Derivation and validation of a noninvasive prediction tool to identify pulmonary hypertension in patients with IPF: Evolution of the model FORD

Physician perspectives on pulmonary hypertension in ILD: results of a cases-based survey

BACKGROUND

Pulmonary hypertension (PH) complicates the course of patients with interstitial lung disease (ILD) in 30-55% of cases and is associated with increased morbidity and mortality. The optimal timing of diagnostic right heart catheterization (RHC) and the impact of transthoracic echocardiographic (TTE) imaging on this decision remain uncertain. This study explores physician decision-making regarding PH suspicion in patients with ILD, and the necessity for TTE and RHC.

METHODS

A case-based survey was conducted among physicians from diverse geographic and professional backgrounds. Participants assessed anonymized ILD cases, providing their clinical suspicion of PH and recommendations for TTE and then RHC both before and after receiving TTE results. Predictive accuracy for PH was compared to the FORD index, a validated scoring system.

RESULTS

There were 10 cases provided, of which 3 had hemodynamically confirmed PH and 7 did not have PH. There were 42 respondents to the survey. Following the TTE results, the proportion of responses indicating high suspicion for PH increased in all PH cases and also increased in some non-PH cases. In PH cases, respondents accurately predicted mPAP ≥ 25 in 98.4% and PVR ≥ 3 Woods Units in 90.5% of responses, although only 24.6% and 20.6% matched the value ranges, respectively. In non-PH cases, mPAP < 25 and PVR < 3 Wood Units were correctly identified in 60.9% and 67.0% of responses, with 30% incorrectly predicting PH. Compared to the FORD index (sensitivity: 43.7%, specificity: 86.6%), respondents demonstrated higher sensitivity (88.9%) but lower specificity (70.1%) for PH diagnosis.

CONCLUSIONS

Physicians demonstrate high sensitivity but moderate specificity in predicting PH, both with and without TTE results. The FORD index had greater specificity and may serve as a complementary tool, reducing the need for unnecessary RHCs. Standardized protocols are needed to facilitate detection of PH while optimizing the timing of RHCs in ILD patients.

A Systematic Review and Expert Recommendation on the Diagnosis of Pulmonary Hypertension Associated With Lung Disease: A Position Paper of the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR)

Pulmonary hypertension (PH) is a common complication of chronic respiratory diseases (CRD) associated with increased morbidity and mortality. Early and individualized identification of PH in these patients is crucial to better understand the evolution of the disease and to assess the application of therapeutic measures aimed at its control. However, there is no consensus on how to approach the diagnostic process. The scarce scientific evidence in this field justifies the creation of this SEPAR position paper, which aims to become a tool to aid in the diagnosis of PH associated with CRD that facilitates decision making for the benefit of patients and the optimization of resources. A panel of 16 SEPAR experts has identified three critical questions. The answers to these questions were developed by the panel members, who were divided into three groups according to their expertise in the underlying disease in question: chronic obstructive pulmonary disease, interstitial lung disease and obesity hypoventilation syndrome. Prior to the discussion and drafting of the document by each group, a systematic review of the literature was performed according to the guidelines recommended by the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). We generated a schematic proposal adjusted to the characteristics of each disease for the diagnostic approach to PH associated with respiratory disease.

Review of the Diagnosis and Management of Pulmonary Hypertension Associated with Interstitial Lung Disease (ILD-PH)

Pulmonary hypertension associated with interstitial lung disease (ILD-PH) frequently complicates the course of patients with fibrotic ILD. In this narrative review, the authors assess current diagnostic tools and management considerations in ILD-PH patients. ILD-PH is associated with increased morbidity and mortality and may be suggested by the presence of symptoms out of proportion to the extent of the ILD. There are other clues to the presence of PH in the context of ILD including the need for supplemental oxygen, a reduced DLCO especially if accompanied by a disproportionately higher forced vital capacity, imaging demonstrating an enlarged pulmonary artery or a dilated right ventricle, or objective evidence of a reduced exercise capacity. While echocardiography is one screening tool, right heart catheterization remains the gold standard for the diagnosis of PH. When appropriate, treatment with inhaled treprostinil, or possibly other pulmonary vasodilators, may be indicated.

Derivation of a simple risk calculator for predicting clinical worsening in patients with pulmonary hypertension due to interstitial lung disease

Background

Pulmonary hypertension due to interstitial lung disease (ILD-PH) portends very poor clinical outcomes, with a median survival time of 1.5 to 2 years. Currently, there is no tool to assess the risk of clinical worsening in patients with ILD-PH. Our aim was to derive a simple and practical risk calculator that could be used to predict risk of clinical worsening in patients with ILD-PH.

Methods

The INCREASE study was a 16-week study that evaluated inhaled treprostinil in patients with ILD-PH. Baseline data from patients who were randomized to the placebo arm (n=163) and thus untreated with any approved pulmonary artery vasodilators were used to derive a risk calculator. The endpoint of interest was the time to clinical worsening. Stepwise regression, Harrell's c-index, and clinician input were used to derive 2 multivariable Cox PH models from a set of candidate variables. The models were then simplified by applying a point-scoring system to the predictors and refitting with total point score as the covariate. Total point scores were grouped into 3 risk strata (lower, intermediate, and higher).

Results

Two versions of a risk calculator were derived. The first was a non-invasive risk calculator which included NT-proBNP and FVC%/DLCO%, and a second adds cardiac index, an invasive parameter, to the above two parameters. For the total point score models, the estimated c-indices were 0.703 (95% CI: 0.635, 0.783) and 0.683 (95% CI: 0.612, 0.761) for the invasive and non-invasive model, respectively.

Conclusion

These two risk calculators provide a simple way to risk stratify ILD-PH patients with clinically useful discrimination. The calculators are easy to employ in clinical practice, since they utilize assessments commonly collected in the care of patients with ILD-PH. Moreover, the calculators can provide clinicians with important prognostic information which can be used to reinforce the benefits of therapy. The risk calculators may also find utility as part of the composite allocation score of ILD-PH patients listed for lung transplant. Future research in this area could include incorporating longer-term outcomes as well as validating the risk models in a separate patient population.

Performance of the FORD Versus Other Available Models for the Noninvasive Prediction of Pulmonary Hypertension in Patients with Interstitial Lung Disease

PURPOSE

Pulmonary hypertension (PH) is associated with morbidity and mortality in patients with interstitial lung disease (ILD). Several prediction models have been proposed to predict PH in ILD patients. We sought to discern how previously described prediction models perform in predicting PH in patients with ILD.

METHODS

Patients with ILD who completed a baseline right heart catheterization, from Inova Fairfax Hospital, Northwestern Memorial Hospital, and Asan Medical Center in Korea were enrolled. The performance of various prediction models (FORD model, the FORD calculator, the PH-ILD Detection tool, and the mean pulmonary artery pressure prediction model) were assessed using receiver operating characteristic (ROC) curves and area under the receiver operating characteristic curve (AUROC). There were four definitions of pulmonary hypertension against which the models were evaluated.

RESULTS

There were a total of 192 patients with ILD, of whom 32.8% (n = 63/192) met the modified 5th world symposium on PH definition of precapillary PH. Among the models assessed, the FORD calculator had an AUROC (0.733) that was marginally highest. Subgroup analysis revealed that the FORD index had the highest AUROC (0.817) in patients with idiopathic pulmonary fibrosis, while the FORD calculator had the highest AUROC (0.751) in patients with non-IPF ILD.

CONCLUSION

The FORD model can be used to predict group 3 PH in both IPF patients and non-IPF ILD patients. It could serve as a tool for ILD patient selection for right heart catheterization as well as an enrichment tool for clinical trials targeting the pulmonary vasculature.

Vascular involvement in idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic, fibrosing and progressive interstitial lung disease of unknown aetiology with a pathogenesis still partly unknown. Several microvascular and macrovascular abnormalities have been demonstrated in the pathogenesis of IPF and related pulmonary hypertension (PH), a complication of the disease.

Methods

We carried out a non-systematic, narrative literature review aimed at describing the role of the vasculature in the natural history of IPF.

Results

The main molecular pathogenetic mechanisms involving vasculature (i.e. endothelial-to-mesenchymal transition, vascular remodelling, endothelial permeability, occult alveolar haemorrhage, vasoconstriction and hypoxia) and the genetic basis of vascular remodelling are described. The prevalence and clinical relevance of associated PH are highlighted with focus on the vasculature as a prognostic marker. The vascular effects of current antifibrotic therapies, the role of pulmonary vasodilators in the treatment of disease, and new pharmacological options with vascular-targeted activity are described.

Conclusions

The vasculature plays a key role in the natural history of IPF from the early phases of disease until development of PH in a subgroup of patients, a complication related to a worse prognosis. Pulmonary vascular volume has emerged as a novel computed tomography finding and a predictor of mortality, independent of PH. New pharmacological options with concomitant vascular-directed activity might be promising in the treatment of IPF.

Screening and diagnosis of pulmonary hypertension associated with chronic lung disease (PH-CLD): A consensus statement from the pulmonary vascular research institute's innovative drug development initiative-group 3 pulmonary hypertension

Pulmonary hypertension (PH) is a frequent complication of chronic lung disease (CLD). However, PH is difficult to diagnose early since accompanying symptoms overlap and are similar to those of the underlying CLD. In most cases the PH is mild to moderate and therefore physical signs may be absent or subtle. This consensus paper provides insight into the clues that might suggest the presence of occult PH in patients with CLD. An overview of current diagnostic tools and emerging diagnostic technologies is provided as well as guidance for the work-up and diagnosis of PH in patients with CLD.

Pulmonary hypertension associated with lung diseases

Pulmonary hypertension (PH) associated with chronic lung disease (CLD) is both common and underrecognised. The presence of PH in the setting of lung disease has been consistently shown to be associated with worse outcomes. Recent epidemiological studies have advanced understanding of the heterogeneity of this patient population and shown that defining both the specific type of CLD as well as the severity of PH (i.e. deeper phenotyping) is necessary to inform natural history and prognosis. A systematic diagnostic approach to screening and confirmation of suspected PH in CLD is recommended. Numerous uncontrolled studies and one phase 3 randomised, controlled trial have suggested a benefit in treating PH in some patients with CLD, specifically those with fibrotic interstitial lung disease (ILD). However, other studies in diseases such as COPD-PH showed adverse outcomes with some therapies. Given the expanding list of approved pharmacological treatments for pulmonary arterial hypertension, developing a treatment algorithm for specific phenotypes of CLD-PH is required. This article will summarise existing data in COPD, ILD and other chronic lung diseases, and provide recommendations for classification of CLD-PH and approach to the diagnosis and management of these challenging patients.

Noninvasive diagnostic modalities and prediction models for detecting pulmonary hypertension associated with interstitial lung disease: a narrative review

Pulmonary hypertension (PH) is highly prevalent in patients with interstitial lung disease (ILD) and is associated with increased morbidity and mortality. Widely available noninvasive screening tools are warranted to identify patients at risk for PH, especially severe PH, that could be managed at expert centres. This review summarises current evidence on noninvasive diagnostic modalities and prediction models for the timely detection of PH in patients with ILD. It critically evaluates these approaches and discusses future perspectives in the field. A comprehensive literature search was carried out in PubMed and Scopus, identifying 39 articles that fulfilled inclusion criteria. There is currently no single noninvasive test capable of accurately detecting and diagnosing PH in ILD patients. Estimated right ventricular pressure (RVSP) on Doppler echocardiography remains the single most predictive factor of PH, with other indirect echocardiographic markers increasing its diagnostic accuracy. However, RVSP can be difficult to estimate in patients due to suboptimal views from extensive lung disease. The majority of existing composite scores, including variables obtained from chest computed tomography, pulmonary function tests and cardiopulmonary exercise tests, were derived from retrospective studies, whilst lacking validation in external cohorts. Only two available scores, one based on a stepwise echocardiographic approach and the other on functional parameters, predicted the presence of PH with sufficient accuracy and used a validation cohort. Although several methodological limitations prohibit their generalisability, their use may help physicians to detect PH earlier. Further research on the potential of artificial intelligence may guide a more tailored approach, for timely PH diagnosis.

Towards a Better Prognosis in Patients with Systemic Sclerosis-Related Pulmonary Arterial Hypertension: Recent Developments and Perspectives

Precapillary pulmonary hypertension (PH) is a significant complication of systemic sclerosis (SSc). It represents one of the leading causes of morbidity and mortality, correlating with a significantly dismal prognosis and quality of life. Despite advancements in the management of patients with pulmonary arterial hypertension associated with SSc (SSc-PAH), no significant improvement has been reported in survival of patients with precapillary SSc-PH associated with extensive lung parenchyma disease. International expert consensus and guidelines for the management of PH recommend annual screening of SSc patients for early detection of pre-capillary PH. The implementation of screening algorithms capable of identifying patients with a high likelihood of developing PH could help limit unnecessary right-heart catheterization procedures and prevent significant delay in diagnosis. Furthermore, early initiation of up-front combination targeted therapy in patients with PAH has shown increase in survival rates, indicating that timely and aggressive medical therapy is key for stabilizing and even improving functional class, hemodynamic parameters and 6 min walking distance (6MWD) in this population. Further research is warranted into the benefit of PAH-targeted therapies in patients with PH associated with lung disease. Lastly, we discuss the potential role of immunosuppression using biologic agents in the therapeutic management of precapillary PH in SSc patients.

Converging Pathways: A Review of Pulmonary Hypertension in Interstitial Lung Disease

Pulmonary hypertension (PH) in interstitial lung disease (ILD) is relatively common, affecting up to 50% of patients with idiopathic pulmonary fibrosis (IPF). It occurs more frequently in advanced fibrotic ILD, although it may also complicate milder disease and carries significant clinical implications in terms of morbidity and mortality. Key pathological processes driving ILD-PH include hypoxic pulmonary vasoconstriction and pulmonary vascular remodelling. While current understanding of the complex cell signalling pathways and molecular mechanisms underlying ILD-PH remains incomplete, there is evidence for an interplay between the disease pathogenesis of fibrotic ILD and PH, with interest in the role of the pulmonary endothelium in driving pulmonary fibrogenesis more recently. This review examines key clinical trials in ILD-PH therapeutics, including recent research showing promise for the treatment of both ILD-PH and the underlying pulmonary fibrotic process, further supporting the hypothesis of interrelated pathogenesis. Other important management considerations are discussed, including the value of accurate phenotyping in ILD-PH and the success of the "pulmonary vascular" phenotype. This article highlights the close and interconnected nature of fibrotic ILD and PH disease pathogenesis, a perspective likely to improve our understanding and therapeutic approach to this complex condition in the future.