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Abstract

Background: Ischemic heart disease, particularly coronary artery disease (CAD), is a leading global cause of morbidity and mortality. Reduced left ventricular ejection fraction (LVEF) complicates disease progression and treatment outcomes. Coronary artery bypass grafting (CABG) is an established surgical intervention for CAD, yet its effectiveness in patients with low EF remains uncertain. Severe LVEF reduction (≤25%) is associated with higher surgical risks, but precise postoperative outcomes require further investigation. Identifying predictors of complications in low EF patients undergoing CABG is critical for improving management and prognosis.
Objective: This study aimed to compare postoperative complications such as stroke, myocardial infarction, and renal failure in patients with low EF undergoing CABG and to identify key predictors of surgical outcomes in this high-risk population.
Methods: A prospective randomized controlled trial was conducted at Rehmatul Lil Alameen Institute of Cardiology (RAIC), Lahore. A total of 100 patients with LVEF ≤25% undergoing isolated CABG were included through simple random sampling. Patients were categorized into three EF groups: ≤25%, 26-35%, and 36-45%. Inclusion criteria consisted of male and female patients aged 45-75 years undergoing primary isolated CABG with cardiopulmonary bypass. Exclusion criteria included incomplete medical records, prior cardiac surgery, or off-pump CABG. Data were analyzed using IBM SPSS-26, with chi-square tests used for categorical variable associations.
Results: Patients with EF ≤25% were older (66.1±7.23 years) compared to EF 26-35% and EF 36-45% groups (both 61.2±7.23 years). Males dominated the EF ≤25% (n=28) and EF 26-35% (n=27) groups, whereas more females were observed in the EF 36-45% group (n=17, p<0.001). Diabetes prevalence was highest in the EF 26-35% group (21%), while COPD was most frequent in EF ≤25% (18%, p<0.001). Stroke occurred more frequently in EF ≤25% (16%) than in EF 26-35% (15%) and EF 36-45% (3%, p=0.029). NYHA class IV symptoms were predominant in EF ≤25% (18 cases, p=0.003). Preoperative intra-aortic balloon pump (IABP) use was highest in EF ≤25% (27 cases, p<0.001). Postoperatively, stroke (5%), sepsis (6%), and renal failure (10%) were more common in the EF ≤25% group, whereas deep sternal wound infection (1%) and bleeding requiring reoperation (2%) were more frequent in the EF 26-35% and EF 36-45% groups.
Conclusion: Patients with LVEF ≤25% exhibited a higher prevalence of comorbid conditions and required greater preoperative hemodynamic support. Despite the increased risks, a significant proportion did not experience major complications, suggesting that optimized perioperative management plays a crucial role in surgical outcomes. Future research should focus on refining risk stratification and improving surgical strategies to enhance CABG outcomes in low EF patients.