CPB and Aortic Cross-Clamp Durations and ICU Length of Stay After CABG Retrospective Observational Cohort Study

Cardiopulmonary bypass (CPB) and aortic cross-clamp (ACC) are essential components of coronary artery bypass graft (CABG) surgery. Prolonged CPB and ACC durations may contribute to systemic inflammatory responses, alterations in organ perfusion, and postoperative morbidity, potentially resulting in delayed postoperative recovery and prolonged intensive care unit (ICU) stay.

This single-center retrospective observational cohort study is designed to investigate the association of CPB and ACC durations with postoperative ICU length of stay in adult patients undergoing elective isolated CABG surgery. The electronic medical records of patients who underwent elective isolated CABG surgery between January 1, 2019, and December 31, 2025, will be retrospectively reviewed.

Demographic and preoperative clinical characteristics, including age, sex, body mass index, left ventricular ejection fraction, diabetes mellitus, chronic obstructive pulmonary disease, and chronic kidney disease, will be collected. Intraoperative data will include operative duration, CPB duration, and ACC duration. Postoperative ICU length of stay will be defined as the time from postoperative ICU admission to transfer from the ICU to the hospital ward.

The primary outcome of the study is postoperative ICU length of stay. CPB and ACC durations will be evaluated as continuous exposure variables measured in minutes. Their independent associations with ICU length of stay will be assessed using separate multivariable regression models adjusted for clinically relevant potential confounders. The distribution of ICU length of stay will be evaluated before multivariable analysis. Depending on the distributional characteristics of the outcome, multivariable linear regression after appropriate transformation or a generalized linear model with an appropriate distribution and link function will be used.

The study involves retrospective analysis of routinely collected clinical data and does not include any additional intervention, diagnostic procedure, or treatment related to the research.

Inclusion criteria

• Age 18 years or older
• Underwent elective isolated coronary artery bypass graft surgery
• Surgery performed between January 1, 2019, and December 31, 2025
• Availability of complete electronic medical records required for the study analyses

Exclusion criteria

• Emergency coronary artery bypass graft surgery
• Concomitant valve surgery
• Concomitant aortic surgery
• Reoperation cases
• Incomplete study-related data
• Intraoperative death