Chronic thromboembolic pulmonary hypertension: advances from bench to patient management

Sympathetic Denervation and Pharmacological Stimulation of Parasympathetic Nervous System Prevent Pulmonary Vascular Bed Remodeling in Rat Model of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) develops in 1.5-2.0% of patients experiencing pulmonary embolism (PE) and is characterized by stable pulmonary artery obstruction, heart failure, and poor prognosis. Little is known about involvement of autonomic nervous system (ANS) in the mechanisms of CTEPH. This study was aimed at evaluation of the effect of vagal and sympathetic denervation, as well as stimulation of the parasympathetic nervous system, on the outcomes of CTEPH in rats. CTEPH was induced by multiple intravenous injections of alginate microspheres. Sympathetic and vagal denervation was performed using unilateral surgical ablation of the stellate ganglion and vagotomy, respectively. Stimulation of the parasympathetic nervous system was carried out by administering pyridostigmine. The effect of neuromodulatory effects was assessed in terms of hemodynamics, histology, and gene expression. The results demonstrated the key role of ANS in the development of CTEPH. Sympathetic denervation as well as parasympathetic stimulation resulted in attenuated pulmonary vascular remodeling. These salutary changes were associated with altered MMP2 and TIMP1 expression in the lung and decreased FGFb level in the blood. Unilateral vagotomy had no effect on physiological and morphological outcomes of the study. The data obtained contribute to the identification of new therapeutic targets for CTEPH treatment.

The Evolving Management and Treatment Options for Patients with Pulmonary Hypertension: Current Evidence and Challenges

Pulmonary hypertension may develop as a disease process specific to pulmonary arteries with no identifiable cause or may occur in relation to other cardiopulmonary and systemic illnesses. The World Health Organization (WHO) classifies pulmonary hypertensive diseases on the basis of primary mechanisms causing increased pulmonary vascular resistance. Effective management of pulmonary hypertension begins with accurately diagnosing and classifying the disease in order to determine appropriate treatment. Pulmonary arterial hypertension (PAH) is a particularly challenging form of pulmonary hypertension as it involves a progressive, hyperproliferative arterial process that leads to right heart failure and death if untreated. Over the last two decades, our understanding of the pathobiology and genetics behind PAH has evolved and led to the development of several targeted disease modifiers that ameliorate hemodynamics and quality of life. Effective risk management strategies and more aggressive treatment protocols have also allowed better outcomes for patients with PAH. For those patients who experience progressive PAH with medical therapy, lung transplantation remains a life-saving option. More recent work has been directed at developing effective treatment strategies for other forms of pulmonary hypertension, such as chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary hypertension due to other lung or heart diseases. The discovery of new disease pathways and modifiers affecting the pulmonary circulation is an ongoing area of intense investigation.

Chronic Thromboembolic Pulmonary Hypertension: An Update

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease observed in a small proportion of patients after acute pulmonary embolism (PE). CTEPH has a high morbidity and mortality rate, related to the PH severity, and a poor prognosis, which mirrors the right ventricular dysfunction involvement. Pulmonary endarterectomy (PEA) reduces pulmonary vascular resistance, making it the treatment of choice and should be offered to operable CTEPH patients, as significant symptomatic and prognostic improvement has been observed. Moreover, these patients may also benefit from the advances made in surgical techniques and pulmonary hypertension-specific medication. However, not all patients are eligible for PEA surgery, as some have either distal pulmonary vascular obstruction and/or significant comorbidities. Therefore, surgical candidates should be carefully selected by an interprofessional team in expert centers. This review aims at making an overview of the risk factors and latest developments in diagnostic tools and treatment options for CTEPH.

Chronic thromboembolic pulmonary hypertension secondary to implantable cardioverter defibrillator lead thrombus in a patient with Brugada syndrome: a rare complication requiring a multidisciplinary approach

We report the case of a 57-year-old male patient with prior syncope associated with sustained ventricular tachycardia in the setting of Brugada syndrome, who was submitted to implantation of a cardioverter defibrillator for secondary prevention. During follow-up, he presented a significant increase in lead impedance, and a transthoracic echocardiogram showed a mass attached to the lead. He was started on oral anticoagulation after infective endocarditis was excluded but nevertheless suffered repeated episodes of pulmonary embolism that led to severe chronic thromboembolic pulmonary hypertension. After heart team discussion, he was referred to pulmonary endarterectomy and replacement of the implantable cardioverter defibrillator with a subcutaneous device. This led to significant improvement of functional class and normalisation of pulmonary haemodynamics. More recently, he suffered syncope in the setting of ventricular fibrillation with appropriate shocks and was started on quinidine without further recurrence of arrhythmic episodes.

Chronic Thromboembolic Pulmonary Hypertension-Management Strategies and Outcomes

Chronic thromboembolic pulmonary hypertension (CTEPH) is rare but complex pathophysiological disease with hallmark features of chronic thrombotic mechanical obstruction, right ventricular dysfunction, and secondary pulmonary arteriopathy. It increasingly is being understood that chronic infection/inflammation, abnormal fibrinolysis, and cytokines play an important role in pathogenesis such that only a subset of patients with pulmonary embolism develop CTEPH. Diagnosis remains challenging given the lack of early clinical signs and overlap with other cardiopulmonary conditions. Pulmonary endarterectomy is the surgical procedure of choice with good postoperative survival and functional outcomes, especially when done at high-volume centers with a multidisciplinary approach. There has been a resurgence of balloon pulmonary angioplasty (BPA) as salvage therapy for inoperable CTEPH or in its newfound hybrid role for persistent postoperative pulmonary hypertension with excellent 1-year and 3-year survival. Use of riociguat has shown promising improvements in functional outcomes up to 2 years after initiation. Endothelin receptor antagonists serve a supplemental role postoperatively or in inoperable CTEPH. The role of drug therapy preoperatively or in tandem with BPA is currently under investigation.

The effect of a multidisciplinary team on the implementation rates of major diagnostic and therapeutic procedures of chronic thromboembolic pulmonary hypertension

BACKGROUND

Although guidelines have recommended that patients with chronic thromboembolic pulmonary hypertension (CTEPH) should be managed by a multidisciplinary team (MDT), there is a lack of clinical data indicating that the MDT improves CTEPH management.

OBJECTIVES

The study aimed to identify the effect of an MDT on CTEPH management.

METHODS

We divided the study period into pre-MDT and post-MDT eras and compared the implementation rates of major diagnostic and therapeutic procedures.

RESULTS

Of 116 patients with CTEPH, 42 (36.2%) were diagnosed in the post-MDT era. The implementation rates of right heart catheterization (10.8% vs. 97.6%, p < 0.001) and pulmonary endarterectomy (32.4% vs. 59.5%, p < 0.005) were significantly increased in the post-MDT era. Balloon pulmonary angioplasty was not performed in the pre-MDT era but was performed in the post-MDT era.

CONCLUSIONS

The MDT appears to be associated with improved CTEPH management.

Consequences of Venous Thromboembolism, Including Chronic Thromboembolic Pulmonary Hypertension

Venous thromboembolism includes both deep vein thrombosis and pulmonary embolism. They pose a significant risk for morbidity and mortality. In an appropriate clinical setting, invasive interventions, including administration of thrombolytics, anticoagulation, and placement of vena cava filter, are warranted. Bleeding, postthrombotic syndrome, recurrence, and filter-associated complications are few of the complications of this disease. More recently, chronic thromboembolic pulmonary hypertension has gained clinical interest in patients with pulmonary embolism and has warranted close follow-up.

[Clinical guidelines for the diagnosis and treatment of chronic thromboembolic pulmonary hypertension (Part 2)]

The paper gives current approaches to treating chronic thromboembolic pulmonary hypertension (CTEPH) from the document «Federal Guidelines for the Diagnosis and Treatment of CTEPH» approved at the Third Russian Congress on Pulmonary Hypertension on December 11, 2015. The guidelines had been elaborated to optimize the treatment of patients with CTEPH on the basis of an analysis of the data of the present-day registries and multicenter randomized clinical trials, national and international guidelines and consensus documents, and documents published in recent years. CTEPH is a unique form of pulmonary hypertension since it is potentially curable by surgical treatment. The paper presents indications for and contraindications to pulmonary thromboendartectomy; preparation for surgery; operating room facilities; the specific features of postoperative management and possible complications; and long-term RESULTS: In terms of therapy, in addition to non-pharmacological measures, the authors discuss maintenance and specific treatment options for CTEPH, balloon pulmonary angioplasty, and lung/heart-lung transplantation. In conclusion they propose a management algorithm in patients with CTEPH and requirements for its problem to the center of experts.

[Clinical guidelines for the diagnosis and treatment of chronic thromboembolic pulmonary hypertension (Part 1)]

Chronic thromboembolic pulmonary hypertension (CTEPH) is precapillary pulmonary hypertension, in which chronic obstruction of large and middle branches of pulmonary arteries (PAs) and secondary changes in the lung microcirculatory bed result in a progressive increase in pulmonary vascular resistance and PA pressure with the development of severe right cardiac dysfunction and heart failure. CTEPH is a unique form of pulmonary hypertension since it is potentially curable by surgical treatment. The diagnostic criteria for CTEPH are a mean PA pressure of ≥25 mm Hg, as evidenced by right heart catheterization; a PA wedge pressure of ≤15 mm Hg; a pulmonary vascular resistance of >2 Wood units; the presence of chronic/organized thrombi/emboli in the elastic PAs (pulmonary trunk, lobular, segmental, subsegmental PAs); effective anticoagulant therapy at therapeutic dosages over at least 3 months. Up to now, our country has had no guidelines for the diagnosis and treatment of this rare severe disease that, when appropriately untreated, has an extremely poor prognosis. The main task in the preparation of this document was to generalize and analyze the data of current registries, multicenter randomized clinical trials, national and international guidelines, and consensus documents recently published on this problem in order to optimize a diagnostic process and treatment in this category of patients. Part 1 gives a definition of CTEPH, its place in the clinical classification, epidemiology and prognosis, risk factors, pathogenesis and morphology, diagnostic approaches and determination of operability in patients, and specific features of differential diagnosis.

2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension

Guidelines summarize and evaluate all available evidence on a particular issue at the time of the writing process, with the aim of assisting health professionals in selecting the best management strategies for an individual patient with a given condition, taking into account the impact on outcome, as well as the risk–benefit ratio of particular diagnostic or therapeutic means. Guidelines and recommendations should help health professionals to make decisions in their daily practice. However, the final decisions concerning an individual patient must be made by the responsible health professional(s) in consultation with the patient and caregiver as appropriate.