Trajectory-Based Phenotyping After Coronary Artery Bypass Surgery

Early Postoperative Trajectory-Based Phenotyping Improves Risk Stratification Beyond EuroSCORE in Patients Undergoing Coronary Artery Bypass Grafting

Coronary artery bypass grafting is a commonly performed heart surgery, but patients may have different risks for postoperative complications even when their preoperative risk scores are similar. EuroSCORE II is widely used to estimate surgical risk before cardiac surgery, but it may not fully reflect how the body responds during the early postoperative period.

This retrospective observational study will evaluate adult patients who underwent elective coronary artery bypass grafting with cardiopulmonary bypass between January 1, 2022 and December 31, 2025. The study will use existing hospital records and laboratory data. No additional treatment, test, or intervention will be given to patients as part of this study.

The main aim is to examine whether early postoperative changes in inflammatory and renal laboratory markers can identify different patient subgroups, called phenotypes. These markers include neutrophil-to-lymphocyte ratio, systemic immune-inflammation index, triglyceride-glucose index, and serum creatinine. The study will evaluate whether these phenotype groups are associated with postoperative acute kidney injury and prolonged intensive care unit stay.

The study will also assess whether this early postoperative phenotype-based classification provides additional risk information beyond EuroSCORE II.

Study Overview

• Status: Not yet recruiting
• Conditions: Postoperative Complications; Coronary Artery Bypass Grafting; Postoperative Acute Kidney Injury; Risk Stratification
• Intervention / Treatment: Other: Early Postoperative Phenotype Classification

Detailed Description

This is a single-center retrospective observational cohort study designed to evaluate the prognostic relevance of early postoperative trajectory-based biological phenotyping in adult patients undergoing elective coronary artery bypass grafting with cardiopulmonary bypass.

The study population will include patients operated between January 1, 2022 and December 31, 2025. Data will be obtained retrospectively from hospital information systems, electronic medical records, laboratory databases, and archived patient files. All data will be anonymized before analysis, and no patient-identifying information will be included in the study dataset.

The study will collect demographic characteristics, comorbidities, preoperative clinical variables, EuroSCORE II, perioperative variables such as cardiopulmonary bypass time and aortic cross-clamp time, and laboratory parameters. Early postoperative laboratory values from postoperative day 0 and postoperative day 1 will be used to calculate inflammatory and metabolic indices, including neutrophil-to-lymphocyte ratio, systemic immune-inflammation index, and triglyceride-glucose index. Serum creatinine changes will be used to evaluate renal response and postoperative acute kidney injury.

Patients will be classified into phenotypic subgroups using unsupervised clustering methods based on early postoperative biomarker trajectories. The clinical characteristics and outcomes of these subgroups will then be compared. The main outcomes of interest are postoperative acute kidney injury and prolonged intensive care unit stay. Additional analyses will assess whether phenotype classification improves risk stratification beyond EuroSCORE II.

The study does not involve any intervention, experimental treatment, additional laboratory testing, or change in clinical care. All analyses will be performed using previously recorded clinical and laboratory data.

• Study Type: Observational
• Enrollment (Estimated): 1000

Contacts and Locations

• Study Contact: Name: Gürcan Güler; Phone Number: +90 541 975 0407; Email: gurcanguler.45@gmail.com
• Study Contact Backup: Name: Gürcan Güler; Phone Number: +90 541 975 04 07; Email: gurcanguler.45@gmail.com

Study Locations

• Turkey (Türkiye)
  • Bursa, Turkey (Türkiye)
    • University of Health Sciences, Bursa Yuksek Ihtisas Training and Research Hospital
    • Contact: Gürcan Güler; Phone Number: +90 541 975 0407; Email: gurcanguler.45@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population will consist of adult patients who underwent elective on-pump coronary artery bypass grafting at University of Health Sciences Bursa Yüksek İhtisas Training and Research Hospital between January 1, 2022 and December 31, 2025. Eligible patients will be identified retrospectively from electronic medical records, laboratory databases, and archived patient files.

Description

Inclusion Criteria:

• Adult patients aged 18 years or older
• Patients who underwent elective on-pump coronary artery bypass grafting
• Patients operated between January 1, 2022 and December 31, 2025
• Patients with available perioperative clinical and laboratory data required for analysis

Exclusion Criteria:

• Patients undergoing emergency surgery
• Patients undergoing concomitant valve surgery
• Patients with missing or inconsistent key clinical or laboratory data

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Elective CABG Cohort; Adult patients who underwent elective coronary artery bypass grafting with cardiopulmonary bypass between January 1, 2022 and December 31, 2025. Patients will be included retrospectively from hospital records, electronic medical records, laboratory databases, and archived patient files. No intervention, experimental treatment, or additional testing will be performed as part of this study.

Other: Early Postoperative Phenotype Classification; Patients will be retrospectively classified into phenotype groups based on early postoperative inflammatory and renal biomarker trajectories. This classification is analytical only and does not involve any intervention, treatment assignment, or additional testing.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Prolonged Postoperative Intensive Care Unit Stay	Prolonged postoperative intensive care unit stay was defined as an intensive care unit length of stay exceeding 4 days after elective on-pump coronary artery bypass grafting.	From surgery to intensive care unit discharge, assessed up to 30 days after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Acute Kidney Injury	Postoperative acute kidney injury defined according to serum creatinine-based KDIGO criteria within the first 72 hours after elective on-pump coronary artery bypass grafting.	Within the first 72 hours after surgery
In-Hospital Mortality	Death from any cause occurring after elective on-pump coronary artery bypass grafting.	From surgery until hospital discharge, assessed up to 30 days after surgery
Reintubation	Requirement for endotracheal reintubation after initial postoperative extubation following elective on-pump coronary artery bypass grafting.	From surgery until hospital discharge, assessed up to 30 days after surgery
Arrhythmia Requiring Treatment	Occurrence of postoperative arrhythmia requiring medical treatment, electrical cardioversion, or another clinically documented therapeutic intervention after elective on-pump coronary artery bypass grafting.	From surgery until hospital discharge, assessed up to 30 days after surgery

Collaborators and Investigators

• Sponsor: Bursa Sevket Yilmaz Training and Research Hospital
• Investigators: Principal Investigator: Gürcan Güler, University of Health Sciences Bursa Yüksek İhtisas Training and Research Hospital

Publications and helpful links

General Publications

• Koyuncu AO, Yesiltas MA, Özsoy SD, Mert AM. Comparison of Systemic Inflammation Indices With Post-Cardiac Surgery Mortality and Morbidity. Heart Surg Forum. 2025 Sep 26;28(9). doi:10.31083/HSF46933
• Magouliotis DE, Sicouri N, Ramlawi L, Baudo M, Androutsopoulou V, Sicouri S. Artificial Intelligence in Adult Cardiovascular Medicine and Surgery: Real-World Deployments and Outcomes. J Pers Med. 2026 Jan 30;16(2):69. doi: 10.3390/jpm16020069.
• Silverborn M, Nielsen S, Karlsson M. The performance of EuroSCORE II in CABG patients in relation to sex, age, and surgical risk: a nationwide study in 14,118 patients. J Cardiothorac Surg. 2023 Jan 19;18(1):40. doi: 10.1186/s13019-023-02141-4.

Study record dates

Study Major Dates

• Study Start (Estimated): May 7, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: May 7, 2026
• First Submitted That Met QC Criteria: May 13, 2026
• First Posted (Actual): May 20, 2026

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: May 13, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Risk stratification; Coronary artery bypass grafting; EuroSCORE II; Postoperative phenotyping
• Additional Relevant MeSH Terms: Pathologic Processes; Pathological Conditions, Signs and Symptoms; Postoperative Complications
• Other Study ID Numbers: 2024-TBEK 2026/05-02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared because the study uses retrospective clinical and laboratory data obtained from hospital records. Although the dataset will be anonymized before analysis, data sharing is not planned due to institutional data privacy regulations and the retrospective nature of the study.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No