Comparative Clinical Outcomes of Patients with Low and Preserved Left Ventricular Ejection Fraction Undergoing Off-Pump Coronary Artery Bypass Surgery – A Single-Center Study

Background: Left ventricular dysfunction is a major risk factor influencing outcomes after coronary artery bypass grafting (CABG). Off-pump CABG (OPCABG) has been proposed as a safer alternative for patients with reduced ejection fraction by avoiding cardiopulmonary bypass-related complications. This study aimed to compare intraoperative and early postoperative outcomes between patients with reduced and preserved left ventricular ejection fraction (LVEF). Methods & Materials: This comparative observational study was conducted in the Department of Cardiac surgery, United Hospital, Dhaka, Bangladesh, from July 2024 to December 2024. A total of 100 patients undergoing OPCABG were included: Group A (LVEF ≤35%, n=50) and Group B (LVEF >35%, n=50). Results: Patients with reduced LVEF were slightly older (61.8 ± 8.2 vs. 58.4 ± 7.9 years; p=0.041) and had more prior myocardial infarctions (64% vs. 44%; p=0.047). Group A received fewer grafts (2.7 ± 0.8 vs. 3.1 ± 0.7; p=0.008) and required longer operative time (220 ± 35 vs. 205 ± 30 min; p=0.03). The need for intra-aortic balloon pump (16% vs. 4%; p=0.046), prolonged inotropic support (42% vs. 20%; p=0.018), ICU stay (3.8 ± 1.6 vs. 2.9 ± 1.1 days; p=0.004), and hospital stay (9.2 ± 2.5 vs. 7.8 ± 2.0 days; p=0.006) were higher in Group A. LVEF improved significantly in both groups, with greater recovery in Group A (Δ% +8.4 ± 4.1 vs. +4.8 ± 3.9; p=0.002). Conclusion: OPCABG is safe and effective even in patients with severe left ventricular dysfunction, resulting in significant improvement in ventricular function and acceptable early morbidity and mortality rates.