An update on sarcoidosis-associated pulmonary hypertension

Sarcoidosis-associated pulmonary hypertension due to pulmonary arteries stenosis - a case report

BACKGROUND

Sarcoidosis-associated pulmonary hypertension (SAPH) is listed in Group 5 of the clinical classification of pulmonary hypertension, due to its complex and multifactorial pathophysiology. The most common cause of SAPH development is advanced lung fibrosis with the associated destruction of the vascular bed, and/or alveolar hypoxia. However, a substantial proportion of SAPH patients (up to 30%) do not have significant fibrosis on chest imaging. In such cases, the development of pulmonary hypertension may be due to the lesions directly affecting the pulmonary vasculature, such as granulomatous angiitis, pulmonary veno-occlusive disease, chronic thromboembolism or external compression of vessels by enlarged lymph nodes. Based on the case of a 69-year-old female who developed SAPH due to pulmonary arteries stenosis, diagnostic difficulties and therapeutic management are discussed.

CASE PRESENTATION

The patient, non-smoking female, diagnosed with stage II sarcoidosis twelve years earlier, presented with progressive dyspnoea on exertion, dry cough, minor haemoptysis and increasing oedema of the lower limbs. Computed tomography pulmonary angiography (CTPA) showed complete occlusion of the right upper lobe artery and narrowing of the left lower lobe artery, with post-stenotic dilatation of the arteries of the basal segments. The vascular pathology was caused by adjacent, enlarged lymph nodes with calcifications and fibrotic tissue surrounding the vessels. Pulmonary artery thrombi were not found. The patient was treated with systemic corticosteroid therapy and subsequently with balloon pulmonary angioplasty. Partial improvement in clinical status and hemodynamic parameters has been achieved.

CONCLUSIONS

An appropriate screening strategy is required for early detection of pulmonary hypertension in sarcoidosis patients. Once SAPH diagnosis is confirmed, it is crucial to determine the appropriate phenotype of pulmonary hypertension and provide the most effective treatment plan. Although determining SAPH phenotype is challenging, one should remember about the possibility of pulmonary arteries occlusion.

The current state-of-the-art in pharmacotherapy for pulmonary sarcoidosis

INTRODUCTION

Sarcoidosis is a chronic granulomatous of unknown etiology that mostly affects lungs with an heterogenous clinical presentation and prognosis. Therefore, therapeutic management of the disease is challenging. The goals of treatment are to prevent or to minimize organ damage, to relieve symptoms, and to improve the patient's quality of life.

AREAS COVERED

The present review covers current pharmacotherapy options for pulmonary sarcoidosis. Corticosteroids are still the first-line treatment option, however, for those patients with prolonged expectation of treatment, undesirable side effects and refractory disease, immunosuppressive drugs are preferred options. Biological drugs are promising third line therapies. Recent evidence shows that antifibrotic agents, such as nintedanib, have a role in fibrotic lung disease, as well as efzofitimob, which has shown promising results in controlling inflammatory lung disease.

EXPERT OPINION

Sarcoidosis treatment is evolving as new molecules are available. The number of studies of therapies for pulmonary sarcoidosis has increased in recent years, however, the information available is still limited and there is no consensus on how to monitor the activity of the disease.

Evolution of pulmonary hypertension in interstitial lung disease: a journey through past, present, and future

Interstitial lung diseases (ILD) are a spectrum of disorders often complicated by pulmonary hypertension (PH) in its course. The pathophysiologic mechanism of WHO group 3 PH is different to other forms of PH. The advent of PH is a harbinger for adverse events like mortality and morbidity, implying that the PH component of disease expedites deteriorated clinical outcomes. In fact, WHO group 3 PH due to ILD has the worse prognosis among all groups of PH. Hence, early detection of PH by a comprehensive screening method is paramount. Given considerable overlap in clinical manifestations between ILD and PH, early detection of PH is often elusive. Despite, the treatment of PH due to ILD has been frustrating until recently. Clinical trials utilizing PAH-specific pulmonary vasodilators have been ongoing for years without desired results. Eventually, the INCREASE study (2018) demonstrated beneficial effect of inhaled Treprostinil to treat PH in ILD. In view of this pioneering development, a paradigm shift in clinical approach to this disease phenotype is happening. There is a renewed vigor to develop a well validated screening tool for early detection and management. Currently inhaled Treprostinil is the only FDA approved therapy to treat this phenotype, but emergence of a therapy has opened a plethora of research toward new drug developments. Regardless of all these recent developments, the overall outlook still remains grim in this condition. This review article dwells on the current state of knowledge of pre-capillary PH due to ILD, especially its diagnosis and management, the recent progresses, and future evolutions in this field.

Updated Hemodynamic Definition and Classification of Pulmonary Hypertension

Pulmonary hypertension (PH) is a pathophysiological manifestation of a heterogeneous group of diseases characterized by abnormally elevated pulmonary arterial pressures diagnosed on right heart catheterization. The 2022 European Society of Cardiology (ESC) and European Respiratory Society (ERS) Guidelines for the diagnosis and treatment of PH provides a new hemodynamic definition to define PH by lowering the threshold of the mean pulmonary artery pressure (mPAP) to 20 mm Hg. Precapillary PH is thus now defined as a mPAP >20 mm Hg together with a normal pulmonary artery wedge pressure (<15 mm Hg) and an increased pulmonary vascular resistance (>2 Wood Units). The ESC/ERS 2022 Guidelines also introduce a revised clinical classification of PH while retaining its previous distinction between the five groups according to the underlying pathophysiology.

Sarcoidosis-associated pulmonary fibrosis: joining the dots

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology. A minority of patients with sarcoidosis develop sarcoidosis-associated pulmonary fibrosis (SAPF), which may become progressive. Genetic profiles differ between patients with progressive and self-limiting disease. The mechanisms of fibrosis in SAPF are not fully understood, but SAPF is likely a distinct clinicopathological entity, rather than a continuum of acute inflammatory sarcoidosis. Risk factors for the development of SAPF have been identified; however, at present, it is not possible to make a robust prediction of risk for an individual patient. The bulk of fibrotic abnormalities in SAPF are located in the upper and middle zones of the lungs. A greater extent of SAPF on imaging is associated with a worse prognosis. Patients with SAPF are typically treated with corticosteroids, second-line agents such as methotrexate or azathioprine, or third-line agents such as tumour necrosis factor inhibitors. The antifibrotic drug nintedanib is an approved treatment for slowing the decline in lung function in patients with progressive fibrosing interstitial lung diseases, but more evidence is needed to assess its efficacy in SAPF. The management of patients with SAPF should include the identification and treatment of complications such as bronchiectasis and pulmonary hypertension. Further research is needed into the mechanisms underlying SAPF and biomarkers that predict its clinical course.

Pulmonary Hypertension in Chronic Lung Diseases: What Role Do Radiologists Play?

Pulmonary hypertension (PH) is a pathophysiological disorder, defined by a mean pulmonary arterial pressure (mPAP) > 20 mmHg at rest, as assessed by right heart catheterization (RHC). PH is not a specific disease, as it may be observed in multiple clinical conditions and may complicate a variety of thoracic diseases. Conditions associated with the risk of developing PH are categorized into five different groups, according to similar clinical presentations, pathological findings, hemodynamic characteristics, and treatment strategy. Most chronic lung diseases that may be complicated by PH belong to group 3 (interstitial lung diseases, chronic obstructive pulmonary disease, combined pulmonary fibrosis, and emphysema) and are associated with the lowest overall survival among all groups. However, some of the chronic pulmonary diseases may develop PH with unclear/multifactorial mechanisms and are included in group 5 PH (sarcoidosis, pulmonary Langerhans' cell histiocytosis, and neurofibromatosis type 1). This paper focuses on PH associated with chronic lung diseases, in which radiological imaging-particularly computed tomography (CT)-plays a crucial role in diagnosis and classification. Radiologists should become familiar with the hemodynamical, physiological, and radiological aspects of PH and chronic lung diseases in patients at risk of developing PH, whose prognosis and treatment depend on the underlying disease.

Management of Pulmonary Hypertension Due to Chronic Lung Disease

Pulmonary hypertension (PH) is a known complication of chronic parenchymal lung diseases, including chronic obstructive lung disease, interstitial lung diseases, and more rare parenchymal lung diseases. Together, these diseases encompass two of the five clinical classifications of PH: group 3 (chronic lung disease [CLD] and/or hypoxia) and group 5 (unclear and/or multifactorial mechanisms). The principal management strategy in PH associated with CLD is optimization of the underlying lung disease. There has been increasing interest in therapies that treat pulmonary arterial hypertension (group 1, PAH), and although some studies have explored the use of these oral PAH-targeted therapies to treat PH associated with CLD, there is currently no evidence to support their routine use; in fact, some studies suggest harm. Inhaled therapies that target the pulmonary vasculature may avoid certain problems observed with oral PAH therapies. Recent studies suggest a promising role for inhaled PAH therapies in group 3 PH, but this requires further study. The objective of this article is to review the current treatment strategies for group 3 and group 5 PH.

Sarcoidosis associated pulmonary hypertension: an update

PURPOSE OF REVIEW

Sarcoidosis associated pulmonary hypertension (SAPH) is a well-recognised complication, associated with a seven-fold increase in mortality. This comprehensive review will summarise these recent developments and proposes the use of a phenotype-based management approach in SAPH.

RECENT FINDINGS

Recent registry-based studies have highlighted the adverse outcomes associated with SAPH and shown that reduced 6-min walk distance and diffusion capacity for carbon monoxide are predictive of poor prognosis. There is increasing interest in methods for early detection of SAPH, although whether early diagnosis impacts on survival remains uncertain. The pathophysiology underpinning SAPH is complex and often incorporates multiple mechanisms. Once the diagnosis is confirmed, understanding the underlying phenotypes of SAPH is key to providing the most effective management plan. There is some evidence that treating patients with precapillary PH with pulmonary vasodilators may improve some haemodynamic and quality life measures. However, more work is needed to determine whether mortality is affected.

SUMMARY

SAPH is associated with worsened survival. A range of phenotypes are recognised in SAPH. Multimodality risk assessment in patients with SAPH is likely to be important and is an area that requires further work. Published evidence for pulmonary vasodilator therapies in SAPH with a Pulmonary arterial hypertension-like phenotype is encouraging so far, but multiple confounding factors affects the quality of the evidence. The role of immunosuppressive agents for improving pulmonary pressures is unclear. Urgent controlled trials are needed.