AKI - Acute Kidney InjuryKIDNEY-IINCT06811805
Post-Marketing Study to Assess the Safety & Efficacy of RenalGuard® Therapy for Prevention CSA-AKI
A study testing RenalGuard Therapy in people with AKI - Acute Kidney Injury and Cardiac Surgery Associated - Acute Kidney Injury, run by CardioRenal Systems, Inc. at 8 sites in 5 countries.
Trial summary
The goal of this clinical trial is to assess the effect of RenalGuard Therapy in reducing the rates of Acute Kidney Injury (AKI) within 72 hours after cardiac surgery in patients at risk of developing Cardiac Surgery Associated AKI (CSA-AKI) compared to standard-of-care (SoC). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- AKI - Acute Kidney Injury, Cardiac Surgery Associated - Acute Kidney Injury
- What is being tested?
- RenalGuard Therapy
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 300 participants
- Where
- 8 sitesin 5 countries
- Study dates
- 23 Feb 2025to 30 Apr 2028
- 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
- Male or female and >18 years of age
- Patient able to give written consent
- Scheduled for the following non-emergent cardiac surgery procedure requiring CPB, isolated or in combination:
- coronary artery bypass graft (CABG)
- aortic valve replacement or repair alone, with or without aortic root repair
- mitral, tricuspid, or pulmonic valve replacement or repair
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- simultaneous replacement of several cardiac valves
- CABG with aortic, mitral, tricuspid, or pulmonic valve replacement or repair
- Surgery on the aorta: aortic root and/ or ascending aorta
- Atrial fibrillation (AF) ablation surgery if combined with other cardiac procedures.
- Atrial septal defect (ASD) closure if combined with other cardiac procedures.
- Excision of myxoma if combined with other cardiac procedures
- Have at least one of the following risk factors for CSA-AKI:
- CKD-EPI eGFR 20-59 mL/min/1.73 m²
- Age ≥ 75 years
- Undergoing combined surgery (e.g. CABG + Valve)
- Logistic EuroScore of ≥5 or, Euroscore II of ≥4 or Society of Thoracic Surgeons (STS) Score ≥4
- Left ventricular ejection fraction (LVEF) ≤ 35% by invasive or noninvasive diagnostic cardiac imaging performed within 90 days prior to surgery.
- Insulin-requiring diabetes
- Non-insulin-requiring diabetes with HbA1C ≥ 6.1% in the last 6 months
- Preoperative anemia within 4 weeks of surgery
Who cannot join
- Patient requiring emergency surgery
- Surgery to be performed without CPB
- Patient receiving furosemide at a dose>100 mg/day orally (or the equivalent dose of an alternative loop diuretic) in the last week
- Patient who cannot be urethrally catheterize for any reason
- Patients already dialysis dependent
- Patients with CKD-EPI eGFR <20 mL/min/1.73 m²
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- Known or suspected AKI (KDIGO criteria) at the time of screening
- Patients participating in another interventional drug or device study or have received an investigational drug or device treatment within the last 30 days
- Pregnant patient, self-reported
- Patients whose planned surgery to be performed under conditions of circulatory arrest or hypothermia with rectal temperature < 28°Celsius (82.4° Fahrenheit)
- Patient with suspected or confirmed bacteraemia, endocarditis, or pyelonephritis at hospital admission
- Patients with pneumonia, aspiration, or bilateral pulmonary infiltrates from an infectious aetiology reported on chest x-ray or CT scan in the last 7 days
- Patients in cardiogenic shock or hemodynamic instability which require inotropes or vasopressors or other mechanical devices (Impella Heart Pump, IABP) within 24 hours prior to surgery
- Patients on extracorporeal membrane oxygenation (ECMO) or durable ventricular assist device (VAD) at the time of screening, or planned use within 24h prior to surgery
- Patients currently treated with chemotherapy or radiation therapy that may have an impact on kidney function.
- Patient underwent prior solid organ transplantation
- Patients underwent major surgery within the last 3 months
- Any condition which, in the judgement of the investigator, might increase the risk to the patient.
Trial locations and contacts
8 sites in 5 countries.
8 sites in 5 countries
Germany2 sites
TUM Klinikum Deutsches Herzzentrum
Munich
Uniklinikum Munster
Münster
Israel2 sites
Rambam Medical Center
Haifa
Rabin Medical Center - Belinson Campus
Petah Tikva
Spain2 sites
Hospital de la Santa Creu i Sant Pau
Barcelona
Hospital Universitario Ramón y Cajal
Madrid
About this study
Official title: Post-Marketing Clinical Follow Up Study to Further Assess the Safety & Efficacy of RenalGuard® Therapy in the Prevention of Cardiac Surgery Associated Acute Kidney Injury (CSA-AKI)
The goal of this clinical trial is to assess the effect of RenalGuard Therapy in reducing the rates of Acute Kidney Injury (AKI) within 72 hours after cardiac surgery in patients at risk of developing Cardiac Surgery Associated AKI (CSA-AKI) compared to standard-of-care (SoC).
Participants will be randomized (1:1) to one of the two study groups. The Treatment study group will be managed with the RenalGuard System. The RenalGuard treatment will start after induction of anesthesiology and will run during surgery and for 6-7 hours in the Intensive Care Unit (ICU). The treatment will aim to achieve a urine rate above a predefined urine rate threshold. Patients in the control group will be managed based on the usual clinical practice in cardiac surgery centres as detailed in the recommendations for CSA-AKI prevention by accepted clinical guidelines.
Read more
For both study groups general anaesthesia, cardiopulmonary bypass (CPB) run and overall patient care will be based on SoC for cardiac surgery.
Patients will be followed up for up to 7 days post surgery or until discharge, which ever comes first.
Long-term follow up will be performed at 90 days post surgery.
- Being tested
- RenalGuard Therapy, Standard of Care (SOC)
- Keywords
- RenalGuard, AKI, Acute Kidney Injury, Cardiac Surgery Associated AKI, CSA-AKI, AKI Prevention, Cardiac Surgery
- Medical subject headings
- Acute Kidney Injury
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RenalGuard TherapyDevice
RenalGuard Therapy
Standard of Care (SOC)Other
Standard of care
| Study group | Role | What they receive |
|---|---|---|
| Control | Active comparator | Standard of care Receives: Other: Standard of Care (SOC) |
| RenalGuard Therapy | Experimental | RenalGuard Therapy Receives: Device: RenalGuard Therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
CSA-AKI incidence between study groups
CSA-AKI is defined as when any of the following three criteria are met:
- An increase in serum creatinine (SCr) by ≥0.3 mg/dl (≥26.5 umol/l) within 72 hours compared to the baseline value; OR
- An increase in SCr by ≥1.5 times from SCr value at baseline within 72 hours; OR
- Use of Renal Replacement Therapy (RRT) within 7 days of surgery or by hospital discharge (whichever is the earliest)
Measured: Within 72 hours
Secondary outcomes (4)
A composite safety endpoint which includes: Significant severe clinically meaningful change in electrolytes (K+, Mg+2, Na+), New onset of postoperative atrial fibrillation, and Pulmonary edema
Measured: Within 72 hours
CSA-AKI Stage
CSA-AKI severity by stage distribution between the study groups
Measured: Within 72 hours
CSA-AKI Incidence
AKI incidence within 7 days based on the KDIGO definition described in the primary endpoint section
Measured: Within 7 days
CSA-AKI Duration
Duration of AKI within 7 days of surgery
Measured: Within 7 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Feb 2025
- Study start23 Feb 2025
- Primary completion31 Dec 2027 (estimated)
- Study completion30 Apr 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for AKI - Acute Kidney InjuryStudies of the same condition, open and under way.
- 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- CardioRenal Systems, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Jacob Raphael, MD, Principal investigator, Thomas Jefferson University Hospitals
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06811805
- Sponsor's protocol ID
- RG-CSA-002
- Acronym
- KIDNEY-II
- Status last verified
- Jan 2026
- First submitted
- 22 Jan 2025
- Last updated
- 23 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All IPD that underlie results in a publication
Publications
Luckraz H, Giri R, Wrigley B, Nagarajan K, Senanayake E, Sharman E, Beare L, Nevill A. Balanced forced-diuresis as a renal protective approach in cardiac surgery: Secondary outcomes of electrolyte changes. J Card Surg. 2021 Nov;36(11):4125-4131. doi: 10.1111/jocs.15925. Epub 2021 Aug 19.
PubMed 34414606Luckraz H, Giri R, Wrigley B, Nagarajan K, Senanayake E, Sharman E, Beare L, Nevill A. Reduction in acute kidney injury post cardiac surgery using balanced forced diuresis: a randomized, controlled trial. Eur J Cardiothorac Surg. 2021 Apr 13;59(3):562-569. doi: 10.1093/ejcts/ezaa395.
PubMed 33236105
Study at a glance
From the registry record, last updated by the sponsor on 23 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Post-Marketing Clinical Follow Up Study to Further Assess the Safety & Efficacy of RenalGuard® Therapy in the Prevention of Cardiac Surgery Associated Acute Kidney Injury (CSA-AKI)
- ClinicalTrials.gov ID
- NCT06811805
- Acronym / sponsor ID
- KIDNEY-II / RG-CSA-002
- Keywords
- RenalGuard, AKI, Acute Kidney Injury, Cardiac Surgery Associated AKI, CSA-AKI, AKI Prevention, Cardiac Surgery
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- CardioRenal Systems, Inc.Industry (pharma, biotech, devices)
- Study start
- 23 Feb 2025 (actual)
- Primary completion
- 31 Dec 2027 (estimated)
- Study completion
- 30 Apr 2028 (estimated)
- First posted
- 6 Feb 2025 (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.
The goal of this clinical trial is to assess the effect of RenalGuard Therapy in reducing the rates of Acute Kidney Injury (AKI) within 72 hours after cardiac surgery in patients at risk of developing Cardiac Surgery Associated AKI (CSA-AKI) compared to standard-of-care (SoC).
Participants will be randomized (1:1) to one of the two study groups. The Treatment study group will be managed with the RenalGuard System. The RenalGuard treatment will start after induction of anesthesiology and will run during surgery and for 6-7 hours in the Intensive Care Unit (ICU). The treatment will aim to achieve a urine rate above a predefined urine rate threshold. Patients in the control group will be managed based on the usual clinical practice in cardiac surgery centres as detailed in the recommendations for CSA-AKI prevention by accepted clinical guidelines.
For both study groups general anaesthesia, cardiopulmonary bypass (CPB) run and overall patient care will be based on SoC for cardiac surgery.
Patients will be followed up for up to 7 days post surgery or until discharge, which ever comes first.
Long-term follow up will be performed at 90 days post surgery.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Control | Active comparator | Other: Standard of Care (SOC)Standard of care |
| RenalGuard Therapy | Experimental | Device: RenalGuard TherapyRenalGuard Therapy |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (21 listed)
- Male or female and >18 years of age
- Patient able to give written consent
- Scheduled for the following non-emergent cardiac surgery procedure requiring CPB, isolated or in combination:
- Have at least one of the following risk factors for CSA-AKI:
Key exclusion criteria (18 listed)
- Patient requiring emergency surgery
- Surgery to be performed without CPB
- Patient receiving furosemide at a dose>100 mg/day orally (or the equivalent dose of an alternative loop diuretic) in the last week
- Patient who cannot be urethrally catheterize for any reason
- Patients already dialysis dependent
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 |
|---|---|---|
| RenalGuard TherapyRenalGuard Therapy | Device | RenalGuard Therapy |
| Standard of Care (SOC)Standard of care | Other | Control |
Primary outcome
CSA-AKI incidence between study groups
Time frame: Within 72 hours
CSA-AKI is defined as when any of the following three criteria are met: 1. An increase in serum creatinine (SCr) by ≥0.3 mg/dl (≥26.5 umol/l) within 72 hours compared to the baseline value; OR 2. An increase in SCr by ≥1.5 times from SCr value at baseline within 72 hours; OR 3. Use of Renal Replacement Therapy (RRT) within 7 days of surgery or by hospital discharge (whichever is the earliest)
4 secondary outcomes
A composite safety endpoint which includes: Significant severe clinically meaningful change in electrolytes (K+, Mg+2, Na+), New onset of postoperative atrial fibrillation, and Pulmonary edema
Time frame: Within 72 hours
CSA-AKI Stage
Time frame: Within 72 hours
CSA-AKI Incidence
Time frame: Within 7 days
CSA-AKI Duration
Time frame: Within 7 days
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 23 Jan 2026.
- Background: PubMed 34414606Luckraz H, Giri R, Wrigley B, Nagarajan K, Senanayake E, Sharman E, Beare L, Nevill A. Balanced forced-diuresis as a renal protective approach in cardiac surgery: Secondary outcomes of electrolyte changes. J Card Surg. 2021 Nov;36(11):4125-4131. doi: 10.1111/jocs.15925. Epub 2021 Aug 19.
- Background: PubMed 33236105Luckraz H, Giri R, Wrigley B, Nagarajan K, Senanayake E, Sharman E, Beare L, Nevill A. Reduction in acute kidney injury post cardiac surgery using balanced forced diuresis: a randomized, controlled trial. Eur J Cardiothorac Surg. 2021 Apr 13;59(3):562-569. doi: 10.1093/ejcts/ezaa395.
- Individual participant dataSharing planned: Yes. All IPD that underlie results in a publication
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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. This study is not recruiting at the moment.
Jacob Raphael, MD principal investigator
Thomas Jefferson University Hospitals
8 sites in 5 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing RenalGuard Therapy in people with AKI - Acute Kidney Injury and Cardiac Surgery Associated - Acute Kidney Injury, run by CardioRenal Systems, Inc. at 8 sites in 5 countries.
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 21 inclusion and 18 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: under way, not looking for participants, as of the sponsor's last update on 23 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 8 sites in Germany, Israel, Spain, Belgium, Sweden. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
CSA-AKI incidence between study groups (time frame: Within 72 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06811805, which also lists 2 linked publications.
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 23 Jan 2026.