Prevalence and outcomes of pulmonary arterial hypertension in advanced idiopathic pulmonary fibrosis

Diagnostic and prognostic significance of serum angiopoietin-1 and -2 concentrations in patients with pulmonary hypertension

Several biomarkers for detecting pulmonary hypertension (PH) have been reported. However, these biomarkers are deemed insufficient to detect PH in its early stages. We evaluated the utility of serum angiopoietin (ANGP), a glycoprotein related to angiogenesis, as a diagnostic and prognostic biomarker of PH. Patients with PH who underwent right-heart catheterization, were retrospectively studied. Serum concentrations of ANGP-1 and ANGP-2 were measured using an enzyme-linked immunosorbent assay in patients with PH (n = 32), those with idiopathic pulmonary fibrosis (IPF) without PH (as a disease control, n = 75), and age-matched healthy controls (HC, n = 60). Nineteen patients (59.4%) with PH had World Health Organization group 3 PH. Serum ANGP-2 concentration, but not ANGP-1, in patients with PH was significantly higher compared with that in HC (p = 0.025) and in patients with IPF without PH (p = 0.008). Serum ANGP-2 concentration in patients with PH positively and significantly correlated with N-terminal pro-B-type natriuretic peptide (r = 0.769, p < 0.001), right ventricular diameter on echocardiography (r = 0.565, p = 0.035), and mean pulmonary arterial pressure (r = 0.449, p = 0.032) and pulmonary vascular resistance (r = 0.451, p = 0.031) on right-heart catheterization. ANGP-1 and ANGP-2 were expressed on lung vascular endothelial cells, as shown by immunohistochemistry. Patients with PH with higher ANGP-2 concentration (≥ 2.48 ng/mL) had significantly worse survival (p = 0.022). Higher ANGP-2 concentration was a significant worse prognostic factor (hazard ratio = 6.063, p = 0.037), while serum ANGP-1 concentration was not. In conclusion, serum ANGP-2 may be a useful diagnostic and prognostic biomarker in patients with PH, especially in patients with group 3 PH.

Group 3 Pulmonary Hypertension: A Review of Diagnostics and Clinical Trials

Group 3 pulmonary hypertension (PH) is a known sequelae of chronic lung disease. Diagnosis and classification can be challenging in the background of chronic lung disease and often requires expert interpretation of numerous diagnostic studies to ascertain the true nature of the PH. Stabilization of the underlying lung disease and adjunctive therapies such as oxygen remain the mainstays of therapy, as there are no Food and Drug Administration-approved therapies for group 3 PH. Referral to PH centers for individualized management and clinical trial enrollment is paramount.

Right ventricular contractility decreases during exercise in patients with non-advanced idiopathic pulmonary fibrosis

Early right ventricular dysfunction in patients with non-advanced idiopathic pulmonary fibrosis (IPF) has not been fully elucidated. Thus, we aimed to assess right ventricular functions in IPF patients and controls by speckle-tracking strain echocardiography at rest and peak exercise.We screened 116 IPF patients from February to August 2019 to include 20 patients with no history of oxygen therapy, peripheral saturation levels ≥92% at rest, Gender-Age-Physiology Index score ≤5, and modified Medical Research Council score ≤3. Additionally, we enrolled 10 matched controls. Transthoracic echocardiography images were acquired at rest and during a cardiopulmonary exercise test. We analyzed 2-dimensional echocardiographic parameters and right ventricular function using the global longitudinal strain assessed by the 2-dimensional speckle-tracking technique.In the control group, we found normal values of right ventricle longitudinal strain (RVLS) at rest and at peak exercise, the latter being much more negative (-23.6 ± 2.2% and -26.8 ± 3.1%, respectively; P < .001). By contrast, RVLS values in the IPF group increased from -21.1 ± 3.8% at rest to -17.0 ± 4.5% at peak exercise (P < .001). The exercise revealed a difference between the 2 groups as the mean RVLS values moved during peak exercise in opposite directions. Patients with IPF got worse, whereas control patients presented improved right ventricular contractility.Right ventricular dysfunction was unveiled by speckle-tracking echocardiography during exercise in non-advanced IPF patients. We suggest that this reflects an inadequate right ventricular-arterial coupling decreasing the right ventricular longitudinal contraction during exercise in these patients. This parameter may be useful as an early index of suspected pulmonary hypertension.

Potential for inhibition of checkpoint kinases 1/2 in pulmonary fibrosis and secondary pulmonary hypertension

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterised by exuberant tissue remodelling and associated with high unmet medical needs. Outcomes are even worse when IPF results in secondary pulmonary hypertension (PH). Importantly, exaggerated resistance to cell death, excessive proliferation and enhanced synthetic capacity are key endophenotypes of both fibroblasts and pulmonary artery smooth muscle cells, suggesting shared molecular pathways. Under persistent injury, sustained activation of the DNA damage response (DDR) is integral to the preservation of cells survival and their capacity to proliferate. Checkpoint kinases 1 and 2 (CHK1/2) are key components of the DDR. The objective of this study was to assess the role of CHK1/2 in the development and progression of IPF and IPF+PH.

METHODS AND RESULTS

Increased expression of DNA damage markers and CHK1/2 were observed in lungs, remodelled pulmonary arteries and isolated fibroblasts from IPF patients and animal models. Blockade of CHK1/2 expression or activity-induced DNA damage overload and reverted the apoptosis-resistant and fibroproliferative phenotype of disease cells. Moreover, inhibition of CHK1/2 was sufficient to interfere with transforming growth factor beta 1-mediated fibroblast activation. Importantly, pharmacological inhibition of CHK1/2 using LY2606368 attenuated fibrosis and pulmonary vascular remodelling leading to improvement in respiratory mechanics and haemodynamic parameters in two animal models mimicking IPF and IPF+PH.

CONCLUSION

This study identifies CHK1/2 as key regulators of lung fibrosis and provides a proof of principle for CHK1/2 inhibition as a potential novel therapeutic option for IPF and IPF+PH.

Management of Pulmonary Hypertension Due to Chronic Lung Disease

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

Pulmonary hypertension in interstitial lung disease: screening, diagnosis and treatment

PURPOSE OF REVIEW

Pulmonary vascular disease resulting in pulmonary hypertension in the context of interstitial lung disease (PH-ILD) is a common complication that presents many challenges in clinical practice. Despite recent advances, the pathogenetic interplay between parenchymal and vascular disease in ILD is not fully understood. This review provides an overview of the current knowledge and recent advances in the field.

RECENT FINDINGS

Clinical trials employing the phosphodiesterase-5-inhibitor sildenafil delivered negative results whereas riociguat showed harmful effects in the PH-ILD population. More recently, inhaled treprostinil showed positive effects on the primary endpoint (six-min walk-distance) in the largest prospective randomized placebo-controlled trial to date in this patient population. Additionally, a pilot trial of ambulatory inhaled nitric oxide suggests beneficial effects based on the novel endpoint of actigraphy.

SUMMARY

In view of these novel developments this review provides an overview of the status quo of screening, diagnosis and management of pulmonary vascular disease and PH in patients with ILD.

Pulmonary vasculopathy in explanted lungs from patients with interstitial lung disease undergoing lung transplantation

BACKGROUND

Pulmonary hypertension (PH) causes increased morbidity and mortality in patients with interstitial lung diseases (ILD). Classification schemes, while well-characterised for the vasculopathy of idiopathic PH, have been applied, unchallenged, to ILD-related PH. We evaluated pulmonary arterial histopathology in explanted human lung tissue from patients who were transplanted for advanced fibrotic ILD.

METHODS

Lung explants from 38 adult patients who underwent lung transplantation were included. Patients were divided into three groups: none, mild/moderate and severe PH by mean pulmonary artery pressure (mPAP) measured at pre lung transplantation right heart catheterisation (RHC). Grading of pulmonary vasculopathy according to Heath and Edwards scheme, and prelung transplantation evaluation data were compared between the groups.

RESULTS

38 patients with fibrotic ILDs were included, the majority (21) with idiopathic pulmonary fibrosis. Of the 38 patients, 18 had severe PH, 13 had mild/moderate PH and 7 had no PH by RHC. 16 of 38 patients had severe pulmonary arterial vasculopathy including vascular occlusion with intimal fibrosis and/or plexiform lesions. There were no correlations between mPAP and lung diffusion with the severity of pulmonary arterial pathological grade (Spearman's rho=0.14, p=0.34, rho=0.11, p=0.49, respectively).

CONCLUSIONS

Patients with end stage ILD had severe pulmonary arterial vasculopathy in their explanted lungs irrespective of the presence and/or severity of PH as measured by RHC. These findings suggest that advanced pulmonary arterial vasculopathy is common in patients with advanced fibrotic ILD and may develop prior to the clinical detection of PH by RHC.

The role of the combination of echo-HRCT score as a tool to evaluate the presence of pulmonary hypertension in idiopathic pulmonary fibrosis

Pulmonary hypertension (PH) is defined as an elevated mean pulmonary artery pressure at rest (mPAP ≥ 25 mmHg), evaluated by right heart catheterization (RHC). The aim of the present study was to evaluate HRCT findings in relation to transthoracic echocardiographic data to better characterize PH in IPF patients and to identify a non-invasive composite index with high predictive value for PH in these patients. 37 IPF patients were enrolled in this retrospective study. All patients underwent a complete assessment for PH, including transthoracic Doppler echocardiography, HRCT scan and right heart catheterization. Right heart catheterization was done in 19 patients (51.3%) as pre-lung transplant assessment and in 18 patients (48.6%) to confirm PH, suspected on the basis of echocardiography. Twenty out of 37 patients (54%) were confirmed to have PH by RHC. Multivariate regression showed that the combination of sPAP, PA area measured by HRCT and the ratio of the diameter of the segmental artery to that of the adjacent bronchus in the apicoposterior segment of the left upper lobe was strongly correlated with mPAP (R² = 0.53; p = 0.0009). The ROC analysis showed that 931.6 was the ULN for PA area, with 86% sensitivity and 61% specificity (0.839 AUC); 20.34 was the ULN for the ratio of PA area to ascending aorta diameter, with 100% sensitivity and 50% specificity (0.804 AUC). The composite index proposed in the present study could help early detection of IPF patients suspected of PH requiring confirmation by RHC (if deemed clinically necessary).

Nitrogen dioxide increases the risk of mortality in idiopathic pulmonary fibrosis

Ambient air pollution is associated with the prognosis of idiopathic pulmonary fibrosis (IPF) patients. We aimed to identify the impacts of individual exposure to particulate matter with a 50% cut-off aerodynamic diameter of 10 μm (PM₁₀) and nitrogen dioxide (NO₂) on IPF patients' mortality.1114 patients (mean age 65.7 years; male 80.5%) diagnosed with IPF between 1995 and 2016 were included in this study. Individual-level long-term concentrations of PM₁₀ and NO₂ at residential addresses of patients were estimated using a national-scale exposure prediction model. The effect of PM₁₀ and NO₂ on mortality was estimated using a Cox proportional hazards model adjusted for individual- and area-level covariates.The median follow-up period was 3.8 years and 69.5% of the patients died or underwent lung transplantation. When adjusted for individual- and area-level covariates, a 10 ppb increase in NO₂ concentration was associated with a 17% increase in mortality (hazard ratio (HR) 1.172, 95% CI 1.030-1.344; p=0.016). When IPF patients were stratified by age (≥65 versus <65 years) or by sex, NO₂ was a significant prognostic factor for mortality in the elderly (HR 1.331, 95% CI 1.010-1.598; p=0.010). When stratified by age and sex jointly, NO₂ showed the stronger association with mortality in elderly males (HR 1.305, 95% CI 1.072-1.598; p=0.008) than in other groups. PM₁₀ was not associated with IPF mortality in all patients and in subgroups stratified by age or sex.Our findings suggest that increased exposure to NO₂ can increase the risk of mortality in patients with IPF, specifically in elderly males.

The prevalence of pulmonary hypertension assessed using the pulmonary vein-to-right pulmonary artery ratio and its association with survival in West Highland white terriers with canine idiopathic pulmonary fibrosis

Background

Pulmonary hypertension (PH) is a known co-morbidity in West Highland white terriers (WHWTs) affected with canine idiopathic pulmonary fibrosis (CIPF). The pulmonary vein-to-right pulmonary artery ratio (PV/PA) has recently been described for the detection of pre-capillary PH in dogs. The objective of the present study was to estimate the prevalence of PH at diagnostic, in WHWTs affected with CIPF, by using PV/PA, in comparison with a group of healthy breed-matched controls (CTRLs). Additional study objective was to explore whether the presence of PH at initial diagnosis of CIPF impacted survival time in dogs treated with sildenafil.

Results

Twenty-five client-owned WHWTs presented with CIPF and 19 CTRLs were included in the study. PV/PA in either two-dimensional mode (2D) or time-motion mode or both were measured from cineloops in each dog. Dogs were classified according to PV/PA value into non/mild PH (PV/PA measured in 2D ≥ 0.7) or moderate/severe PH (PV/PA < 0.7). Survival data of WHWTs affected with CIPF were extracted from medical record to assess association between presence of PH at diagnosis and outcome. 60 % overall prevalence for moderate/severe PH was estimated in this cohort of WHWTs presented with CIPF vs. 5 % in CTRLS (P = 0.0002). The presence of moderate/severe PH at initial presentation was not associated with survival.

Conclusions

Results of the present study confirm a high prevalence of PH at diagnosis in WHWTs affected with CIPF and highlight the utility of PV/PA as a non-invasive surrogate for assessment of PH in this population.

Idiopathic pulmonary fibrosis beyond the lung: understanding disease mechanisms to improve diagnosis and management

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive disorder with an estimated median survival time of 3–5 years after diagnosis. This condition occurs primarily in elderly subjects, and epidemiological studies suggest that the main risk factors, ageing and exposure to cigarette smoke, are associated with both pulmonary and extrapulmonary comorbidities (defined as the occurrence of two or more disorders in a single individual). Ageing and senescence, through interactions with environmental factors, may contribute to the pathogenesis of IPF by various mechanisms, causing lung epithelium damage and increasing the resistance of myofibroblasts to apoptosis, eventually resulting in extracellular matrix accumulation and pulmonary fibrosis. As a paradigm, syndromes featuring short telomeres represent archetypal premature ageing syndromes and are often associated with pulmonary fibrosis. The pathophysiological features induced by ageing and senescence in patients with IPF may translate to pulmonary and extrapulmonary features, including emphysema, pulmonary hypertension, lung cancer, coronary artery disease, gastro-oesophageal reflux, diabetes mellitus and many other chronic diseases, which may lead to substantial negative consequences in terms of various outcome parameters in IPF. Therefore, the careful diagnosis and treatment of comorbidities may represent an outstanding chance to improve quality of life and survival, and it is necessary to contemplate all possible management options for IPF, including early identification and treatment of comorbidities.

Impact of the new definition for pulmonary hypertension in patients with lung disease: an analysis of the United Network for Organ Sharing database

The implications of the recent change in the definition of pulmonary hypertension on epidemiology and outcomes are not known. We sought to determine the percentage of patients with the two most common lung diseases that would be reclassified regarding the presence/absence of pulmonary hypertension with the revised definition. A query of the United Network for Organ Sharing database was performed. The percentage of patients meeting the current and previous definition of pulmonary hypertension was described. Outcomes of patients stratified by the current and previous definitions were compared. There were 15,563 patients with right heart catheterization data analyzed. Pulmonary hypertension was more prevalent in both chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis under the new definition at 52.4% versus 82.4%, and 47.6% versus 73.6%, respectively. “Pre-capillary” pulmonary hypertension by the new definition was lower at 28.1% for chronic obstructive pulmonary disease and 36.8% for idiopathic pulmonary fibrosis. Of the patients with pulmonary hypertension by the old definition, 23.9% of chronic obstructive pulmonary disease patients and 18.7% of idiopathic pulmonary fibrosis patients were not classified as pulmonary hypertension by the new definition. Conversely, 15.9% of chronic obstructive pulmonary disease patients and 15.1% of idiopathic pulmonary fibrosis patients who did not meet diagnostic criteria for pulmonary hypertension by the old definition did have pulmonary hypertension by the new definition. Patients in both disease categories had shorter transplant-free waitlist survival in the presence of pulmonary hypertension by both the new and old definitions. There was a trend toward the new definition of pre-capillary pulmonary hypertension better discerning outcomes compared to the old definition of pulmonary hypertension in idiopathic pulmonary fibrosis patients. Most patients with advanced lung disease who are listed for lung transplantation have pulmonary hypertension, but fewer have pre-capillary pulmonary hypertension than pulmonary hypertension by the old definition. Both the old and new definition of precapillary pulmonary hypertension appear to discern outcomes among the two groups of lung disease analyzed, with some evidence to suggest that the new definition performs slightly better in the idiopathic pulmonary fibrosis population.

Impact of lung morphology on clinical outcomes with riociguat in patients with pulmonary hypertension and idiopathic interstitial pneumonia: A post hoc subgroup analysis of the RISE-IIP study

BACKGROUND

Riociguat in Patients with Symptomatic Pulmonary Hypertension associated with Idiopathic Interstitial Pneumonias (RISE-IIP), a randomized, controlled, phase 2b trial of riociguat for pulmonary hypertension associated with idiopathic interstitial pneumonia, was terminated early due to increased mortality in riociguat-treated patients. Baseline characteristics of enrolled patients demonstrated a low diffusing capacity of the lung for carbon monoxide (DL_CO) with preserved lung volumes at baseline, suggesting the presence of combined pulmonary fibrosis and emphysema (CPFE) in some patients. This post hoc analysis of RISE-IIP was undertaken to explore lung morphology, assessed by high-resolution computed tomography, and associated clinical outcomes.

METHODS

Available baseline/pre-baseline high-resolution computed tomography scans were reviewed centrally by 2 radiologists. The extent of emphysema and fibrosis was retrospectively scored and combined to provide the total CPFE score.

RESULTS

Data were available for 65/147 patients (44%), including 15/27 fatal cases (56%). Of these, 41/65 patients (63%) had CPFE. Mortality was higher in patients with CPFE (12/41; 29%) than those without (3/24; 13%). Fourteen patients with CPFE had emphysema > fibrosis (4 died). No relationship was observed between CPFE score, survival status, and treatment assignment. A low DL_CO, short 6-min walking distance, and high forced vital capacity:DL_CO ratio at baseline also appeared to be risk factors for mortality.

CONCLUSIONS

High parenchymal lung disease burden and the presence of more emphysema than fibrosis might have predisposed patients with pulmonary hypertension associated with idiopathic interstitial pneumonia to poor outcomes in RISE-IIP. Future studies of therapy for group 3 pulmonary hypertension should include centrally adjudicated imaging for morphologic phenotyping and disease burden evaluation during screening.

Pulmonary hypertension in fibrosing idiopathic interstitial pneumonia: Uncertainties, challenges and opportunities

Pulmonary hypertension is a serious complication of chronic fibrosing idiopathic interstitial pneumonia (PH-fIIP) leading to greater morbidity and mortality. The pathophysiologic basis for PH in fIIP is not completely understood, but microvascular rarefaction may play a key role. Severe hypoxemia and reduced diffusion capacity are characteristic. Doppler echocardiography has limited diagnostic utility and right heart catheterization is required to confirm the diagnosis. Lung volumes can be minimally affected, and radiographic findings can be subtle, making the distinction from pulmonary arterial hypertension challenging. Several randomized controlled trials of pulmonary arterial hypertension targeted therapies have recently been completed. Endothelin-receptor antagonists have shown either no benefit or harm. Sildenafil may have some favorable short-term effects but does not appear to impact long-term outcomes. Riociguat treatment increased hospitalizations and mortality. A recent trial of inhaled treprostinil demonstrated improved exercise capacity, but the impact on long-term morbidity and mortality are unknown. Currently, the only viable option for improved survival is lung transplantation. Early referral is imperative to optimize post-transplant outcomes.

Targeting HIF2α-ARNT hetero-dimerisation as a novel therapeutic strategy for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a destructive disease of the pulmonary vasculature often leading to right heart failure and death. Current therapeutic intervention strategies only slow disease progression. The role of aberrant hypoxia-inducible factor (HIF)2α stability and function in the initiation and development of pulmonary hypertension (PH) has been an area of intense interest for nearly two decades.Here we determine the effect of a novel HIF2α inhibitor (PT2567) on PH disease initiation and progression, using two pre-clinical models of PH. Haemodynamic measurements were performed, followed by collection of heart, lung and blood for pathological, gene expression and biochemical analysis. Blood outgrowth endothelial cells from idiopathic PAH patients were used to determine the impact of HIF2α-inhibition on endothelial function.Global inhibition of HIF2a reduced pulmonary vascular haemodynamics and pulmonary vascular remodelling in both su5416/hypoxia prevention and intervention models. PT2567 intervention reduced the expression of PH-associated target genes in both lung and cardiac tissues and restored plasma nitrite concentration. Treatment of monocrotaline-exposed rodents with PT2567 reduced the impact on cardiovascular haemodynamics and promoted a survival advantage. In vitro, loss of HIF2α signalling in human pulmonary arterial endothelial cells suppresses target genes associated with inflammation, and PT2567 reduced the hyperproliferative phenotype and overactive arginase activity in blood outgrowth endothelial cells from idiopathic PAH patients. These data suggest that targeting HIF2α hetero-dimerisation with an orally bioavailable compound could offer a new therapeutic approach for PAH. Future studies are required to determine the role of HIF in the heterogeneous PAH population.

Parenteral prostanoids for severe Group 3 pulmonary hypertension with right ventricular dysfunction

Background

Group 3 pulmonary hypertension (PH) is a common complication in patients with lung diseases but there are currently no FDA-approved therapies. The data is conflicting, but a few small studies suggest potential benefits in using Group 1 PH therapies in these patients, particularly in severe PH with right ventricular (RV) dysfunction.

Methods

A retrospective cohort study of patients with severe Group 3 PH with RV dysfunction who received parenteral prostanoids from 2007–2018 at our institution was undertaken. Severe PH was defined as mean pulmonary arterial pressure (mPAP) ≥35 mmHg or mPAP 25–34 with cardiac index (CI) <2.4 L/min/m². Routine prognostic studies including N-terminal prohormone of brain natriuretic peptide (NT-proBNP), 6-minute walk distance (6MWD), WHO Functional Class assessment, oxygen requirement, arterial oxygen saturation, right ventricular systolic pressure (RVSP) and right heart catheterization (RHC) pressures, were obtained before initiation of parenteral therapy and at first clinical follow-up.

Results

Nine patients were included. Five were female (55.6%) with a median [interquartile range (IQR)] of 69 [54–71] years. Median CI was 1.8 (1.6–2.4) L/min/m² and median pulmonary vascular resistance (PVR) was 14.7 (10.7–17.1) Wood units (WU). We found no statistically significant improvement in NT-proBNP levels, exercise capacity, or functional class. Resting oxygen requirement worsened from 4 to 6 L/min (P=0.04) and exertional oxygen saturation nadir worsened from 90% to 83% (P=0.01) despite the increase in FiO₂ with exertion. Overall results were heterogenous: several patients demonstrated clinical stabilization, with two undergoing lung transplantation and one showing long-term stability with medical therapy. Symptoms remained severe for most: three patients discontinued prostanoid therapy, choosing to pursue hospice care.

Conclusions

We found no statistically significant improvement in NT-proBNP levels, exercise capacity, or functional class, while oxygen requirement at rest and oxygen saturation during exertion significantly worsened. Our results suggest that parenteral prostanoids should not generally be considered in the treatment of Group 3 PH patients.

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.

Vascular Pruning on CT and Interstitial Lung Abnormalities in the Framingham Heart Study

BACKGROUND

Pulmonary vascular disease is associated with poor outcomes in individuals affected by interstitial lung disease. The pulmonary vessels can be quantified with noninvasive imaging, but whether radiographic indicators of vasculopathy are associated with early interstitial changes is not known.

RESEARCH QUESTION

Are pulmonary vascular volumes, quantified from CT scans, associated with interstitial lung abnormalities (ILA) in a community-based sample with a low burden of lung disease?

STUDY DESIGN AND METHODS

In 2,386 participants of the Framingham Heart Study, we used CT imaging to calculate pulmonary vascular volumes, including the small vessel fraction (a surrogate of vascular pruning). We constructed multivariable logistic regression models to investigate associations of vascular volumes with ILA, progression of ILA, and restrictive pattern on spirometry. In secondary analyses, we additionally adjusted for diffusing capacity and emphysema, and performed a sensitivity analysis restricted to participants with normal FVC and diffusing capacity.

RESULTS

In adjusted models, we found that lower pulmonary vascular volumes on CT were associated with greater odds of ILA, antecedent ILA progression, and restrictive pattern on spirometry. For example, each SD lower small vessel fraction was associated with 1.81-fold greater odds of ILA (95% CI, 1.41-2.31; P < .0001), and 1.63-fold greater odds of restriction on spirometry (95% CI, 1.18-2.24; P = .003). Similar patterns were seen after adjustment for diffusing capacity for carbon monoxide, emphysema, and among participants with normal lung function.

INTERPRETATION

In this cohort of community-dwelling adults not selected on the basis of lung disease, more severe vascular pruning on CT was associated with greater odds of ILA, ILA progression, and restrictive pattern on spirometry. Pruning on CT may be an indicator of early pulmonary vasculopathy associated with interstitial lung disease.

Added benefits of early detection of other diseases on low-dose CT screening

Low-dose CT screening for lung cancer provides images of the entire chest and upper abdomen. While the focus of screening is on finding early lung cancer, radiology leadership has embraced the fact that the information contained in the images presents a new challenge to the radiology profession. Other findings in the chest and upper abdomen were not the reason for obtaining the screening CT scan, nor symptom-prompted, but still need to be reported. Reporting these findings and making recommendations for further workup requires careful consideration to avoid unnecessary workup or interventions while still maximizing the benefit that early identification of these other diseases provided. Other potential findings, such as cardiovascular disease and chronic pulmonary obstructive diseases actually cause more deaths than lung cancer. Existing recommendations for workup of abnormal CT findings are based on symptom-prompted indications for imaging. These recommendations may be different when the abnormalities are identified in asymptomatic people undergoing CT screening for lung cancer. I-ELCAP, a large prospectively collected multi-institutional and multi-national database of screenings, was used to analyze CT findings identified in screening for lung cancer. These analyses and recommendations were made by radiologists in collaboration with clinicians in different medical specialties.

Coronary artery disease and heart failure in patients with idiopathic pulmonary fibrosis

The aim of this study was to investigate the prevalence and prognostic value of coronary artery disease (CAD) and heart failure (HF) in patients with idiopathic pulmonary fibrosis (IPF). Thirteen hundred and fifty-eight patients with interstitial lung disease [851 (62%) males, mean age: 68 ± 10 years] were retrospectively analyzed. CAD was defined as (1) the presence of a clinical diagnosis of angina pectoris, (2) clinical diagnosis of a myocardial infarction, and (3) coronary angiography showing ≥ 1 vessel with a stenosis of > 75%. The definition of HF was made according to the modified Framingham criteria. Compared to the non-IPF group (n = 790), the IPF group (n = 568) had a significantly higher prevalence of CAD (9.3% vs. 4.4%, p < 0.001) and HF (8.2% vs. 3.7%, p < 0.001). During a median follow-up of 1.6 years, 152 deaths were identified. The patients with HF had a significantly worse prognosis than those without HF both in the non-IPF group and IPF group (both p < 0.05). However, the prognosis did not significantly differ between the patients with CAD and those without CAD both in the non-IPF group and IPF group. The presence of HF was an independent predictor of death in the IPF [hazard ratio (HR) 3.67, 95% confidence interval (CI) 1.57-8.56, p = 0.0025] and non-IPF (HR 5.07, 95% CI 1.44-17.86, p = 0.011) patients. The prevalence of CAD and HF was significantly higher in IPF than non-IPF patients. In addition, the presence of HF was a significant prognostic factor for both IPF and non-IPF patients. These results indicated that the importance of HF as a comorbidity for patients with ILD.

Perioperative Right Ventricular Dysfunction: Analysis of Outcomes

Right ventricular dysfunction (RVD) is a well-known prognostic factor for adverse outcomes in cardiovascular medicine. The right ventricle (RV) in medically managed heart failure patients and in surgical patients perioperatively generally is overshadowed by left ventricular disease. However, with advancement of various diagnostic tools and better understanding of its functional anatomy, the role of the RV is emerging in many clinical conditions. The failure of one ventricle has significant effect on the function of the other ventricle and it is predominantly due to ventricular interdependence.¹ The etiology of RVD is multifactorial and irrespective of etiology. RVD has been associated with significant increases in morbidity and mortality in various clinical scenarios.^2,3 The primary objective of this comprehensive review is to analyze various etiology-related outcomes of RVD in the perioperative population.

Idiopathic pulmonary fibrosis patients with severe physiologic impairment: characteristics and outcomes

RESEARCH QUESTION

There is no widely accepted grading system for IPF disease severity, although physiologic impairment based on pulmonary function testing is frequently employed. We sought to describe clinical and functional characteristics as well as outcomes of patients with severe physiologic impairment.

PATIENTS AND METHODS

IPF patients with severe physiologic impairment defined by FVC ≤ 50% and/or DLco ≤ 30% predicted evaluated in the Inova Advanced Lung Disease Program between 2011 and 2019 were included. Demographic, physiologic, functional treatment and outcome data were collated.

RESULTS

There were 531 patients with IPF evaluated of whom 242 (46%) had severe physiologic impairment. Mean age was 72 ± 8 years; baseline FVC was 53 ± 17% and DL_CO 28 ± 9% of predicted. The mean 6 min walks test (6MWT) distance was 304 ± 121 m with 59% of the patients requiring supplemental oxygen ([Formula: see text] group). There was a poor correlation between the 6MWT distance and both FVC% and DLco%. Patients in the 6MWT_RA group had a better transplant-free survival than the [Formula: see text] group (p = 0.002). Patients managed before October 2014 and not receiving antifibrotic therapy had worse outcomes with reduced transplant-free survival compared with patients presenting after this date who did receive antifibrotic therapy (n = 113) (log rank p < 0.0001).

CONCLUSION

IPF patients often present with severe physiologic impairment which may be poorly correlated with their functional status. Assessment of IPF disease severity should not be based on physiologic impairment alone, but should also encompass functional status as well as need for supplemental oxygen. Antifibrotic therapy in patients with severe physiologic impairment is associated with improved outcomes.

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.

Predictors of Mortality in Patients with Interstitial Lung Disease-Associated Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is a well-established complication in interstitial lung disease (ILD) patients. The aim of this study is to investigate the physiological and hemodynamic parameters that predict mortality in patients with ILD-PH.

METHODS

Consecutive ILD patients who underwent right heart catheterization (n = 340) were included. The information analyzed included demographics and physiological and hemodynamic parameters. Cox regression models were used to identify independent predictors of survival.

RESULTS

In total, 96 patients had PH and an additional 56 patients had severe PH. The overall survival of idiopathic pulmonary fibrosis (IPF) patients with PH was significantly worse than the survival of patients with other types of ILD with PH (p < 0.0001 by log-rank analysis). Patients with a reduced diffusing capacity of the lung for carbon monoxide (DLco) (<35% predicted), six-minute walk test final oxygen saturation by pulse oximetry (SpO2) <88% and pulmonary vascular resistance ≥4.5 Wood units in the ILD-PH cohort had significantly worse survival. IPF diagnosis, forced vital capacity, DLco, systolic pulmonary artery pressure and cardiac index were identified as independent predictors of survival among the ILD-PH cohort.

CONCLUSIONS

Patients with ILD-PH have poor prognosis. Physiological and hemodynamic parameters were important factors independently associated with outcome.

Pulmonary hypertension secondary to pulmonary fibrosis: clinical data, histopathology and molecular insights

Pulmonary hypertension (PH) developing secondarily in pulmonary fibrosis (PF) patients (PF-PH) is a frequent co-morbidity. The high prevalence of PH in PF patients is very concerning since the presence of PH is a strong predictor of mortality in PF patients. Until recently, PH was thought to arise solely from fibrotic destruction of the lung parenchyma, leading to hypoxic vasoconstriction and loss of vascular bed density. Thus, potential cellular and molecular dysregulation of vascular remodeling as a driver of PF-PH has been under-investigated. The recent demonstrations that there is no correlation between the severity of the fibrosis and development of PH, along with the finding that significant vascular histological and molecular differences exist between patients with and without PH have shifted the etiological paradigm of PF-PH. This review aims to provide a comprehensive translational overview of PH in PF patients from clinical diagnosis and outcome to the latest understanding of the histology and molecular pathophysiology of PF-PH.

Impairment of right ventricular strain evaluated by cardiovascular magnetic resonance feature tracking in patients with interstitial lung disease

OBJECTIVES

The aims of this study were to investigate the relationship between pulmonary hypertension (PH) and right ventricular (RV) strain, and to evaluate the prognostic value of RV strain by cardiac magnetic resonance (CMR) feature tracking for patients with interstitial lung disease (ILD).

METHODS

A total of seventy ILD patients (mean age: 71 ± 8 years, 39 [56%] males) who underwent CMR and right heart catheterization (RHC) were studied. Using a 1.5T magnetic resonance (MR) scanner, steady-state free precession cine MR images encompassing the RV were acquired in all patients and 20 control subjects. RV longitudinal strain were calculated with a feature tracking algorithm. PH was defined as a mean pulmonary artery pressure of more than 20 mmHg at rest and a pulmonary vascular resistance ≥3 Woods unit.

RESULTS

The RV longitudinal strain was significantly impaired in the ILD patients with PH (n=18) than ILD patients without PH (n=52) (-13.3 ± 5.4% vs. -16.9±5.4%, p=0.048). The RV longitudinal strain differed significantly between the ILD patients without PH and the controls (n=20) (-16.9 ± 5.4% vs. -20.8 ± 6.2%, p=0.002). Five of 70 (7%) patients died within one-year after CMR scan. Area under receiver operating characteristics curve for predicting death was 0.900 (95%CI: 0.800 to 1.000) for RV strain, 0.643 (95%CI: 0.454 to 0.832) for RVEF.

CONCLUSIONS

Presence of PH was associated with impairment of RV strain, and RV strain could predict short-term mortality in patients with ILD. RV strain by feature tracking might be useful as a non-invasive prognostic marker for patients with ILD.

GLP-1 receptor agonist ameliorates experimental lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fatal lung disease. This disease is characterized by an excessive accumulation of extracellular matrix deposition that modify normal lung physiology. Up to date, there are not efficient therapeutic tools to fight IPF. Glucagon-like peptide-1 receptor (GLP-1R) activation plays an essential role in lung functions in normal and in pathological conditions. The aim of the present study was to study the possible beneficial effects of the administration of the GLP-1R agonist, liraglutide, in the pathogenesis of the fibrotic process in an animal model of pulmonary fibrosis induced by bleomycin. We observed that liraglutide decreased mRNA expression of collagen, hydroxyproline and key enzymes for the synthesis of collagen. In addition, GLP-1R activation restored the ACE2 mRNA levels modulating the activities of the RAS components, increased the production of surfactant proteins (SFTPa1, SFTPb, SFTPc) and promoted an improvement in pulmonary and cardiac functionality, including a partial restoration of lung alveolar structure. Liraglutide effects are shown at both the pro-inflammatory and fibrosis phases of the experimental disease. For these reasons, GLP-1 might be regarded as a promising drug for treating pulmonary fibrosis.

Right ventricular dysfunction in patients with non-severe idiopathic pulmonary fibrosis: a cross-sectional prospective single-center study

BACKGROUND

Little is known about right ventricular dysfunction in non-advanced idiopathic pulmonary fibrosis (IPF) patients without hypoxemia at rest. We evaluated it at rest and during exercise.

RESEARCH DESIGN AND METHODS

123 IPF patients were evaluated, and 27 met all the following criteria: Gender-Age-Physiology Index score ≤5, modified Medical Research Council dyspnea score ≤3, peripheral oxygen saturation ≥92% at rest, and no history of oxygen therapy. They were submitted to two-dimensional speckle-tracking echocardiography at rest and during cardiopulmonary exercise to analyze right ventricular global longitudinal strain.

RESULTS

Abnormal speckle-tracking echocardiography findings were identified in 10/27 patients (37%), indicating right ventricular (RV) dysfunction. No patients had abnormalities observed in conventional echocardiographic parameters. Significant differences in mPAP were observed between patients with RV dysfunction and those without dysfunction (at rest: 26.0 ± 4.8 vs. 19.1 ± 4.2 mmHg, p = 0.001; during exercise: 51.3 ± 6.4 vs. 36.9 ± 14.7 mmHg, p = 0.002).

CONCLUSIONS

RV dysfunction was detected in 37% of non-advanced IPF patients and early recognition was only possible using speckle-tracking echocardiography. Special attention should be given to these patients as RV dysfunction is suggestive of worse prognosis. These patients could benefit from new specific drugs or even oxygen therapy for transitory hypoxia.

Alveolar cells under mechanical stressed niche: critical contributors to pulmonary fibrosis

Pulmonary fibrosis arises from the repeated epithelial mild injuries and insufficient repair lead to over activation of fibroblasts and excessive deposition of extracellular matrix, which result in a mechanical stretched niche. However, increasing mechanical stress likely exists before the establishment of fibrosis since early micro injuries increase local vascular permeability and prompt cytoskeletal remodeling which alter cellular mechanical forces. It is noteworthy that COVID-19 patients with severe hypoxemia will receive mechanical ventilation as supportive treatment and subsequent pathology studies indicate lung fibrosis pattern. At advanced stages, mechanical stress originates mainly from the stiff matrix since boundaries between stiff and compliant parts of the tissue could generate mechanical stress. Therefore, mechanical stress has a significant role in the whole development process of pulmonary fibrosis. The alveoli are covered by abundant capillaries and function as the main gas exchange unit. Constantly subject to variety of damages, the alveolar epithelium injuries were recently recognized to play a vital role in the onset and development of idiopathic pulmonary fibrosis. In this review, we summarize the literature regarding the effects of mechanical stress on the fundamental cells constituting the alveoli in the process of pulmonary fibrosis, particularly on epithelial cells, capillary endothelial cells, fibroblasts, mast cells, macrophages and stem cells. Finally, we briefly review this issue from a more comprehensive perspective: the metabolic and epigenetic regulation.

Developments in lung transplantation over the past decade

With an improved median survival of 6.2 years, lung transplantation has become an increasingly acceptable treatment option for end-stage lung disease. Besides survival benefit, improvement of quality of life is achieved in the vast majority of patients. Many developments have taken place in the field of lung transplantation over the past decade. Broadened indication criteria and bridging techniques for patients awaiting lung transplantation have led to increased waiting lists and changes in allocation schemes worldwide. Moreover, the use of previously unacceptable donor lungs for lung transplantation has increased, with donations from donors after cardiac death, donors with increasing age and donors with positive smoking status extending the donor pool substantially. Use of ex vivo lung perfusion further increased the number of lungs suitable for lung transplantation. Nonetheless, the use of these previously unacceptable lungs did not have detrimental effects on survival and long-term graft outcomes, and has decreased waiting list mortality. To further improve long-term outcomes, strategies have been proposed to modify chronic lung allograft dysfunction progression and minimise toxic immunosuppressive effects. This review summarises the developments in clinical lung transplantation over the past decade.

Allopurinol in Patients with Pulmonary Hypertension Associated with Chronic Lung Disease

Background

Oxidative stress (OS) has been implicated in the development of pulmonary hypertension (PH) and ventricular hypertrophy. Xanthine oxidase is a well-recognised source of reactive oxygen species, which lead to OS. The aim of this proof of concept study was to assess whether allopurinol (xanthine oxidase inhibitor) would reduce right ventricular mass (RVM) in patients with PH-associated chronic lung disease (PH-CLD).

Methods

We conducted a randomised, double-blind, parallel-group, placebo-controlled trial in patients with PH-CLD (93% COPD, 7% IPF) who were randomly assigned to receive allopurinol or placebo for 12 months. The primary outcome was the mean change in RVM, as assessed by cardiac magnetic resonance imaging (CMRI). Secondary outcomes included quality of life (QOL), spirometry and six-minute walk test (6MWT).

Results

Seventy-one patients were recruited: mean age 71 years, mean pulmonary arterial pressure 30 mm Hg, FEV₁ 60% and resting SpO₂ 96%. After 12 months, there was no significant difference in the change in RVM from baseline (allopurinol 1.85g vs placebo 0.97g with mean difference 0.88g, CI −4.77 to 3.01, p =0.7). There were also no significant changes in other cardiac parameters measured on MRI, in QOL, spirometry and 6MWT. Subgroup analysis showed that allopurinol significantly reduced RVM compared to placebo with -6.16g vs 0.75g and mean difference 6.92g (CI 1.14 to 12.69, p = 0.02) in COPD patients with more severe airflow limitation.

Conclusion

Allopurinol had no overall impact on patients with PH-CLD but had potential benefit in COPD patients with more severe airflow limitation.

Extended Exhaled Nitric Oxide Analysis in Interstitial Lung Diseases: A Systematic Review

Fractional exhaled nitric oxide (FeNO) is a well-known and widely accepted biomarker of airways inflammation that can be useful in the therapeutic management, and adherence to inhalation therapy control, in asthmatic patients. However, the multiple-flows assessment of FeNO can provide a reliable measurement of bronchial and alveolar production of NO, supporting its potential value as biomarker also in peripheral lung diseases, such as interstitial lung diseases (ILD). In this review, we first discuss the role of NO in the pathobiology of lung fibrosis and the technique currently approved for the measurement of maximum bronchial flux of NO (J'awNO) and alveolar concentration of NO (CaNO). We systematically report the published evidence regarding extended FeNO analysis in the management of patients with different ILDs, focusing on its potential role in differential diagnosis, prognostic evaluation and severity assessment of disease. The few available data concerning extended FeNO analysis, and the most common comorbidities of ILD, are explored too. In conclusion, multiple-flows FeNO analysis, and CaNO in particular, appears to be a promising tool to be implemented in the diagnostic and prognostic pathways of patients affected with ILDs.

Cardiovascular implications of idiopathic pulmonary fibrosis: A way forward together?

Cardiovascular disease has an increased prevalence among patients with idiopathic pulmonary fibrosis (IPF). Cardiovascular disease and IPF share similar symptoms with overlapping demographics and risk factors for disease development. Common cellular mediators leading to disease development and progression have been identified in both the cardiovascular and pulmonary organ systems. In this context, discovery of new therapeutic targets and medical therapies could be mutually beneficial across cardiopulmonary diseases. Here we present (1) a clinical review of IPF for the cardiovascular clinician and (2) common cellular mechanisms responsible for fibrosis in the heart and lungs and (3) highlight future research considerations and the potential role of novel therapeutic agents which may be mutually beneficial in cardiac and pulmonary fibrosis.

Endothelial to mesenchymal transition (EndMT) and vascular remodeling in pulmonary hypertension and idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and irreversible fibrotic disease associated with respiratory failure. The disease remains idiopathic, but repeated alveolar epithelium injury, disruption of alveolar-capillary integrity, abnormal vascular repair, and pulmonary vascular remodeling are considered possible pathogenic mechanisms. Also, the development of comorbidities such as pulmonary hypertension (PH) could further impact disease outcome, quality of life and survival rates in IPF.

AREAS COVERED

The current review provides a comprehensive literature survey of the mechanisms involved in the development and manifestations of IPF and their links to PH pathology. This review also provides the current understanding of molecular mechanisms that link the two pathologies and will specifically decipher the role of endothelial to mesenchymal transition (EndMT) along with the possible triggers of EndMT. The possibility of targeting EndMT as a therapeutic option in IPF is discussed.

EXPERT OPINION

With a steady increase in prevalence and mortality, IPF is no longer considered a rare disease. Thus, it is of utmost importance and urgency that the underlying profibrotic pathways and mechanisms are fully understood, to enable the development of novel therapeutic strategies.

Complications in Idiopathic Pulmonary Fibrosis: Focus on Their Clinical and Radiological Features

Idiopathic pulmonary fibrosis (IPF) is a fibrotic lung disease with uncertain origins and pathogenesis; it represents the most common interstitial lung disease (ILD), associated with a pathological pattern of usual interstitial pneumonitis (UIP). This disease has a poor prognosis, having the most lethal prognosis among ILDs. In fact, the progressive fibrosis related to IPF could lead to the development of complications, such as acute exacerbation, lung cancer, infections, pneumothorax and pulmonary hypertension. Pneumologists, radiologists and pathologists play a key role in the identification of IPF disease, and in the characterization of its complications-which unfortunately increase disease mortality and reduce overall survival. The early identification of these complications is very important, and requires an integrated approach among specialists, in order to plane the correct treatment. In some cases, the degree of severity of patients having IPF complications may require a personalized approach, based on palliative care services. Therefore, in this paper, we have focused on clinical and radiological features of the complications that occurred in our IPF patients, providing a comprehensive and accurate pictorial essay for clinicians, radiologists and surgeons involved in their management.

Measurement and Interpretation of Exercise Ventilatory Efficiency

Cardiopulmonary exercise testing (CPET) is a method for evaluating pulmonary and cardiocirculatory abnormalities, dyspnea, and exercise tolerance in healthy individuals and patients with chronic conditions. During exercise, ventilation (V˙_E) increases in proportion to metabolic demand [i.e., carbon dioxide production (V˙CO₂)] to maintain arterial blood gas and acid-base balance. The response of V˙_E relative to V˙CO₂ (V˙_E/V˙CO₂) is commonly termed ventilatory efficiency and is becoming a common physiological tool, in conjunction with other key variables such as operating lung volumes, to evaluate exercise responses in patients with chronic conditions. A growing body of research has shown that the V˙_E/V˙CO₂ response to exercise is elevated in conditions such as chronic heart failure (CHF), pulmonary hypertension (PH), interstitial lung disease (ILD), and chronic obstructive pulmonary disease (COPD). Importantly, this potentiated V˙_E/V˙CO₂ response contributes to dyspnea and exercise intolerance. The clinical significance of ventilatory inefficiency is demonstrated by findings showing that the elevated V˙_E/V˙CO₂ response to exercise is an independent predictor of mortality in patients with CHF, PH, and COPD. In this article, the underlying physiology, measurement, and interpretation of exercise ventilatory efficiency during CPET are reviewed. Additionally, exercise ventilatory efficiency in varying disease states is briefly discussed.

Can a New Scoring System Improve Prediction of Pulmonary Hypertension in Newly Recognised Interstitial Lung Diseases?

INTRODUCTION

Pulmonary hypertension (PH) is a well-recognised complication of interstitial lung diseases (ILD), which worsens prognosis and impairs exercise capacity. Echocardiography is the most widely used, non-invasive method for PH assessment. The aim of our study was to identify the factors predictive for echocardiographic signs of PH in newly recognised ILD patients.

METHODS

Ninety-three consecutive patients (28F/65M) with different ILD were prospectively evaluated from January 2009 to March 2014. Pulmonary function testing, 6-min walk distance (6MWD), initial and sixth minute room air oxygen saturation, NT-proBNP and echocardiography were assessed in each patient. Echocardiographic PH probability was determined according to the 2009 ESC/ERS guidelines.

RESULTS

In 41 patients (Group B) increased PH possibility has been diagnosed on echocardiography, in 52 patients (Group A)-low PH probability. Most pronounced differences (p ≤ 0.0005) between groups B and A concerned: age, 6MWD, room air oxygen saturation at 6 min, DLCO and TLC/DLCO index (57.6 vs 43.8 years; 478 vs 583 m; 89.1% vs 93.4%; 54.8% predicted vs 70.5% predicted and 1.86 vs 1.44; respectively). Univariate analysis showed four-fold increased probability of PH when TLC/DLCO exceeded 1.67. A scoring system incorporating age, TLC/DLCO index, 6MWD and room air oxygen saturation at 6 min provided high diagnostic utility, AUC 0.867 (95% CI 0.792-0.867).

CONCLUSION

ILD patients with TLC/DLCO index > 1.67 have a high likelihood of PH and should undergo further evaluation. The composite model of PH prediction, including age, 6-min walk test and TLC/DLCO was highly specific for recognition of PH on echocardiography.

Early left atrial dysfunction in idiopathic pulmonary fibrosis patients without chronic right heart failure

No data are actually available regarding the left atrial (LA) functional assessment by two-dimensional speckle tracking echocardiography (2D-STE) in early-stage idiopathic pulmonary fibrosis (IPF). The primary end-point of our study was to assess whether global LA peak strain (GLAPS), measured by 2D-STE analysis, may detect early alterations in LA function in IPF patients without right heart failure (RHF). Between September 2017 and January 2019, 50 consecutive IPF patients (73.8 ± 6.8 years, 36 males) without chronic RHF and 30 controls matched by age, sex and cardiovascular risk factors, were enrolled in an observational retrospective case-control study. All patients underwent a complete echocardiographic study implemented with 2D-STE analysis. GLAPS, left ventricular (LV) global longitudinal strain (GLS), right atrial (RA) reservoir strain (GSA+) and right ventricular (RV)-GLS were obtained in each patient. LVFP were significantly increased in IPF patients in comparison to controls (average E/e' ratio 14.4 ± 3.0 vs 9.6 ± 1.5, p < 0.0001), while LV-GLS was slightly reduced in IPF patients compared to controls (19.4 ± 3.6% vs 21.0 ± 2.2%, p = 0.03).Moreover, GLAPS was significantly impaired in IPF patients in comparison to controls (18.4 ± 3.7% vs 28.4 ± 5.6%, p < 0.0001).Finally, the two groups of patients did not show any statistically significant difference in both RA-GSA + (23.9 ± 3.7% vs 24.5 ± 4.0%, p = 0.49) and RV-GLS (- 22.6 ± 3.3% vs - 23.5 ± 3.0%, p = 0.22). Notably, LV-GLS was strongly inversely correlated both with RV/LV basal diameter ratio and TRV in IPF patients (r = - 0.87 and - 0.82, respectively) but not in controls (r = - 0.29 and - 0.27, respectively). This finding highlights a likely process of ventricular interdependence in non-advanced IPF, with consequent LV diastolic dysfunction and secondary impairment in LV-GLS and GLAPS. Early LA reservoir dysfunction in IPF patients may be secondary to LV diastolic dysfunction induced by ventricular interdependence and may develop before RV diastolic and systolic dysfunction.

Lung transplantation for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is characterized by relentlessly progressive lung function impairment that is consistently fatal in the absence of lung transplantation, as no curative pharmacological treatment exists. The pace of progression varies across patients, and acute life-threatening exacerbations occur unpredictably, causing further sharp drops in lung function. Recently introduced antifibrotic agents slow the pace of disease progression and may improve survival but fail to stop the fibrotic process. Moreover, the magnitude and kinetics of the response to these drugs cannot be predicted in the individual patient. These characteristics require that lung transplantation be considered early in the course of the disease. However, given the shortage of donor lungs, lung transplantation must be carefully targeted to those patients most likely to benefit. Current guidelines for lung transplantation listing may need reappraisal in the light of recent treatment advances. Patients with IPF often have multiple comorbidities such as coronary heart disease, frailty, and gastro-oesophageal reflux disease (GERD). Consequently, extensive screening for and effective treatment of concomitant conditions is crucial to appropriate candidate selection and outcome optimisation. A multidisciplinary approach is mandatory. Pulmonologists with expertise in IPF must work closely with lung transplant teams. Careful consideration must be given to preoperative optimisation, surgical technique, and pulmonary rehabilitation to produce the best post-transplantation outcomes.

Evolution and treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic and devastating disease of unknown etiology, characterized by irreversible morphological changes, ultimately leading to lung fibrosis and death. In recent years, significant progress has been achieved in understanding the pathogenesis of IPF. Moreover, we assisted to the conceptual change of the pathogenic hypothesis that currently considers IPF as a primarily fibrotic driven disease. However, despite the undeniable progress, the diagnosis of IPF remains still very complex requiring the presence of a team of experts to achieve the highest level of diagnostic confidence. The advent of antifibrotics has radically changed the treatment landscape of IPF and new promising drugs are currently under evaluation. Furthermore, a more extensive use of non-pharmacological treatments has also to be encouraged in all patients both to reduce symptoms and improve quality of life.

The Trouble With Group 3 Pulmonary Hypertension in Interstitial Lung Disease: Dilemmas in Diagnosis and the Conundrum of Treatment

Pulmonary hypertension (PH) due to interstitial lung disease (ILD; PH-ILD) can complicate a multitude of ILDs, including idiopathic pulmonary fibrosis, chronic hypersensitivity pneumonitis, and nonspecific interstitial pneumonia. Development of PH-ILD is associated with increased need for supplemental oxygen, reduced mobility, and decreased survival. A high index of suspicion is required to make the diagnosis, given the substantial overlap in symptoms with those of ILD without PH. Severely reduced diffusing capacity or 6-min walk test distance, prominent exertional desaturation, and impaired heart rate recovery after exercise are all suggestive of the development of PH-ILD. Traditional transthoracic echocardiography is the most commonly used screening test for PH-ILD, but it lacks sensitivity and specificity. Newer echocardiographic tools involving 3-dimensional assessment of the right ventricle may have a role in both prognosis and the monitoring of patients with PH-ILD. Right-sided heart catheterization remains the gold standard for confirming a diagnosis of PH-ILD. Although there is little debate about the use of supplemental oxygen and diuretic therapy in the treatment of PH-ILD, treatment with pulmonary vasodilator therapy remains controversial. Although several studies have been terminated prematurely for harm, the recently completed INCREASE trial of inhaled treprostinil appears to validate the concept of treating PH-ILD with pulmonary vasodilators and, we hope, will serve as a foundation from which future studies can be developed.

[Exacerbation of idiopathic pulmonary fibrosis]

Idiopathic pulmonary fibrosis (IPF) is usually characterized by a chronic and slowly progressive course. According to several studies, a small number of patients with IPF (about 515%) develops an acute deterioration of deasese exacerbation of IPF. Exacerbations of IPF can occur at any time of the disease and sometimes becomes the first manifestation of IPF. Pulmonary hypertension in IPF is a fairly frequent complication, which leads to severe violations of gas exchange and reduced tolerance to physical stress. Currently, proven effective treatments for exacerbations of IPF do not exist, the management of this condition is based on supportive therapy (oxygen, respiratory support) and interventions with inadequate evidences (corticosteroids, immunosuppressant). During exacerbation of IPF a careful search of all the possible triggers is justified. In the presented clinical case of exacerbation of IPF there was demonstrated the efficacy of complex therapy including antifibrotic therapy, PAH-specific medicines and enhanced oxygen therapy.

Sitagliptin Inhibits Extracellular Matrix Accumulation and Proliferation in Lung Fibroblasts

BACKGROUND Fibroblasts activation-induced fibrosis can cause idiopathic pulmonary fibrosis (IPF). Excessive activation of fibroblasts contributes to poor healing or severe visceral fibrosis and even organ dysfunction. Sitagliptin acts as a dipeptidyl peptidase 4 inhibitor to reduce glucose level in type 2 diabetes, but its role in fibrosis of lung fibroblasts is elusive. We investigated the mechanism of sitagliptin in TGF-ß-activated lung fibroblasts and evaluated the efficacy of sitagliptin in extracellular matrix accumulation and fibroblasts proliferation. MATERIAL AND METHODS By in vitro lung fibroblasts culture, we assessed the expression of lung fibroblasts biomarker (alpha-SMA) and extracellular matrix (Col-1, Col-3, fibronectin) following TGF-ß stimulation and treatment with sitagliptin. Mechanistically, the phosphorylation level of Smad-3 protein in cells was analyzed using Western blotting, and the apoptosis level was assessed by Western blotting and flow cytometry. The degree of proliferation was determined using immunofluorescence and scratch-healing assay. RESULTS We found that treatment with sitagliptin attenuates fibroblasts activation following TGF-ß stimulation. Furthermore, the extracellular matrix was decreased by sitagliptin treatment by suppressing the phosphorylation level of Smad-3 protein. We found that sitagliptin does not affect apoptosis in fibroblasts, but it does affect the degree of proliferation of lung fibroblasts, thus ameliorating fibrosis after TGF-ß stimulation. CONCLUSIONS Sitagliptin inhibits fibrosis in TGF-ß-induced lung fibroblasts activation, which restrains extracellular matrix formation and cell proliferation in fibroblasts. Therefore, sitagliptin appears to have promise as a treatment of fibroproliferative disease caused by activation and proliferation of fibroblasts.

Nintedanib and Sildenafil in Patients with Idiopathic Pulmonary Fibrosis and Right Heart Dysfunction. A Prespecified Subgroup Analysis of a Double-Blind Randomized Clinical Trial (INSTAGE)

Rationale: In the INSTAGE trial in patients with idiopathic pulmonary fibrosis (IPF) and severely impaired gas exchange, nintedanib plus sildenafil was associated with numerical benefits on St. George's Respiratory Questionnaire (SGRQ) total score, brain natriuretic peptide (BNP), and FVC decline versus nintedanib alone. Exploratory analyses of the STEP-IPF (Sildenafil Trial of Exercise Performance in IPF) trial suggested that sildenafil may have a greater effect on SGRQ score in patients with IPF who have right heart dysfunction (RHD).Objectives: Assess whether RHD influenced the effects of nintedanib plus sildenafil versus nintedanib alone in the INSTAGE trial.Methods: Subgroup analyses of patients with (n = 117) versus those without (n = 156) echocardiographic signs of RHD at baseline.Measurements and Main Results: There was no heterogeneity between subgroups by presence of RHD in the effect of nintedanib plus sildenafil versus nintedanib alone on change in SGRQ total score at Week 12 (P = 0.74) or Week 24 (P = 0.90), or change in FVC at Week 12 (P = 0.58) or Week 24 (P = 0.55). In both subgroups, nintedanib plus sildenafil had a numerically greater effect on reducing FVC decline versus nintedanib alone. Between-group differences in change in BNP at Week 24 were -119.9 ng/L (95% confidence interval = -171.3 to -68.5) and -3.6 ng/L (95% confidence interval = -47.2 to 40.0) in patients with and without signs of RHD at baseline, respectively (P < 0.01).Conclusions: In the INSTAGE trial, there were no significant differences in the effects of nintedanib plus sildenafil versus nintedanib alone on changes in SGRQ and FVC between patients with or without echocardiographic signs of RHD at baseline. The benefit of combination therapy on stabilizing BNP was more pronounced in patients with RHD at baseline.Clinical trial registered with www.clinicaltrials.gov (NCT02802345).