Exploratory Metabolomics Study of Exhaled Breath in Pulmonary Embolism

Study Overview
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Brief Summary
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Pulmonary embolism is a frequent and recurrent pathology, especially in the elderly. It is often preventable, with high mortality and morbidity, making it a major public health issue. The clinical presentation of pulmonary embolism is non-specific and very highly variable, ranging from asymptomatic thrombus diagnosed incidentally to sudden death. The current diagnosis of pulmonary embolism is based on several diagnostic techniques, mainly non-invasive, which should be used sequentially. We propose to sample the volatile organic compounds using a device that allows them to be trapped on polymer cartridges. Sampling will be performed under monitoring of respiratory pressure and a capnograph to collect alveolar and upper respiratory tract air separately without contamination of the oral cavity or sinuses. This exploratory metabolic analysis will be non-targeted (analysis of all molecules detectable without a priori). The main objective of the study is to identify specific metabolic profiles to predict the results of ventilation-perfusion pulmonary tomoscintigraphy in subjects undergoing this examination for suspected acute pulmonary embolism. Secondary purposes : To identify metabolic profiles to be used to predict, in combination with clinical probability scores, the results of ventilation-perfusion pulmonary tomoscintigraphy in subjects undergoing this examination for suspected acute pulmonary embolism.; To correlate metabolic profiles with the topography of embolized lung territories

Official Title
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Exploratory Metabolomics Study of Exhaled Breath in Pulmonary Embolism

Conditions
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Pulmonary Embolism

Intervention / Treatment
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* Other: Pulmonary embolism diagnosis by nuclear medicine imaging


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female, at least 18 years old Patients with clinical suspected pulmonary embolism Patient willing and able to provide informed consent Exclusion Criteria: Contraindications to pulmonary ventilator-perfusion tomoscintigraphy All types of thrombolytic or anticoagulant treatment Diagnosis of pulmonary embolism established prior to inclusion in the study Massive pulmonary embolism (systolic pressure < 90 mm Hg) Pregnancy Breastfeeding

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Presence of pulmonary embolism<br>≥ 1 noninfused and normoventilated segment(s) by pulmonary tomoscintigraphy | Other: Pulmonary embolism diagnosis by nuclear medicine imaging<br>* nuclear medicine imaging<br>|
| No pulmonary embolism<br>Pulmonary perfusion without anomaly (segmental or sub-segmental) by pulmonary tomoscintigraphy | Other: Pulmonary embolism diagnosis by nuclear medicine imaging<br>* nuclear medicine imaging<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| quantitative comparison of metabolic profiles | The quantitative variables compared between the two contributive groups are the relative quantities of volatile organic compounds (metabolites) detected by chromatographic techniques coupled with mass spectrometry in exhaled air samples. | Metabolites are collected immediately before pulmonary tomoscintigraphy | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Wells score or revised Geneva score | The first secondary outcome consists of the primary outcome (quantitative metabolic variables) to which are added quantitative variables of clinical probability score for pulmonary embolism (Wells score or revised Geneva score). | Clinical scores are collected immediately before pulmonary tomoscintigraphy | 
| number and location of deficient segments on ventilation-perfusion pulmonary tomoscintigraphy. | number and location of deficient segments on ventilation-perfusion pulmonary tomoscintigraphy. | day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Early diagnosis, Mass spectrometry, Volatile Organic Compounds, Metabolomics, Breath Tests, Biomarkers