Development and Validation of a Risk Prediction Model for Cardiac Surgery-associated Acute Kidney Injury Based on the Gut-Kidney Axis, Incorporating Gut Microbiota and Their Metabolites

July 28, 2026 updated by: Peking Union Medical College Hospital
This is a single-center prospective observational cohort study enrolling adult patients scheduled for cardiac surgery. Multi-timepoint clinical indicators, stool samples for gut microbiota and metabolomics profiling and artery blood will be collected before and after surgery. We aim to construct and validate a multi-dimensional preoperative predictive model for CSA-AKI based on clinical, microbial and metabolic signatures. Meanwhile, this research will explore the potential mediating role of the gut-kidney axis in the pathogenesis of cardiac surgery-associated acute kidney injury, and provide novel mechanistic evidence for early risk stratification and intervention of CSA-AKI.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Cardiac surgery-associated acute kidney injury (CSA-AKI) is one of the most common severe postoperative complications after cardiac surgery, which significantly increases the risks of prolonged hospitalization, chronic kidney disease and all-cause mortality. Current single-index risk scoring systems cannot fully predict individual CSA-AKI risk, and the underlying pathological mechanism remains incompletely clarified. Emerging evidence reveals that gut dysbiosis and altered intestinal metabolites participate in kidney injury via the gut-kidney axis, while few prospective cohort studies integrate multi-omics data to develop preoperative predictive models for CSA-AKI.

This prospective cohort study will consecutively recruit adult subjects receiving elective cardiac surgery at Peking Union Medical College Hospital. Basic demographic data, laboratory examinations, intraoperative and postoperative clinical parameters will be recorded at multiple perioperative time points. Fresh stool specimens and artery blood will be collected from all participants before surgery, 24 hours and 7 days after cardiac surgery for 16S rRNA gene sequencing and untargeted metabolomics analysis to characterize gut microbial composition and metabolite profiles.

The primary objective is to develop and internally validate a multi-dimensional predictive model combining clinical variables, gut flora biomarkers and metabolic signatures to stratify preoperative CSA-AKI risk of cardiac surgical patients. Secondary objectives include comparing the differences of intestinal microbiota and metabolites between patients with and without subsequent CSA-AKI, screening key microbial strains and differential metabolites related to postoperative renal impairment, and elucidate the molecular pathways of the gut-kidney axis mediating CSA-AKI occurrence.

All participants will receive standardized perioperative management following clinical guidelines. Subjects will be followed up until 7 days after surgery to identify CSA-AKI events defined by standardized serum creatinine criteria. The performance of the established prediction model will be evaluated by area under the receiver operating characteristic curve (AUC), calibration curve and decision curve analysis. All specimen testing and statistical analyses will be conducted following standardized omics and clinical research workflows. This study is approved by the institutional ethics committee, and written informed consent will be obtained from all enrolled patients prior to sample and data collection.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
182

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

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Beijing Municipality
      • Beijing, Beijing Municipality, China, 100730
        • Peking Union Medical College Hospital
        • 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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

This single-center prospective observational cohort will consecutively enroll adult patients aged ≥18 years who receive elective cardiac surgery at Peking Union Medical College Hospital. Eligible subjects include patients undergoing valve surgery, coronary artery bypass grafting (CABG), or combined cardiac procedures.All enrolled participants will complete standardized perioperative data collection and serial stool sample and blood collection at preoperative baseline, postoperative day 1 and postoperative day 7. Subjects will be followed up until postoperative day 7 to identify CSA-AKI events based on KDIGO 2012 criteria.

Description

Inclusion Criteria:

  1. Aged 18 years or older;
  2. Scheduled for elective cardiac surgery;
  3. Surgery performed under cardiopulmonary bypass (CPB);
  4. Able to complete preoperative stool and blood sample collection independently;
  5. The patient and their family members voluntarily participate in this study, agree to the collection of preoperative stool samples, blood samples and clinical data, cooperate with follow-up visits, and sign the informed consent form.-

Exclusion Criteria:

（1) Patients with end-stage renal disease or dependence on renal replacement therapy before surgery; (2) Patients with a preoperative estimated glomerular filtration rate (eGFR) < 30 ml/min/1.73m² or severe chronic kidney disease (CKD stage 4-5); (3) Patients with a history of renal transplantation or unilateral nephrectomy; (4) Patients who received antibiotic treatment within 4 weeks before surgery; (5) Patients who took probiotic or prebiotic preparations within 4 weeks before surgery; (6) Patients with a previous history of intestinal surgery, such as colectomy and small bowel resection; (7) Patients with active inflammatory bowel disease, chronic diarrhea or constipation requiring pharmacological intervention; (8) Patients with preoperative intestinal obstruction, gastrointestinal bleeding, or those requiring fasting for more than 24 hours; (9) Patients undergoing emergency surgery (time from admission to surgery < 24 hours), or those unable to complete preoperative informed consent, dietary investigation and baseline sample collection; (10) Patients who received mechanical bowel preparation (e.g., enema) within 24 hours before surgery; (11) Patients with preoperative active infection or sepsis; (12) Patients treated with preoperative glucocorticoids or immunosuppressants (excluding routine doses); (13) Patients who died intraoperatively or within 24 hours postoperatively, or those who could not complete the evaluation of the primary outcome (postoperative 7-day acute kidney injury [AKI]); (14) Female patients who are pregnant, lactating or in menstruation; (15) Patients complicated with gastrointestinal malignant tumors or receiving systemic chemotherapy, targeted therapy or abdominal radiotherapy; (16) Patients with severe liver disease (Child-Pugh grade B or above).

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

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
all patients undergoing elective cardiac surgery
Consecutive adult patients scheduled for cardiac surgery. Multi-timepoint clinical data and stool samples are collected to build preoperative CSA-AKI prediction model, subgroup analysis will be performed according to postoperative AKI outcomes.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Predictive performance of multi-dimensional gut microbiota-metabolite model for postoperative CSA-AKI
Time Frame: From preoperative sample collection to postoperative day 7 (CSA-AKI confirmation)
The primary outcome is the discriminative ability (AUC) of the combined preoperative gut microbiota and metabolomic signature model to predict cardiac surgery-associated acute kidney injury (CSA-AKI). CSA-AKI is diagnosed per KDIGO 2012 criteria: serum creatinine rises ≥0.3 mg/dL within 48h postoperatively or ≥1.5-fold baseline within 7 days after cardiac surgery. The predictive performance of the multi-omics combined model will be quantified by the area under the receiver operating characteristic curve (AUC-ROC).
From preoperative sample collection to postoperative day 7 (CSA-AKI confirmation)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incidence of cardiac surgery-associated acute kidney injury (CSA-AKI) within 7 days after cardiac surgery
Time Frame: 7 days after cardiac surgery
CSA-AKI is diagnosed in accordance with the KDIGO 2012 AKI standard: serum creatinine increases by ≥0.3 mg/dL within 48 hours postoperatively, or serum creatinine reaches ≥1.5 times the preoperative baseline value within 7 days after cardiac surgery. The incidence rate is calculated as the proportion of patients who meet the CSA-AKI diagnostic criteria among all enrolled subjects.
7 days after cardiac surgery
Severity grading of CSA-AKI according to KDIGO 2012 staging criteria
Time Frame: 7 days after cardiac surgery
For subjects diagnosed with CSA-AKI within postoperative 7 days, stratify patients into KDIGO Stage 1, Stage 2 and Stage 3 based on the maximum serum creatinine elevation during follow-up, and compare the distribution of AKI severity grades in the cohort.
7 days after cardiac surgery

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Peking Union Medical College Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Yu, Peking Union Medical College Hospital

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 28, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 28, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 31, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 31, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 28, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • K10744

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data (including perioperative clinical laboratory data, gut microbiota sequencing raw data, stool metabolomics and blood data, and standardized case report forms) will be shared with qualified researchers after the completion of primary study analysis and the publication of core research manuscripts. All personal identifiable information will be permanently removed to protect patient privacy in compliance with Chinese medical research ethics regulations.

IPD Sharing Access Criteria

Data will become available 6 months after full study completion and primary manuscript publication; data access will remain available for 5 years after publication.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

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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