B-type Natriuretic Peptide in the Diagnosis of Heart Failure Related Ascites

December 19, 2012 updated by: Alberto Queiroz Farias, University of Sao Paulo

The serum albumin ascites gradient (SAAG) is a recommended tool for ascites diagnosis since values ≥1.1 g/dl are found in nearly 97% of patients with portal hypertension. However, it mislabels chronic liver disease and heart failure as the cause of ascites. Because type-B Natriuretic Peptide (BNP) is increased in several body fluids of patients with both systolic and diastolic dysfunction, it was found to be a useful marker for diagnosing heart failure and pleural effusion due to heart failure. Nevertheless, to date, the performance of BNP testing for assessing the etiology of ascites has not been examined. The current prospective study is aimed at comparing the following strategies for diagnosing heart failure as the cause of ascites: 1) SAAG plus total protein concentration in ascitic fluid (gold standard); 2) SAAG plus BNP concentration in ascitic fluid; 3) SAAG plus BNP concentration in serum; 4) serum BNP concentrations.

SAAG, ascitic fluid protein concentration, serum and ascites type-B Natriuretic Peptide and echocardiography will be performed in all patients. The final diagnosis of the cause of ascites will be adjudicated by independent physicians, blinded for the results of ascitic fluid biochemistry and BNP. Patients will be divided into four groups: Heart failure, Liver cirrhosis, concurrent heart failure and liver cirrhosis (mixed) and other causes of ascites.

Study Overview

Detailed Description

Diagnostic criteria for the cause of ascites - two independent cardiologists and two hepatologists will interview and examine the enrolled patients and review the clinical records, laboratory and imaging findings to adjudicate the correct final cause of the ascites. They will have access to all exams that patients undergo, including results of biopsies, laboratory tests, chest radiography, Doppler ultrasound, computerized tomography, magnetic resonance imaging, echocardiography and cardiac catheterism. Liver cirrhosis diagnosis will be biopsy proven or established on clinical basis in patients with known etiology of liver disease, peripheral signs of chronic liver disease, esophageal varices at endoscopy and a compatible imaging method. Heart failure will be diagnosed in patients fulfilling Framingham and/or Boston criteria and by rest echocardiography. Other causes of ascites will be diagnosed by appropriate laboratory and imaging tests and by histology when appropriate.

SAAG, ascitic fluid protein concentration and type-B Natriuretic Peptide - will be assessed in all patients. BNP measurements will be carried out according to the instructions of the manufacturer in fresh samples (ADVIA Centaur BNP Siemens Inc, San Diego, CA, USA). This assay is a fully automated two-site sandwich immunoassay based on chemiluminescent technology, standardized with synthetic purified protein preparation of human BNP (aminoacid 77 to 108), for quantitative BNP within the range of <2.0 to 5,000 pg/ml. The BNP assay is reliable in presence of increased values of several biochemical parameters usually found in patients with decompensated cirrhosis. No interference in measurement has been reported from urea up to 200 mg/dL, creatinine up to 2.5 mg/dL, unconjugated bilirubin up to 25 mg/dL, conjugated bilirubin up to 25 mg/dL, triglycerides up to 800 mg/dL, cholesterol up to 1000 mg/dL and from commonly used pharmaceutical drugs. For testing in whole blood, a 4 ml sample will be collected in an EDTA containing tube. A 10 ml of ascitic fluid will be collected at the same time by paracentesis before infusion of albumin or volume overload. Laboratory staff will be unaware of both the clinical diagnosis and routine laboratory results.

Echocardiography - will performed at rest in all patients for assessing the following parameters: ejection fraction, left atrium diameter, systolic and diastolic left ventricle diameter and diastolic dysfunction.

Base-line demographical,past medical history and laboratory test results of all patients will be recorded.

Study Type

Interventional

Enrollment (Actual)

278

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Sao Paulo, Brazil, 05403-000
        • Hospital das Clinicas. University of São Paulo
    • Espirito Santo
      • Vitoria, Espirito Santo, Brazil, 29045-402
        • Federal University of Espirito Santo

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

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • more than 18 years old.
  • must have signed the written informed consent.
  • ascites of any etiology on clinical and laboratory imaging.
  • fulfil stringent diagnostic criteria for the cause of the ascites.

Exclusion Criteria:

  • contra-indication for paracentesis (hemodynamic instability, shock, active variceal bleeding etc).
  • sepsis.
  • fulminant liver failure.
  • pregnancy.
  • history of recent transfusion of blood components and/or derivates or volume expansion.

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

  • Primary Purpose: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Heart failure
Patients must fulfill Framingham and/or Boston criteria for heart failure and have systolic or diastolic disfunction in rest echocardiography.
diagnostic tests
Other Names:
  • BNP kit ADVIA Centaur BNP Siemens Inc, San Diego, CA, USA
Active Comparator: Liver Cirrhosis
Patients must have a biopsy proven diagnosis of liver cirrhosis or the diagnosis established on clinical basis in cases of known etiology of liver disease, peripheral signs of chronic liver disease, esophageal varices at endoscopy and an imaging method with evidence of cirrhosis.
diagnostic tests
Other Names:
  • BNP kit ADVIA Centaur BNP Siemens Inc, San Diego, CA, USA
Active Comparator: Other causes of ascites
Patients must fulfill stringent diagnostic criteria for the cause of ascites, by clinical criteria, laboratory and imaging tests and histology when appropriate.
diagnostic tests
Other Names:
  • BNP kit ADVIA Centaur BNP Siemens Inc, San Diego, CA, USA
Active Comparator: Concurrent heart failure and cirrhosis
Patients must fulfill the aforementioned criteria for both conditions.
diagnostic tests
Other Names:
  • BNP kit ADVIA Centaur BNP Siemens Inc, San Diego, CA, USA

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
diagnostic accuracy of BNP for the diagnosis of ascites due to heart failure
Time Frame: 6 months
  • ROC curves of different strategies with and without BNP levels for diagnosing heart failure as the cause of ascites.
  • Sensitivity, specificity, accuracy, predictive values, likelihood ratios.
6 months

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Alberto Q. Farias, MD, PhD, University of Sao Paulo School of Medicine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

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

June 1, 2010

Primary Completion (Actual)

November 1, 2011

Study Completion (Actual)

March 1, 2012

Study Registration Dates

First Submitted

June 23, 2010

First Submitted That Met QC Criteria

June 24, 2010

First Posted (Estimate)

June 28, 2010

Study Record Updates

Last Update Posted (Estimate)

December 20, 2012

Last Update Submitted That Met QC Criteria

December 19, 2012

Last Verified

December 1, 2012

More Information

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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