role of Strain by Cardiac Magnetic Resonance Imaging in Predicting the Prognosis of Patients with Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by thrombotic obstruction of the pulmonary arteries, and right ventricular (RV) dysfunction is a major cause of death. Cardiac magnetic resonance (CMR) is the gold standard for assessing heart wall deformation; therefore, we aimed to determine the prognostic value of CMR strain in patients with CTEPH. Strain derived by CMR was measured at the time of diagnosis in 45 patients with CTEPH, and the relationship between RV strain and prognosis was determined through follow-up. The value of RV strain in the prognostic model was compared with that of pulmonary arterial hypertension (PAH) risk stratification. The RV global peak longitudinal strain (GLS) and global peak circumferential strain (GCS) in CTEPH patients were lower than the normal references of RV strain in the control group. GLS and longitudinal strain in the basal segment were independent risk factors for adverse events (P < .050). Adding CMR parameters to PAH risk stratification improved its predictive power in patients with CTEPH. GLS and GCS scores were impaired in patients with chronic RV overload. RV strain derived by CMR imaging is a promising noninvasive tool for the follow-up of patients with CTEPH.

Evaluation of balloon pulmonary angioplasty using lung perfusion SPECT in patients with chronic thromboembolic pulmonary hypertension

BACKGROUND

The aim of this study was to evaluate the effect of balloon pulmonary angioplasty (BPA) using lung perfusion single-photon emission computed tomography (SPECT) in patients with chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS AND RESULTS

20 consecutive patients (64 ± 15 years) who were diagnosed with CTEPH and underwent BPA were included in this study. All patients underwent lung perfusion SPECT before and after BPA. The relationship between functional %volume of the lung calculated from the lung perfusion SPECT (FVL-LPSPECT), and other clinical parameters before and after BPA was assessed using the Wilcoxon signed-rank test. The correlation between each parameter and mean pulmonary artery pressure (mPAP) using the Spearman's correlation was performed. To determine predictors of mPAP for evaluating treatment effectiveness, significant parameters were included in multiple regression analysis. After BPA, world health organization functional classification, six-minute walk distance (6MWD), mPAP, and FVL-LPSPECT significantly improved. FVL-LPSPECT (r = - 0.728, P < 0.001) and 6MWD (r = - 0.571, P = 0.009) were significant correlation of mPAP. In the multiple regression analysis, FVL-LPSPECT was the most significant predictor of improvement in mPAP after BPA (P < 0.001).

CONCLUSIONS

This study demonstrated that the lung perfusion SPECT could be a potential measurement of the effectiveness of BPA in patients with CTEPH.

Does Age Matter? Pulmonary Endarterectomy in the Elderly Patient with CTEPH

BACKGROUND

The gold standard treatment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) is pulmonary endarterectomy (PEA). Little is known about the influence of advanced age on surgical outcome. Therefore, the aim of this study was to investigate the impact of patient's age on postoperative morbidity, mortality, and quality of life in a German referral center.

METHODS

Prospectively collected data from 386 consecutive patients undergoing PEA between 01/2014 and 12/2016 were analyzed. Patients were divided into three groups according to their age: group 1: ≤ 50 years, group 2: > 50 ≤ 70 years, group 3: > 70 years.

RESULTS

After PEA, distinct improvements in pulmonary hemodynamics, physical capacity (World Health Organization [WHO] functional class and 6-minute walking distance) and quality of life were found in all groups. There were more complications in elderly patients with longer time of invasive ventilation, intensive care, and in-hospital stay. However, the in-hospital mortality was comparable (0% in group 1, 2.6% in group 2, and 2.1% in group 3 [p = 0.326]). Furthermore, the all-cause mortality at 1 year was 1.1% in group 1, 3.2% in group 2, and 6.3% in group 3 (p = 0.122).

CONCLUSIONS

PEA is an effective treatment for CTEPH patients of all ages accompanied by low perioperative and 1-year mortality. CTEPH patients in advanced age carefully selected by thorough preoperative evaluation should be offered PEA in expert centers to improve quality of life, symptoms, and pulmonary hemodynamics.

Treatment of Vascular Injury During Balloon Pulmonary Angioplasty in Patients With Chronic Thromboembolic Pulmonary Hypertension

Background

Treatment strategy for vascular injury during balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) was uncertain.

Objectives

This study aimed to identify an optimal therapeutic strategy for vascular injury during BPA in patients with CTEPH.

Methods

This study reviewed 207 patients with CTEPH and 956 BPA procedures between November 1, 2012 and November 30, 2015. Patients who were diagnosed with vascular injury during BPA, which was defined as angiographic signs or sudden respiratory and hemodynamic defects were included in this study. The study investigated the safety and efficacy of the hierarchically systematic treatment strategy including gelatin sponge embolization (GSE).

Results

More than one-half of the 79 patients and 133 procedures with vascular injury were improved by general treatment with reversal of heparin and high-flow oxygen administration. The investigators performed conventional treatment of proximal vessel occlusion using a guiding or balloon catheter in 47 procedures (35%) in which the culprit vessels could be detected under patients' stable conditions. In 32 procedures (24%) without detected culprit lesions or improvement by conventional treatment, GSE could significantly improve patient condition. The treatment strategy obtained successful bailout in 98% of procedures with vascular injury. No patients who underwent GSE died within 30 days after the treatment. There was no significant difference in cumulative mortality rate (median follow-up: 6.6 years) between groups with or without GSE (15.6% vs 8.2%; adjusted HR: 1.47; 95% CI: 0.25-8.69; P = 0.67).

Conclusions

Treatment strategy including GSE would be promising for vascular injury during BPA in patients with CTEPH.

Heterogeneity of Lung Density in Patients With Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

RATIONALE AND OBJECTIVES

Pulmonary endarterectomy (PEA) is one of the most effective treatments for chronic thromboembolic pulmonary hypertension (CTEPH). Right heart catheterization (RHC) is the gold standard assessment for pulmonary circulatory dynamics. However, computed tomography (CT) is less invasive than RHC and can elucidate some of the morphological changes caused by thromboembolism. We hypothesized that CT could facilitate the evaluation of heterogeneous pulmonary perfusion. This study investigated whether CT imaging features reflect the disease severity and changes in pulmonary circulatory dynamics in patients with CTEPH before and after PEA.

MATERIALS AND METHODS

This retrospective study included 58 patients with CTEPH who underwent PEA. Pre-PEA and post-PEA CT images were assessed for heterogeneity using CT texture analysis (CTTA). The CT parameters were compared with the results of the RHC and other clinical indices and analyzed with receiver operating characteristic curves analysis for patients with and without residual pulmonary hypertension (PH) (post-PEA mean pulmonary artery pressure ≥ 25 mmHg).

RESULTS

CT measurements reflecting heterogeneity were significantly correlated with mean pulmonary artery pressure. Kurtosis, skewness, and uniformity were significantly lower, and entropy was significantly higher in patients with residual PH than patients without residual PH. Area under the curve values of pre-PEA and post-PEA entropy between patients with and without residual PH were 0.71 (95% confidence interval 0.57-0.84) and 0.75 (0.63-0.88), respectively.

CONCLUSION

Heterogeneity of lung density might reflect pulmonary circulatory dynamics, and CTTA for heterogeneity could be a less invasive technique for evaluation of changes in pulmonary circulatory dynamics in patients with CTEPH undergoing PEA.

Chronic Thromboembolic Pulmonary Hypertension in Females: Clinical Features and Survival

Sparse data are available on the female-specific features of chronic thromboembolic pulmonary hypertension (CTEPH). We prospectively enrolled 160 consecutive female patients who were firstly diagnosed with CTEPH between 2013 and 2019 to explore their clinical phenotypes, treatment patterns, and long-term survival. The patients’ mean age was 54.7 ± 13.8 years, 70.6% provided a confirmed history of venous thromboembolism, 46 (28.8%) patients underwent pulmonary endarterectomy (PEA), 65 (40.6%) received balloon pulmonary angioplasty (BPA), and 49 (30.6%) were treated with medical therapy alone. The patients were followed for a median of 51 (34–70) months; three patients were lost to follow-up, and twenty-two patients died. The estimated survival rates at 1, 3, 5, and 7 years were 98.1% (95% CI 96.0–100), 96.9% (95% CI 94.2–99.6), 85.1% (95% CI 78.1–92.2), and 76.2% (95% CI 65.2–87.2), respectively. After adjusting for the confounders, the results of the multivariate Cox analysis showed that the presence of anemia (5.56, 95% CI 1.6–19.22) was associated with an increased risk of all-cause death, and compared with medical treatment, receiving PEA and BPA decreased the risk of death by 74% (0.26, 95% CI 0.07–0.97) and 86% (0.14, 95% CI 0.04–0.57), respectively. In conclusion, in the modern era of CTEPH treatment, invasive revascularization combined with targeted therapy display good clinical outcomes for females; anemia should be actively modified, which may lead to clinical improvements. (ClinicalTrials.gov Identifier: NCT05360992).

Acute on Chronic Thromboembolic Pulmonary Hypertension: Case Series and Review of Management

Chronic thromboembolic pulmonary hypertension (CTEPH) is a distinct form of precapillary pulmonary hypertension classified as group 4 by the World Symposium on Pulmonary Hypertension (WSPH) and should be excluded during an episode of acute pulmonary embolism (PE). Patients presenting to emergency departments with sudden onset of signs and symptoms of acute PE may already have a pre-existing CTEPH condition decompensated by the new PE episode. Identifying an underlying and undiagnosed CTEPH during acute PE, while challenging, is an important consideration as it will alter the patients’ acute and long-term management. Differential diagnosis and evaluation require an interdisciplinary expert team. Analysis of the clinical condition, the CT angiogram, and the hemodynamic situation are important considerations; patients with CTEPH usually have significantly higher sPAP at the time of index PE, which is unusual and unattainable in the context of acute PE and a naïve right ventricle. The imaging may reveal signs of chronic disease such as right ventricle hypertrophy bronchial collaterals and atypical morphology of the thrombus. There is no standard for the management of acute on chronic CTEPH. Herein, we provide a diagnostic and management algorithm informed by several case descriptions and a review of the literature.

Platelet, Fibrinolytic and Other Coagulation Abnormalities in Newly-Diagnosed Patients with Chronic Thromboembolic Pulmonary Hypertension

The pathophysiological background of chronic thromboembolic pulmonary hypertension (CTEPH) has not been fully elucidated. Evidence suggests that abnormal platelet function and ineffective fibrinolysis may play a key role in the development of the disease. The purpose of this study was to evaluate platelet and coagulation function in CTEPH, using non-conventional global coagulation assays, and platelet activation and endothelial dysfunction laboratory markers. A total of 40 newly-diagnosed CTEPH patients were studied, along with 35 healthy controls. Blood samples from CTEPH patients were taken directly from the pulmonary artery. All subjects were assessed with platelet function analyzer-100, light transmission aggregometry, thromboelastometry, endogenous thrombin potential. von Willebrand antigen and activity, p-selectin, thromboxane A2 and serotonin levels were also assessed. The results showed that CTEPH patients present diminished platelet aggregation, presence of disaggregation, decreased rate of fibrinolysis, defective thrombin generation and increased levels of thromboxane A2, p-selectin, von Willebrand antigen and activity. Serotonin levels did not present any differences between the two groups. The results of this study suggest that CTEPH patients present platelet function, fibrinolytic, thrombin generation and other clot formation abnormalities. Well-designed clinical studies are needed to further evaluate the complex hemostatic abnormalities in the CTEPH setting and assess their potential clinical applications.

Pulmonary thromboendarterectomy-the Royal Papworth experience

BACKGROUND

Pulmonary thromboendarterectomy (PTE) was first introduced to the UK 25 years ago, and the UK national service is provided by a single hospital. The aim of this work is to summarize our experience and review activity and outcomes by era at a high-volume PTE center. During this period the understanding of chronic thromboembolic pulmonary hypertension (CTEPH) increased and drug treatments and balloon angioplasty were developed. We also review our contribution to the better understanding of this surgery and CTEPH.

METHODS

We retrospectively reviewed all patients undergoing PTE for CTEPH at our center between Jan 1997 and Sept 2019, dividing them into four equal cohorts. Pre-operative characteristics and post-operative outcomes are described by era. A MEDLINE search was performed and original scientific clinical publications from this unit were reviewed. Their contemporary relevance and influence to the evolution of the clinical service are discussed.

RESULTS

Over this 23-year period from the commencement of our program, 2,116 consecutive PTE were performed. The mean patient age was 57.8 years (range, 11-89 years). The first 25% of our PTE were performed over 12 years whilst the most recent 25% were performed in less than three years. Over time, the average pre-operative mean pulmonary artery pressure has not changed significantly. The 30-day mortality by era quartile has progressively fallen from 12.3% to 1.9% most recently (P<0.001). Overall, one year survival exceeded 90%. 17 publications influenced our practice development during this period.

CONCLUSIONS

There was a consistent increase in activity and significant improvement in outcomes between the first and last quartiles of activity studied.

Pulmonary thromboendarterectomy in chronic thromboembolic pulmonary hypertension: the Spanish experience

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) can be cured by pulmonary endarterectomy (PEA). It is considered the best and only curable treatment option for patients with accessible lesions evaluated as optimal candidates. We describe the experience of the two reference centers in Spain, in order to reinforce the need for referring CTEPH patients to a specialized center to be assessed by a Multidisciplinary Expert Team.

METHODS

We included a population of 338 patients who met the definition for CTEPH and underwent PEA between January 2007 and December 2019. The surgery was indicated in almost 60% of patients assessed. Demographic, anthropometric, hemodynamic and echocardiographic features are listed for PEA patients. Immediate and one-year postoperative outcomes as well as overall mortality were analyzed.

RESULTS

Mean age was 53.5±15.0 years, 53.8% were men; a total of 68.5% were in WHO functional class III-IV; and most of them were in a preoperative hemodynamic condition: mean pulmonary arterial pressure (mPAP) was 46.5±13.1 mmHg and mean pulmonary vascular resistance (PVR) was 764.5±392.8 dyn·s·cm-5. PEA surgery was performed with cardiopulmonary bypass (CBP) and circulatory arrest, with very few complications [including neurological, postoperative reperfusion edema, extracorporeal membrane oxygenation (ECMO) implant and cardiac failure] and optimal postoperative results, where exercise capacity increased and mPAP and PVR values decreased significantly. Presence of persistent pulmonary hypertension (PH) at the six-month right heart catheterization was evaluated. A 3.3% perioperative mortality was achieved. Overall, one-, three- and five-year survival rates were analyzed by Kaplan-Meier's method (94.8%, 93.3% and 90.5% respectively), as well as for residual PH patients. Mortality risk factors were assessed.

CONCLUSIONS

Outstanding PEA results were seen in the immediate, one-year and long-term outcomes. The incidence of complications, including in-hospital mortality and long-term mortality were also below European rates.

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

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

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

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

Detection of patients with chronic thromboembolic pulmonary hypertension by volumetric iodine quantification in the lung-a case control study

Background

To evaluate whether volumetric iodine quantification of the lung allows for the automatic identification of patients with chronic thromboembolic pulmonary hypertension (CTEPH) and whether the extent of pulmonary malperfusion correlates with invasive hemodynamic parameters.

Methods

Retrospective data base search identified 30 consecutive patients with CTEPH who underwent CT pulmonary angiography (CTPA) on a spectral-detector CT scanner. Thirty consecutive patients who underwent an identical CT examination for evaluation of suspected acute pulmonary embolism and had no signs of pulmonary embolism or PH, served as control cohort. Lungs were automatically segmented for all patients and normal and malperfused volumes were segmented based on iodine density thresholds. Results were compared between groups. For correlation analysis between the extent of malperfused volume and mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) 3 patients were excluded because of a time span of more than 30 days between CTPA and right heart catheterization.

Results

Patients with CTEPH had a higher percentage of malperfused lung compared to controls (43.25%±24.72% vs. 21.82%±20.72%; P=0.001) and showed reduced mean iodine density in malperfused and normal-perfused lung areas, as well as in the vessel volume. Controls showed a left-tailed distribution of iodine density in malperfused lung areas while patients with CTEPH had a more symmetrical distribution (Skew: -0.382±0.435 vs. -0.010±0.396; P=0.004). Patients with CTEPH showed a significant correlation between the percentage of malperfused lung volume and the PVR (r=0.57, P=0.001).

Conclusions

Volumetric iodine quantification helps to identify patients with CTEPH by showing increased areas of malperfusion. The extent of malperfusion might provide a measurement for disease severity in patients with CTEPH.

Association of Electrocardiographic Signs of Right Ventricular Hypertrophy and Clot Localization in Chronic Thromboembolic Pulmonary Hypertension

The role of electrocardiography (ECG) in chronic thromboembolic pulmonary hypertension (CTEPH) diagnosis and prognosticating has not been yet established. We aimed to assess the relationships of the recommended ECG criteria of right ventricular hypertrophy (RVH) with clot localization in CTEPH patients. ECG patterns of RVH according to the American College of Cardiology Foundation were assessed in patients with newly diagnosed CTEPH. We enrolled 58 (45.3%) patients with proximal and 70 (54.7%) with distal CTEPH. Receiver-operating characteristics curves analysis indicated that the following ECG abnormalities predicted proximal CTEPH localization: R_V1 > 6 mm—AUC 0.75 (CI: 0.66–0.84, p < 0.00001); S_V6 > 3 mm—AUC 0.70 (CI: 0.60–0.79, p < 0.00001); S_I > R_I wave—AUC 0.67 (CI: 0.58–0.77, p = 0.0004); R_V1:S_V1 > 1.0—AUC 0.66 (CI: 0.56–0.76, p = 0.0009); R_V1 peak > 0.035 s (QRS < 120 ms)—AUC 0.66 (CI: 0.56–0.75, p = 0.0016); R_V1:S_V1 > R_V3(V4):S_V3(V4)—AUC-0.65 (CI: 0.54–0.75, p = 0.0081); R_aVR > 4 mm—AUC 0.62 (CI: 0.52–0.71, p = 0.002) and P_II > 2.5 mm—AUC 0.62 (CI: 0.52–0.72, p = 0.00162). Pulmonary vascular resistance significantly correlated with amplitudes of R_V1 (r = 0.34, p = 0.008), S_V6 (r = 0.53, p = 0.000027) and P_II (r = 0.44, p = 0.00007). In patients with CTEPH, only 8 out of 23 ECG RVH criteria were useful for differentiating between proximal and distal CTEPH localization and we found that R_V1 and S_V6 may contribute as potential discriminators.