Aortic manipulation and prolonged ischemia during cardiopulmonary bypass remain major drivers of perioperative complications. Optimizing clamping strategies is crucial to minimize iatrogenic blood loss and improve recovery profiles within a Patient Blood Management (PBM) framework. 

Objectives: This study aimed to evaluate the impact of two different aortic clamping strategies—single cross-clamping versus side-clamping—on early hematologic outcomes within a Patient Blood Management (PBM) framework in patients undergoing on-pump coronary artery bypass grafting (CABG). 

Methods: In this retrospective cohort study, 265 patients who underwent elective isolated 3-vessel on-pump CABG between January 2019 and April 2025 were analyzed. Patients were divided into two groups: the Side-Clamp group (n = 132), where proximal anastomoses were performed under partial occlusion after releasing the main cross-clamp, and the Single Cross-Clamp group (n = 133), where all anastomoses were completed during a single arrest period. The primary outcomes were postoperative hemoglobin (Hb) drop and 24-h chest tube drainage. 

Results: The side-clamp technique was associated with significantly shorter cardioplegic arrest times (34.5 ± 3.7 vs. 52.0 ± 3.9 min; p < 0.001). Key findings revealed that the postoperative hemoglobin drop was significantly lower in the side-clamp group (1.9 ± 0.4 g/dL vs. 2.1 ± 0.4 g/dL; p = 0.005). Notably, the side-clamp group also exhibited significantly lower 24-h chest tube drainage (123.4 ± 28.3 mL vs. 131.0 ± 27.4 mL; p = 0.027). Multivariate linear regression analysis, adjusting for age, sex, and CPB time, confirmed the side-clamp technique as an independent predictor of superior hemoglobin preservation (β = −0.115, p = 0.009). No significant differences were observed regarding the incidence of postoperative AF (13.6% vs. 15.8%; p = 0.748) or 30-day mortality. 

Conclusions: The side-clamp strategy is associated with modest but statistically significant reductions in postoperative hemoglobin decline and 24-h chest tube drainage. While these differences did not translate into a significant reduction in RBC transfusion or early mortality, the side-clamp technique represents a useful technical component within a broader Patient Blood Management strategy in routine on-pump CABG practice.