The Association Between Preoperative HbA1c Levels and Postoperative Acute Kidney Injury in Isolated Coronary Artery Bypass Surgery

NCT07445997 | Recruiting

• 1 other identifier: 2024-TBEK 2025/12-16
• Study Type: observational
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

Renal complications are frequently encountered in cardiac surgery and constitute significant causes of morbidity and mortality. They most commonly present in the form of acute kidney injury (AKI). The etiological factors of AKI include hemodynamic alterations, hemolysis and pigment nephropathy, inflammatory response and cytokine storm, ischemia-reperfusion injury, use of nephrotoxic agents, patient-related risk factors (advanced age, diabetes mellitus, preoperative renal insufficiency, congestive heart failure, hypertension, anemia), duration of surgery, and postoperative complications such as low cardiac output syndrome, sepsis, bleeding and reoperation, hypoalbuminemia, and fluid imbalance. Previous studies have demonstrated several mechanisms through which elevated HbA1c levels may contribute to acute renal injury, including glomerular damage and hyperfiltration, endothelial dysfunction and microvascular injury, tubular damage, accumulation of glycation products and advanced glycation end products (AGEs), structural changes in blood vessels, and metabolic and systemic factors. The evaluation of acute renal failure relies on fundamental scoring systems, biomarkers, and imaging modalities. Among the scoring systems, the most current and widely used is the KDIGO (Kidney Disease: Improving Global Outcomes) classification. According to the KDIGO definition, the diagnosis of AKI can be established when at least one of the following three criteria is met: an increase in serum creatinine of ≥0.3 mg/dL within 48 hours, an increase in serum creatinine to ≥1.5 times baseline within 7 days, or a urine output of \<0.5 mL/kg/hour for more than 6 hours. AKI staging is performed based on these parameters. Imaging modalities used in the assessment of renal function include renal ultrasonography (US), Doppler ultrasonography with measurement of the renal resistive index (RRI), renal MRI/MR angiography, and renal computed tomography (particularly CT angiography). RRI is a non-invasive, bedside-applicable method that provides direct information about renal vascular resistance by evaluating renal arterial flow patterns. In our clinic, the rationale of the present study is to measure preoperative HbA1c and Doppler-derived RRI values in patients undergoing isolated coronary artery bypass surgery, and to evaluate their relationship with postoperative KDIGO classification and Doppler RRI values in order to gain insight into the development of AKI.

Conditions

Acute Kidney Injuries; Hemoglobin A1c Protein, Human; Coronary Bypass Graft Surgery; Renal Resistive Index

Keywords

acute kidney injuries; hemoglobin A1c protein; coronary bypass graft surgery; renal resistive index

Outcome Measures

Primary Outcomes (1)

• To evaluate the correlation between preoperative HbA1c Level, Doppler-Derived Renal Resistive Index (RRI), and development of acute kidney injury (KDIGO Criteria) after isolated coronary artery bypass grafting

  Preoperative HbA1c Level; Glycated hemoglobin level will be measured from blood samples preoperatively. Unit of Measure: Percentage (%) Measurement Tool:Standard laboratory high-performance liquid chromatography (HPLC) assay Preoperative and Postoperative Renal Resistive Index(RRI) RRI will be measured using Doppler ultrasonography from segmental or interlobar renal arteries. Unit of Measure: Dimensionless ratio (RRI value) Measurement Tool: Doppler ultrasonography Normal Value Reference: RRI \< 0.70 Outcome Measure Title: Incidence of Acute Kidney Injury (KDIGO Criteria) Acute kidney injury will be assessed according to KDIGO criteria. Unit of Measure: Incidence of AKI (% of patients meeting KDIGO criteria) AKI Stage (Stage 1-3 classification) Measurement Tool: Serum creatinine measurement (mg/dL) Urine output monitoring Definition: Increase in serum creatinine ≥0.3 mg/dL within 48 hours OR increase to ≥1.5 times baseline within 7 days OR urine output \<0.5 mL/kg/hour for ≥6 hours

  Preoperative HbA1c Level Time Frame: Within 7 days prior to surgery Preoperative and Postoperative Renal Resistive Index (RRI) within 24 hours preoperatively and within 24 hours postoperatively KDIGO : 48 hours postoperatively,7 days postoperatively

Secondary Outcomes (2)

• To evaluate the correlation between preoperative HbA1c Level, Doppler-Derived Renal Resistive Index (RRI), and intensive care unit length of stay after isolated coronary artery bypass grafting

  Time Frame: From ICU admission after surgery until ICU discharge, up to one month

• To evaluate the correlation between preoperative HbA1c Level, Doppler-Derived Renal Resistive Index (RRI), and hospital length of stay after isolated coronary artery bypass grafting

  Time Frame: From date of surgery until hospital discharge, up to 3 month

Other Outcomes (1)

• To evaluate the correlation between preoperative HbA1c level, Doppler-Derived Renal Resistive Index (RRI), and duration of mechanical ventilation after Isolated coronary artery bypass grafting

  From ICU admission after surgery until successful extubation, up to one month

Study Arms (1)

isolated coronary bypass graft surgery patients

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

isolated coronary bypass graft surgery patients

You may qualify if:

• Patients undergoing isolated elective CABG surgery
• Patients with available preoperative and postoperative Doppler RRI measurements
• Patients with available HbA1c data

You may not qualify if:

• Patients with chronic kidney disease
• Emergency surgeries
• Redo/revision surgeries
• Patients undergoing concomitant valve surgery
• Presence of acute infection or sepsis
• Advanced heart failure (EF \<30%)
• Requirement for intra-aortic balloon pump, pacemaker, or mechanical circulatory support
• History of nephrectomy or single kidney
• Preoperative serum creatinine \>2.0 mg/dL
• Pregnancy
• Refusal to participate in the study

Sponsors & Collaborators

• Osman Sila Aydin: lead

Study Sites (1)

University of Health Sciences, Bursa Yuksek Ihtisas Training & Research Hospital

Bursa, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Acute Kidney Injury

Condition Hierarchy (Ancestors)

Renal Insufficiency; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases

Central Study Contacts

OSMAN SILA AYDIN

CONTACT

+(90)5059661014; osmansila@gmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 7 Days
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: anesthesiology and reanimation specialist

Study Record Dates

• First Submitted: January 29, 2026
• First Posted: March 3, 2026
• Study Start: January 20, 2026
• Primary Completion (Estimated): August 30, 2026
• Study Completion (Estimated): August 30, 2026
• Last Updated: March 3, 2026

Record last verified: 2026-02

Locations

TU (1)