Interventional therapy in sarcoidosis-associated pulmonary arterial stenosis and 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.

Sarcoidosis-Associated Pulmonary Hypertension

Sarcoidosis-associated pulmonary hypertension (SAPH) is a very severe complication of the disease, largely impacting its morbidity and being one of its strongest predictors of mortality. With the recent modifications of the hemodynamic definition of pulmonary hypertension (mean arterial pulmonary pressure >20 instead of <25 mmHg,) its prevalence is presently not precisely known, but it affects from 3 to 20% of sarcoid patients; mostly, although not exclusively, those with an advanced, fibrotic pulmonary disease. Its gold-standard diagnostic tool remains right heart catheterization (RHC). The decision to perform it relies on an expert decision after a non-invasive work-up, in which echocardiography remains the screening tool of choice. The mechanisms underlying SAPH, very often entangled, are crucial to define, as appropriate and personalized therapeutic strategies will aim at targeting the most significant ones. There are no recommendations so far as to the indications and modalities of the medical treatment of SAPH, which is based upon the opinion of a multidisciplinary team of sarcoidosis, pulmonary hypertension and sometimes lung transplant experts.

Sarcoidosis-Associated Pulmonary Hypertension

Pulmonary hypertension is a life-threatening complication of advanced sarcoidosis. Many mechanisms can cause an elevation of pulmonary pressure in sarcoidosis, leading to precapillary or postcapillary pulmonary hypertension. Sarcoidosis-associated pulmonary hypertension contributes to severe exertional dyspnea, reduced exercise capacity, and notably compromised the survival. Despite the critical functional and prognostic implications of pulmonary hypertension in sarcoidosis, there is a scarcity of specific guidelines on the management of these patients due to a lack of evidence. Hence, further research is required to identify subgroups of patients who may benefit from pulmonary arterial hypertension-targeted therapies and/or immunosuppressive therapies.

Phenotypes of Sarcoidosis-Associated Pulmonary Hypertension-A Challenging Mystery

Sarcoidosis has been a well-recognised risk factor for pulmonary hypertension (PH) for a long time, but still, the knowledge about this concatenation is incomplete. Sarcoidosis-associated PH (SAPH) is an uncommon but serious complication associated with increased morbidity and mortality among sarcoidosis patients. The real epidemiology of SAPH remains unknown, and its pathomechanisms are not fully explained. Sarcoidosis is a heterogeneous and dynamic condition, and SAPH pathogenesis is believed to be multifactorial. The main roles in SAPH development play: parenchymal lung disease with the destruction of pulmonary vessels, the extrinsic compression of pulmonary vessels by conglomerate masses, lymphadenopathy or fibrosing mediastinitis, pulmonary vasculopathy, LV dysfunction, and portal hypertension. Recently, it has been recommended to individually tailor SAPH management according to the predominant pathomechanism, i.e., SAPH phenotype. Unfortunately, SAPH phenotyping is not a straightforward process. First, there are gaps in our understanding of undergoing processes. Second, the assessment of such a pivotal element as pulmonary vasculature on a microscopic level is non-feasible in SAPH patients antemortem. Finally, SAPH is a dynamic condition, multiple phenotypes usually coexist, and patients can switch between phenotypes during the course of sarcoidosis. In this article, we summarise the basic knowledge of SAPH, describe SAPH phenotypes, and highlight some practical problems related to SAPH phenotyping.

Successful simultaneous stenting of a pulmonary artery and vein in pulmonary vascular stenosis due to silicosis. Case report and literature review

A 58-year-old patient was admitted to the emergency department due to severe respiratory insufficiency. Anamnesis revealed that the patient had experienced increasing stress dyspnea for a few months. Upon imaging, an acute pulmonary embolism was excluded, but peribronchial and hilar soft tissue proliferation with compression of central parts of the pulmonary circulation was found. The patient had a history of silicosis. The histology report showed tumor-free lymph node particles with prominent anthracotic pigment and dust depositions without evidence of IgG4-associated disease. The patient was administered steroid therapy and underwent simultaneous stenting of the left interlobular pulmonary artery and the upper right pulmonary vein. As a result, a significant improvement in symptoms and physical performance was achieved. The diagnosis of inflammatory or, in particular, fibrosing mediastinal processes can be challenging and important clinical symptoms must be taken into account, especially if the pulmonary vasculature is involved. In such cases, the possibility of interventional procedures should be examined in addition to drug therapy options.

WASOG statement on the diagnosis and management of sarcoidosis-associated pulmonary hypertension

Sarcoidosis-associated pulmonary hypertension (SAPH) is an important complication of advanced sarcoidosis. Over the past few years, there have been several studies dealing with screening, diagnosis and treatment of SAPH. This includes the results of two large SAPH-specific registries. A task force was established by the World Association of Sarcoidosis and Other Granulomatous disease (WASOG) to summarise the current level of knowledge in the area and provide guidance for the management of patients. A group of sarcoidosis and pulmonary hypertension experts participated in this task force. The committee developed a consensus regarding initial screening including who should undergo more specific testing with echocardiogram. Based on the results, the committee agreed upon who should undergo right-heart catheterisation and how to interpret the results. The committee felt there was no specific phenotype of a SAPH patient in whom pulmonary hypertension-specific therapy could be definitively recommended. They recommended that treatment decisions be made jointly with a sarcoidosis and pulmonary hypertension expert. The committee recognised that there were significant defects in the current knowledge regarding SAPH, but felt the statement would be useful in directing future studies.

Management of Advanced Pulmonary Sarcoidosis

The term "advanced sarcoidosis" is used for forms of sarcoidosis with a significant risk of loss of organ function or death. Advanced sarcoidosis often involves the lung and is described as "Advanced Pulmonary Sarcoidosis" (APS) which includes advanced pulmonary fibrosis, associated complications such as bronchiectasis and infections, and pulmonary hypertension. While APS affects a small proportion of patients with sarcoidosis, it is the leading cause of poor outcomes including death. Herein we review the major patterns of APS with a focus on the current management as well as potential approaches for improved outcomes for this most serious sarcoidosis phenotype.

An update on sarcoidosis-associated pulmonary hypertension

PURPOSE OF REVIEW

Pulmonary hypertension in sarcoidosis is a well known entity. Sarcoidosis-associated pulmonary hypertension (SAPH) incurs substantial morbidity and mortality. This review examines recent literatures published on epidemiology, prognosis and therapeutic management in SAPH.

RECENT FINDINGS

Several registries have been published between 2017 and 2020. The consensus conclusion - SAPH is a harbinger for poor prognosis. Several factors were noted for predicting adverse outcome in SAPH like reduced 6-min walk distance and diffusing capacity for carbon monoxide. Given its adverse outcome, experts have now focused on methods for early screening of SAPH in sarcoid patients. The exploration of pulmonary vasodilator drugs in SAPH is ongoing. In recent times, trials have been published utilizing Macitentan and parenteral prostacyclin in severe SAPH. Although these trials show encouraging results, the evidence from these studies are limited to approve these agents as preferred drugs for treating SAPH. A large multicentric trial of drugs used for pulmonary arterial hypertension with meaningful, yet feasible, event driven endpoint is still lacking. Lately, interventional treatment by pulmonary artery balloon pulmonary angioplasty and stenting has gained traction for treating pulmonary artery stenosis and chronic thromboembolic pulmonary hypertension. However, the conclusion is still based on small cohorts or case series.

SUMMARY

Several registries have highlighted SAPH portends an unfavorable consequence. On the contrary, no published guideline exists to treat SAPH. The precise role of immunosuppressive agents is unclear. The limited evidence favoring use of pulmonary vasodilators arise from small retrospective case series and/or single-center nonrandomized observational studies. Further multicenter randomized research is warranted to better define patient population to treat and how best to treat them.

Sarcoidosis-Associated Pulmonary Hypertension

Pulmonary hypertension (PH) is a well-known complication of sarcoidosis, defined by a mean pulmonary artery pressure of ≥25 mm Hg. Since both PH and sarcoidosis are rare diseases, data on sarcoidosis-associated PH (SAPH) is retrieved mostly from small retrospective studies. Estimated prevalence of SAPH ranges from 3% in patients referred to a tertiary center up to 79% in patients awaiting lung transplant. Most patients with SAPH show advanced parenchymal disease as the underlying mechanism. However, some patients have disproportional elevated pulmonary artery pressure, and PH can occur in sarcoidosis patients without parenchymal disease. Other mechanisms such as vascular disease, pulmonary embolisms, postcapillary PH, extrinsic compression, and other sarcoidosis-related comorbidities might contribute to SAPH. The diagnosis of PH in sarcoidosis is challenging since symptoms and signs overlap. Suspicion can be raised based on symptoms or tests, such as pulmonary function tests, laboratory findings, electrocardiography, or chest CT. PH screening mainly relies on transthoracic echocardiography. Right heart catheterization should be considered on a case-by-case basis in patients with clinical suspicion of PH, taking into account clinical consequences. Treatment options are considered on patient level in a PH expert center, and might include oxygen therapy, immunosuppressive, or PH-specific therapy. However, qualitative evidence is scarce. Furthermore, in a subset of patients, interventional therapy or eventually lung transplant can be considered. SAPH is associated with high morbidity. Mortality is higher in sarcoidosis patients with PH compared with those without PH, and increases in patients with more advanced stages of sarcoidosis and/or PH.

Diagnosis and Detection of Sarcoidosis. An Official American Thoracic Society Clinical Practice Guideline

Background: The diagnosis of sarcoidosis is not standardized but is based on three major criteria: a compatible clinical presentation, finding nonnecrotizing granulomatous inflammation in one or more tissue samples, and the exclusion of alternative causes of granulomatous disease. There are no universally accepted measures to determine if each diagnostic criterion has been satisfied; therefore, the diagnosis of sarcoidosis is never fully secure.

Methods: Systematic reviews and, when appropriate, meta-analyses were performed to summarize the best available evidence. The evidence was appraised using the Grading of Recommendations, Assessment, Development, and Evaluation approach and then discussed by a multidisciplinary panel. Recommendations for or against various diagnostic tests were formulated and graded after the expert panel weighed desirable and undesirable consequences, certainty of estimates, feasibility, and acceptability.

Results: The clinical presentation, histopathology, and exclusion of alternative diagnoses were summarized. On the basis of the available evidence, the expert committee made 1 strong recommendation for baseline serum calcium testing, 13 conditional recommendations, and 1 best practice statement. All evidence was very low quality.

Conclusions: The panel used systematic reviews of the evidence to inform clinical recommendations in favor of or against various diagnostic tests in patients with suspected or known sarcoidosis. The evidence and recommendations should be revisited as new evidence becomes available.

Characteristics and Outcomes of Pulmonary Angioplasty With or Without Stenting for Sarcoidosis-Associated Pulmonary Hypertension: Systematic Review and Individual Participant Data Meta-Analysis

BACKGROUND

Pulmonary angioplasty has been performed in patients with sarcoidosis-associated pulmonary hypertension (SAPH) but most evidence comes from case reports and small case series. Overall outcomes remain unclear. We conducted an individual participant data (IPD) meta-analysis of baseline, procedural, and outcome data of pulmonary angioplasty in patients with SAPH.

METHODS

We performed searches and systematically reviewed references from PubMed, Embase, Cochrane, ClinicalTrials.gov, and grey literature. We included IPD of patients who underwent pulmonary angioplasty for SAPH. Those without definitive diagnosis of sarcoidosis or with other causes of pulmonary vascular stenosis or compression were excluded.

RESULTS

Of 1293 screened references, 7 were included. IPD was obtained for 17 patients (mean age 58.6 (±9.1) years; 82.4% female); most of whom were Scadding stages III or IV and had NYHA FC III or IV. All patients with documented changes in 6-minute-walk distance (6MWD) had a significant improvement that ranged from 12.6 to 102.4% (P < 0.01). There were no deaths during a median follow-up of 6 (3-18) months.

CONCLUSIONS

Pulmonary angioplasty with or without stenting of focal stenosis or compressions of pulmonary vessels may lead to significant improvement in 6MWD in patients with SAPH. However, this study had a small sample and some methodological limitations, such as analysis mostly of case reports and series. Randomized controlled clinical trials and/or large multicenter registry studies are needed to provide higher evidence in this topic.

Sarcoidosis-Associated Pulmonary Hypertension: An Updated Review and Discussion of the Clinical Conundrum

Pulmonary hypertension (PH) is a life-threatening disease with complex pathophysiology. The World Health Organization has classified PH in 5 groups according to etiology, the fifth of which corresponds to PH due to unknown or multiple mechanisms; including sarcoidosis-associated PH (SAPH). Although this system has been used to guide treatment recommendations according to each group, it does not provide much insight into the heterogeneous group 5. Furthermore, pulmonary vasodilators have been contraindicated for patients in this cluster which represents a challenge for the management of SAPH which can sometimes improve with these PH-directed drugs. In this review, we discuss the classification of SAPH; as well as the evidence behind the use of pulmonary vasodilator, invasive procedures, and lung transplantation for treating SAPH; and the little that is known about his disease in the setting of cardiac sarcoidosis.