Predictive Preoperative Score of Prolonged Mechanical Ventilation After Coronary Artery Bypass Grafting

Background and Objective: Prolonged mechanical ventilation (PMV) after cardiac surgery is a common complication associated with increased morbidity, mortality and intensive care resource utilization. Our aim was to determine predictors of PMV > 48 h in patients undergoing coronary artery bypass grafting (CABG). Methods: This was a single-center retrospective observational study including adult patients who underwent CABG between January 2011 and December 2024. The primary outcome was PMV. Results: From 2083 patients, 241 had PMV (11.6%). Compared with patients without PMV, those with PMV had lower hemoglobin levels (12.6 ± 2.1 vs. 13.4 ± 1.9 g/dL, p < 0.001) and worse estimated Glomerular Filtration Rate (67.1 ± 26.9 vs. 78.1 ± 22.6 mL/min, p < 0.001). The model with preoperative variables predicted the risk of PMV (with an area under the receiver operating characteristic curve [AUROC] of 0.789). The prediction improved with the addition of intraoperative variables (AUROC 0.832) and with the further addition of early postoperative re-exploration for bleeding (AUROC 0.847). A simplified preoperative score showed good discrimination (AUROC 0.78; 95% CI 0.749-0.81) and stratified patients into clinically meaningful risk categories. Restricted cubic spline analysis showed a non-linear association between cardiopulmonary bypass duration and PMV, with risk increasing progressively after 120 min. Conclusions: PMV after CABG can be predicted using simple preoperative variables. This prediction has relevant implications for clinical management, intensive care resource allocation, and surgical scheduling. Preoperative anemia. Preoperative anemia was independently associated with PMV and represents a potentially modifiable perioperative risk factor.