Pulmonary hypertension in interstitial lung disease: Prevalence, prognosis and 6 min walk test

Interstitial lung disease in rheumatic diseases: an update of the 2018 review

INTRODUCTION

Interstitial lung disease (ILD) is a potential severe complication of various rheumatic diseases, typically connective tissue diseases (CTD), associated with significant morbidity and mortality. ILD may occur during the course of the disease but may also be its first manifestation. Several cell types are involved in ILD's pathogenesis, and if not controlled, pulmonary inflammation may lead to pulmonary fibrosis.

AREAS COVERED

We searched PubMed, Medline, and the Cochrane Library for papers published between 1995 and February 2017 in the first version, and between 2017 and April 2023 using combinations of words. The most frequent systemic rheumatic diseases associated with ILD are systemic sclerosis (SSc), rheumatoid arthritis (RA), and idiopathic inflammatory myositis. Treatment and monitoring guidelines are still lacking, and current treatment strategies have been extrapolated from the literature on SSc and established treatments for non-pulmonary systemic rheumatic manifestations.

EXPERT OPINION

Given the complexity of diagnosis and the paucity of treatment trials, managing CTD patients with ILD is challenging. It requires the skills of multidisciplinary CTD-ILD clinics including at least rheumatologists and lung specialists.

A PrOsPective Cohort Study on Interstitial Lung Disease-Associated Pulmonary Hypertension with a ParticulaR Focus on the Subset with Pulmonary Arterial Hypertension Features (POPLAR Study)

INTRODUCTION

The pathogenesis and clinical profiles of patients with pulmonary hypertension (PH) associated with interstitial lung disease (ILD-PH) are poorly understood. Whether and to what extent pulmonary arterial hypertension (PAH)-specific therapy improves hemodynamic and outcome in ILD-PH are also unknown.

STUDY OBJECTIVE

This study aims to clarify the characteristics, clinical course and response to PAH-specific therapy of ILD and/or PH by enrolling three unique subsets: PAH, ILD-PH, and ILD.

METHODS

The proposed study is a retrospective and prospective, multi-centre, observational cohort study of patients treated at any of three university hospitals in the Hokkaido region of Japan who have any one of the following: PAH; ILD-PH with or without PAH features; or ILD without PH. We aim to enrol 250 patients in total. For the retrospective observation period, data obtained after 1 January 2010, will be analysed, and the prospective observation period will be 1 year. We will compare the clinical data of patients with ILD-PH with those of patients with PAH and those of patients with ILD without PH in the real-world clinical setting. In addition, within the cohort of patients with ILD-PH, we will explore the subset with "ILD-PH with PAH features" and compare the response to PAH-specific therapy with that of PAH. The primary outcome will be the change in pulmonary vascular resistance from first treatment to follow-up in patients with PAH and ILD-PH with PAH features (excluding ILD-PH without PAH feature and ILD-no-PH for the primary outcome). The exploratory outcomes will include analyses of PH-associated biomarkers, right ventricular function and patient-reported outcomes.

RESULTS

This is a protocol article and the results will be presented after data collection is completed.

CONCLUSION

The POPLAR study will provide data that help better understand the pathophysiology of ILD-PH and improve the quality of life and outcome of patients with PH and/or ILD.

TRIAL REGISTRATION

Japan Registry of Clinical Trials: jRCT1010230018.

Pulmonary Hypertension in Interstitial Lung Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Pulmonary hypertension (PH) is a key complication in interstitial lung disease (ILD), with recent therapeutic advances.

RESEARCH QUESTION

What are the diagnostic evaluation, epidemiologic features, associated factors, prognostic significance, and outcome measures in interventional trials for PH in patients with ILD in the current literature?

STUDY DESIGN AND METHODS

Ovid MEDLINE, Embase, and CENTRAL databases were searched for original research evaluating PH in participants with ILD of any cause. The definition of PH was based on the investigators' criteria.

RESULTS

Three hundred two studies were included, with varying diagnostic evaluations used to define PH. Commonly used diagnostic tests were right heart catheterization (RHC; 56%) and transthoracic echocardiography (TTE; 50%). The pooled prevalence for PH in general populations with ILD was 36% (95% CI, 30%-42%) using RHC and 34% (95% CI, 29%-38%) using TTE. Lower diffusion capacity of the lungs for carbon monoxide, worse oxygenation status, reduced exercise capacity, increased pulmonary artery to aorta ratio and pulmonary artery diameter, and elevated serum brain natriuretic peptide consistently were associated with the presence of PH in at least 60% of reported studies. The presence of PH was associated with increased symptom burden and worse prognosis. Outcome measures in interventional trials of PH in ILD focused on changes in pulmonary vascular hemodynamics and 6-min walk distance.

INTERPRETATION

PH is a common complication in ILD with significant health impacts. A standardized definition with prospective evaluation of risk-stratified assessments for PH using identified associated risk factors is warranted. Our findings provide an evidence base for validation as surrogate end points in future PH interventional trials in ILD.

TRIAL REGISTRY

International Prospective Register of Systematic Reviews; No.: CRD42021255394; URL: https://www.crd.york.ac.uk/prospero/.

Unmasking a Silent Threat: Improving Pulmonary Hypertension Screening Methods for Interstitial Lung Disease Patients

This article provides a comprehensive overview of the latest literature on the diagnostics and treatment of pulmonary hypertension (PH) associated with interstitial lung disease (ILD). Heightened suspicion for PH arises when the advancement of dyspnoea in ILD patients diverges from the expected pattern of decline in pulmonary function parameters. The complexity of PH associated with ILD (PH-ILD) diagnostics is emphasized by the limitations of transthoracic echocardiography in the ILD population, necessitating the exploration of alternative diagnostic approaches. Cardiac magnetic resonance imaging (MRI) emerges as a promising tool, offering insights into hemodynamic parameters and providing valuable prognostic information. The potential of biomarkers, alongside pulmonary function and cardiopulmonary exercise tests, is explored for enhanced diagnostic and prognostic precision. While specific treatments for PH-ILD remain limited, recent studies on inhaled treprostinil provide new hope for improved patient outcomes.

Pulmonary hypertension associated with lung disease: new insights into pathomechanisms, diagnosis, and management

Patients with chronic lung diseases, particularly interstitial lung disease and chronic obstructive pulmonary disease, frequently develop pulmonary hypertension, which results in clinical deterioration, worsening of oxygen uptake, and an increased mortality risk. Pulmonary hypertension can develop and progress independently from the underlying lung disease. The pulmonary vasculopathy is distinct from that of other forms of pulmonary hypertension, with vascular ablation due to loss of small pulmonary vessels being a key feature. Long-term tobacco exposure might contribute to this type of pulmonary vascular remodelling. The distinct pathomechanisms together with the underlying lung disease might explain why treatment options for this condition remain scarce. Most drugs approved for pulmonary arterial hypertension have shown no or sometimes harmful effects in pulmonary hypertension associated with lung disease. An exception is inhaled treprostinil, which improves exercise capacity in patients with interstitial lung disease and pulmonary hypertension. There is a pressing need for safe, effective treatment options and for reliable, non-invasive diagnostic tools to detect and characterise pulmonary hypertension in patients with chronic lung disease.

Long-term inhaled treprostinil for pulmonary hypertension due to interstitial lung disease: INCREASE open-label extension study

INTRODUCTION

The 16-week randomised, placebo-controlled INCREASE trial (RCT) met its primary end-point by improving 6-min walk distance (6MWD) in patients receiving inhaled treprostinil for pulmonary hypertension due to interstitial lung disease (PH-ILD). The open-label extension (OLE) evaluated long-term effects of inhaled treprostinil in PH-ILD.

METHODS

Of 258 eligible patients, 242 enrolled in the INCREASE OLE and received inhaled treprostinil. Assessments included 6MWD, pulmonary function testing, N-terminal pro-brain natriuretic peptide (NT-proBNP), quality of life and adverse events. Hospitalisations, exacerbations of underlying lung disease and death were recorded.

RESULTS

At INCREASE OLE baseline, patients had a median age of 70 years and a mean 6MWD of 274.2 m; 52.1% were male. For the overall population, the mean 6MWD at week 52 was 279.1 m and the mean change from INCREASE RCT baseline was 3.5 m (22.1 m for the prior inhaled treprostinil arm and -19.5 m for the prior placebo arm); the median NT-proBNP decreased from 389 pg·mL-1 at RCT baseline to 359 pg·mL-1 at week 64; and the absolute (% predicted) mean forced vital capacity change from RCT baseline to week 64 was 51 mL (2.8%). Patients who received inhaled treprostinil versus placebo in the RCT had a 31% lower relative risk of exacerbation of underlying lung disease in the OLE (hazard ratio 0.69 (95% CI 0.49-0.97); p=0.03). Adverse events leading to drug discontinuation occurred in 54 (22.3%) patients.

CONCLUSIONS

These results support the long-term safety and efficacy of inhaled treprostinil in patients with PH-ILD, and are consistent with the results observed in the INCREASE RCT.

Diagnosis and Management of Myositis-Associated Lung Disease

Although interstitial lung disease (ILD) is a leading cause of morbidity and mortality in patients with inflammatory myopathies, the current definition and diagnostic criteria of autoimmune myositis remain inadequate to capture the large proportion of patients with lung-dominant disease. As a result, these patients present unique diagnostic and treatment challenges for even the most experienced clinicians. This article highlights the emerging role of autoantibodies in the diagnosis, classification, and management of patients with ILD. We propose alternative nomenclature to facilitate research on this unique patient population. Additionally, evidence supporting the various therapies used in the treatment of myositis-associated ILD is reviewed. The classification and treatment of patients with myositis-associated ILD remains challenging. A standardized therapeutic approach to these patients is lacking, and prospective studies in the field are needed to determine optimal treatment regimens.

Unmet needs and perspectives in rheumatoid arthritis-associated interstitial lung disease: A critical review

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by synovitis as the most common clinical manifestation, and interstitial lung disease (RA-ILD) represents one of the most common and potentially severe extra-articular features. Our current understanding of the mechanisms and predictors of RA-ILD is limited despite the demonstration that an early identification of progressive fibrosing forms is crucial to provide timely treatment with antifibrotic therapies. While high resolution computed tomography is the gold standard technique for the diagnosis and follow-up of RA-ILD, it has been hypothesized that serum biomarkers (including novel and rare autoantibodies), new imaging techniques such as ultrasound of the lung, or the application of innovative radiologic algorithms may help towards predicting and detecting early forms of diseases. Further, while new treatments are becoming available for idiopathic and connective tissue disease-associated forms of lung fibrosis, the treatment of RA-ILD remains anecdotal and largely unexplored. We are convinced that a better understanding of the mechanisms connecting RA with ILD in a subgroup of patients as well as the creation of adequate diagnostic pathways will be mandatory steps for a more effective management of this clinically challenging entity.

Echocardiographic Characteristics of Patients with Anti‐synthetase Syndrome

Right ventricular (RV) dysfunction and pulmonary hypertension (PH) occurs in approximately one‐third of patients with interstitial lung disease (ILD) and is associated with reduced 6‐minute walk distance (6MWD), and increased hospitalizations and mortality. Although the impact of RV dysfunction and PH has been well described in several types of ILD, data is scarce on antisynthetase syndrome. Therefore, we sought to examine the presence of RV dysfunction and PH in patients with antisynthetase syndrome and the impact on clinical outcomes. We conducted a retrospective study of patients with antisynthetase syndrome. Seventy‐five subjects were identified. Fifty‐one (68%) subjects had echocardiographic data. Patients were grouped into those with normal fractional area change (FAC) ≥ 35% and reduced FAC < 35%. Clinical, echocardiographic, and right heart catheterization data were compared between the two groups. Subjects with FAC < 35% had lower diffusion capacity of the lung for carbon monoxide (29% vs. 47%, p = 0.004), fibrotic features on computed tomography of the chest (79% vs. 33%, p = 0.005), larger RV diameter (5.4 vs. 3.9 cm, p < 0.001), higher right atrial pressures (8 vs. 5 mmHg, p = 0.02), and required supplemental oxygen more frequently (100% vs. 44%, p < 0.001) compared to those with FAC ≥ 35%. We found no difference in 6MWD and hospitalizations between the two groups. The presence of RV dysfunction in antisynthetase syndrome may identify patients at risk of poor outcomes.

Risk assessment in interstitial lung disease: the incremental prognostic value of cardiopulmonary ultrasound

Background

The mortality risk of chronic interstitial lung disease (ILD) is currently assessed using the ILD-GAP score. The present study evaluates whether the addition of cardiopulmonary ultrasound parameters to the ILD-GAP score can further improve the predictive value of ILD-GAP.

Methods

Medical records from 91 patients with ILD hospitalized from June 2015 to March 2016 were retrospectively examined. The Lung ultrasound (LUS) score, right ventricular (RV) function, and mechanics were obtained from the cardiopulmonary ultrasound. The ILD-GAP score was calculated from demographic characteristics and pulmonary function parameters. Patients were followed up with until May 2020. The primary endpoint was all-cause death.

Results

After exclusions, 74 patients with ILD were included in the analysis. During the follow-up period, 36 patients with ILD survived (ILD_s), and 38 patients died (ILD_d). Compared to ILD_s, the ILD_d cases exhibited a higher number of B-lines, LUS score, and RV end-diastolic base dimension (RVD), but lower RV function. In multivariate analysis, the ILD-GAP score (hazard ratio, 2.88; 95% CI 1.38–5.99, P = 0.005), LUS score (hazard ratio 1.13; 95% CI 1.04–1.24, P = 0.006), and RVD (hazard ratio 1.09, 95% CI 1.03–1.16, P = 0.004) were significantly related to the risk of death. Adding the LUS score and RVD to the ILD-GAP score significantly improved the predictive value compared to the ILD-GAP score alone (C statistics 0.90 vs 0.76, P = 0.018).

Conclusion

We investigated the utility of a new prognostic model for ILD that includes both cardiopulmonary ultrasound parameters (LUS score and RVD) and the ILD-GAP score. This model better reflects the severity of pulmonary fibrosis and cardiac involvement, and has incremental predictive value over the ILD-GAP score alone.

Management and support of patients with fibrosing interstitial lung diseases

ABSTRACT

Fibrosing interstitial lung diseases have a variable clinical course. Regular monitoring is important to assess disease progression and inform patient care and counseling. NPs play a key role in helping patients understand their disease and its treatment and manage the adverse reactions of pharmacologic therapies.

Impact of post-capillary pulmonary hypertension on mortality in interstitial lung disease

BACKGROUND

Pulmonary hypertension (PH) influences mortality in patients with interstitial lung disease (ILD). Almost all studies on patients with ILD, have focused on the clinical impact of pre-capillary PH on survival. Therefore, little is known about the influence of post-capillary PH. We aimed to assess the prevalence of post-capillary PH and its clinical impact on survival in patients with ILD, followed by comparison with pre-capillary PH.

METHODS

This retrospective study enrolled 1152 patients with ILD who were diagnosed with PH using right heart catheterization between May 2007 and December 2015. We analyzed the demographics and composite outcomes (defined as death from any cause or lung transplantation) of patients with post-capillary PH and compared them with patients with pre-capillary PH.

RESULTS

Thirty-two (20%) of the 157 patients with ILD-PH were diagnosed with post-capillary PH. Patients with post-capillary PH had significantly lower modified Medical Research Council scores, higher diffusion capacity for carbon monoxide, higher resting PaO₂, lower pulmonary vascular resistance (PVR), and higher lowest oxygen saturation during the 6-min walk test compared to those with pre-capillary PH. Cardiovascular diseases were associated with a higher risk of mortality in patients with post-capillary PH. Multivariate Cox proportional hazards analysis demonstrated no significant difference between the composite outcomes in pre-capillary and post-capillary PH, while PVR and the ILD Gender-Age-Physiology Index were significantly associated with the composite outcome.

CONCLUSIONS

We found that approximately one-fifth of patients with ILD-PH were diagnosed with post-capillary PH, and that PVR and not post-capillary PH was associated with mortality.

Computed tomography appearances of the lung parenchyma in pulmonary hypertension

Computed tomography (CT) is a valuable tool in the workup of patients under investigation for pulmonary hypertension (PH) and may be the first test to suggest the diagnosis. CT parenchymal lung changes can help to differentiate the aetiology of PH. CT can demonstrate interstitial lung disease, emphysema associated with chronic obstructive pulmonary disease, features of left heart failure (including interstitial oedema), and changes secondary to miscellaneous conditions such as sarcoidosis. CT also demonstrates parenchymal changes secondary to chronic thromboembolic disease and venous diseases such as pulmonary venous occlusive disease (PVOD) and pulmonary capillary haemangiomatosis (PCH). It is important for the radiologist to be aware of the various manifestations of PH in the lung, to help facilitate an accurate and timely diagnosis. This pictorial review illustrates the parenchymal lung changes that can be seen in the various conditions causing PH.

Pulmonary hypertension in patients with interstitial pneumonia with autoimmune features

Pulmonary hypertension in interstitial lung diseases is associated with increased mortality and hospitalizations and reduced exercise capacity. Interstitial pneumonia with autoimmune features (IPAF) is a recently described interstitial lung disease. The characteristics of pulmonary hypertension in IPAF patients are unknown. We sought to characterize patients with IPAF based on their echocardiographic probability of pulmonary hypertension and compare patients with and without pulmonary hypertension identified by right heart catheterization. We conducted a retrospective study of patients seen in the interstitial lung disease clinic from 2015 to 2018. Forty-seven patients with IPAF were identified. Patients were classified into low, intermediate and high echocardiographic pulmonary hypertension probabilities. A sub-group analysis of patients with pulmonary hypertension and without pulmonary hypertension (IPAF-PH vs. IPAF-no PH) identified by right heart catheterization was also performed. Linear regression analysis was performed to study the association between 6-min-walk-distance (6MWD) and pulmonary vascular resistance (PVR) while adjusting for age and body mass index. Right ventricular hypertrophy (>5 mm), right ventricular enlargement (>41 mm) and right ventricular systolic dysfunction defined as fractional area change% ≤35 was present in 76%, 24%, and 39% of patients, respectively. Pulmonary hypertension was identified in 12.7% of patients. IPAF-PH patients had higher mean pulmonary artery pressure and lower cardiac output compared to the IPAF-no PH group (34 mmHg vs. 19 mmHg, p = 0.002 and 4.0 vs. 5.7 L/min, p = 0.023, respectively). Lower 6MWD was associated with higher PVR on regression analysis (p = 0.002). Pulmonologists should be aware that a significant number of IPAF patients may develop pulmonary hypertension. Reduced 6MWD may suggest the presence of pulmonary hypertension in IPAF patients.

Study of cognitive functions in major idiopathic interstitial pneumonias

Background

Cognitive dysfunction in idiopathic interstitial pneumonia (IIP) is an important clinical co-morbidity that is associated with impaired lung function. The aim of the work is to assess cognitive function in major IIP and to find out the relation between cognitive dysfunction and the oxygenation parameters.

Results

Fifty individuals were involved in the study; 30 patients with major IIP and 20 healthy individuals. Patients with IIP had significantly lower mini mental state examination (MMSE) score compared to the control group (P < 0.001). Wechsler Deterioration Index (WDI) revealed that 33.3% (n = 10) of the patients with IIP had sure cognitive impairment and 26.6% (n = 8) had ongoing cognitive deterioration. Patients with idiopathic pulmonary fibrosis (IPF) had lower cognitive function than other IIP.

Conclusion

There is an impairment of cognitive function in patients with major IIP, particularly in IPF, as measured by WDI and MMSE. Further large studies are needed to assess the possible predictors of cognitive impairment and their effects on the patients’ outcome.

Automated CT Analysis of Major Forms of Interstitial Lung Disease

This study aimed to determine diagnostic and prognostic differences in major forms of interstitial lung disease using quantitative CT imaging. A retrospective study of 225 subjects with a multidisciplinary diagnosis of idiopathic pulmonary fibrosis (IPF), interstitial pneumonia with autoimmune features (IPAF), connective tissue disease (CTD), or chronic hypersensitivity pneumonitis (cHP) was conducted. Non-contrast CT scans were analyzed using the Computer Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER) program. Resulting data were analyzed statistically using ANOVA and Student’s t-test. Univariate, multivariable, and receiver operating characteristic analyses were conducted on patient mortality data. CALIPER analysis of axial distribution on CT scans in those with IPF demonstrated greater peripheral volumes of reticulation than either CTD (p = 0.033) or cHP (p = 0.007). CTD showed lower peripheral ground-glass opacity than IPF (p = 0.005) and IPAF (p = 0.004). Statistical analysis of zonal distributions revealed reduced lower zone ground-glass opacity in cHP than IPF (p = 0.044) or IPAF (p = 0.018). Analysis of pulmonary vascular-related structure (VRS) volume by diagnosis indicated greater VRS volume in IPF compared to CTD (p = 0.003) and cHP (p = 0.003) as well as in IPAF compared to CTD (p = 0.007) and cHP (p = 0.007). Increased reticulation (p = 0.043) and ground glass opacity (p = 0.032) were predictive of mortality on univariate analysis. Increased pulmonary VRS volume was predictive of mortality (p < 0.001) even after multivariate analysis (p = 0.041). Quantitative CT imaging revealed significant differences between ILD diagnoses in specific CT findings in axial and, to a lesser degree, zonal distributions. Increased pulmonary VRS volume seems to be associated with both diagnosis and survival.

Exercise Pathophysiology in Interstitial Lung Disease

Interstitial lung disease (ILD) is a heterogeneous group of disorders that primarily affect the lung parenchyma. Patients with ILD have reduced lung volumes, impaired pulmonary gas exchange, and decreased cardiovascular function. These pathologic features of ILD become exacerbated during physical exertion, leading to exercise intolerance and abnormally high levels of exertional dyspnea. In this review, the authors summarize the primary pathophysiologic features of patients with ILD and their effect on the integrative response to exercise.

Remodeling of the pulmonary artery in idiopathic pleuroparenchymal fibroelastosis

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare subtype of idiopathic interstitial pneumonia that consists of alveolar septal elastosis and intra-alveolar collagenosis, which is predominantly located in the upper lobes. The aim of this study was to examine the remodeling of the pulmonary arteries in patients with IPPFE. This study included 18 patients with IPPFE, 24 patients with idiopathic pulmonary fibrosis (IPF), and 5 patients without pulmonary disease as controls. We selected muscular pulmonary arteries and calculated the percentage of the thickness of each layer of the wall (intima, media, and adventitia) in relation to the external diameter. We also quantified the percentage of areas of elastic fiber in the media divided by the whole area of the media (medial elastic fiber score). The percentage of adventitial thickness in IPPFE was significantly higher than that in IPF and in control lungs. The percentage of medial thickness did not differ statistically between IPPFE and IPF. However, the medial elastic fiber score in IPPFE was also significantly larger than that in IPF and control lungs. These results suggest that collagenous thickening of the adventitia and medial elastosis are distinct histological features in the muscular pulmonary arteries of patients with IPPFE.

Acute Respiratory Failure in Interstitial Lung Disease Complicated by Pulmonary Hypertension

Interstitial lung disease represents a group of diffuse parenchymal lung diseases with overwhelming morbidity and mortality when complicated by acute respiratory failure. Recently, trials investigating outcomes and their determinants have provided insight into these high mortality rates. Pulmonary hypertension is a known complication of interstitial lung disease and there is high prevalence in idiopathic pulmonary fibrosis, connective tissue disease, and sarcoidosis subtypes. Interstitial lung disease associated pulmonary hypertension has further increased mortality with acute respiratory failure, and there is limited evidence to guide management. This review describes investigations and management of interstitial lung disease associated acute respiratory failure complicated by pulmonary hypertension. Despite the emerging attention on interstitial lung disease associated acute respiratory failure and the influence of pulmonary hypertension, critical care management remains a clinical and ethical challenge.

Clinical Retrospective Analysis of Interstitial Lung Disease Patients Associated with Pulmonary Hypertension

BACKGROUND Pulmonary hypertension is a common complication of interstitial lung disease. This study was conducted to retrospectively analyze the incidence of pulmonary hypertension among interstitial lung disease patients and the correlation between systolic pulmonary artery pressure (PASP) and pulmonary functions. We also intended to investigate whether antinuclear antibody (ANA) could be an effective indicator of pulmonary hypertension. MATERIAL AND METHODS There were 182 patients diagnosed with interstitial lung disease through high-resolution computed tomography (HRCT). Pulmonary hypertension was defined as an increase of mean pulmonary arterial pressure (PAPm) ≥25 mmHg (~PASP ≥40 mmHg) at rest. Severe pulmonary hypertension was defined as PAPm ≥35 mmHg. There were 104 cases including in this study. There were 67 cases from the ANA positive (ANA+) group and 37 cases from the ANA negative (ANA-) group. All study patients had pulmonary function tests, which included the measurements of maximal voluntary ventilation (MVV), residual volume (RV), total lung capacity (TLC), forced expiratory volume (FVC), vital capacity (VC), and diffusing capacity of the lungs for carbon monoxide (DLCO). RESULTS The pulmonary hypertension incidence in the study cohort was 25%, and the severe pulmonary hypertension incidence was 6.48%. The incidence of pulmonary hypertension in ANA+ cases was 22.22%. The incidence of pulmonary hypertension in the ANA- cases was 32.14%. The lung function test results showed moderate relationships between DLCO, FVC%, VC%, and PASP; no relationship between MVV, FEV1/FVC%, RV/TLC, and PASP; minimum relationship between FVC%, VC%, and PASP in the ANA+ group; and moderate relationship between FVC%, VC%, and PASP in the ANA- group. CONCLUSIONS Pulmonary hypertension occurred in 25% of the 182 interstitial lung disease patients and was negatively associated with deteriorated lung functions (specifically VC%, FVC%, and DLCO parameters). ANA level was not associated with the prognosis of pulmonary hypertension of patients with interstitial lung disease, and it did not significantly affect the correlation between PASP and pulmonary functions. Thus, ANA level did not seem to be a necessary indicator of pulmonary hypertension, and a more effective treatment method for pulmonary hypertension of patients with interstitial lung disease is urgently needed.

Progression of right ventricular dysfunction and predictors of mortality in patients with idiopathic interstitial pneumonias

BACKGROUND

Few studies have examined the relationship between echocardiographic indices of right ventricular (RV) function and the severity of pulmonary disease, or their prognostic impact. We evaluated the RV function in patients with interstitial pneumonia and its prognostic impact at each stage of disease severity.

METHOD

A total of 176 patients with idiopathic interstitial pneumonias (IIPs) were retrospectively enrolled and we evaluated RV function by transthoracic echocardiography. The severity of IIPs was graded according to the Goh score. The primary outcome was all-cause death.

RESULTS

There were 55 patients in mild group (31%), 66 in moderate group (38%), and 55 in severe group (31%). Regarding RV function, RV free wall longitudinal strain and tricuspid annular plane systolic excursion (TAPSE) deteriorated with increasing severity of IIPs, but fractional area change (FAC) decreased significantly only in severe group. There were 64 all-cause deaths during the follow-up period (median 908 days). In moderate group, TAPSE [hazard ratio (HR): 0.85, 95% confidence interval (CI): 0.74-0.97, p=0.017], FAC (HR: 0.89, 95% CI: 0.83-0.96, p=0.001), and mean pulmonary artery pressure (PAP)/cardiac output (HR: 1.50, 95% CI: 1.08-2.09, p=0.015) were independent predictors of all-cause death, even after adjusting for age and log brain natriuretic peptide (BNP). On the other hand, not RV function or PAP but male sex and BNP level were associated with mortality in severe group.

CONCLUSIONS

Among patients with IIPs, RV longitudinal function deteriorated with increasing severity of IIPs. Echocardiographic indices of RV function were independently associated with mortality in moderate-stage IIPs.

Pulmonary hypertension secondary to respiratory disease and/or hypoxia in dogs: Clinical features, diagnostic testing and survival

Pulmonary hypertension (PH) is associated with substantial morbidity and if untreated, mortality. The human classification of PH is based on pathological, hemodynamic characteristics, and therapeutic approaches. Despite being a leading cause of PH, little is known about dogs with respiratory disease and/or hypoxia (RD/H)-associated PH. Therefore, our objectives were to retrospectively describe clinical features, diagnostic evaluations, final diagnoses and identify prognostic variables in dogs with RD/H and PH. In 47 dogs identified with RD/H and PH, chronic airway obstructive disorders, bronchiectasis, bronchiolar disease, emphysema, pulmonary fibrosis, neoplasia and other parenchymal disorders were identified using thoracic radiography, computed tomography, fluoroscopy, tracheobronchoscopy, bronchoalveolar lavage, and histopathology. PH was diagnosed using transthoracic echocardiography. Overall median survival was 276.0 days (SE, 95% CI; 216, 0-699 days). Dogs with an estimated systolic pulmonary arterial pressure (sPAP) ≥47mmHg (n=21; 9 days; 95% CI, 0-85 days) had significantly shorter survival times than those <47mmHg (n=16; P=0.001). Estimated sPAP at a cutoff of ≥47mmHg was a fair predictor of non-survival with sensitivity of 0.78 (95% CI, 0.52-0.94) and specificity of 0.63 (95% CI, 0.38-0.84). Phosphodiesterase-5 (PDE5) inhibitor administration was the sole independent predictor of survival in a multivariable analysis (hazard ratio: 4.0, P=0.02). Canine PH is present in a diverse spectrum of respiratory diseases, most commonly obstructive disorders. Similar to people, severity of PH is prognostic in dogs with RD/H and PDE5 inhibition could be a viable therapy to improve outcome.

Secondary pulmonary arterial hypertension: to treat or not to treat?

PURPOSE OF REVIEW

The purpose of this review is to review recent literature related to mechanisms and treatment options for 'secondary' (i.e., WHO Groups 3 and 5) pulmonary arterial hypertension (PAH).

RECENT FINDINGS

Published randomized controlled trials, in general, do not support the use of approved therapies for 'primary' (i.e., WHO Group 1) PAH patients in patients with Group 3 PAH because of the small numbers of patients and inconsistent benefit. Therefore, we currently recommend against the use of these medications for Group 3 PAH. Similarly, there is limited evidence supporting the use of Group 1 PAH medications in Group 5 patients. In most patients with Group 5 PAH, treatment should be directed to the underlying disease.

SUMMARY

The utility of PAH-specific therapy in WHO Group 3 PAH is unclear because of the small numbers of patients evaluated and inconsistent beneficial effects observed. There is limited evidence supporting the use of PAH medications in Group 5 patients, and they may be harmful in some cases.

Imaging of Pulmonary Hypertension: Pictorial Essay

Pulmonary hypertension (PH) is an end result of a diverse array of complex clinical conditions that invoke hemodynamic and pathophysiological changes in the pulmonary vasculature. Many patients' symptoms begin with dyspnea on exertion for which screening tests such as chest roentgenograms and more definitive noninvasive tests such as CT scans are ordered initially. It is imperative that clinicians are cognizant of subtle clues on these imaging modalities that alert them to the possibility of PH. These clues may serve as a stepping stone towards more advanced noninvasive (echocardiogram) and invasive (right heart catheterization) testing. On the CT scan, the signs are classified into mediastinal and lung parenchymal abnormalities. In addition to suspecting the diagnosis of PH, this paper provides a pictorial essay to guide health care professionals in identifying the etiology of PH. This paper also provides concrete definitions, wherever possible, of what constitutes abnormalities in PH, such as dilated pulmonary arteries, pruning of vessels, and increased thickness of free wall of the right ventricle. The sensitivities and specificities of each sign are enumerated. The common radiographic and clinical features of many different etiologies of PH are tabulated for the convenience of the readers. Some newer imaging modalities such as dual-energy CT of the chest that hold promise for the future are also described.

Six-minute walk distance and survival time in patients with idiopathic pulmonary fibrosis in Brazil

OBJECTIVE

To determine the cut-off point for the six-minute walk distance (6MWD) that indicates lower survival time in patients with idiopathic pulmonary fibrosis (IPF) in Brazil.

METHODS

This was retrospective study carried out in two referral centers for IPF. The 6MWT was performed twice, considering the highest value of the 6MWD. Various cut-off points were estimated, in absolute values and in percentage of predicted values, using ROC curves, the Kaplan-Meier method, and data from other studies.

RESULTS

The sample comprised 70 patients with IPF. The mean age was 71.9 ± 6.4 years, and 50 patients (71.4%) were male. The mean FVC was 76.6 ± 18.2% of predicted value. The mean SpO2 at rest before and after 6MWT were 93.8 ± 2.5% and 85.3 ± 6.5%, respectively. The median survival time was 44 months (95% CI: 37-51 months). The mean 6MWD was 381 ± 115 m (79.2 ± 24.0% of predicted). After the analyses, the best cut-off points for estimating survival were 6MWD < 330 m and < 70% of predicted. The median survival time of patients with a 6MWD < 330 m was 24 months (95% CI: 3-45 months), whereas that of those with a 6MWD ≥ 330 m was 59 months (95% CI: 41-77 months; p = 0.009). Similarly, the median survival times of those with a 6MWD < 70% and ≥ 70% of predicted, respectively, were 24 months (95% CI: 13-35 months) and 59 months (95% CI: 38-80 months; p = 0.013). Cox multivariate regression models including age, sex, smoking status, SpO2 at the end of the 6MWT, and FVC% showed that 6MWD remained significantly associated with survival (p = 0.003).

CONCLUSIONS

Values of 6MWD < 330 m and < 70% of predicted value were associated with lower survival time in IPF patients in Brazil.

Right ventricular function and dyssynchrony measured by echocardiography in dogs with precapillary pulmonary hypertension

INTRODUCTION

Assessment of the right ventricular (RV) function by echocardiography is important in dogs with pulmonary hypertension (PH). Few reports are available on RV function and dyssynchrony in dogs, especially in the context of precapillary PH.

ANIMALS

The study included 79 client-owned dogs: 25 dogs with precapillary PH and 54 control dogs.

METHODS

Dogs with precapillary PH were prospectively enrolled between December 2013 and February 2017. The echocardiographic indices of RV function, including RV strain and the dyssynchrony index by speckle-tracking echocardiography, were measured. Multivariate analysis was used to determine independent predictors of the RV dyssynchrony index.

RESULTS

Dogs with precapillary PH showed RV dilation, hypertrophy and right atrial dilation. Impaired echocardiographic indices of RV function, including RV strain, were observed. In addition, RV dyssynchrony occurred in dogs with precapillary PH. Multivariate analysis revealed that tricuspid regurgitation velocity and RV dilation were independent predictors of the RV dyssynchrony index.

CONCLUSIONS

Echocardiographic RV function indices are impaired in dogs with precapillary PH. In addition, RV dilation and elevated systolic pulmonary arterial pressure estimated by echocardiography are associated with RV dyssynchrony.

Management of Chronic Respiratory Failure in Interstitial Lung Diseases: Overview and Clinical Insights

Interstitial lung diseases (ILDs) may be complicated by chronic respiratory failure (CRF), especially in the advanced stages. Aim of this narrative review is to evaluate the current evidence in management of CRF in ILDs. Many physiological mechanisms underlie CRF in ILDs, including lung restriction, ventilation/perfusion mismatch, impaired diffusion capacity and pulmonary vascular damage. Intermittent exertional hypoxemia is often the initial sign of CRF, evolving, as ILD progresses, into continuous hypoxemia. In the majority of the cases, the development of CRF is secondary to the worsening of the underlying disease; however, associated comorbidities may also play a role. When managing CRF in ILDs, the need for pulmonary rehabilitation, the referral to lung transplant centers and palliative care should be assessed and, if necessary, promptly offered. Long-term oxygen therapy is commonly prescribed in case of resting or exertional hypoxemia with the purpose to decrease dyspnea and improve exercise tolerance. High-Flow Nasal Cannula oxygen therapy may be used as an alternative to conventional oxygen therapy for ILD patients with severe hypoxemia requiring both high flows and high oxygen concentrations. Non-Invasive Ventilation may be used in the chronic setting for palliation of end-stage ILD patients, although the evidence to support this application is very limited.

Pulmonary hypertension due to unclassified interstitial lung disease in a Pembroke Welsh corgi

A 12 year-old intact male Pembroke Welsh corgi weighing 10.8 kg was presented for evaluation of a 3-month history of dyspnea, and a 1-week history of exercise intolerance and anorexia. Severe hypoxemia (PaO₂ 56 mmHg), diffuse lung alveolar infiltration, and severe pulmonary hypertension (PH) (tricuspid regurgitation pressure gradient was 81 mmHg) were identified. A tentative diagnosis of severe PH due to lung disease or pulmonary thromboembolism was made and treated intensively. After 5 days of hospitalization, the dog died despite oxygen supplementation and anticoagulant therapy. This dog was diagnosed as unclassified interstitial lung disease based on histopathological findings.

Pulmonary hypertension in patients with interstitial lung disease

Interstitial lung diseases (ILDs) comprise a broad and heterogeneous group of more than two hundred diseases with common functional characteristics. Their diagnosis and management require a multidisciplinary approach. This multidisciplinary approach involves the assessment of comorbid conditions including pulmonary hypertension (PH) that exerts a dramatic impact on survival. The current World Health Organization (WHO) classification of PH encompasses many of the interstitial lung diseases into WHO Group 3, while sarcoidosis, Pulmonary Langerhans Cell Histiocytosis and lymphangioleiomyomatosis are placed into WHO Group 5 as diseases with unclear or multifactorial mechanisms. Connective tissue diseases could span any of the 5 WHO groups based on the primary phenotype into which they manifest. Interestingly, several challenging phenotypes present with features that overlap between two or more WHO PH groups. Currently, PH-specific treatment is recommended only for patients classified into WHO Group 1 PH. The lack of specific treatment for other groups, including PH in the setting of ILD, reflects the poor outcomes of these patients. Thus, identification of the optimal strategy for ILD patients with PH remains an amenable need. This review article provides a brief overview of biomarkers indicative of vascular remodeling in interstitial lung disease, summarizes the current state of knowledge regarding patients with PH and ILD and highlights future perspectives that remain to be addressed.

Pulmonary hypertension associated with lung diseases and hypoxemia

Pulmonary hypertension that develops in the setting of underlying lung diseases such as COPD or idiopathic pulmonary fibrosis (IPF) is associated with decreased functional status, worsening hypoxemia and quality of life, and increased mortality. This complication of lung disease is complex in its origin and carries a unique set of diagnostic and therapeutic issues. This review attempts to provide an overview of mechanisms associated with the onset of pulmonary hypertension in COPD and IPF, touches on appropriate evaluation, and reviews the state of knowledge on treating pulmonary hypertension related to underlying lung disease.

Pulmonary hypertension in childhood interstitial lung disease: A systematic review of the literature

Childhood interstitial lung disease (chILD) comprises a wide heterogeneous group of rare parenchymal lung disorders associated with substantial morbidity and mortality. Pulmonary hypertension is a common comorbidity in adults with interstitial lung disease (ILD) and associated with poor survival. We aimed to systematically review the literature regarding the occurrence of pulmonary hypertension (PH) in chILD, its effect on prognosis and healthcare use, and its treatment in clinical practice. Searches of PubMed and EMBASE databases (up to February 2016), and American Thoracic Society conference abstracts (2009-2015) were conducted using relevant keywords. References from selected articles and review papers were scanned to identify further relevant articles. A total of 20 articles were included; estimates of PH in chILD ranged from 1% to 64% with estimates among specific chILD entities ranging from 0% to 43%. Comparisons between studies were limited by differences in the study populations, including the size, age range, and heterogeneous composition of the ILD case series in terms of the nature and severity of the clinical entities, and also the methods used to diagnose PH. Three studies found that among patients with chILD, those with PH had a significantly higher risk (up to sevenfold) of death compared with those without PH. Information on the treatment of pulmonary hypertension in chILD or the effect of PH on healthcare use was not available. Data on the use and effectiveness of treatments for pulmonary hypertension in chILD are required to address this area of unmet need. Pediatr Pulmonol. 2017;52:689-698. © 2016 Wiley Periodicals, Inc.

Chronic use of PAH-specific therapy in World Health Organization Group III Pulmonary Hypertension: a systematic review and meta-analysis

Pulmonary hypertension (PH) complicating chronic obstructive pulmonary disease (COPD-PH) and interstitial lung disease (ILD-PH) (World Health Organization [WHO] Group III PH) increases medical costs and reduces survival. Despite limited data, many clinicians are using pulmonary arterial hypertension (PAH)-specific therapy to treat WHO Group III PH patients. To further investigate the utility of PAH-specific therapy in WHO Group III PH, we performed a systematic review and meta-analysis. Relevant studies from January 2000 through May 2016 were identified in the MEDLINE, EMBASE, and COCHRANE electronic databases and www.clinicaltrials.gov. Change in six-minute walk distance (6MWD) was estimated using random effects meta-analysis techniques. Five randomized controlled trials (RCTs) in COPD-PH (128 placebo or standard treatment and 129 PAH-medication treated patients), two RCTs in ILD-PH (23 placebo and 46 treated patients), and four single-arm clinical trials (50 patients) in ILD-PH were identified. Treatment in both COPD-PH and ILD-PH did not worsen hypoxemia. Symptomatic burden was not consistently reduced but there were trends for reduced pulmonary artery pressures and pulmonary vascular resistance with PAH-specific therapy. As compared to placebo, 6MWD was not significantly improved with PAH-specific therapy in the five COPD-PH RCTs (42.7 m; 95% confidence interval [CI], –1.0 – 86.3). In the four single-arm studies in ILD-PH patients, there was a significant improvement in 6MWD after PAH-specific treatment (46.2 m; 95% CI, 27.9–64.4), but in the two ILD-PH RCTs there was not an improvement (21.6 m; 95% CI, –17.8 – 61.0) in exercise capacity when compared to placebo. Due to the small numbers of patients evaluated and inconsistent beneficial effects, the utility of PAH-specific therapy in WHO Group III PH remains unproven. A future clinical trial that is appropriately powered is needed to definitively determine the efficacy of this widely implemented treatment approach.

Treatment of idiopathic pulmonary fibrosis: a position paper from a Nordic expert group

Idiopathic pulmonary fibrosis (IPF) is a fatal progressive lung disease occurring in adults. In the last decade, the results of a number of clinical trials based on the updated disease classification have been published. The registration of pirfenidone and nintedanib, the first two pharmacological treatment options approved for IPF, marks a new chapter in the management of patients with this disease. Other nonpharmacological treatments such as lung transplantation, rehabilitation and palliation have also been shown to be beneficial for these patients. In this review, past and present management is discussed based on a comprehensive literature search. A treatment algorithm is presented based on available evidence and our overall clinical experience. In addition, unmet needs with regard to treatment are highlighted and discussed. We describe the development of various treatment options for IPF from the first consensus to recent guidelines based on evidence from large-scale, multinational, randomized clinical trials, which have led to registration of the first drugs for IPF.

Pulmonary vascular and cardiac impairment in interstitial lung disease

Pulmonary vascular and cardiac impairment is increasingly appreciated as a major adverse factor in the natural history of interstitial lung disease. This clinically orientated review focuses on the current concepts in the pathogenesis, pathophysiology and implications of the detrimental sequence of increased pulmonary vascular resistance, pre-capillary pulmonary hypertension and right heart failure in interstitial lung disease, and provides guidance on its management.

Development of pulmonary hypertension is a major adverse factor in the natural history of interstitial lung diseasehttp://ow.ly/nJB0302XAmD

Can a Six-Minute Walk Distance Predict Right Ventricular Dysfunction in Patients with Diffuse Parenchymal Lung Disease and Pulmonary Hypertension?

OBJECTIVES

Pulmonary hypertension (PH) is commonly observed in patients with diffuse parenchymal lung disease (DPLD). The purpose of this study was to explore the influence of the 6-minute walk test (6MWT) as a simple, non-invasive tool to assess right ventricular (RV) function in patients with DPLD and to identify the need for an echocardiogram (ECHO) to screen for PH.

METHODS

We retrospectively reviewed 48 patients with PH secondary to DPLD, who were evaluated in the PH clinic at the Mayo Clinic in Jacksonville, Florida, from January 1999 to December 2014.

RESULTS

Fifty-two percent of patients had RV dysfunction. They had a significantly greater right heart pressure by ECHO and mean pulmonary arterial pressure (MPAP) from right heart catheterization (RHC) than those with normal RV function. A reduced 6-minute walk distance (6MWD) did not predict RV dysfunction (OR 0.995; 95% CI 0.980-1.001, p = 0.138). In addition, worsening restrictive physiology, heart rate at one-minute recovery and desaturation were not different between patients with and without RV dysfunction. However, there were inverse correlations between 6MWD and MPAP from RHC (r = -0.41, 
p = 0.010), 6MWD and RV systolic pressure (r = -0.51, p < 0.001), and 6MWD and MPAP measured by ECHO (r = -0.46, p =0.013). We also found no significant correlation between 6MWD and pulmonary function test parameters.

CONCLUSIONS

Our single-center cohort of patients with PH secondary to DPLD, PH was found to have an impact on 6MWD. In contrast to our expectations, 6MWD was not useful to predict RV dysfunction. Interestingly, a severe reduction in the 6MWD was related to PH and not to pulmonary function; therefore, it may be used to justify an ECHO to identify patients with a worse prognosis.

NT-proBNP <95 ng/l can exclude pulmonary hypertension on echocardiography at diagnostic workup in patients with interstitial lung disease

Background

Pulmonary hypertension (PH) is a serious complication to interstitial lung disease (ILD) and has a poor prognosis. PH is often diagnosed by screening with echocardiography followed by right heart catheterisation. A previous study has shown that a value of NT-pro-brain natriuretic peptide (NT-proBNP) <95 ng/l could be used to rule out PH in patients with ILD.

Aim

To evaluate this rule-out test for PH in a new cohort of incident patients with ILD.

Methods

An established database with data from 148 consecutive patients referred from January 2012 to October 2014 was used to identify patients and obtain data from echocardiography, NT-proBNP, diagnosis and lung function. Signs of PH on echocardiography were defined as a tricuspid pressure gradient (TR) ≥40 mmHg, decreased right ventricular systolic function or dilatation. Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of NT-proBNP >95 ng/l for signs of PH on echocardiography were calculated. The study was approved by the Danish Health Authority.

Results

In 118 patients, data from both echocardiography and measurements of NT-proBNP were available. Eleven of these were screened positive for PH on echocardiography. Sensitivity, specificity, NPV and PPV of NT-proBNP <95 ng/l for PH were 100, 44, 16 and 100%, respectively. Furthermore, no patients with left heart failure as the cause of dyspnoea were missed using this cut-off value.

Conclusion

NT-proBNP <95 ng/l precludes a positive echocardiographic screen for PH in ILD patients at referral for diagnostic workup.

Comorbidities in idiopathic pulmonary fibrosis patients: a systematic literature review

Idiopathic pulmonary fibrosis (IPF) is associated with a fatal prognosis and manifests in patients over 60 years old who may have comorbidities. The prevalence and impact of comorbidities on the clinical course of IPF is unclear.

This systematic literature review examined the prevalence of comorbidities and mortality associated with comorbidities in IPF patients. Relevant observational studies published in English from January 1990 to January 2015 identifiedviaMEDLINE and EMBASE were included; bibliographies of articles were also searched.

Among the 126 studies included, prevalence of pulmonary hypertension (PH) was 3–86%, 6–91% for obstructive sleep apnoea, 3–48% for lung cancer and 6–67% for chronic obstructive pulmonary disease (COPD). Nonrespiratory comorbidities included ischaemic heart disease (IHD) (3–68%) and gastro-oesophageal reflux (GER) (0–94%). Mortality was highest among patients with IPF and lung cancer. Most studies assessed relatively small samples of patients with IPF.

PH, COPD, lung cancer, GER and IHD are significant comorbidities; differences in IPF severity, case definitions and patient characteristics limited the comparability of findings. The identification and prompt treatment of comorbidities may have a clinically significant impact on overall outcome that is meaningful for patients with IPF.

Managing comorbidities in idiopathic pulmonary fibrosis

Major risk factors for idiopathic pulmonary fibrosis (IPF) include older age and a history of smoking, which predispose to several pulmonary and extra-pulmonary diseases. IPF can be associated with additional comorbidities through other mechanisms as either a cause or a consequence of these diseases. We review the literature regarding the management of common pulmonary and extra-pulmonary comorbidities, including chronic obstructive pulmonary disease, lung cancer, pulmonary hypertension, venous thromboembolism, sleep-disordered breathing, gastroesophageal reflux disease, coronary artery disease, depression and anxiety, and deconditioning. Recent studies have provided some guidance on the management of these diseases in IPF; however, most treatment recommendations are extrapolated from studies of non-IPF patients. Additional studies are required to more accurately determine the clinical features of these comorbidities in patients with IPF and to evaluate conventional treatments and management strategies that are beneficial in non-IPF populations.

Influence of Pulmonary Hypertension on Patients With Idiopathic Pulmonary Fibrosis Awaiting Lung Transplantation

BACKGROUND

The influence of varying levels of pulmonary hypertension (PH) on survival in idiopathic pulmonary fibrosis is not well defined.

METHODS

The United Network for Organ Sharing database was queried from 2005 to 2013 to identify first-time lung transplant candidates listed for lung transplantation who were tracked from waitlist entry date until death or censoring to determine the influence of PH on patients with advanced lung disease. Using data for right heart catheterization measurements, mild PH was defined as mean pulmonary artery pressure of 25 mm Hg or more, and severe as 35 mm Hg or more.

RESULTS

Of 6,657 idiopathic pulmonary fibrosis patients, 6,651 were used for univariate analysis, 6,126 for Kaplan-Meier survival function, 6,013 for multivariate Cox models, and 5,186 (mild PH) and 2,014 (severe PH) for propensity score matching, respectively. Univariate Cox proportional hazards analysis found significant differences in survival for mild PH (hazard ratio [HR] 1.689, 95% confidence interval [CI]: 1.434 to 1.988, p < 0.001) and severe PH (HR 2.068, 95% CI: 1.715 to 2.493, p < 0.001). Further assessment by multivariate Cox models identified significant risk for death for mild PH (HR 1.433, 95% CI: 1.203 to 1.706, p < 0.001) and severe PH (HR 1.597, 95% CI: 1.308 to 1.949, p < 0.001). Propensity score matching confirmed the risk for death for mild PH (HR 1.530, 95% CI: 1.189 to 1.969, p = 0.001) and severe PH (HR 2.103, 95% CI: 1.436 to 3.078, p < 0.001).

CONCLUSIONS

The manifestation of PH, even with mild severity, is associated with significantly increased risk for death among patients with idiopathic pulmonary fibrosis awaiting lung transplantation, so referral should be considered early in the disease course.

Outcome of patients with severe PH due to lung disease with and without targeted therapy

INTRODUCTION

Pulmonary hypertension (PH) can occur in patients with lung disease and worsen prognosis. Endothelin receptor antagonists, phosphodiesterase 5-inhibitors, and prostacyclin analogs, referred to as targeted therapy, have not been shown in a limited number of controlled clinical studies to improve exercise capacity in these patients. Possibly targeted therapy could be of benefit in patients with severe PH due to lung disease, but this subgroup is not well studied.

AIMS

To analyze influence of PH severity and use of targeted therapy on exercise capacity and survival in patients with PH due to lung disease.

METHODS

Consecutive patients with PH (mean pulmonary artery pressure ≥25 mmHg at rest) due to lung disease diagnosed by right heart catheterization between 1/2005 and 9/2011 were retrospectively included. Severe PH was defined as mean pulmonary artery pressure ≥35 mmHg. Patients were followed until 4/2012 for exercise capacity, survival, and targeted therapy use.

RESULTS

Patients with severe PH (n = 40) received significantly more often targeted therapy compared to the 32 patients with less severe PH (65% vs. 25%, P = 0.001). Survival was not significantly different between these groups (P = 0.310). Patients on targeted therapy were older, more often female, and had worse hemodynamic impairment, but significantly higher estimated 1-, 3-, and 5-year survival rates compared to untreated patients (97%, 81%, and 75% vs. 83%, 54%, and 19%, respectively; P = 0.002). This effect was mainly driven by the patients with severe PH, in whom the survival advantage was statistically significant on subgroup analysis (HR 0.182, P = 0.002). Exercise capacity was not significantly altered in any patient group.

CONCLUSION

Patients with severe PH due to lung disease may have a survival benefit from targeted therapy compared to untreated patients with less severe PH. Prospective clinical trials utilizing targeted therapy and long-term endpoints are justified in this patient group.

Use of pulmonary arterial hypertension-approved therapy in the treatment of non-group 1 pulmonary hypertension at US referral centers

Pulmonary hypertension (PH) is a frequent complication of left heart disease and parenchymal lung disease, and it portends increased mortality. A growing number of medications are approved for the treatment of World Health Organization (WHO) group 1 pulmonary arterial hypertension (PAH). However, they are not well studied in PH of other etiologies (WHO groups 2-5). We sought to assess treatment approaches used by PAH referral centers in this diverse group of patients. We developed a semiquantitative online survey designed to evaluate the use of PAH-approved therapy by pulmonary vascular disease centers in the United States for management of non-group 1 PH. Thirty of 50 centers completed the survey. Almost all centers (93%) reported using PAH therapy for patients with non-group 1 PH, including 77% with group 2 PH and 80% with group 3 PH. Elevated transpulmonary gradient or pulmonary vascular resistance and the presence of right ventricular (RV) dysfunction were commonly cited as supporting use of PAH therapy in patients with PH secondary to left heart disease. For patients with PH and concomitant parenchymal lung disease, degree of pulmonary function impairment and RV dysfunction were most important in influencing use of PAH therapy. In conclusion, pulmonary vascular disease treatment centers use PAH-approved therapy for patients with WHO group 2-5 PH, mostly relying on hemodynamics and assessment of RV function to identify candidates for therapy. Clinical trials designed to test the efficacy of PAH therapy in PH due to left heart and lung disease are needed, as clinical practice has extended beyond the evidence for these etiologies of PH.

Pulmonary vascular response patterns during exercise in interstitial lung disease

When overt pulmonary hypertension arises in interstitial lung disease (ILD), it contributes to exercise intolerance. We sought to determine the functional significance of abnormal pulmonary arterial pressure (PAP) responses to exercise in ILD.27 ILD patients and 11 age-matched controls underwent invasive cardiopulmonary exercise testing (iCPET). Mean PAP (mPAP) was indexed to cardiac output (Q'T) during exercise, with a mPAP-Q'T slope ≥3 mmHg·min·L(-1) defined as an abnormal pulmonary vascular response.All control subjects had mPAP-Q'T slopes <3 mmHg·min·L(-1) (mean±sem 1.5±0.1 mmHg·min·L(-1)). 15 ILD patients had mPAP-Q'T slopes ≥3 mmHg·min·L(-1) (4.1±0.2 mmHg·min·L(-1)) and were labelled as having ILD plus pulmonary vascular dysfunction (PVD). Subjects without pulmonary hypertension and with mPAP-Q´T slopes <3 mmHg·min·L(-1) (1.9±0. 2 mmHg·min·L(-1)) were labelled as ILD minus PVD (n=12). ILD+PVD and ILD-PVD patients did not differ in terms of age, sex, body mass index, pulmonary function testing or degree of exercise oxygen desaturation. Peak oxygen consumption was lower in ILD+PVD than in ILD-PVD (13.0±0.9 versus 17±1.1 mL·kg(-1)·min(-1), p=0.012) and controls (19.8±1.7 mL·kg(-1)·min(-1), p=0.003). ILD+PVD patients had increased dead space volume (VD)/tidal volume (VT) and minute ventilation/carbon dioxide production at the anaerobic threshold.In ILD, mPAP-Q'T slope ≥3 mmHg·min·L(-1) is associated with lower peak oxygen consumption, increased VD/VT and inefficient ventilation. While noninvasive parameters were unable to predict those with abnormal pulmonary vascular responses to exercise, iCPET-derived mPAP-Q'T slope may aid in identifying physiologically significant, early pulmonary vascular disease in ILD.