Effect of Cardiovascular Autonomic Neuropathy on AKI and Outcomes in Isolated CABG Surgery (CAN-AKI-CABG)

April 9, 2026 updated by: Emel Gunduz, Akdeniz University

Effects of Cardiovascular Autonomic Neuropathy (CAN) on Acute Kidney Injury and Clinical Outcomes in Patients Undergoing Isolated Coronary Artery Bypass Surgery

This study aims to investigate the effects of Cardiovascular Autonomic Neuropathy (CAN) on Acute Kidney Injury (AKI) and clinical outcomes in patients undergoing isolated Coronary Artery Bypass Graft (CABG) surgery requiring extracorporeal circulation(ECC).

Preoperative data including demographics, comorbidities, kidney function tests, hemodynamic parameters, and baseline regional cerebral oxygen saturation (rSO2) will be recorded. Intraoperative data will include hemodynamics, urine output, blood gases, cardiopulmonary bypass and aortic cross-clamp times, cardioplegia details, number of coronary anastomoses, and rSO2 changes at defined time points.

Postoperatively, kidney function, neurological status, mechanical ventilation duration, inotropic drug use, transfusion requirements, complications, ICU and hospital length of stay, and mortality will be evaluated. Acute Kidney Injury will be classified according to KDIGO criteria.

The primary objective is to analyze the effect of CAN on AKI. Secondary objectives include assessing the impact of CAN on other clinical outcomes and exploring the relationship between CAN and intraoperative cerebral oxygen changes.

This study has been approved by the Acıbadem University and Acıbadem Healthcare Institutions Medical Research Ethics Committee (ATADEK) and will be conducted following ethical principles and good clinical practice.

Study Overview

Status

Completed

Conditions

Detailed Description

This is a prospective, multicenter study investigating the effects of Cardiovascular Autonomic Neuropathy (CAN) on Acute Kidney Injury (AKI) and other clinical outcomes in adult patients undergoing isolated Coronary Artery Bypass Graft (CABG) surgery with planned extracorporeal circulation (ECC). The study aims to determine whether CAN is associated with AKI incidence and other postoperative outcomes.

Study Population:

Adults aged 18 years or older scheduled for elective isolated CABG surgery with planned ECC.

Inclusion Criteria:

Elective isolated CABG surgery Age ≥18 years

Exclusion Criteria:

Emergency or revision surgeries

Orthopedic conditions preventing standing tests

Chronic respiratory diseases affecting test reliability (COPD, asthma, chronic bronchitis)

Uncontrolled hypertension

Use of antiarrhythmic drugs affecting heart rate-based tests

Chronic kidney failure

Preoperative Assessment:

CAN diagnosis using Valsalva maneuver, sitting-to-standing test, and cold/heat test (positive if ≥2 tests are abnormal).

Collection of demographic data, comorbidities, laboratory tests (BUN, creatinine, GFR, ), hemodynamic parameters, and baseline regional cerebral oxygen saturation (rSO2).

Intraoperative Monitoring:

Hemodynamic parameters, urine output, blood gases, cardiopulmonary bypass and aortic cross-clamp times, and number of coronary anastomoses recorded.

Regional cerebral oxygen saturation (rSO2) continuously monitored during ECC, with values recorded for analysis but not used for clinical decisions.

Mean arterial pressure maintained at 60-100 mmHg; crystalloids infused at ≥100 ml/h; ephedrine administered if MAP <60 mmHg.

Postoperative Evaluation:

Kidney function monitored at 24h, 48h, and 7 days postoperatively using KDIGO criteria.

Evaluation of neurological outcomes, mechanical ventilation duration, inotropic support, transfusion requirements, postoperative complications (reoperation, mediastinitis, myocardial infarction), ICU and hospital length of stay, and mortality.

Study Objectives:

Primary: Assess the effect of CAN on AKI incidence.

Secondary: Evaluate CAN's impact on other clinical outcomes

Ethics and Compliance:

Approved by Acıbadem University and Acıbadem Healthcare Institutions Medical Research Ethics Committee (ATADEK), approval number 2020-21/13.

Conducted according to ethical principles and Good Clinical Practice (GCP) standards.

Study Type

Observational

Enrollment (Actual)

912

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

Turkey (Türkiye)
- Antalya
  - Antalya, Antalya, Turkey (Türkiye), 07050
    - Akdeniz University, Faculty of Medicine, Department of Anesthesiology and Reanimation

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

Adult
Older Adult

Accepts Healthy Volunteers

Sampling Method

Non-Probability Sample

Study Population

This study includes adult patients (≥18 years old) scheduled for elective isolated Coronary Artery Bypass Graft (CABG) surgery with planned extracorporeal circulation (ECC). Participants will be evaluated preoperatively for cardiovascular autonomic neuropathy (CAN) using standardized tests. Patients with chronic kidney failure, severe chronic respiratory disease, uncontrolled hypertension, or conditions preventing autonomic testing are excluded. Both male and female adults are eligible, and all participants must provide informed consent.

Description

Inclusion Criteria:

Adults aged 18 years or older

Scheduled for elective isolated Coronary Artery Bypass Graft (CABG) surgery with planned extracorporeal circulation (ECC)

Provide informed consent

Exclusion Criteria:Emergency or revision CABG surgeries

Chronic kidney failure or dialysis

Severe chronic respiratory disease (COPD, asthma, chronic bronchitis) affecting test reliability

Uncontrolled hypertension

Use of antiarrhythmic drugs affecting heart rate-based autonomic tests

Orthopedic or neurological conditions preventing standing tests

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

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
CABG Surgery Cohort This cohort includes adult patients undergoing isolated coronary artery bypass graft (CABG) surgery with extracorporeal circulation (ECC). Each participant is evaluated preoperatively for cardiovascular autonomic neuropathy (CAN) using the Valsalva maneuver, sitting-to-standing test, and cold/heat test. Demographic, hemodynamic, and laboratory data, as well as regional cerebral oxygen saturation (rSO₂), are recorded. Postoperative outcomes include acute kidney injury (AKI) assessed by KDIGO criteria, complications, ICU and hospital stay, and mortality. No intervention is applied.

Group / Cohort

CABG Surgery Cohort

This cohort includes adult patients undergoing isolated coronary artery bypass graft (CABG) surgery with extracorporeal circulation (ECC). Each participant is evaluated preoperatively for cardiovascular autonomic neuropathy (CAN) using the Valsalva maneuver, sitting-to-standing test, and cold/heat test. Demographic, hemodynamic, and laboratory data, as well as regional cerebral oxygen saturation (rSO₂), are recorded. Postoperative outcomes include acute kidney injury (AKI) assessed by KDIGO criteria, complications, ICU and hospital stay, and mortality. No intervention is applied.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Acute Kidney Injury (AKI) Time Frame: Postoperative 7 days	AKI will be assessed according to KDIGO criteria using serum creatinine, BUN, GFR values, and urine output within the first 7 days postoperatively.	Postoperative 7 days

Collaborators and Investigators

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

Sponsor

Akdeniz University

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.

Helpful Links

Systematic review on the association between diabetic peripheral neuropathy and cardiac autonomic neuropathy.

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 (Actual)

November 4, 2021

Primary Completion (Actual)

January 10, 2025

Study Completion (Actual)

March 10, 2025

Study Registration Dates

First Submitted

November 18, 2025

First Submitted That Met QC Criteria

November 25, 2025

First Posted (Actual)

November 28, 2025

Study Record Updates

Last Update Posted (Actual)

April 13, 2026

Last Update Submitted That Met QC Criteria

April 9, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

CAN_AKI_STUDY

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

IPD Plan Description

Individual participant data will not be shared. The data will be used solely for the purposes of this study."

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Studies a U.S. FDA-regulated device product

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