Effect of Cardiovascular Autonomic Neuropathy on AKI and Outcomes in Isolated CABG Surgery

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.

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

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