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

The role of N-terminal pro-brain natriuretic peptide, chromogranin A, and 5-hydroxyindoleacetic acid in screening for carcinoid heart disease

Carcinoid heart disease (CHD) is a serious complication for patients with neuroendocrine tumors (NETs), and early detection is crucial. We aimed to investigate N-terminal pro-brain natriuretic peptide (NT-proBNP), chromogranin A (CgA), and plasma 5-hydroxyindoleacetic acid (P-5-HIAA) as a screening tool for detection of CHD. We prospectively included patients with disseminated small intestinal NETs (SI-NETs) and performed transthoracic echocardiography (TTE), questionnaires, and biochemical assessment of NT-proBNP, CgA, and P-5-HIAA. The presence and severity of CHD was assessed using a scoring system based on echocardiographic characteristics. A total of 93 patients were included in the final analysis. Fifteen (16%) were diagnosed with CHD. The median NT-proBNP (219 ng/L vs. 124 ng/L, p = .05), CgA (3930 pmol/L vs. 256 pmoL/L, p < .0001), and P-5-HIAA (1160 nmol/L vs. 210 nmoL/L, p < .0001) were significantly higher in patients with CHD compared to non-CHD patients. For NT-proBNP, the area under the receiver operating characteristic (AUROC) curve for detection of CHD was 0.67 (95% CI: 0.50-0.84), and at a 260 ng/L cutoff level, the sensitivity and specificity were 46% and 79%. For CgA, the AUROC was 0.91 (95% CI: 0.84-0.97), and at a cutoff level of 598 pmol/L, the sensitivity and specificity were 100% and 69%. For P-5-HIAA, the AUROC was 0.89 (95% CI: 0.80-0.98), and at a cutoff level of 752 nmol/L, the sensitivity and specificity were 92% and 85%. In conclusion, CgA and P-5-HIAA proved excellent markers of CHD while NT-proBNP lacked the required diagnostic accuracy to be used as a screening tool.

Clinical assessment for pulmonary hypertension in interstitial lung disease

BACKGROUND

Pulmonary hypertension (PH) is an important complication of interstitial lung disease (ILD), as its development confers a poor prognosis. There are no specific recommendations for methods of assessment for PH in ILD populations.

AIMS

To determine current assessment practices for PH in an Australian ILD centre.

METHODS

In the Austin Health ILD database, 162 consecutive patients with idiopathic pulmonary fibrosis or connective tissue disease-associated ILD were identified and retrospectively evaluated for methods of PH assessment with transthoracic echocardiography (TTE), serum N-terminal pro-brain natriuretic peptide (NT-proBNP) and right heart catheterisation (RHC) in relation to patient demographic and physiological parameters.

RESULTS

The median follow-up was 30 (14.4-56.4) months. At baseline, vital capacity was 80.0 ± 18.4% predicted, and diffusing capacity for carbon monoxide was 59.6 ± 15.2% predicted. Evaluation for PH was performed in 147 (90.7%) patients, among whom 105 (64.8%) had TTE performed at least once. At the initial TTE, 33.7% patients had high probability of PH, defined as RVSP >40 mmHg + RAp and/or right ventricular dysfunction. At the time of the most recent TTE, these criteria were met in 45 (52.3%) patients. Elevated serum NT-proBNP levels during the first year were observed in 47 (38.8%) patients. Only 14 (8.6%) patients had RHC.

CONCLUSION

Our institutional PH assessment practice in ILD demonstrates a substantial prevalence of probable PH at baseline. As new therapies emerge for the treatment of PH in ILD, well-defined screening practices are important in this population for early identification and optimal management.

The PH-ILD Detection tool: External validation and use in patients with ILD

Pulmonary hypertension (PH) results in increased morbidity and mortality in patients with interstitial lung disease (ILD). Early recognition of PH in this population is essential for planning diagnostic testing, initiating therapy, and evaluating for lung transplantation. The previously developed PH-ILD Detection tool has significant potential in the evaluation and treatment of ILD patients; the aim of this study was to validate the tool in an independent, multicenter cohort of patients. We conducted a retrospective review of prospectively collected data from 161 ILD patients. Patients were stratified into low- (n = 78, 48.4%), intermediate- (n = 54, 33.5%), and high-risk (n = 29, 18.0%) groups based on the score obtained with the tool. Intermediate- and high-risk patients underwent follow-up echocardiogram (TTE); 49.4% (n = 41) had an abnormal TTE suggestive of underlying PH. These patients underwent right heart catheterization; PH-ILD was diagnosed in 73.2% (n = 30) of these cases. The PH-ILD Detection tool has a sensitivity of 93.3%, specificity of 90.9%, and area-under-the-curve of 0.921 for diagnosing PH in ILD patients, validating the findings from the original study and establishing the tool as a fundamental resource for early recognition of PH in ILD patients.

Pulmonary hypertension in interstitial lung disease: Clinical trial design and endpoints: A consensus statement from the Pulmonary Vascular Research Institute's Innovative Drug Development Initiative-Group 3 Pulmonary Hypertension

Pulmonary hypertension (PH) associated with interstitial lung disease (ILD) is an attractive target for clinical trials of PH medications. There are many factors that need to be considered to prime such studies for success. The patient phenotype most likely to respond to the intervention requires weighing the extent of the parenchymal lung disease against the severity of the hemodynamic impairment. The inclusion criteria should not be too restrictive, thus enabling recruitment. The trial should be of sufficient duration to meet the chosen endpoint which should reflect how the patient feels, functions, or survives. This paper summarizes prior studies in PH-ILD and provides a framework of the type of studies to be considered. Inclusion criteria, clinical trial endpoints, and pharmacovigilance in the context of PH-ILD trials are also addressed. Through lessons learnt from prior studies, suggestions and guidance for future clinical trials in PH-ILD are also provided.

Natriuretic peptides in elderly patients with chronic obstructive pulmonary disease

Background

Natriuretic peptides (NPs) are considered a useful tool for diagnosing the cardiac or pulmonary origin of acute dyspnea in the emergency department. The aim of this study was to evaluate NP in elderly patients with chronic obstructive pulmonary disease (COPD).

Materials and methods

In the PubMed and Hinari databases, we identified 465 comprehensive articles in English, published in the years 1990–2021, which provided information on natriuretic peptides in elderly patients with COPD. The final bibliography contains 49 relevant sources.

Results

NP, specially BNP/NT-proBNP values are frequently elevated in patients with COPD, reflecting three complex aspects of the interrelated cardio-pulmonary continuum: (1) left ventricular systolic and diastolic dysfunction, (2) pulmonary vascular and right heart remodeling, (3) global cardiovascular risk and comorbidities. The additional increase in BNP/NT-proBNP values during acute exacerbation of COPD is probably a marker for both, acute estate of COPD and varying degrees of underlying cardiopulmonary disease.

The results of the studies suggest the role of natriuretic peptides as relevant prognostic biomarkers not only for patients with cardiovascular disease, but also for patients with chronic obstructive pulmonary disease, which has an important clinical implication. The determination of these biomarkers in patients with chronic obstructive pulmonary disease allows stratification for prognosis: it is able to select a subgroup of patients at higher risk, which requires increased attention and optimization of treatment.

Conclusion

NPs, especially BNP/NT-proBNP are relevant prognostic biomarkers not only for patients with cardiovascular disease, but also for patients with COPD, acute exacerbations and haemodynamic disorders like PH and cor pulmonale. Estimating BNP/NT-proBNP in COPD patients has an important clinical implication: it allows the selection of a subgroup of patients at higher risk, which requires increased attention and treatment optimization.

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.

Heterogeneity in Unclassifiable Interstitial Lung Disease. A Systematic Review and Meta-Analysis

RATIONALE

Accurate diagnosis of interstitial lung disease is necessary to identify the most appropriate management strategy and to inform prognosis. Many patients cannot be provided a confident diagnosis, despite an exhaustive search for potential etiologies and review in a multidisciplinary conference, and are consequently labeled with unclassifiable interstitial lung disease.

OBJECTIVES

To systematically review and meta-analyze previous studies reporting on the diagnostic criteria, prevalence, clinical features, and outcome of unclassifiable interstitial lung disease.

METHODS

MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials databases were systematically searched for all studies related to unclassifiable interstitial lung disease published before September 1, 2017. Two authors independently screened each citation for eligibility criteria, serially reviewing the title, abstract, and full-text manuscript, and then abstracted data pertaining to the study objectives from eligible studies. Articles were stratified by risk of selection bias, whether the publication stated that patients were reviewed in a multidisciplinary discussion, and by the frequency of surgical lung biopsy. Meta-analyses and meta-regression were performed to calculate the pooled prevalence of unclassifiable interstitial lung disease within an interstitial lung disease population and within specific subgroups to identify reasons for across-study heterogeneity.

RESULTS

The search identified 10,130 unique citations, 313 articles underwent full-text review, and eligibility criteria were met in 88 articles. Twenty-two studies were deemed low risk of selection bias, including 1,060 patients with unclassifiable interstitial lung disease from a total of 10,174 patients with interstitial lung disease. The terminology and definition of unclassifiable interstitial lung disease varied substantially across publications, with inconsistent diagnostic criteria and evaluation processes. The prevalence of unclassifiable interstitial lung disease was 11.9% (95% confidence interval, 8.5-15.6%), with lower prevalence in centers that reported use of a formal multidisciplinary discussion of cases (9.5% vs. 14.5%). Four articles reported survival of unclassifiable interstitial lung disease, with 1-year, 2-year, and 5-year survival of 84% to 89%, 70% to 76%, and 46% to 70%, respectively.

CONCLUSIONS

This systematic review and meta-analysis shows that unclassifiable interstitial lung disease is common but has substantial heterogeneity and inconsistent definitions across interstitial lung disease cohorts. These findings highlight important limitations in multicenter studies of fibrotic interstitial lung disease and the need for a standardized approach to interstitial lung disease diagnostic classification.

Idiopathic Pulmonary Fibrosis for Cardiologists: Differential Diagnosis, Cardiovascular Comorbidities, and Patient Management

The presence of rare comorbidities in patients with cardiovascular disease (CVD) presents a diagnostic challenge to cardiologists. In evaluating these patients, cardiologists are faced with a unique opportunity to shorten diagnosis times and direct patients towards correct treatment pathways. Idiopathic pulmonary fibrosis (IPF), a type of interstitial lung disease (ILD), is an example of a rare disease where patients frequently demonstrate comorbid CVD. Both CVD and IPF most commonly affect a similar patient demographic: men over the age of 60 years with a history of smoking. Moreover, IPF and heart failure (HF) share a number of symptoms. As a result, patients with IPF can be misdiagnosed with HF and vice versa. This article aims to increase awareness of IPF among cardiologists, providing an overview for cardiologists on the differential diagnosis of IPF from HF, and describing the signs and symptoms that would warrant referral to a pulmonologist with expertise in ILD. Once patients with IPF have received a diagnosis, cardiologists can have an important role in managing patients who are candidates for a lung transplant or those who develop pulmonary hypertension (PH). Group 3 PH is one of the most common cardiovascular complications diagnosed in patients with IPF, its prevalence varying between reports but most often cited as between 30% and 50%. This review summarizes the current knowledge on Group 3 PH in IPF, discusses data from clinical trials assessing treatments for Group 1 PH in patients with IPF, and highlights that treatment guidelines recommend against these therapies in IPF. Finally, this article provides the cardiologist with an overview on the use of the two approved treatments for IPF, the antifibrotics pirfenidone and nintedanib, in patients with IPF and CVD comorbidities. Conversely, the impact of treatments for CVD comorbidities on patients with IPF is also discussed.

Funding: F. Hoffmann-La Roche, Ltd.

Plain Language Summary: Plain language summary available for this article.

Role of Pro-Brain Natriuretic Peptide Serum Concentration in the Detection of Pulmonary Hypertension in Patients With End-Stage Lung Diseases Referred for Lung Transplantation

BACKGROUND

Serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration is elevated in patients with pulmonary hypertension (PH); however, its role in the detection of PH associated with lung disease is not well established.

AIM

The aim of this study was to assess the value of NT-proBNP in the detection of PH in patients with end-stage lung disease (esLD) referred for lung transplantation.

MATERIALS AND METHODS

The study population consisted of 65 patients: 37 with idiopathic pulmonary fibrosis (IPF), 20 with chronic obstructive pulmonary disease, and 8 patients with other interstitial lung diseases (75% men, mean age 53.3 ± 9.5 years). Serum concentration of NT-proBNP was assessed with an immunoradiometric assay kit. The mean pulmonary artery pressure (mPAP) was measured using a Swan-Ganz catheter. PH was defined as mPAP ≥ 25 mm Hg.

RESULTS

Median NT-proBNP concentrations were significantly higher in patients with PH than in patients without PH: 139 (49-1236) pg/mL vs 67 (38-116) pg/mL, respectively; P = .016. Receiver operating characteristic (ROC) analysis revealed that NT-proBNP concentration higher than 131.5 pg/mL was a predictor of PH with good specificity (81%) and positive predictive value (78.9%) but low sensitivity (55.6%) and negative predictive value (58.6%). The area under the ROC curve of serum NT-proBNP concentration for PH was 0.71 (95% confidence interval 0.57-0.85, P = .039).

CONCLUSION

Serum concentration of NT-proBNP may be useful in the diagnosis of PH in patients with esLD referred for lung transplantation.