Comparison of the Best Method for Measuring Anti-Xa Activity in Children Receiving Unfractionated Heparin in Cardiac Intensive Care (COMPAXE-HNF) (COMPAXE-HNF)

January 16, 2026 updated by: Centre Hospitalier Universitaire de la Réunion
This study aims to compare the accuracy of two different blood sampling methods from a central venous catheter (CVC) for measuring anti-Xa activity in children receiving unfractionated heparin (UFH) from this CVC. The results will be compared to a "gold standard" sample taken from an arterial catheter (KTA) whithout UFH. The objective is to identify a more reliable method for monitoring UFH, thereby reducing the risk of bleeding or thrombosis in these patients.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

  • Scientific Justification: UFH is widely used in pediatric cardiac intensive care for its short half-life and availability of an antidote. However, monitoring its effect via anti-Xa activity is challenging. The standard method of sampling from a CVC is known to be prone to heparin contamination, leading to inaccurate results (over- or under-anticoagulation). This lack of precision can lead to dangerous complications like major bleeding or thrombotic events. As studies by Palermo et al. (1980) and Bauman et al. (2012) have shown, the unreliability of CVC samples justifies the search for a safer alternative. The arterial catheter (KTA) provides a contamination-free "gold standard," making it the ideal comparison for evaluating the more reliable sampling method.
  • Procedure: The study will compare two CVC sampling methods (a standard flush protocol and a new experimental method) against the gold standard (KTA sampling without UFH)
  • Follow-up: The study will be conducted over three consecutive days. Each day, three sets of blood samples will be collected every 6 hours per patient (KTA, standard CVC, and experimental CVC).

Study Type

Interventional

Enrollment (Estimated)

22

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 Contact

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

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Minors aged 0 to 17 inclusive
  • Weight greater than or equal to 3.5 kg
  • Admitted to resuscitation or congenital cardiac intensive care
  • Requiring treatment with unfractionated heparin at curative doses administered via central venous access
  • Equipped with a central arterial and venous catheter
  • Affiliated with or beneficiary of a social security scheme
  • Free, informed, and written consent signed by one of the two representatives of parental authority and the investigator (no later than the day of inclusion and before any examination required by the research).

Exclusion Criteria:

  • Newborns < 37 weeks gestation
  • Patients treated by a humanitarian organization

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: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: anti-Xa activity monitoring
All patients included in the study
Procedure: blood sampling for measuring anti-Xa activity

Each patient included in the study will have a series of three samples taken every 4 hours for 3 days:

  • Sample taken from a non-heparinized arterial catheter (Gold Standard), performed as part of routine care: Method ①
  • Sample taken from a central venous catheter without stopping the HNF: Method ②
  • Sampling from a central venous catheter with an HNF pause: Method ③

At each anti-Xa activity check in the included patients, the nurse will take the 3 blood samples.

The order in which samples ② and ③ are taken will be determined by randomization.

Procedure: measurement of anti-XA activity

Each patient will have, each time that anti-Xa activity needs to be measured, three successive samples taken:

  • Sample taken from a non-heparinized arterial catheter (gold standard), performed as part of routine care: Method ①
  • Sample taken from a central venous catheter without stopping the HNF: Method ②
  • Sample from central venous catheter with HNF pause: Method ③

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Measurement of anti-Xa activity (in IU/mL) from two samples (with and without HNF pause) taken from the central venous line where HNF is administered, compared to a sample taken from a non-heparinized arterial catheter (i.e., gold standard).
Time Frame: "From enrollment to the end of study at 72hours"

Anti-Xa activity and APTT measurements will be performed at the university hospital's central laboratory, which guarantees the consistency of the reagents, automated systems, and techniques used.

The recommended therapeutic target is between 0.3 and 0.6 IU/mL.
"From enrollment to the end of study at 72hours"

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Measurement of APTT from two samples (with and without HNF pause) taken from the central venous line where HNF is administered, compared to a sample taken from a non-heparinized arterial catheter (i.e., gold standard).
Time Frame: "From enrollment to the end of study at 72 hours"

Activated partial thromboplastin time (APTT):

Mainly used in the United States and in some French intensive care units, the APTT provides an overall assessment of the activity of several coagulation factors: factor I (or fibrinogen), factor II (or prothrombin), factor V, factor VIII, factor IX, factor X, factor XI, and factor XII. (Figure 1) The APTT is a measure of blood clotting time. It is expressed as a ratio between the patient's APTT and a "control" APTT, which is that of the laboratory. It is expressed in seconds.

Normal values for the patient APTT/control APTT ratio are between 0.80 s and 1.20 s.

  • Above this range: the risk of bleeding increases.
  • Below this range: treatment is ineffective, with a risk of clot formation.
"From enrollment to the end of study at 72 hours"
Measurement of APTT and anti-Xa activity (in IU/mL) from a sample taken from a non-heparinized arterial catheter (i.e., gold standard)
Time Frame: From enrollment to the end of study at 72 hours
The TCA measurement is performed in the same way.
From enrollment to the end of study at 72 hours

Collaborators and Investigators

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

Sponsor

Centre Hospitalier Universitaire de la Réunion

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)

April 1, 2026

Primary Completion (Estimated)

April 5, 2029

Study Completion (Estimated)

April 5, 2029

Study Registration Dates

First Submitted

January 16, 2026

First Submitted That Met QC Criteria

January 16, 2026

First Posted (Actual)

January 26, 2026

Study Record Updates

Last Update Posted (Actual)

January 26, 2026

Last Update Submitted That Met QC Criteria

January 16, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2025/RUN/0031
  • Ethics Committee (Other Identifier: Marmara University Faculty of Dentistry)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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