Comparing N-terminal-proB-type Natriuretic Peptide With Other Criteria in Pleural Fluid Analysis

Study Overview
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Brief Summary
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To assess the discriminative properties of pleural fluid (PF) N-terminal-proB-type-natriuretic-peptide (NTproBNP) levels in identifying heart failure (HF)-associated pleural effusions (PE).

Detailed Description
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Objective: To assess the discriminative properties of pleural fluid (PF) N-terminal-proB-type-natriuretic-peptide (NTproBNP) levels in identifying heart failure (HF)-associated pleural effusions (PE). Hypothesis to be tested: The PF NTproBNP levels are superior to existing methods including Light's criteria, serum/pleural fluid (S/PF) protein gradient, and albumin gradient, in identifying transudates and distinguishing between HF- and non-HF-associated PE. Design and subjects: A prospective case-control study involving patients with PE requiring thoracentesis, caused by hypervolaemia due to HF, diseases other than HF, and patients with pleural effusion without hypervolaemia. Patient characteristics, PF results and effusion aetiology will be analysed. Patient outcomes will be followed up to 3 months to confirm the aetiology of PE. Clinical management of patients will not be affected. Study instruments: PF of recruited patients will be analysed for albumin, protein, lactate dehydrogenase (LDH) levels and NTproBNP. The diagnosis of HF will be based on clinical features, serum NTproBNP and echocardiogram. Main outcome measures: The performance of PF NTproBNP level in identifying HF-associated PE. Data analysis: The PF NTproBNP level will be compared between effusions of different aetiologies. The optimal pleural fluid NTproBNP level with largest area under the receiver operating characteristic curve in identifying HF-associated PE will be determined. Performance of PF NTproBNP level in identifying HF-associated PE, and other biochemical criteria in identifying transudates will be compared. Echocardiographic findings will be correlated with the PF NTproBNP levels. Expected results: The diagnostic performance of PF NTproBNP will be significantly better in identifying HF-associated effusion than other biochemical criteria.

Official Title
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Comparing N-terminal-proB-type Natriuretic Peptide With Other Diagnostic Criteria in Discriminating Heart Failure-associated From Non-heart Failure-associated Pleural Effusions

Conditions
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Pleural Effusion, Heart Failure, Malignant Neoplasm, Fluid Overload, Hypoalbuminemia, Renal Failure, Cirrhosis, Infections

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients hospitalized for heart failure and pleural effusion Pleural tapping indicated for pleural fluid analysis. Aged 18 years old or above Exclusion Criteria: History of intrapleural therapy (including talc and fibrinolytic) in the ipsilateral pleural space. History of surgical decortication or pleurodesis in the ipsilateral pleural space. Ipsilateral thoracic or cardiac surgery in the past 3 months. Failure to obtain informed consent due to the patient's refusal or cognitive impairment.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Heart Failure-Associated Pleural Effusion<br>Patients with pleural effusion with an underlying aetiology of heart failure | |
| Non-Heart Failure, Fluid Overload-Associated Pleural Effusion<br>Patients with pleural effusion with an underlying aetiology of fluid overload excluding heart failure | |
| Control group<br>Patients with pleural effusion due to exudative, or non-fluid overload causes | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of the diagnostic performance of PF NTproBNP level in the diagnosis of HF-associated pleural effusions with other conventional biochemical criteria | Pleural fluid NTproBNP will be measured in patients with pleural effusion of various aetiologies including malignancy, pleural infection, heart failure and other causes of volume overload. The sensitivity and specificity of an elevated pleural fluid NTproBNP level in successfully identifying a pleural effusion due to underlying heart failure will be measured and compared against existing classification criteria for pleural effusion such as Light's Criteria, pleural-serum protein gradient or albumin gradient. | 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To measure the PF NTproBNP level in patients with pleural effusion of various aetiologies |  | 24 months | 
| Correlation of clinical factors that may affect the levels of pleural fluid NTproBNP such as echocardiographic features, presence of comorbidities, nutritional status, serum albumin level, levels of inflammatory markers and presence of infection | Clinical data of patients admitted to the hospital with pleural effusion will be measured and recorded. Statistical analysis will then be performed to evaluate for degree of correlation between the presence or severity of a clinical parameter, echocardiogram results e.g. severe valvular stenosis, or, e.g. presence of medical comorbidities or presence of concomitant infection, and the levels of NTproBNP identified in the patient's pleural fluid detected within same admission. | 24 months | 
| To correlate the PF NTproBNP levels with the echocardiographic features and prognosis of patients with heart failure |  | 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pleural fluid, heart failure, malignancy, cancer, echocardiography, infection, tuberculosis, respiratory medicine