End-Stage Kidney DiseaseCITRA-HDFNCT07618858
Comparison of Citrate and Heparin Anticoagulation During Postdilution Hemodiafiltration
A study testing Regional citrate anticoagulation and Unfractionated heparin in people with End-Stage Kidney Disease and Hemodiafiltration, run by University Medical Centre Ljubljana at 1 site in Slovenia.
Trial summary
This randomized crossover clinical trial will compare regional citrate anticoagulation (RCA) and standard heparin anticoagulation (HA) during postdilution hemodiafiltration (HDF) in chronic dialysis patients with end-stage kidney disease. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- End-Stage Kidney Disease, Hemodiafiltration, Chronic Hemodialysis
- What is being tested?
- Regional citrate anticoagulation and Unfractionated heparin
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteSlovenia
- Study dates
- 5 Jun 2026to 1 Apr 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18 years or older
- End-stage kidney disease requiring maintenance postdilution hemodiafiltration
- Stable chronic hemodialysis treatment three times weekly
- Functional arteriovenous fistula
Who cannot join
- Therapeutic anticoagulation therapy
- Dual antiplatelet therapy
- Significant coagulopathy
- Active bleeding
- Acute kidney injury
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Slovenia1 site
University Medical Centre Ljubljana
Ljubljana, 1000
Milena MD Andonova, +38615228123, milena.andonova@kclj.si
About this study
Official title: Efficiency and Biocompatibility of Postdilution Hemodiafiltration Using Different Anticoagulation Methods: A Randomized Crossover Clinical Trial
This randomized crossover clinical trial will compare regional citrate anticoagulation (RCA) and standard heparin anticoagulation (HA) during postdilution hemodiafiltration (HDF) in chronic dialysis patients with end-stage kidney disease.
The primary aim of the study is to evaluate biocompatibility during HDF by measuring markers of complement activation (C3a), platelet activation (PF4), and coagulation activation (thrombin-antithrombin complex, TAT).
Read more
Secondary aims include comparison of solute removal efficiency, including beta-2 microglobulin, phosphate, and urea removal, as well as assessment of citrate, calcium, and magnesium kinetics during citrate anticoagulation.
Twenty adult chronic dialysis patients will undergo two study HDF procedures in randomized order: one procedure using heparin anticoagulation and one procedure using regional citrate anticoagulation with a one-week interval between procedures.
The study aims to improve understanding of the effects of anticoagulation methods on hemodiafiltration biocompatibility and dialysis efficiency and may contribute to optimization of citrate anticoagulation protocols in chronic hemodiafiltration patients.
Read the detailed description
Hemodiafiltration (HDF) is an advanced renal replacement therapy combining diffusion and convection, allowing improved removal of middle and larger molecular weight solutes compared with standard hemodialysis. During extracorporeal circulation, blood contact with artificial membranes and tubing activates complement, platelets, leukocytes, and coagulation pathways, requiring anticoagulation during the procedure.
Unfractionated heparin is routinely used for anticoagulation during HDF. Regional citrate anticoagulation (RCA) is mainly used in patients at increased bleeding risk. Previous studies in hemodialysis have suggested that citrate anticoagulation may improve biocompatibility because many blood-material interactions are calcium- and magnesium-dependent. However, biocompatibility during HDF using citrate versus heparin anticoagulation has not been systematically investigated.
This prospective randomized crossover clinical trial will include 20 adult patients with end-stage kidney disease receiving maintenance postdilution hemodiafiltration three times weekly. Patients will be randomized to one of two anticoagulation sequences: heparin-citrate or citrate-heparin. Each participant will undergo two study HDF procedures separated by a one-week interval.
During heparin anticoagulation, unfractionated heparin will be administered according to body weight using standard clinical protocols. During citrate anticoagulation, 8% trisodium citrate infusion and calcium-free dialysate will be used, with continuous calcium chloride substitution adjusted according to ionized calcium levels.
Biocompatibility markers including complement activation marker C3a, platelet factor 4 (PF4), thrombin-antithrombin complex (TAT), blood cell counts, and coagulation parameters will be assessed before HDF, after 15 minutes, and at the end of the procedure.
Dialysis efficiency will be evaluated by measurement of reduction ratios and total removal of beta-2 microglobulin, phosphate, and urea using partial dialysate collection methodology.
Additional secondary outcomes include assessment of citrate, calcium, and magnesium kinetics during RCA-HDF, visual clotting score evaluation of the extracorporeal circuit, and optimization of citrate anticoagulation protocols during postdilution HDF.
The study may contribute to improved understanding of anticoagulation-related biocompatibility during HDF and support wider evidence-based use of regional citrate anticoagulation in chronic dialysis patients.
- Being tested
- Regional citrate anticoagulation, Unfractionated heparin
- Keywords
- Citrate anticoagulation, Heparin anticoagulation, Hemodiafiltration, Dialysis, Biocompatibility, Beta-2 microglobulin, Complement activation, Regional citrate anticoagulation, Chronic dialysis, Thrombin-antithrombin complex, Platelet factor 4
- Medical subject headings
- Kidney Failure, Chronic, Renal Insufficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Regional citrate anticoagulationDrug
Regional citrate anticoagulation using 8% trisodium citrate infusion during postdilution hemodiafiltration with calcium substitution adjusted according to ionized calcium levels.
Unfractionated heparinDrug
Standard unfractionated heparin anticoagulation administered according to routine clinical protocol during postdilution hemodiafiltration.
| Study group | Role | What they receive |
|---|---|---|
| Citrate anticoagulation | Experimental | Participants will undergo postdilution hemodiafiltration using regional citrate anticoagulation with 8% trisodium citrate infusion and calcium substitution according to ionized calcium measurements Receives: Drug: Regional citrate anticoagulation |
| Heparin anticoagulation | Active comparator | Participants will undergo postdilution hemodiafiltration using standard unfractionated heparin anticoagulation according to routine clinical protocol. Receives: Drug: Unfractionated heparin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Biocompatibility markers (C3a, PF4, TAT)
Comparison of complement activation marker C3a, platelet factor 4 (PF4), and thrombin-antithrombin complex (TAT) concentrations between citrate and heparin anticoagulation during postdilution hemodiafiltration.
Measured: Before hemodiafiltration, after 15 minutes of treatment, and immediately before the end of the procedure.
Secondary outcomes (5)
Beta-2 microglobulin removal
Reduction ratio and total removal of beta-2 microglobulin during hemodiafiltration.
Measured: Before, after 30 minutes and at the end of the procedure hemodiafiltration procedure.
instantaneous urea clearance after 30 minutes
instantaneous urea clearance after 30 minutes
Measured: after 30 minutes of dialysis
p-cresyl sulfat removal
P-cresyl sulfat removal before, after 30 minutes and at the end of the procedure
Measured: P-cresyl sulfat removal before, during and to the end of procedure
Ionized calcium kinetics
During citrate anticoagulation procedure
Measured: During the 4-hour hemodiafiltration procedure
Extracorporeal circuit clotting score
Measured: At the end of hemodiafiltration procedure.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jun 2026
- Study start5 Jun 2026 (estimated)
- Primary completion15 Dec 2026 (estimated)
- Study completion1 Apr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for End-Stage Kidney DiseaseStudies of the same condition, open and under way.
- More trials run by University Medical Centre LjubljanaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Participants will undergo two study hemodiafiltration procedures in randomized order: one procedure using heparin anticoagulation and one procedure using regional citrate anticoagulation, with a one-week interval between procedures.
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Medical Centre Ljubljana
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Milena Andonova, University Medical Centre Ljubljana
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07618858
- Sponsor's protocol ID
- BIOCOMP-HDF
- Other IDs
- 0120-610/2025-2711-5
- Acronym
- CITRA-HDF
- Status last verified
- May 2026
- First submitted
- 16 May 2026
- Last updated
- 1 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be publicly available due to privacy and institutional data protection regulations.
Study at a glance
From the registry record, last updated by the sponsor on 1 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficiency and Biocompatibility of Postdilution Hemodiafiltration Using Different Anticoagulation Methods: A Randomized Crossover Clinical Trial
- ClinicalTrials.gov ID
- NCT07618858
- Acronym / sponsor ID
- CITRA-HDF / BIOCOMP-HDF
- Keywords
- Citrate anticoagulation, Heparin anticoagulation, Hemodiafiltration, Dialysis, Biocompatibility, Beta-2 microglobulin, Complement activation, Regional citrate anticoagulation
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University Medical Centre LjubljanaUniversity, hospital or other
- Study start
- 5 Jun 2026 (estimated)
- Primary completion
- 15 Dec 2026 (estimated)
- Study completion
- 1 Apr 2027 (estimated)
- First posted
- 1 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This randomized crossover clinical trial will compare regional citrate anticoagulation (RCA) and standard heparin anticoagulation (HA) during postdilution hemodiafiltration (HDF) in chronic dialysis patients with end-stage kidney disease.
The primary aim of the study is to evaluate biocompatibility during HDF by measuring markers of complement activation (C3a), platelet activation (PF4), and coagulation activation (thrombin-antithrombin complex, TAT).
Secondary aims include comparison of solute removal efficiency, including beta-2 microglobulin, phosphate, and urea removal, as well as assessment of citrate, calcium, and magnesium kinetics during citrate anticoagulation.
Twenty adult chronic dialysis patients will undergo two study HDF procedures in randomized order: one procedure using heparin anticoagulation and one procedure using regional citrate anticoagulation with a one-week interval between procedures.
The study aims to improve understanding of the effects of anticoagulation methods on hemodiafiltration biocompatibility and dialysis efficiency and may contribute to optimization of citrate anticoagulation protocols in chronic hemodiafiltration patients.
Detailed description
Hemodiafiltration (HDF) is an advanced renal replacement therapy combining diffusion and convection, allowing improved removal of middle and larger molecular weight solutes compared with standard hemodialysis. During extracorporeal circulation, blood contact with artificial membranes and tubing activates complement, platelets, leukocytes, and coagulation pathways, requiring anticoagulation during the procedure.
Unfractionated heparin is routinely used for anticoagulation during HDF. Regional citrate anticoagulation (RCA) is mainly used in patients at increased bleeding risk. Previous studies in hemodialysis have suggested that citrate anticoagulation may improve biocompatibility because many blood-material interactions are calcium- and magnesium-dependent. However, biocompatibility during HDF using citrate versus heparin anticoagulation has not been systematically investigated.
This prospective randomized crossover clinical trial will include 20 adult patients with end-stage kidney disease receiving maintenance postdilution hemodiafiltration three times weekly. Patients will be randomized to one of two anticoagulation sequences: heparin-citrate or citrate-heparin. Each participant will undergo two study HDF procedures separated by a one-week interval.
During heparin anticoagulation, unfractionated heparin will be administered according to body weight using standard clinical protocols. During citrate anticoagulation, 8% trisodium citrate infusion and calcium-free dialysate will be used, with continuous calcium chloride substitution adjusted according to ionized calcium levels.
Biocompatibility markers including complement activation marker C3a, platelet factor 4 (PF4), thrombin-antithrombin complex (TAT), blood cell counts, and coagulation parameters will be assessed before HDF, after 15 minutes, and at the end of the procedure.
Dialysis efficiency will be evaluated by measurement of reduction ratios and total removal of beta-2 microglobulin, phosphate, and urea using partial dialysate collection methodology.
Additional secondary outcomes include assessment of citrate, calcium, and magnesium kinetics during RCA-HDF, visual clotting score evaluation of the extracorporeal circuit, and optimization of citrate anticoagulation protocols during postdilution HDF.
The study may contribute to improved understanding of anticoagulation-related biocompatibility during HDF and support wider evidence-based use of regional citrate anticoagulation in chronic dialysis patients.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Participants will undergo two study hemodiafiltration procedures in randomized order: one procedure using heparin anticoagulation and one procedure using regional citrate anticoagulation, with a one-week interval between procedures.
| Arm | Type | Receives |
|---|---|---|
| Citrate anticoagulation | Experimental | Drug: Regional citrate anticoagulationParticipants will undergo postdilution hemodiafiltration using regional citrate anticoagulation with 8% trisodium citrate infusion and calcium substitution according to ionized calcium measurements |
| Heparin anticoagulation | Active comparator | Drug: Unfractionated heparinParticipants will undergo postdilution hemodiafiltration using standard unfractionated heparin anticoagulation according to routine clinical protocol. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adults aged 18 years or older
- End-stage kidney disease requiring maintenance postdilution hemodiafiltration
- Stable chronic hemodialysis treatment three times weekly
- Functional arteriovenous fistula
Key exclusion criteria (5 listed)
- Therapeutic anticoagulation therapy
- Dual antiplatelet therapy
- Significant coagulopathy
- Active bleeding
- Acute kidney injury
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Regional citrate anticoagulationRegional citrate anticoagulation using 8% trisodium citrate infusion during postdilution hemodiafiltration with calcium substitution adjusted according to ionized calcium levels. | Drug | Citrate anticoagulation |
| Unfractionated heparinStandard unfractionated heparin anticoagulation administered according to routine clinical protocol during postdilution hemodiafiltration. | Drug | Heparin anticoagulation |
Primary outcome
Biocompatibility markers (C3a, PF4, TAT)
Time frame: Before hemodiafiltration, after 15 minutes of treatment, and immediately before the end of the procedure.
Comparison of complement activation marker C3a, platelet factor 4 (PF4), and thrombin-antithrombin complex (TAT) concentrations between citrate and heparin anticoagulation during postdilution hemodiafiltration.
5 secondary outcomes
Beta-2 microglobulin removal
Time frame: Before, after 30 minutes and at the end of the procedure hemodiafiltration procedure.
instantaneous urea clearance after 30 minutes
Time frame: after 30 minutes of dialysis
p-cresyl sulfat removal
Time frame: P-cresyl sulfat removal before, during and to the end of procedure
Ionized calcium kinetics
Time frame: During the 4-hour hemodiafiltration procedure
Extracorporeal circuit clotting score
Time frame: At the end of hemodiafiltration procedure.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Jun 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be publicly available due to privacy and institutional data protection regulations.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Regional citrate anticoagulation and Unfractionated heparin in people with End-Stage Kidney Disease and Hemodiafiltration, run by University Medical Centre Ljubljana at 1 site in Slovenia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 1 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Slovenia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Milena MD Andonova (+38615228123, milena.andonova@kclj.si), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Biocompatibility markers (C3a, PF4, TAT) (time frame: Before hemodiafiltration, after 15 minutes of treatment, and immediately before the end of the procedure.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Jun 2026.