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

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

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

Safety and efficacy of balloon pulmonary angioplasty for technically operable chronic thromboembolic pulmonary hypertension

Balloon pulmonary angioplasty (BPA) has been proven effective for addressing technically inoperable chronic thromboembolic pulmonary hypertension (CTEPH). However, the effectiveness of BPA in technically operable CTEPH patients who, for various reasons, did not undergo the procedure remains an area requiring exploration. This study sought to assess the safety and efficacy of BPA in such cases. We collected and reviewed data from CTEPH patients who underwent BPA in a consecutive manner. Following multidisciplinary team (MDT) decisions, patients were classified into two groups: technically inoperable (group A) and operable (group B). Group B comprised patients deemed technically suitable for pulmonary endarterectomy (PEA) but who did not undergo the procedure for various reasons. All patients underwent a comprehensive diagnostic work-up, including right heart categorization at baseline and the last intervention. This study compared changes in hemodynamic parameters, functional capacity, and quality of life between the two groups. In total, 161 patients underwent 414 procedures at our center, with Group A comprising 112 patients who underwent 282 BPA sessions and group B comprising 49 patients who underwent 132 BPA sessions. Significantly, both groups exhibited improvements in hemodynamics, functional capacity, and quality of life. The occurrence rate of complications, including hemoptysis and lung injury, was similar [12 (63.2%) vs. 7 (36.8%), p = 0.68]. BPA demonstrated favorable outcomes in patients with proximal CTEPH who did not undergo pulmonary endarterectomy. However, the clinical impact of BPA in technically operable CTEPH was found to be less significant than in inoperable cases.

Clinical-radiological-pathological correlation in chronic thromboembolic pulmonary hypertension

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

Monographic Issue on Pulmonary Hypertension: Medical and Interventional Treatment for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. The reasons why clots do not resorb are incompletely understood, but the result is partial or complete fibrothrombotic obstruction of pulmonary arteries. A secondary microvasculopathy aggravates the pulmonary hypertension (PH) as a consequence of high flow and shear stress in the nonoccluded arteries. The treatment of CTEPH has long been purely surgical, but many patients were inoperable because of inaccessible lesions or severe comorbidities. Alternatives were developed, including medical therapy and more recently balloon pulmonary angioplasty (BPA). Depending on the generation of the obstructed vessels, the treatment will be surgical, up to the (sub)segmental level, or by BPA for more distal vessels. PH drugs are used to treat the microvasculopathy. The current paper describes the therapeutic management of inoperable patients: the medical approach with PH drugs used in mono- or combination therapy; the proper use of anticoagulants in CTEPH; the technique, indications, and results at short- and long-term of BPA; the multimodal approach for inoperable patients combining PH drugs and BPA; and the effects of rehabilitation. It shows the importance of a multidisciplinary approach to the disease.

[Chronic thromboembolic pulmonary hypertension]

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease, but an important late sequela after acute pulmonary embolism. Therefore, follow-up after at least three months of sufficient anticoagulation is recommended. Patients with suspected CTEPH should be referred to specialized CTEPH centers for further evaluation and treatment.Three treatment modalities are available: pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA) and pulmonary hypertension-targeted drugs. The indication for surgery depends mainly on the localization of the pulmonary arterial obstructions. Severe comorbidities as well as advanced age need individual evaluation, but do not present strict exclusion criteria. Multimodal treatments are common practice in inoperable CTEPH. However, treatment decision making in an experienced multidisciplinary team is mandatory.

Chronic thromboembolic pulmonary hypertension: realising the potential of multimodal management

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. Important advances have enabled better understanding, characterisation, and treatment of this condition. Guidelines recommending systematic follow-up after acute pulmonary embolism, and the insight that CTEPH can mimic acute pulmonary embolism on initial presentation, have led to the definition of CTEPH imaging characteristics, the introduction of artificial intelligence diagnosis pathways, and thus the prospect of easier and earlier CTEPH diagnosis. In this Series paper, we show how the understanding of CTEPH as a sequela of inflammatory thrombosis has driven successful multidisciplinary management that integrates surgical, interventional, and medical treatments. We provide imaging examples of classical major vessel targets, describe microvascular targets, define available tools, and depict an algorithm facilitating the initial treatment strategy in people with newly diagnosed CTEPH based on a multidisciplinary team discussion at a CTEPH centre. Further work is needed to optimise the use and combination of multimodal therapeutic options in CTEPH to improve long-term outcomes for patients.

Emerging Role of Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Disease-Insights from the 2022 ESC Guidelines

In this article, we discuss the topic of chronic thromboembolic pulmonary disease (CTEPD) and the growing role of balloon pulmonary angioplasty (BPA) in its treatment. We present the pathophysiology of CTEPD which arises from an incomplete resolution of thrombi in the pulmonary arteries and leads to stenosis and occlusion of the vessels. The article focuses mainly on the chronic thromboembolic pulmonary hypertension (CTEPH) subpopulation for which prognosis is very poor when left untreated. We describe a multimodal approach to treating CTEPH, including pulmonary endarterectomy (PEA), BPA, and pharmacological therapies. Additionally, the benefits of pharmacological pre-treatment before BPA and the technical aspects of the procedure itself are outlined. It is emphasized that BPA does not replace PEA but serves as a complementary treatment option for eligible patients. We summarized efficacy and treatment goals including an improvement in functional and biochemical parameters before and after BPA. Patients who received pre-treatment with riociguat prior to BPA exhibited a notable reduction in the occurrence of less severe complications. However, elderly patients are still perceived as an especially vulnerable group. It is shown that the prognosis of patients undergoing BPA is similar to PEA in the first years after the procedure but the long-term prognosis of BPA still remains unclear. The 2022 ESC/ERS guidelines highlight the significant role of BPA in the multimodal treatment of CTEPH, emphasizing its effectiveness and recommending its consideration as a therapeutic option for patients with CTEPD, both with and without pulmonary hypertension. This review summarizes the available evidence for BPA, patient selection, procedural details, and prognosis and discusses the potential future role of BPA in the management of CTEPH.

Chronic thromboembolic pulmonary hypertension-medical, interventional, and surgical therapy

Chronic thromboembolic pulmonary hypertension (CTEPH) is an important late sequela of pulmonary embolism and a common form of pulmonary hypertension. Currently, three specific treatment modalities are available: pulmonary endarterectomy, balloon pulmonary angioplasty, and targeted medical therapy. The treatment decision depends mainly on the exact localization of the underlying pulmonary arterial obstructions. Pulmonary endarterectomy is the gold standard treatment of CTEPH. For inoperable patients, riociguat and treprostinil are approved. In addition, interventional therapy is recommended if appropriate target lesions are proven. Evaluation and treatment of patients with CTEPH in experienced centers are mandatory.

Balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension: a clinical consensus statement of the ESC working group on pulmonary circulation and right ventricular function

The current treatment algorithm for chronic thromboembolic pulmonary hypertension (CTEPH) as depicted in the 2022 European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines on the diagnosis and treatment of pulmonary hypertension (PH) includes a multimodal approach of combinations of pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA) and medical therapies to target major vessel pulmonary vascular lesions, and microvasculopathy. Today, BPA of >1700 patients has been reported in the literature from centers in Asia, the US, and also Europe; many more patients have been treated outside literature reports. As BPA becomes part of routine care of patients with CTEPH, benchmarks for safe and effective care delivery become increasingly important. In light of this development, the ESC Working Group on Pulmonary Circulation and Right Ventricular Function has decided to publish a document that helps standardize BPA to meet the need of uniformity in patient selection, procedural planning, technical approach, materials and devices, treatment goals, complications including their management, and patient follow-up, thus complementing the guidelines. Delphi methodology was utilized for statements that were not evidence based. First, an anatomical nomenclature and a description of vascular lesions are provided. Second, treatment goals and definitions of complete BPA are outlined. Third, definitions of complications are presented which may be the basis for a standardized reporting in studies involving BPA. The document is intended to serve as a companion to the official ESC/ERS guidelines.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Right ventricle remodeling in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is an underdiagnosed, but potentially curable pulmonary vascular disease. The increased pulmonary vascular resistance in CTEPH is caused by unresolved proximal thrombus and secondary microvasculopathy in the pulmonary vasculature, leading to adaptive and maladaptive remodeling of the right ventricle (RV), eventual right heart failure, and death. Knowledge on the RV remodeling process in CTEPH is limited. The progression to RV failure in CTEPH is a markedly slower process. A detailed understanding of the pathophysiology and underlying mechanisms of RV remodeling may facilitate early diagnosis and the development of targeted therapy. While ultrasound, magnetic resonance imaging, right heart catheterization, and serum biomarkers have been used to assess cardiac function, the current treatment strategies reduce the afterload of the right heart, but are less effective in improving the maladaptive remodeling of the right heart. This review systematically summarizes the current knowledge on adaptive and maladaptive remodeling of the right heart in CTEPH from molecular mechanisms to clinical practice.

Prognostic Value of Pulmonary Artery Pulsatility Index in Right Ventricle Failure-Related Mortality in Inoperable Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is an ominous disease leading to progressive right ventricular failure (RVF) and death. There is no reliable risk stratification strategy for patients with CTEPH. The pulmonary artery pulsatility index (PAPI) is a novel hemodynamic index that predicts the occurrence RVF. We aimed to investigate prognostic value of PAPI in inoperable CTEPH. Consecutive patients with inoperable CTEPH were enrolled. PAPI was calculated from baseline right heart catheterization data. A prognostic cut-off value was determined, and characteristics of low- and high-PAPI groups were compared. The association between risk assessment and survival was also evaluated. We included 50 patients (mean age 64 ± 12.2 years, 60% female). The number of deaths was 12 (24%), and the mean follow-up time was 52 ± 19.3 months. The established prognostic cut-off value for PAPI was 3.9. The low-PAPI group had significantly higher mean values of mean atrial pressure (14.9 vs. 7.8, p = 0.0001), end-diastolic right ventricular pressure (16.5 vs. 11.2, p = 0.004), and diastolic pulmonary artery pressure (35.8 vs. 27.7, p = 0.0012). The low-PAPI group had lower survival as compared to high-PAPI (log-rank p < 0.0001). PAPI was independently associated with survival and may be applicable for risk stratification in inoperable CTEPH.

An unusual case of CTEPH treated by BPA in a patient with a single lung after cancer surgery

A 46‐year‐old man 1 year after left‐sided pneumonectomy for squamous cell lung cancer presented with severely limited exercise tolerance and dyspnea corresponding to World Health Organization functional class IV (WHO Class IV). After right heart catheterization (RHC), mean pulmonary artery pressure (mPAP) was 43 mmHg and pulmonary vascular resistance (PVR) was 10.2 Wood units (WU). Arteriography revealed organized clots located at the proximal level of the right pulmonary artery, leading to a diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH). The CTEPH team disqualified the patient from surgical treatment due to high perioperative risk and referred him for balloon pulmonary angioplasty (BPA) together with pulmonary hypertension‐specific pharmacotherapy (sildenafil). The patient underwent a cycle of nine BPA sessions and completed treatment without complications. Follow‐up showed sustained hemodynamic improvement in RHC (mPAP 23 mmHg, PVR 2.6 WU), improved physical capacity (WHO Class II), and relief of dyspnea symptoms.

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.

Circulating Blood-Based Biomarkers in Pulmonary Hypertension

Pulmonary hypertension (PH) is a serious hemodynamic condition, characterized by increased pulmonary vascular resistance (PVR), leading to right heart failure (HF) and death when not properly treated. The prognosis of PH depends on etiology, hemodynamic and biochemical parameters, as well as on response to specific treatment. Biomarkers appear to be useful noninvasive tools, providing information about the disease severity, treatment response, and prognosis. However, given the complexity of PH, it is impossible for a single biomarker to be adequate for the broad assessment of patients with different types of PH. The search for novel emerging biomarkers is still ongoing, resulting in a few potential biomarkers mirroring numerous pathophysiological courses. In this review, markers related to HF, myocardial remodeling, inflammation, hypoxia and tissue damage, and endothelial and pulmonary smooth muscle cell dysfunction are discussed in terms of diagnosis and prognosis. Extracellular vesicles and other markers with complex backgrounds are also reviewed. In conclusion, although many promising biomarkers have been identified and studied in recent years, there are still insufficient data on the application of multimarker strategies for monitoring and risk stratification in PH patients.

Assessment of Clinical Usefulness of Resting Electrocardiogram (PH-ECG Score) in Monitoring the Efficacy of Balloon Pulmonary Angioplasty (BPA) in Patients with Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

BACKGROUND

Balloon pulmonary angioplasty (BPA) is a form of therapy for chronic thromboembolic pulmonary hypertension (CTEPH). The study objective is to assess the clinical usefulness of resting ECG (PH-ECG score) in monitoring the efficacy of BPA in CTEPH patients.

METHODS AND RESULTS

Ninety-four (n = 94) CTEPH patients were included in the analysis. A standard 12-lead-ECG was performed before the first BPA session and after completion of treatment. The whole analysed population (n = 94) was divided into the following two groups: derivation cohort (n = 41) and validation cohort (n = 53). The derivation cohort was divided into the following two subgroups: patients with mean pulmonary artery pressure (mPAP) after the completion of therapy < 25 mmHg (n = 21) and patients with mPAP after the completion of therapy ≥ 25 mmHg (n = 20). In the first subgroup, four (R-wave V1 + S-wave V5/V6 > 10.5 mm, QRS-wave axis > 110 degrees, R-wave V1 > S-wave V1, SIQIII pattern) of the six ECG parameters of overload of the right cardiac chambers showed statistically significant differences (p < 0.005). That was followed by a determination of the sensitivity and specificity, positive (PPV) and negative predictive value (NPV), and ROC curve (AUC 0.9; 95% CI: 0.792-1.000) for the variable that was a sum of the above four ECG parameters (PH-ECG score). The absence of all of the four ECG parameters at rest (PH-ECG score = 0) well reflected patients with mPAP < 25 mmHg (sensitivity, 100%; specificity, 80%; PPV, 84%; NPV, 100%). In the validation cohort with mPAP < 25 mmHg and PH-ECG score = 0, sensitivity, specificity, PPV, and NPV were 86%, 77%, 73%, and 89%, respectively.

CONCLUSIONS

Resting ECG trace is clinically useful in the monitoring of therapeutical effects of BPA in CTEPH patients.