Predictors of Pulmonary Embolism in Interstitial Lung Disease With Worsening Symptoms

July 22, 2026 updated by: Ziad Abd Elhady Sayed Abd Elaal, Assiut University

Predictors of Pulmonary Embolism in Patients With Interstitial Lung Diseases Presenting With Worsening Respiratory Symptoms

People with interstitial lung disease (ILD) can sometimes experience a sudden and severe worsening of their breathing. While this can be caused by a flare-up of the lung disease itself, it can also be caused by a blood clot in the lungs, known as a pulmonary embolism (PE). It is often difficult for doctors to tell the difference between these two emergencies because their symptoms, such as shortness of breath and low oxygen levels, are very similar. Traditional scoring systems used to predict blood clots are often less accurate for patients who already have chronic lung diseases like ILD.

The main goal of this observational study is to find better, more reliable ways to predict which ILD patients with worsening breathing symptoms actually have a pulmonary embolism.

Researchers will observe 70 adult patients with ILD who come to the hospital with a sudden worsening of their symptoms (such as shortness of breath, chest pain, or low oxygen) and who require a specific type of CT scan (Computed Tomography Pulmonary Angiography, or CTPA) as part of their standard medical care to check for blood clots.

The study will compare the patients whose CT scan confirms a blood clot to those whose scan does not show a clot. By comparing these two groups, the research team will evaluate various clinical signs, routine blood tests, novel inflammatory markers, and heart/lung imaging details.

Identifying strong predictors of pulmonary embolism in this specific group of patients could help doctors diagnose lung blood clots faster and more accurately, leading to better clinical decision-making and improved patient outcomes

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Interstitial lung diseases (ILDs) comprise a heterogeneous group of diffuse parenchymal lung disorders characterized by inflammation and fibrosis, often leading to progressive respiratory failure. Patients with ILD carry a heightened risk of venous thromboembolism, specifically pulmonary embolism (PE), driven by chronic inflammation, endothelial dysfunction, hypoxemia, reduced mobility, and a systemic pro-thrombotic state. The development of PE in ILD patients is associated with prolonged hospitalization, increased morbidity, and poor survival outcomes.

Diagnosing PE in this specific population remains clinically challenging because the acute manifestations, such as worsening dyspnea and hypoxemia, closely mimic those of an acute ILD exacerbation. Furthermore, conventional clinical prediction models, such as the Wells and Revised Geneva scores, frequently exhibit limited diagnostic accuracy in this cohort because respiratory distress and baseline hypoxia are already common underlying features of ILD.

To address this diagnostic gap, this prospective observational study will evaluate patients with a confirmed diagnosis of ILD who present with an acute, unexplained worsening of respiratory symptoms and undergo Computed Tomography Pulmonary Angiography (CTPA).

Comprehensive clinical, laboratory, and radiological data will be systematically collected for all participants to identify independent predictors of PE. The study workflow includes:

  • Clinical Scoring: Calculation of established pre-test probability and mortality risk scores, including the traditional and simplified Wells score, Revised Geneva score, Pulmonary Embolism Severity Index (PESI), and Simplified PESI (SPESI).
  • Laboratory Assessment: Evaluation of novel inflammatory indices, including the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). Additional laboratory profiling includes D-dimer, C-reactive protein (CRP), serum total protein, serum albumin, renal and liver function tests, and arterial blood gas analysis to calculate the A-a oxygen gradient.
  • Radiological & Echocardiographic Evaluation: High-Resolution CT (HRCT) will be used to quantify ILD disease severity and extent via the Warrick Score. CTPA scans will be analyzed for embolus location, right ventricular (RV) diameter, RV/LV diameter ratio, and main pulmonary artery diameter. When available, transthoracic echocardiography will assess RV size and systolic function, TAPSE, fractional area change, McConnell sign, the 60/60 sign, and inferior vena cava collapsibility.

Through multivariable logistic regression and Receiver Operating Characteristic (ROC) curve analysis, the study will compare these parameters between patients with CTPA-confirmed PE and those with negative scans. The goal is to validate the predictive strength of these biomarkers and imaging parameters, supporting the development of a disease-specific diagnostic prediction model to enhance clinical decision-making for ILD patients.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
70

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

N/A

Sampling Method

Non-Probability Sample

Study Population

The study population consists of adult patients (aged 18 years and older) with a confirmed diagnosis of interstitial lung disease (ILD) who are admitted to the Chest Department and Respiratory Intensive Care Unit at Assiut University Hospital, Egypt. Eligible participants are those presenting with an acute, unexplained worsening of respiratory symptoms, such as dyspnea, hypoxemia, chest pain, or syncope, or those who have a clinical suspicion of pulmonary embolism and are undergoing Computed Tomography Pulmonary Angiography (CTPA) as part of their routine clinical care.

Description

Inclusion Criteria:

  • Age ≥ 18 years
  • Confirmed diagnosis of ILD based on multidisciplinary discussion and HRCT findings, with or without histopathological confirmation
  • Acute unexplained worsening of dyspnea, hypoxemia, chest pain, syncope, or clinical suspicion of PE
  • Undergoing CTPA as part of routine clinical management
  • Provision of informed consent

Exclusion Criteria:

  • Age < 18 years
  • Pregnancy
  • Previously diagnosed acute pulmonary embolism receiving anticoagulant therapy
  • Active malignancy
  • Known inherited or acquired thrombophilia
  • Acute myocardial infarction or ischemic stroke within the previous month
  • Major surgery or trauma within four weeks
  • Severe renal impairment contraindicating contrast-enhanced CTPA

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
ILD with Pulmonary Embolism (Cases)
This group consists of adult patients (aged 18 years and older) with a confirmed diagnosis of Interstitial Lung Disease (ILD) who present with an acute unexplained worsening of respiratory symptoms (such as dyspnea, hypoxemia, chest pain, or syncope). These patients undergo Computed Tomography Pulmonary Angiography (CTPA) as part of routine clinical management and are confirmed to have acute pulmonary embolism.
ILD without Pulmonary Embolism (Controls)
This group consists of adult patients (aged 18 years and older) with a confirmed diagnosis of Interstitial Lung Disease (ILD) who present with an acute unexplained worsening of respiratory symptoms (such as dyspnea, hypoxemia, chest pain, or syncope). These patients undergo Computed Tomography Pulmonary Angiography (CTPA) as part of routine clinical management but have negative findings, confirming the absence of acute pulmonary embolism.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Presence of Acute Pulmonary Embolism
Time Frame: Baseline
The primary outcome is the binary assessment (presence or absence) of an acute pulmonary embolism, which is definitively diagnosed and confirmed using Computed Tomography Pulmonary Angiography (CTPA) imaging.
Baseline

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Rate of Admission to the Respiratory Intensive Care Unit (RICU)
Time Frame: From hospital admission to hospital discharge, assessed up to 30 days.
The proportion of patients requiring admission to the Respiratory Intensive Care Unit (RICU) for advanced management during their acute worsening respiratory episode.
From hospital admission to hospital discharge, assessed up to 30 days.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Assiut University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 22, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 22, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 27, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 22, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PE Predictors in ILD Patients

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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