Early Outcomes and Perioperative Physiological Alterations After Isolated CABG Performed With Conventional Open Cardiopulmonary Bypass in a Limited-Resource Setting: A Retrospective Single-Center Cohort Study

Background: Conventional on-pump cardiopulmonary bypass (CPB) remains widely used in coronary artery bypass grafting (CABG), particularly in limited-resource healthcare systems because of its lower upfront cost and technical simplicity. However, conventional extracorporeal circulation has been associated with systemic inflammation, hemodilution, organ dysfunction, transfusion exposure, and increased postoperative resource utilization. This study evaluated early postoperative outcomes following isolated elective CABG performed using conventional open CPB and explored potentially modifiable determinants of postoperative morbidity. Methods: This retrospective single-center observational study included 122 consecutive adult patients undergoing isolated elective on-pump CABG between January 2024 and March 2025. Emergency procedures, redo surgery, combined procedures, and off-pump CABG were excluded. Primary endpoints were 30-day mortality and acute kidney injury (AKI). Secondary endpoints included postoperative bleeding, postoperative atrial fibrillation (POAF), transfusion requirement, mechanical ventilation time, intensive care unit (ICU) stay, postoperative hospital stay, and re-exploration for bleeding. Results: Thirty-day mortality was 0%. Mean CPB time was 62.6 ± 16 minutes and mean cross-clamp time was 34.9 ± 10.1 minutes. Patients received a mean of 2.99 ± 0.64 grafts, with at least one internal mammary artery used in all cases. AKI occurred in 28.7% of patients, predominantly Kidney Disease: Improving Global Outcomes (KDIGO) stage 1. Significant perioperative hemodilution was observed, with hematocrit decreasing from 43.4% preoperatively to 32.4% on ICU admission. Mean 24-hour chest drainage was 411.8 ± 169.3 mL, while transfusion was required in 9.8% of patients. POAF occurred in 18% of cases and re-exploration for bleeding in 3.3%. Mean ventilation time was 3.4 ± 1.7 hours, ICU stay was 1.15 ± 0.44 days, and postoperative hospital stay was 6.77 ± 1.32 days. CPB duration was not significantly associated with AKI, transfusion, or POAF. However, transfusion exposure was strongly associated with prolonged ventilation and ICU stay. Conclusions: In this exploratory, retrospective single-center analysis without a comparator group, conventional open CPB enabled excellent short-term survival and rapid postoperative recovery when combined with efficient surgical execution and standardized perioperative care. Nevertheless, clinically significant perioperative physiological disturbances remained evident despite favorable early clinical outcomes, particularly in the form of AKI, persistent perioperative hemodilution, and transfusion-associated ICU prolongation. Favorable early clinical outcomes may coexist with measurable postoperative physiological burden, potentially increasing downstream healthcare resource utilization. Progressive implementation of goal-directed perfusion, blood conservation strategies, viscoelastic coagulation monitoring, and more biocompatible extracorporeal circulation technologies may further improve outcomes and healthcare sustainability, particularly in resource-limited settings.