Pulmonary hypertension associated with sarcoidosis: mechanisms, haemodynamics and prognosis

[Pulmonary hypertension in chronic respiratory diseases]

Pulmonary hypertension is frequent in advanced chronic respiratory diseases, with an estimated prevalence at the time of pulmonary transplantation of 30-50 % in idiopathic pulmonary fibrosis, 30-50 % in chronic obstructive pulmonary disease, 50 % in combined pulmonary fibrosis and emphysema, 75 % in sarcoidosis, and more than 75 % of cases in pulmonary Langerhans cell histiocytosis. Histologic features include varying degrees of pulmonary arterial remodeling (prominent), vascular rarefaction (emphysema), fibrosis or specific involvement of the pulmonary arteries (idiopathic pulmonary fibrosis, sarcoidosis, lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis), in situ thrombosis, and frequently associated involvement of the pulmonary veins (idiopathic pulmonary fibrosis, sarcoidosis). Pulmonary hypertension is usually detected using echocardiography with Doppler, however right heart catheterisation is required to confirm precapillary pulmonary hypertension defined by pulmonary artery pressure ≥ 25 mm Hg, with pulmonary artery wedge pressure ≤ 15 mm Hg. When present, it is associated with decreased exercise capacity and worse mortality. Pulmonary hypertension in chronic respiratory disease is almost invariably multifactorial; hypoxia is one of its main determinants, however supplemental oxygen therapy rarely reverses pulmonary hypertension. Management of pulmonary hypertension in chronic respiratory disease is mostly based on the optimal treatment of the underlying disease. Available data do not support the use of drug therapies specific for pulmonary hypertension in the setting of chronic respiratory diseases, however very few clinical studies have been conducted so far specifically in this context.

Current best practice in the management of pulmonary and systemic sarcoidosis

Sarcoidosis is a systemic inflammatory disease of unknown etiology that is characterized by the presence of granulomatous inflammation in affected tissues. It can affect essentially any organ system but shows a predilection for the lungs, eyes, and skin. Accurate epidemiological data are not available in the USA, but sarcoidosis is considered a 'rare disease' (prevalence less than 200,000). However, recent epidemiologic studies indicate that regional prevalence is much higher than previously estimated, especially among African American women. Additionally, mortality rates of patients with sarcoidosis are increasing by 3% per year over the past two decades. The most common causes of death are attributed to progressive lung disease and cardiac sarcoidosis, and the health of the patients is further compromised by other systemic manifestations. As such, the management of sarcoidosis requires a collaborative multidisciplinary approach. We aim to discuss the principles of managing sarcoidosis, including standards of care relating to pulmonary disease as well as recent advances relating to the detection and treatment of extrapulmonary manifestations.

Sarcoidosis-associated pulmonary hypertension and lung transplantation for sarcoidosis

Pulmonary hypertension (PH) is a significant complication of sarcoidosis, occurring in approximately 6 to > 20% of cases, and markedly increases mortality among these patients. The clinician should exercise a high index of suspicion for sarcoidosis-associated PH (SAPH) given the nonspecific symptomatology and the limitations of echocardiography in this patient population. The pathophysiology of PH in sarcoidosis is complex and multifactorial. Importantly, there are inherent differences in the pathogenesis of SAPH compared with idiopathic pulmonary arterial hypertension, making the optimal management of SAPH controversial. In this article, we review the epidemiology, diagnosis, prognosis, and treatment considerations for SAPH. Lung transplantation (LT) is a viable therapeutic option for sarcoid patients with severe pulmonary fibrocystic sarcoidosis or SAPH refractory to medical therapy. We discuss the role for LT in patients with sarcoidosis, review the global experience with LT in this population, and discuss indications and contraindications to LT.

Clinical and molecular study of 4 cases of pulmonary hypertension associated with sarcoidosis

Sarcoidosis is a pleomorphic disease that can present with pulmonary hypertension (PH). What little information is available about the association of these two diseases comes mainly from small series of patients scheduled for transplant. We present 4 cases of mild pulmonary involvement in whom right catheterisation was performed and PH-specific therapy was administered. After obtaining written consent, a genetic study was performed that showed mutations in PH-related genes in 3 of the patients. This is the first study of its kind to yield genetic information for this type of PH.

Bosentan for sarcoidosis-associated pulmonary hypertension: a double-blind placebo controlled randomized trial

BACKGROUND

Sarcoidosis-associated pulmonary hypertension (SAPH) is a common problem in patients with persistent dyspneic sarcoidosis. The objective of this study was to determine the effect of bosentan therapy on pulmonary arterial hemodynamics in patients with SAPH.

METHODS

This 16-week study was a double-blind, placebo-controlled trial of either bosentan or placebo in patients with SAPH confirmed by right-sided heart catheterization. Patients were enrolled from multiple academic centers specializing in sarcoidosis care. They were stable on sarcoidosis therapy and were receiving no therapy for pulmonary hypertension. The cohort was randomized two to one to receive bosentan at a maximal dose of 125 mg or placebo bid for 16 weeks. Pulmonary function studies, 6-min walk test, and right-sided heart hemodynamics, including pulmonary artery mean pressure and pulmonary vascular resistance (PVR), were performed before and after 16 weeks of therapy.

RESULTS

Thirty-five patients completed 16 weeks of therapy (23 treated with bosentan, 12 with placebo). For those treated with bosentan, repeat hemodynamic studies at 16 weeks demonstrated a significant mean±SD fall in PA mean pressure (-4±6.6 mm Hg, P=.0105) and PVR (-1.7±2.75 Wood units, P=.0104). For the patients treated with placebo, there was no significant change in either PA mean pressure (1±3.7 mm Hg, P>.05) or PVR (0.1±1.42 Wood units, P>.05). There was no significant change in 6-min walk distance for either group. Two patients treated with bosentan required an increase of supplemental oxygen by >2 L after 16 weeks of therapy.

CONCLUSIONS

This study demonstrated that bosentan significantly improved pulmonary hemodynamics in patients with SAPH.

TRIAL REGISTRY

ClinicalTrials.gov; No: NCT00581607; URL: www.clinicaltrials.gov.

Pulmonary fibrosis in sarcoidosis. Clinical features and outcomes

Sarcoidosis is a systemic inflammatory disease with a predilection for the respiratory system. Although most patients enter remission and have good long-term outcomes, up to 20% develop fibrotic lung disease, whereby granulomatous inflammation evolves to pulmonary fibrosis. There are several radiographic patterns of pulmonary fibrosis in sarcoidosis; bronchial distortion is common, and other patterns, including honeycombing, are variably observed. The development of pulmonary fibrosis is associated with significant morbidity and can be fatal. Dyspnea, cough, and hypoxemia are frequent clinical manifestations. Pulmonary function testing often demonstrates restriction from parenchymal involvement, although airflow obstruction from airway-centric fibrosis is also recognized. Complications of fibrotic pulmonary sarcoidosis include pulmonary hypertension from capillary obliteration and chronic aspergillus disease, with hemoptysis a common and potentially life-threatening manifestation. Immunosuppression is not always indicated in end-stage sarcoidosis. Lung transplantation should be considered for patients with severe fibrotic pulmonary sarcoidosis, as mortality is high in these patients.

Sarcoidosis-associated pulmonary hypertension

PURPOSE OF REVIEW

Pulmonary hypertension is a serious complication of sarcoidosis. This review discusses clinical characteristics of patients with sarcoid-associated pulmonary hypertension (SAPH) and pitfalls in the diagnosis, and highlights potential therapies.

RECENT FINDINGS

SAPH is common in patients with advanced disease, but it can occur in patients with minimal disease burden. Risk factors for SAPH include restrictive lung physiology, hypoxemia, advanced Scadding chest X-ray stage, and low carbon monoxide diffusion capacity. Echocardiogram is a good initial screening tool in the diagnosis of pulmonary hypertension, but right heart catheterization is necessary to confirm the diagnosis. Treatment with pulmonary vasodilators, including endothelin antagonists, can lead to improvements in pulmonary hemodynamics in some patients but may not improve their exercise capacity. Forced vital capacity is an important predictor of exercise performance in patients with SAPH. Clinical observations and response to specific therapies for pulmonary hypertension suggest the presence of different SAPH phenotypes.

SUMMARY

Patients who complain of persistent dyspnea should be screened for the presence of pulmonary hypertension. The prognosis of SAPH is poor and it is prudent to consider referral of these patients for lung transplantation. In some patients with SAPH, treatment with anti-inflammatory agents and pulmonary vasodilators can lower pulmonary arterial pressures, improve dyspnea and functionality, and enhance overall quality of life.

Pulmonary hypertension in chronic lung diseases

Chronic obstructive lung disease (COPD) and diffuse parenchymal lung diseases (DPLD), including idiopathic pulmonary fibrosis (IPF) and sarcoidosis, are associated with a high incidence of pulmonary hypertension (PH), which is linked with exercise limitation and a worse prognosis. Patients with combined pulmonary fibrosis and emphysema (CPFE) are particularly prone to the development of PH. Echocardiography and right heart catheterization are the principal modalities for the diagnosis of COPD and DPLD. For discrimination between group 1 PH patients with concomitant respiratory abnormalities and group 3 PH patients (PH caused by lung disease), patients should be transferred to a center with expertise in both PH and lung diseases for comprehensive evaluation. The task force encompassing the authors of this article provided criteria for this discrimination and suggested using the following definitions for group 3 patients, as exemplified for COPD, IPF, and CPFE: COPD/IPF/CPFE without PH (mean pulmonary artery pressure [mPAP] <25 mm Hg); COPD/IPF/CPFE with PH (mPAP ≥25 mm Hg); PH-COPD, PH-IPF, and PH-CPFE); COPD/IPF/CPFE with severe PH (mPAP ≥35 mm Hg or mPAP ≥25 mm Hg with low cardiac index [CI <2.0 l/min/m(2)]; severe PH-COPD, severe PH-IPF, and severe PH-CPFE). The "severe PH group" includes only a minority of chronic lung disease patients who are suspected of having strong general vascular abnormalities (remodeling) accompanying the parenchymal disease and with evidence of an exhausted circulatory reserve rather than an exhausted ventilatory reserve underlying the limitation of exercise capacity. Exertional dyspnea disproportionate to pulmonary function tests, low carbon monoxide diffusion capacity, and rapid decline of arterial oxygenation upon exercise are typical clinical features of this subgroup with poor prognosis. Studies evaluating the effect of pulmonary arterial hypertension drugs currently not approved for group 3 PH patients should focus on this severe PH group, and for the time being, these patients should be transferred to expert centers for individualized patient care.

Learning from the pulmonary veins

The purpose of this article is to review the basic embryology and anatomy of the pulmonary veins and the various imaging techniques used to evaluate the pulmonary veins, as well as the radiologic findings in diseases affecting these structures. Specific cases highlight the clinical importance of the imaging features, particularly the findings obtained with multidetector computed tomography (CT). Pulmonary vein disease can be broadly classified into congenital or acquired conditions. Congenital disease, which often goes unnoticed until patients are adults, mainly includes (a) anomalies in the number or diameter of the vessels and (b) abnormal drainage or connection with the pulmonary arterial tree. Acquired disease can be grouped into (a) stenosis and obstruction, (b) hypertension, (c) thrombosis, (d) calcifications, and (e) collateral circulation. Pulmonary vein stenosis or obstruction, which often has important clinical repercussions, is frequently a result of radiofrequency ablation complications, neoplastic infiltration, or fibrosing mediastinitis. The most common cause of pulmonary venous hypertension is chronic left ventricular failure. This condition is difficult to differentiate from veno-occlusive pulmonary disease, which requires a completely different treatment. Pulmonary vein thrombosis is a rare, potentially severe condition that can have a local or distant cause. Calcifications have been described in rheumatic mitral valve disease and chronic renal failure. Finally, the pulmonary veins can act as conduits for collateral circulation in cases of obstruction of the superior vena cava. Multidetector CT is an excellent modality for imaging evaluation of the pulmonary veins, even when the examination is not specifically tailored for their assessment.

Rare causes of pulmonary hypertension: spectrum of radiological findings and review of the literature

Following a brief introduction covering the clinical signs and symptoms of pulmonary hypertension (PH), its most recent classification into six groups, and the computed tomography (CT) features common to all forms of PH, this paper illustrates the typical patterns that can be found on chest radiography and CT in rare causes of PH. We present and compare with the existing literature our personal series of cases of rare forms of PH, found in the following diseases: veno-occlusive disease, pulmonary capillary haemangiomatosis, non-thrombotic pulmonary embolism (tumour embolism and carcinomatous lymphangitis, talcosis, hydatid disease), pulmonary artery sarcoma, neurofibromatosis, sarcoidosis, and Langerhans cell histiocytosis. Rare forms of PH show low incidence and prevalence, and are, therefore, poorly recognised. Their diagnosis is a challenge for clinicians, pathologists, and radiologists, and any additional knowledge about the CT findings may help the diagnosis in the case of patients affected by PH of unknown origin.

Pathogenesis of pulmonary hypertension: a case for caveolin-1 and cell membrane integrity

Pulmonary hypertension (PH) is a progressive disease with a high morbidity and mortality rate. Despite important advances in the field, the precise mechanisms leading to PH are not yet understood. Main features of PH are loss of vasodilatory response, the activation of proliferative and antiapoptotic pathways leading to pulmonary vascular remodeling and obstruction, elevated pressure and right ventricular hypertrophy, resulting in right ventricular failure and death. Experimental studies suggest that endothelial dysfunction may be the key underlying feature in PH. Caveolin-1, a major protein constituent of caveolae, interacts with several signaling molecules including the ones implicated in PH and modulates them. Disruption and progressive loss of endothelial caveolin-1 with reciprocal activation of proliferative pathways occur before the onset of PH, and the rescue of caveolin-1 inhibits proliferative pathways and attenuates PH. Extensive endothelial damage/loss occurs during the progression of the disease with subsequent enhanced expression of caveolin-1 in smooth muscle cells. This caveolin-1 in smooth muscle cells switches from being an antiproliferative factor to a proproliferative one and participates in cell proliferation and cell migration, possibly leading to irreversible PH. In contrast, the disruption of endothelial caveolin-1 is not observed in the hypoxia-induced PH, a reversible form of PH. However, proliferative pathways are activated in this model, indicating caveolin-1 dysfunction. Thus disruption or dysfunction of endothelial caveolin-1 leads to PH, and the status of caveolin-1 may determine the reversibility versus irreversibility of PH. This article reviews the role of caveolin-1 and cell membrane integrity in the pathogenesis and progression of PH.

World Health Organization group 5 pulmonary hypertension

World Health Organization (WHO) group 5 pulmonary hypertension (PH) entails a heterogeneous group of disorders that may cause PH by unclear and/or multiple mechanisms. In particular, group 5 includes PH caused by hematologic disorders, systemic diseases, metabolic disorders, chronic renal failure, and disorders leading to pulmonary vascular occlusion or compression. This article discusses common pathogenic mechanisms leading to group 5 PH, followed by a detailed overview of epidemiology, pathogenesis, and disease-specific management of the individual group 5 conditions. Off-label use of vasomodulatory therapies, typically indicated for pulmonary arterial hypertension (WHO group 1 PH), in group 5 conditions is also discussed.

Pulmonary hypertension due to lung disease and/or hypoxia

Pulmonary hypertension may complicate the course of patients with many forms of advanced lung disease. The cause is likely multifactorial with pathogenic pathways both common and unique to the specific disease entities. The occurrence of pulmonary hypertension is associated with worse outcomes, but whether this is an adaptive or maladaptive phenomenon remains unknown. The treatment of pulmonary hypertension with vasoactive medications in lung disease remains unproved. Specific disease phenotypes that might benefit, and those in which such therapies might be deleterious, remain to be determined.

Differentiation between sarcoidosis and Hodgkin's lymphoma based on mediastinal lymph node involvement pattern: Evaluation using spiral CT scan

Background:

The purpose of this study was to determine the specific and detailed anatomic sites and morphologic characteristics of mediastinal lymph nodes on spiral computed tomography for the purpose of differentiation between sarcoidosis and Hodgkin’s lymphoma.

Material/Methods:

Anatomical distribution of mediastinal lymph nodes on spiral CT was reviewed in 39 patients with sarcoidosis and 37 patients with Hodgkin’s lymphoma using the International Association for the Study of Lung Cancer (IASLC) lymph node map. Other morphologic features such as lymph node calcification or coalescence of adjacent lymph nodes were also compared.

Results:

Zone 10 was involved more often in sarcoidosis than in Hodgkin’s lymphoma. On the other hand, there was a higher tendency for presence of zone 1 and 3 as well as retrocrural and internal mammary lymphadenopathy in Hodgkin’s lymphoma than in sarcoidosis. Sarcoidosis presented with intranodal calcifications more often than Hodgkin’s lymphoma. Coalescence, pressure effect on adjacent structures and central cavitations were significantly more common in Hodgkin’s lymphoma.

Conclusions:

Findings of the present study indicate that specific anatomical distribution and morphological patterns of mediastinal lymph nodes, as demonstrated on spiral CT, can be useful in differentiating sarcoidosis from Hodgkin’s lymphoma.

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease leading to right heart failure and ultimately death if untreated. The first classification of PH was proposed in 1973. In 2008, the fourth World Symposium on PH held in Dana Point (California, USA) revised previous classifications. Currently, PH is devided into five subgroups. Group 1 includes patients suffering from idiopathic or familial PAH with or without germline mutations. Patients with a diagnosis of PAH should systematically been screened regarding to underlying mutations of BMPR2 gene (bone morphogenetic protein receptor type 2) or more rarely of ACVRL1 (activine receptor-like kinase type 1), ENG (endogline) or Smad8 genes. Pulmonary veno occusive disease and pulmonary capillary hemagiomatosis are individualized and designated as clinical group 1'. Group 2 'Pulmonary hypertension due to left heart diseases' is divided into three sub-groups: systolic dysfonction, diastolic dysfonction and valvular dysfonction. Group 3 'Pulmonary hypertension due to respiratory diseases' includes a heterogenous subgroup of respiratory diseases like PH due to pulmonary fibrosis, COPD, lung emphysema or interstitial lung disease for exemple. Group 4 includes chronic thromboembolic pulmonary hypertension without any distinction of proximal or distal forms. Group 5 regroup PH patients with unclear multifactorial mechanisms. Invasive hemodynamic assessment with right heart catheterization is requested to confirm the definite diagnosis of PH showing a resting mean pulmonary artery pressure (mPAP) of ≥ 25 mmHg and a normal pulmonary capillary wedge pressure (PCWP) of ≤ 15 mmHg. The assessment of PCWP may allow the distinction between pre-capillary and post-capillary PH (PCWP > 15 mmHg). Echocardiography is an important tool in the management of patients with underlying suspicion of PH. The European Society of Cardiology and the European Respiratory Society (ESC-ERS) guidelines specify its role, essentially in the screening proposing criteria for estimating the presence of PH mainly based on tricuspid regurgitation peak velocity and systolic artery pressure (sPAP). The therapy of PAH consists of non-specific drugs including oral anticoagulation and diuretics as well as PAH specific therapy. Diuretics are one of the most important treatment in the setting of PH because right heart failure leads to fluid retention, hepatic congestion, ascites and peripheral edema. Current recommendations propose oral anticoagulation aiming for targeting an International Normalized Ratio (INR) between 1.5-2.5. Target INR for patients displaying chronic thromboembolic PH is between 2–3. Better understanding in pathophysiological mechanisms of PH over the past quarter of a century has led to the development of medical therapeutics, even though no cure for PAH exists. Several specific therapeutic agents were developed for the medical management of PAH including prostanoids (epoprostenol, trepoprostenil, iloprost), endothelin receptor antagonists (bosentan, ambrisentan) and phosphodiesterase type 5 inhibitors (sildenafil, tadalafil). This review discusses the current state of art regarding to epidemiologic aspects of PH, diagnostic approaches and the current classification of PH. In addition, currently available specific PAH therapy is discussed as well as future treatments.

Pulmonary hypertension in Saudi Arabia: A single center experience

CONTEXT

Several international studies have described the epidemiology of pulmonary hypertension (PH). However, information about the incidence and prevalence of PH in Saudi Arabia is unknown.

AIMS

To report cases of PH and compare the demographic and clinical characteristics of PH due to various causes in a Saudi population.

METHODS

Newly diagnosed cases of PH [defined as mean pulmonary artery pressure >25 mmHg at right heart cauterization (RHC)] were prospectively collected at a single tertiary care hospital from January 2009 and June 2012. Detailed demographic and clinical data were collected at the time of diagnosis, along with hemodynamic parameters.

RESULTS

Of the total 264 patients who underwent RHC, 112 were identified as having PH. The mean age at diagnosis was 55.8 ± 15.8 years, and there was a female preponderance of 72.3%. About 88 (78.6%) of the PH patients were native Saudis and 24 (21.4%) had other origins. Twelve PH patients (10.7%) were classified in group 1 (pulmonary arterial hypertension), 7 (6.2%) in group 2 (PH due to left heart disease), 73 (65.2%) in group 3 (PH due to lung disease), 4 (3.6%) in group 4 (chronic thromboembolic PH), and 16 (14.3%) in group 5 (PH due to multifactorial mechanisms). PH associated with diastolic dysfunction was noted in 28.6% of group 2 patients, 31.5% of group 3 patients, and 25% of group 5 patients.

CONCLUSIONS

These results offer the first report of incident cases of PH across five groups in Saudi Arabia.

Correlation of late gadolinium enhancement MRI and quantitative T2 measurement in cardiac sarcoidosis

PURPOSE

To investigate the potentially improved detection and quantification of cardiac involvement using novel late-gadolinium-enhancement (LGE) cardiac magnetic resonance imaging (MRI) and quantitative T2 measurement to achieve better myocardial tissue characterization in systemic sarcoidosis.

MATERIALS AND METHODS

Twenty-eight patients with systemic sarcoidosis underwent a cardiac magnetic resonance imaging (CMR) study on a 1.5T system. Precontrast CMR included left ventricular (LV) and right ventricular (RV) function and quantitative T2 measurement. Postcontrast LGE-MRI included inversion-recovery fast-gradient-echo (IR-FGRE) and multicontrast late-enhancement imaging (MCLE).

RESULTS

LV functional parameters were normal in all patients (LVEF=61.2±8.5%) including with cardiac involvement (LVEF=59.4±12.1%) and without (LVEF=61.7±7.5%) while the average RV function was comparatively decreased (RVEF=48.0±6.6%, P<0.0001). 21.4% of patients had cardiac involvement showing patchy or multiple focal hyperenhancement patterns in LV free wall, papillary muscles (PM), or interventricular septum. In two cases with PM involvement, the PM abnormal LGE foci were only observed on MCLE. For precontrast T2 measurements, a significantly decreased T2 measurement was observed in regions demonstrating LGE, compared to the LGE-negative group (focal LGE-positive regions vs. negative: 40.0±2.4 msec vs. 53.0±2.6 msec, P<0.0001).

CONCLUSION

LGE-MRI can identify cardiac involvement in systemic sarcoidosis. MCLE might be more sensitive at detecting subtle myocardial lesion. The decreased T2 observed in cardiac sarcoid may reflect its inactive phase, thus might provide a noninvasive method for monitoring disease activity or therapy.

NT-proatrial natriuretic peptide as a possible biomarker of cardiopulmonary involvement in sarcoidosis

BACKGROUND

Lung diffusion for carbon monoxide (DLCO) has been shown to associate with the risk of pulmonary arterial hypertension development and, most likely, with right ventricular (RV) myocardial dysfunction in sarcoidosis patients. Besides its known role as a marker of left ventricular dysfunction, experimental evidence suggests a role of NT-proAtrial Natriuretic Peptide (NT-proANP) also in modulating pulmonary circulation. We therefore investigated possible relationships between NT-proANP, lung diffusion impairment and RV dysfunction.

METHODS

Thirty-two pulmonary sarcoidosis outpatients and eighteen volunteers underwent full clinical assessment, including full lung function tests and Doppler echocardiography integrated with tissue Doppler imaging (TDI) study. Resting circulating NT-proBNP and NT-proANP plasma levels were also determined.

RESULTS

NT-proANP and RV-myocardial performance index (RV-MPI) were significantly higher in those patients with the greatest DLCO impairment, whereas no differences were found for NT-proBNP values. At multivariable analysis, only DLCO (β: -0.496; standard error: 3.38; p=0.000) and RV-MPI (β: 0.373; standard error: 6.56; p=0.031) remained significantly associated with NT-proANP levels.

CONCLUSIONS

Our finding may support a key role of NT-proANP in the complex mechanisms underlying modulation of lung function. An early increase in pulmonary vascular resistance may stimulate NT-proANP increase, thus explaining its association with signs of early RV myocardial dysfunction. This hypothesis warrants further confirmation.

Pulmonary Langerhans cell histiocytosis-associated pulmonary hypertension: clinical characteristics and impact of pulmonary arterial hypertension therapies

BACKGROUND

Precapillary pulmonary hypertension (PH) is a complication of pulmonary Langerhans cell histiocytosis (PLCH) associated with increased mortality. However, outcomes and efficacy of pulmonary arterial hypertension (PAH) therapies in patients with PH complicating PLCH(PLCH-PH) remain unknown.

METHODS

Consecutive patients with PLCH with PH confirmed by right-sided heart catheterization were included in the study. Characteristics at baseline and during follow-up as well as survival were analyzed.

RESULTS

Twenty-nine patients were studied. Baseline characteristics of patients with PLCH-PH wereas follows: 83% of patients in World Health Organization (WHO) functional class III to IV, mean 6-min walk distance of 355 ±95 m, mean pulmonary arterial pressure (mPAP) of 45 ±14 mm Hg,cardiac index of 3.2± 0.9 L/min/m 2 , and pulmonary vascular resistance (PVR) of 555 ±253 dyne/s/cm 5. Use of PAH therapy in 12 patients was followed by an improvement in mPAP (56±14 mm Hg and 45±12 mm Hg, P 5 .03) and PVR (701±239 dyne/s/cm 5 and 469±210 dyne/s/cm 5 , P = .01) between baseline and follow-up evaluations. No significant oxygen worsening was observed in the treated group. The 1-, 3-, and 5-year survival estimates of the 29 patients were 96%, 92%, and 73%,respectively. Except a trend toward a better survival rate associated with the use of PAH therapy,WHO functional class was the only variable significantly associated with death.

CONCLUSIONS

In this group of patients, PAH therapies improved hemodynamics without oxygen worsening or pulmonary edema. WHO functional class was the only prognostic factor identified.Prospective clinical trials focusing on this population of patients are warranted

Pulmonary hypertension in rheumatic diseases: epidemiology and pathogenesis

The focus of this review is to increase awareness of pulmonary arterial hypertension (PAH) in patients with rheumatic diseases. Epidemiology and pathogenesis of PAH in rheumatic diseases is reviewed, with recommendations for early screening and diagnosis and suggestion of possible role of immunosuppressive therapy in treatment for PAH in rheumatic diseases. A MEDLINE search for articles published between January 1970 and June 2012 was conducted using the following keywords: pulmonary hypertension, scleroderma, systemic sclerosis, pulmonary arterial hypertension, connective tissues disease, systemic lupus erythematosus, mixed connective tissue disease, rheumatoid arthritis, Sjogren's syndrome, vasculitis, sarcoidosis, inflammatory myopathies, dermatomyositis, ankylosing spondylitis, spondyloarthropathies, diagnosis and treatment. Pathogenesis and disease burden of PAH in rheumatic diseases was highlighted, with emphasis on early consideration and workup of PAH. Screening recommendations and treatment were touched upon. PAH is most commonly seen in systemic sclerosis and may be seen in isolation or in association with interstitial lung disease. Several pathophysiologic processes have been identified including an obliterative vasculopathy, veno-occlusive disease, formation of microthrombi and pulmonary fibrosis. PAH in systemic lupus erythematosus is associated with higher prevalence of antiphospholipid and anticardiolipin antibodies and the presence of Raynaud's phenomenon. Endothelial proliferation with vascular remodeling, abnormal coagulation with thrombus formation and immune-mediated vasculopathy are the postulated mechanisms. Improvement with immunosuppressive medications has been reported. Pulmonary fibrosis, extrinsic compression of pulmonary arteries and granulomatous vasculitis have been reported in patients with sarcoidosis. Intimal and medial hyperplasia with luminal narrowing has been observed in Sjogren's syndrome, mixed connective tissue disease and inflammatory myopathies. Pulmonary arterial hypertension (PAH) associated with rheumatic diseases carries a particularly grim prognosis with faster progression of disease and poor response to therapy. Though largely associated with systemic sclerosis, it is being increasingly recognized in other rheumatic diseases. An underlying inflammatory component may explain the poor response to therapy in patients with rheumatic diseases and is a rationale for consideration of immunosuppressive therapy in conjunction with vasodilator therapy in treatment for PAH. Further studies identifying pathogenetic pathways and possible targets of therapy, especially the role of immunomodulatory medications, are warranted.

Clinical characteristics, haemodynamics and treatment of pulmonary hypertension in sarcoidosis in a single centre, and meta-analysis of the published data

Pulmonary hypertension (PH) in sarcoidosis is associated with bad outcomes. Although there is interest in using pulmonary vasodilators (PVs) for PH in sarcoidosis, there are few data to support their use. In this study, a retrospective review of a cohort of patients with PH and sarcoidosis was conducted, focusing on those treated with PVs, and a meta-analysis of published reports indexed in MEDLINE was performed. Twenty-four patients were found. The rate of mortality or transplantation rate was 41.2%. Median survival without transplantation was 5.3 years. More patients who died or underwent transplantation during follow-up had moderate or severe lung fibrosis (66.7% vs 15.4%), had right ventricular dysfunction (80% vs 7.7%), and were in World Health Organization class IV (66.7% vs 30.8%). Body surface areas were lower in patients with events, as was cardiac output. Mortality was not different between patients treated with PVs and those not treated (54.5% vs 38.5%, p = 0.44) despite the treated patients' having more right ventricular dysfunction and worse hemodynamics. In a Cox regression survival model, lower body surface area, right ventricular dysfunction, and the presence of moderate or severe lung fibrosis were predictors of worse outcomes, but not treatment with PVs. PV-treated patients (n = 11) showed improved 6-minute walk distances and decreased N-terminal pro-B-type natriuretic peptide levels during follow-up. There was a trend toward improvement in hemodynamic profile. Four studies plus the data from this study were included in the meta-analysis. Six-minute walk distance improved by 30.64 m after treatment. Hemodynamics improved, with a reduction in mean pulmonary arterial pressure of 8.03 mm Hg and a decrease in pulmonary vascular resistance of 4.23 Wood units. In conclusion, PH in sarcoidosis is associated with adverse outcomes, particularly when accompanied by right ventricular dysfunction and/or moderate or severe lung fibrosis. Treating selected patients can improve hemodynamics and functional parameters.

Classification of pulmonary hypertension

Pulmonary hypertension (PH) can develop in association with many different diseases and risk factors, and its presence is nearly always associated with reduced survival. The prognosis and management of PH is largely dependent upon its underlying etiology and severity of disease. The combination of clinical and hemodynamic classifications of PH provides a framework for the diagnostic evaluation of PH to establish a final clinical diagnosis that guides therapy. As our understanding of the different pathologic mechanisms that underlie the syndrome of PH evolves, so too will the classification and treatment of PH.

The clinical and immunologic features of pulmonary fibrosis in sarcoidosis

Sarcoidosis is a multisystem, granulomatous disease that most often affects the lungs. The clinical course is highly variable; many patients undergo spontaneous remission, but up to a third of patients progresses to a chronic disease course. The development of pulmonary fibrosis (PF) in a subset of patients with chronic disease has a negative impact on morbidity and mortality. While sarcoidosis-associated PF can be progressive, it is often referred to as "burnt out" disease, a designation reflecting inactive granulomatous inflammation. The immune mechanisms of sarcoidosis-associated PF are not well understood. It is not clear if fibrotic processes are active from the onset of sarcoidosis in predisposed individuals, or whether a profibrotic state develops as a response to ongoing inflammation. Transforming growth factor β (TGF-β) is an important profibrotic cytokine, and in sarcoidosis, distinct genotypes of TGF-β have been identified in those with PF. The overall cytokine profile in sarcoidosis-associated PF has not been well characterized, although a transition from a T helper 1 to a T helper 2 signature has been proposed. Macrophages have important regulatory interactions with fibroblasts, and the role of alveolar macrophages in sarcoidosis-associated PF is a compelling target for further study. Elucidating the natural history of sarcoidosis-associated PF will inform our understanding of the fundamental derangements, and will enhance prognostication and the development of therapeutic strategies.

Pulmonary hypertension in parenchymal lung disease

Idiopathic pulmonary arterial hypertension (IPAH) has been extensively investigated, although it represents a less common form of the pulmonary hypertension (PH) family, as shown by international registries. Interestingly, in types of PH that are encountered in parenchymal lung diseases such as interstitial lung diseases (ILDs), chronic obstructive pulmonary disease (COPD), and many other diffuse parenchymal lung diseases, some of which are very common, the available data is limited. In this paper, we try to browse in the latest available data regarding the occurrence, pathogenesis, and treatment of PH in chronic parenchymal lung diseases.

Right ventricular dysfunction in chronic lung disease

Right ventricular (RV) dysfunction arises in chronic lung disease when chronic hypoxemia and disruption of pulmonary vascular beds increase ventricular afterload. RV dysfunction is defined by hypertrophy with preserved myocardial contractility and cardiac output. RV hypertrophy seems to be a common complication of chronic and advanced lung disease. RV failure is rare, except during acute exacerbations of chronic lung disease or when multiple comorbidities are present. Treatment is targeted at correcting hypoxia and improving pulmonary gas exchange and mechanics. There are no data supporting the use of pulmonary hypertension-specific therapies for patients with RV dysfunction secondary to chronic lung disease.

The treatment of pulmonary sarcoidosis

This manuscript offers an approach to the treatment of pulmonary sarcoidosis based on current available information. The treatment of pulmonary sarcoidosis is not mandatory as the disease may be self-limiting and therapy is often associated with significant drug side effects. The decision to treat rests predominantly on the presence of significant symptoms or functional limitation. Corticosteroids are the drug of choice. Alternative agents to corticosteroids may be useful primarily as corticosteroid sparing agents.

Therapy for sarcoidosis: evidence-based recommendations

The options for treatment of sarcoidosis have expanded. In this article, we outline a stepwise approach to treatment. Recommendations for treatment are based on available evidence. While corticosteroids remain the treatment of choice for initial systemic therapy, other agents have been shown to be steroid sparing, and therefore useful for long-term management. In addition, new agents have proved to be useful for patients with refractory disease.

[Disproportionate pulmonary arterial hypertension and lung respiratory diseases: distinctive clinical, hemodynamic and prognosis of patients versus primary pulmonary arterial hypertension]

OBJECTIVES

To characterize and compare patients with disproportionate PH versus patients with primary pulmonary arterial hypertension (PAH).

METHODS

All patients referred to our cardiology unit for echocardiography from November 2006 to May 2008 and who have been followed by our pneumologist were screened for severe PH (i.e mean arterial pulmonary pressure>35-40 mmHg at rest). Patients were excluded if a factor that could influence pulmonary hemodynamics was present. We investigated these patients by pulmonary function tests, echocardiography and right heart catheterisation.

RESULTS

We reported 16 cases of severe PH in stable patients (n=8, chronic obstructive pulmonary disease-emphysema) and 13 patients with PAH. Our findings suggest that the patients with disproportionate PH had right heart dysfunction similar to that observed in PAH. But their outcomes were more severe. It seemed that specific vasodilatator therapy was not efficient.

Hypoxic pulmonary vasoconstriction

It has been known for more than 60 years, and suspected for over 100, that alveolar hypoxia causes pulmonary vasoconstriction by means of mechanisms local to the lung. For the last 20 years, it has been clear that the essential sensor, transduction, and effector mechanisms responsible for hypoxic pulmonary vasoconstriction (HPV) reside in the pulmonary arterial smooth muscle cell. The main focus of this review is the cellular and molecular work performed to clarify these intrinsic mechanisms and to determine how they are facilitated and inhibited by the extrinsic influences of other cells. Because the interaction of intrinsic and extrinsic mechanisms is likely to shape expression of HPV in vivo, we relate results obtained in cells to HPV in more intact preparations, such as intact and isolated lungs and isolated pulmonary vessels. Finally, we evaluate evidence regarding the contribution of HPV to the physiological and pathophysiological processes involved in the transition from fetal to neonatal life, pulmonary gas exchange, high-altitude pulmonary edema, and pulmonary hypertension. Although understanding of HPV has advanced significantly, major areas of ignorance and uncertainty await resolution.

Pulmonary hypertension secondary to interstitial lung disease

Interstitial lung diseases (ILDs) may be complicated by the development of pulmonary hypertension (PH), which is associated with worse functional impairment and a poorer prognosis. This article reviews the current state of knowledge on the prevalence, pathogenesis, diagnosis and prognosis of ILD-related PH. Whether the treatment of ILD-related PH changes clinical outcomes is currently unknown, but the current studies are summarized and the authors' perspective is offered.

Sarcoidosis-associated pulmonary hypertension: Clinical features and outcomes in Arab patients

BACKGROUND:

Pulmonary hypertension (PH) occurs in many patients with interstitial lung disease, including sarcoidosis. We explored the frequency, clinical characteristics and outcomes of PH in Arab patients diagnosed with pulmonary sarcoidosis.

METHODS:

A retrospective study in three tertiary hospitals was performed on 96 patients who underwent Doppler echocardiography. Demographic and clinical characteristics, physiological studies and computed tomography (CT) results were collected, and compared between patients with and without PH.

RESULTS:

Twenty (20.8%) patients were found to have PH. Patients with PH were more likely to be symptomatic (cough, P = 0.008; dyspnea, P = 0.04), to have an advanced radiographic stage (P = 0.001), and to be receiving systemic therapy (P = 0.001), compared to those without PH. Physiological data including pulmonary function test parameters, arterial blood gas levels and oxygen saturation at rest and after exercise were all significantly lower in patients with PH compared to those without PH. Comparison of CT patterns between patients with and without PH showed significant differences in the frequencies of ground-glass opacity (61.5 vs. 28.8%, P = 0.032) and fibrosis (76.9 vs. 44.2%, P = 0.035). In total, four patients died during the study period, including three with evidence of PH.

CONCLUSIONS:

The frequency of PH in the present study was 20.8%. Clinical, physiologic and radiographic characteristics appeared to differentiate patients with PH from those without PH. The presence of PH contributed to poor outcomes in patients with pulmonary sarcoidosis.